InVivoMAb rat IgG1 isotype control, anti-horseradish peroxidase
Product Details
The HRPN monoclonal antibody reacts with horseradish peroxidase (HRP). Because HRP is not expressed by mammals this antibody is ideal for use as an isotype-matched control for rat IgG1 antibodies in most in vivo and in vitro applications. This antibody can interfere with HRP detection based assays. If using downstream HRP based assays to analyze samples derived from treated animals, please consider using our alternative rat IgG1 isotype control antibody BP0290.Specifications
| Isotype | Rat IgG1,Ā Īŗ |
|---|---|
| Recommended Dilution Buffer | InVivoPure pH 7.0 Dilution Buffer |
| Conjugation | This product is unconjugated. Conjugation is available via our Antibody Conjugation Services. |
| Formulation |
PBS, pH 7.0 Contains no stabilizers or preservatives |
| Endotoxin |
<2EU/mg (<0.002EU/Ī¼g) Determined by LAL gel clotting assay |
| Purity |
>95% Determined by SDS-PAGE |
| Sterility | 0.2 Āµm filtration |
| Production | Purified from cell culture supernatant in an animal-free facility |
| Purification | Protein G |
| RRID | AB_1107775 |
| Molecular Weight | 150 kDa |
| Storage | The antibody solution should be stored at the stock concentration at 4Ā°C. Do not freeze. |
Additional Formats
Recommended Products
-
Recommended Dilution Buffer
InVivoPure pH 7.0 Dilution Buffer
Goschl, L., et al. (2018). "A T cell-specific deletion of HDAC1 protects against experimental autoimmune encephalomyelitis" J Autoimmun 86: 51-61. PubMed
Multiple sclerosis (MS) is a human neurodegenerative disease characterized by the invasion of autoreactive T cells from the periphery into the CNS. Application of pan-histone deacetylase inhibitors (HDACi) ameliorates experimental autoimmune encephalomyelitis (EAE), an animal model for MS, suggesting that HDACi might be a potential therapeutic strategy for MS. However, the function of individual HDAC members in the pathogenesis of EAE is not known. In this study we report that mice with a T cell-specific deletion of HDAC1 (using the Cd4-Cre deleter strain; HDAC1-cKO) were completely resistant to EAE despite the ability of HDAC1cKO CD4(+) T cells to differentiate into Th17 cells. RNA sequencing revealed STAT1 as a prominent upstream regulator of differentially expressed genes in activated HDAC1-cKO CD4(+) T cells and this was accompanied by a strong increase in phosphorylated STAT1 (pSTAT1). This suggests that HDAC1 controls STAT1 activity in activated CD4(+) T cells. Increased pSTAT1 levels correlated with a reduced expression of the chemokine receptors Ccr4 and Ccr6, which are important for the migration of T cells into the CNS. Finally, EAE susceptibility was restored in WT:HDAC1-cKO mixed BM chimeric mice, indicating a cell-autonomous defect. Our data demonstrate a novel pathophysiological role for HDAC1 in EAE and provide evidence that selective inhibition of HDAC1 might be a promising strategy for the treatment of MS.
Clemente-Casares, X., et al. (2016). "Expanding antigen-specific regulatory networks to treat autoimmunity" Nature 530(7591): 434-440. PubMed
Regulatory T cells hold promise as targets for therapeutic intervention in autoimmunity, but approaches capable of expanding antigen-specific regulatory T cells in vivo are currently not available. Here we show that systemic delivery of nanoparticles coated with autoimmune-disease-relevant peptides bound to major histocompatibility complex class II (pMHCII) molecules triggers the generation and expansion of antigen-specific regulatory CD4(+) T cell type 1 (TR1)-like cells in different mouse models, including mice humanized with lymphocytes from patients, leading to resolution of established autoimmune phenomena. Ten pMHCII-based nanomedicines show similar biological effects, regardless of genetic background, prevalence of the cognate T-cell population or MHC restriction. These nanomedicines promote the differentiation of disease-primed autoreactive T cells into TR1-like cells, which in turn suppress autoantigen-loaded antigen-presenting cells and drive the differentiation of cognate B cells into disease-suppressing regulatory B cells, without compromising systemic immunity. pMHCII-based nanomedicines thus represent a new class of drugs, potentially useful for treating a broad spectrum of autoimmune conditions in a disease-specific manner.
Sell, S., et al. (2015). "Control of murine cytomegalovirus infection by gammadelta T cells" PLoS Pathog 11(2): e1004481. PubMed
Infections with cytomegalovirus (CMV) can cause severe disease in immunosuppressed patients and infected newborns. Innate as well as cellular and humoral adaptive immune effector functions contribute to the control of CMV in immunocompetent individuals. None of the innate or adaptive immune functions are essential for virus control, however. Expansion of gammadelta T cells has been observed during human CMV (HCMV) infection in the fetus and in transplant patients with HCMV reactivation but the protective function of gammadelta T cells under these conditions remains unclear. Here we show for murine CMV (MCMV) infections that mice that lack CD8 and CD4 alphabeta-T cells as well as B lymphocytes can control a MCMV infection that is lethal in RAG-1(-/-) mice lacking any T- and B-cells. gammadelta T cells, isolated from infected mice can kill MCMV infected target cells in vitro and, importantly, provide long-term protection in infected RAG-1(-/-) mice after adoptive transfer. gammadelta T cells in MCMV infected hosts undergo a prominent and long-lasting phenotypic change most compatible with the view that the majority of the gammadelta T cell population persists in an effector/memory state even after resolution of the acute phase of the infection. A clonotypically focused Vgamma1 and Vgamma2 repertoire was observed at later stages of the infection in the organs where MCMV persists. These findings add gammadelta T cells as yet another protective component to the anti-CMV immune response. Our data provide clear evidence that gammadelta T cells can provide an effective control mechanism of acute CMV infections, particularly when conventional adaptive immune mechanisms are insufficient or absent, like in transplant patient or in the developing immune system in utero. The findings have implications in the stem cell transplant setting, as antigen recognition by gammadelta T cells is not MHC-restricted and dual reactivity against CMV and tumors has been described.
Grinberg-Bleyer, Y., et al. (2015). "Cutting edge: NF-kappaB p65 and c-Rel control epidermal development and immune homeostasis in the skin" J Immunol 194(6): 2472-2476. PubMed
Psoriasis is an inflammatory skin disease in which activated immune cells and the proinflammatory cytokine TNF are well-known mediators of pathogenesis. The transcription factor NF-kappaB is a key regulator of TNF production and TNF-induced proinflammatory gene expression, and both the psoriatic transcriptome and genetic susceptibility further implicate NF-kappaB in psoriasis etiopathology. However, the role of NF-kappaB in psoriasis remains controversial. We analyzed the function of canonical NF-kappaB in the epidermis using CRE-mediated deletion of p65 and c-Rel in keratinocytes. In contrast to animals lacking p65 or c-Rel alone, mice lacking both subunits developed severe dermatitis after birth. Consistent with its partial histological similarity to human psoriasis, this condition could be prevented by anti-TNF treatment. Moreover, regulatory T cells in lesional skin played an important role in disease remission. Our results demonstrate that canonical NF-kappaB in keratinocytes is essential for the maintenance of skin immune homeostasis and is protective against spontaneous dermatitis.
Park, H. J., et al. (2015). "PD-1 upregulated on regulatory T cells during chronic virus infection enhances the suppression of CD8+ T cell immune response via the interaction with PD-L1 expressed on CD8+ T cells" J Immunol 194(12): 5801-5811. PubMed
Regulatory T (Treg) cells act as terminators of T cell immuniy during acute phase of viral infection; however, their role and suppressive mechanism in chronic viral infection are not completely understood. In this study, we compared the phenotype and function of Treg cells during acute or chronic infection with lymphocytic choriomeningitis virus. Chronic infection, unlike acute infection, led to a large expansion of Treg cells and their upregulation of programmed death-1 (PD-1). Treg cells from chronically infected mice (chronic Treg cells) displayed greater suppressive capacity for inhibiting both CD8(+) and CD4(+) T cell proliferation and subsequent cytokine production than those from naive or acutely infected mice. A contact between Treg and CD8(+) T cells was necessary for the potent suppression of CD8(+) T cell immune response. More importantly, the suppression required cell-specific expression and interaction of PD-1 on chronic Treg cells and PD-1 ligand on CD8(+) T cells. Our study defines PD-1 upregulated on Treg cells and its interaction with PD-1 ligand on effector T cells as one cause for the potent T cell suppression and proposes the role of PD-1 on Treg cells, in addition to that on exhausted T cells, during chronic viral infection.
Meisen, W. H., et al. (2015). "The Impact of Macrophage- and Microglia-Secreted TNFalpha on Oncolytic HSV-1 Therapy in the Glioblastoma Tumor Microenvironment" Clin Cancer Res 21(14): 3274-3285. PubMed
PURPOSE: Oncolytic herpes simplex viruses (oHSV) represent a promising therapy for glioblastoma (GBM), but their clinical success has been limited. Early innate immune responses to viral infection reduce oHSV replication, tumor destruction, and efficacy. Here, we characterized the antiviral effects of macrophages and microglia on viral therapy for GBM. EXPERIMENTAL DESIGN: Quantitative flow cytometry of mice with intracranial gliomas (+/-oHSV) was used to examine macrophage/microglia infiltration and activation. In vitro coculture assays of infected glioma cells with microglia/macrophages were used to test their impact on oHSV replication. Macrophages from TNFalpha-knockout mice and blocking antibodies were used to evaluate the biologic effects of TNFalpha on virus replication. TNFalpha blocking antibodies were used to evaluate the impact of TNFalpha on oHSV therapy in vivo. RESULTS: Flow-cytometry analysis revealed a 7.9-fold increase in macrophage infiltration after virus treatment. Tumor-infiltrating macrophages/microglia were polarized toward a M1, proinflammatory phenotype, and they expressed high levels of CD86, MHCII, and Ly6C. Macrophages/microglia produced significant amounts of TNFalpha in response to infected glioma cells in vitro and in vivo. Using TNFalpha-blocking antibodies and macrophages derived from TNFalpha-knockout mice, we discovered TNFalpha-induced apoptosis in infected tumor cells and inhibited virus replication. Finally, we demonstrated the transient blockade of TNFalpha from the tumor microenvironment with TNFalpha-blocking antibodies significantly enhanced virus replication and survival in GBM intracranial tumors. CONCLUSIONS: The results of these studies suggest that FDA approved TNFalpha inhibitors may significantly improve the efficacy of oncolytic virus therapy.
Ellis, G. T., et al. (2015). "TRAIL+ monocytes and monocyte-related cells cause lung damage and thereby increase susceptibility to influenza-Streptococcus pneumoniae coinfection" EMBO Rep 16(9): 1203-1218. PubMed
Streptococcus pneumoniae coinfection is a major cause of influenza-associated mortality; however, the mechanisms underlying pathogenesis or protection remain unclear. Using a clinically relevant mouse model, we identify immune-mediated damage early during coinfection as a new mechanism causing susceptibility. Coinfected CCR2(-/-) mice lacking monocytes and monocyte-derived cells control bacterial invasion better, show reduced epithelial damage and are overall more resistant than wild-type controls. In influenza-infected wild-type lungs, monocytes and monocyte-derived cells are the major cell populations expressing the apoptosis-inducing ligand TRAIL. Accordingly, anti-TRAIL treatment reduces bacterial load and protects against coinfection if administered during viral infection, but not following bacterial exposure. Post-influenza bacterial outgrowth induces a strong proinflammatory cytokine response and massive inflammatory cell infiltrate. Depletion of neutrophils or blockade of TNF-alpha facilitate bacterial outgrowth, leading to increased mortality, demonstrating that these factors aid bacterial control. We conclude that inflammatory monocytes recruited early, during the viral phase of coinfection, induce TRAIL-mediated lung damage, which facilitates bacterial invasion, while TNF-alpha and neutrophil responses help control subsequent bacterial outgrowth. We thus identify novel determinants of protection versus pathology in influenza-Streptococcus pneumoniae coinfection.
Walsh, K. B., et al. (2014). "Animal model of respiratory syncytial virus: CD8+ T cells cause a cytokine storm that is chemically tractable by sphingosine-1-phosphate 1 receptor agonist therapy" J Virol 88(11): 6281-6293. PubMed
The cytokine storm is an intensified, dysregulated, tissue-injurious inflammatory response driven by cytokine and immune cell components. The cytokine storm during influenza virus infection, whereby the amplified innate immune response is primarily responsible for pulmonary damage, has been well characterized. Now we describe a novel event where virus-specific T cells induce a cytokine storm. The paramyxovirus pneumonia virus of mice (PVM) is a model of human respiratory syncytial virus (hRSV). Unexpectedly, when C57BL/6 mice were infected with PVM, the innate inflammatory response was undetectable until day 5 postinfection, at which time CD8(+) T cells infiltrated into the lung, initiating a cytokine storm by their production of gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha). Administration of an immunomodulatory sphingosine-1-phosphate (S1P) receptor 1 (S1P1R) agonist significantly inhibited PVM-elicited cytokine storm by blunting the PVM-specific CD8(+) T cell response, resulting in diminished pulmonary disease and enhanced survival. IMPORTANCE: A dysregulated overly exuberant immune response, termed a ācytokine storm,ā accompanies virus-induced acute respiratory diseases (VARV), is primarily responsible for the accompanying high morbidity and mortality, and can be controlled therapeutically in influenza virus infection of mice and ferrets by administration of sphingosine-1-phosphate 1 receptor (S1P1R) agonists. Here, two novel findings are recorded. First, in contrast to influenza infection, where the cytokine storm is initiated early by the innate immune system, for pneumonia virus of mice (PVM), a model of RSV, the cytokine storm is initiated late in infection by the adaptive immune response: specifically, by virus-specific CD8 T cells via their release of IFN-gamma and TNF-alpha. Blockading these cytokines with neutralizing antibodies blunts the cytokine storm and protects the host. Second, PVM infection is controlled by administration of an S1P1R agonist.
Beug, S. T., et al. (2014). "Smac mimetics and innate immune stimuli synergize to promote tumor death" Nat Biotechnol 32(2): 182-190. PubMed
Smac mimetic compounds (SMC), a class of drugs that sensitize cells to apoptosis by counteracting the activity of inhibitor of apoptosis (IAP) proteins, have proven safe in phase 1 clinical trials in cancer patients. However, because SMCs act by enabling transduction of pro-apoptotic signals, SMC monotherapy may be efficacious only in the subset of patients whose tumors produce large quantities of death-inducing proteins such as inflammatory cytokines. Therefore, we reasoned that SMCs would synergize with agents that stimulate a potent yet safe ācytokine storm.ā Here we show that oncolytic viruses and adjuvants such as poly(I:C) and CpG induce bystander death of cancer cells treated with SMCs that is mediated by interferon beta (IFN-beta), tumor necrosis factor alpha (TNF-alpha) and/or TNF-related apoptosis-inducing ligand (TRAIL). This combinatorial treatment resulted in tumor regression and extended survival in two mouse models of cancer. As these and other adjuvants have been proven safe in clinical trials, it may be worthwhile to explore their clinical efficacy in combination with SMCs.
DeBerge, M. P., et al. (2014). "Soluble, but not transmembrane, TNF-alpha is required during influenza infection to limit the magnitude of immune responses and the extent of immunopathology" J Immunol 192(12): 5839-5851. PubMed
TNF-alpha is a pleotropic cytokine that has both proinflammatory and anti-inflammatory functions during influenza infection. TNF-alpha is first expressed as a transmembrane protein that is proteolytically processed to release a soluble form. Transmembrane TNF-alpha (memTNF-alpha) and soluble TNF-alpha (solTNF-alpha) have been shown to exert distinct tissue-protective or tissue-pathologic effects in several disease models. However, the relative contributions of memTNF-alpha or solTNF-alpha in regulating pulmonary immunopathology following influenza infection are unclear. Therefore, we performed intranasal influenza infection in mice exclusively expressing noncleavable memTNF-alpha or lacking TNF-alpha entirely and examined the outcomes. We found that solTNF-alpha, but not memTNF-alpha, was required to limit the size of the immune response and the extent of injury. In the absence of solTNF-alpha, there was a significant increase in the CD8(+) T cell response, including virus-specific CD8(+) T cells, which was due in part to an increased resistance to activation-induced cell death. We found that solTNF-alpha mediates these immunoregulatory effects primarily through TNFR1, because mice deficient in TNFR1, but not TNFR2, exhibited dysregulated immune responses and exacerbated injury similar to that observed in mice lacking solTNF-alpha. We also found that solTNF-alpha expression was required early during infection to regulate the magnitude of the CD8(+) T cell response, indicating that early inflammatory events are critical for the regulation of the effector phase. Taken together, these findings suggest that processing of memTNF-alpha to release solTNF-alpha is a critical event regulating the immune response during influenza infection.
Perng, O. A., et al. (2014). "The degree of CD4+ T cell autoreactivity determines cellular pathways underlying inflammatory arthritis" J Immunol 192(7): 3043-3056. PubMed
Although therapies targeting distinct cellular pathways (e.g., anticytokine versus anti-B cell therapy) have been found to be an effective strategy for at least some patients with inflammatory arthritis, the mechanisms that determine which pathways promote arthritis development are poorly understood. We have used a transgenic mouse model to examine how variations in the CD4(+) T cell response to a surrogate self-peptide can affect the cellular pathways that are required for arthritis development. CD4(+) T cells that are highly reactive with the self-peptide induce inflammatory arthritis that affects male and female mice equally. Arthritis develops by a B cell-independent mechanism, although it can be suppressed by an anti-TNF treatment, which prevented the accumulation of effector CD4(+) Th17 cells in the joints of treated mice. By contrast, arthritis develops with a significant female bias in the context of a more weakly autoreactive CD4(+) T cell response, and B cells play a prominent role in disease pathogenesis. In this setting of lower CD4(+) T cell autoreactivity, B cells promote the formation of autoreactive CD4(+) effector T cells (including Th17 cells), and IL-17 is required for arthritis development. These studies show that the degree of CD4(+) T cell reactivity for a self-peptide can play a prominent role in determining whether distinct cellular pathways can be targeted to prevent the development of inflammatory arthritis.
Weinlich, R., et al. (2013). "Protective roles for caspase-8 and cFLIP in adult homeostasis" Cell Rep 5(2): 340-348. PubMed
Caspase-8 or cellular FLICE-like inhibitor protein (cFLIP) deficiency leads to embryonic lethality in mice due to defects in endothelial tissues. Caspase-8(-/-) and receptor-interacting protein kinase-3 (RIPK3)(-/-), but not cFLIP(-/-) and RIPK3(-/-), double-knockout animals develop normally, indicating that caspase-8 antagonizes the lethal effects of RIPK3 during development. Here, we show that the acute deletion of caspase-8 in the gut of adult mice induces enterocyte death, disruption of tissue homeostasis, and inflammation, resulting in sepsis and mortality. Likewise, acute deletion of caspase-8 in a focal region of the skin induces local keratinocyte death, tissue disruption, and inflammation. Strikingly, RIPK3 ablation rescues both phenotypes. However, acute loss of cFLIP in the skin produces a similar phenotype that is not rescued by RIPK3 ablation. TNF neutralization protects from either acute loss of caspase-8 or cFLIP. These results demonstrate that caspase-8-mediated suppression of RIPK3-induced death is required not only during development but also for adult homeostasis. Furthermore, RIPK3-dependent inflammation is dispensable for the skin phenotype.
Mohr, E., et al. (2010). "IFN-{gamma} produced by CD8 T cells induces T-bet-dependent and -independent class switching in B cells in responses to alum-precipitated protein vaccine" Proc Natl Acad Sci U S A 107(40): 17292-17297. PubMed
Alum-precipitated protein (alum protein) vaccines elicit long-lasting neutralizing antibody responses that prevent bacterial exotoxins and viruses from entering cells. Typically, these vaccines induce CD4 T cells to become T helper 2 (Th2) cells that induce Ig class switching to IgG1. We now report that CD8 T cells also respond to alum proteins, proliferating extensively and producing IFN-gamma, a key Th1 cytokine. These findings led us to question whether adoptive transfer of antigen-specific CD8 T cells alters the characteristic CD4 Th2 response to alum proteins and the switching pattern in responding B cells. To this end, WT mice given transgenic ovalbumin (OVA)-specific CD4 (OTII) or CD8 (OTI) T cells, or both, were immunized with alum-precipitated OVA. Cotransfer of antigen-specific CD8 T cells skewed switching patterns in responding B cells from IgG1 to IgG2a and IgG2b. Blocking with anti-IFN-gamma antibody largely inhibited this altered B-cell switching pattern. The transcription factor T-bet is required in B cells for IFN-gamma-dependent switching to IgG2a. By contrast, we show that this transcription factor is dispensable in B cells both for IFN-gamma-induced switching to IgG2b and for inhibition of switching to IgG1. Thus, T-bet dependence identifies distinct transcriptional pathways in B cells that regulate IFN-gamma-induced switching to different IgG isotypes.
- In Vivo,
- Mus musculus (House mouse),
- Genetics,
- Immunology and Microbiology
Enhanced durability of a Zika virus self-amplifying RNA vaccine through combinatorial OX40 and 4-1BB agonism.
In JCI Insight on 22 May 2025 by Lu, H. H., dos Santos Alves, R. P., et al.
The SARS-CoV-2 pandemic highlighted the potential of mRNA vaccines in rapidly responding to emerging pathogens. However, immunity induced by conventional mRNA vaccines wanes quickly, requiring frequent boosters. Self-amplifying RNA (saRNA) vaccines, which extend antigen expression via self-replication, offer a promising strategy to induce more durable immune responses. In this study, we developed an saRNA vaccine encoding Zika virus (ZIKV) membrane and envelope proteins and evaluated its efficacy in mice. A single vaccination elicited strong humoral and cellular immune responses and reduced viral loads but only for 28 days. By day 84, antibody titers and T cell responses had significantly declined, resulting in reduced efficacy. To address this, we evaluated agonist antibodies targeting the T cell costimulatory molecules OX40 and 4-1BB. Coadministration of agonist antibodies enhanced CD8+ T cell responses to vaccination, resulting in sustained immunity and reduced viral loads at day 84. Depletion and passive transfer studies verified that long-term antiviral immunity was primarily CD8+ T cell dependent, with minimal contributions from antibody responses. These findings suggest that agonists targeting members of the tumor necrosis receptor superfamily, such as OX40 and 4-1BB, might enhance the durability of saRNA vaccine-induced protection, addressing a key limitation of current mRNA vaccine platforms.
- Cancer Research
Hepatic iNKT cells facilitate colorectal cancer metastasis by inducing a fibrotic niche in the liver.
In IScience on 16 May 2025 by Nater, M., BrĆ¼gger, M., et al.
The liver is an important metastatic organ that contains many innate immune cells, yet little is known about their role in anti-metastatic defense. We investigated how invariant natural killer T (iNKT) cells influence colorectal cancer-derived liver metastasis using different models in immunocompetent mice. We found that hepatic iNKT cells promote metastasis by creating a supportive niche for disseminated cancer cells. Mechanistically, iNKT cells respond to disseminating cancer cells by producing the fibrogenic cytokines interleukin-4 (IL-4) and IL-13 in a TĀ cell receptor-independent manner. Selective abrogation of IL-4 and IL-13 sensing in hepatic stellate cells prevented their transdifferentiation into extracellular matrix-producing myofibroblasts, which hindered metastatic outgrowth of disseminated cancer cells. This study highlights a novel tumor-promoting axis driven by iNKT cells in the initial stages of metastasis. Ā© 2025 The Author(s).
- Cancer Research,
- Immunology and Microbiology
Macrophages suppress CD8ā+āT cell cytotoxic function in triple negative breast cancer via VISTA.
In British Journal of Cancer on 2 May 2025 by Abudula, M., Astuti, Y., et al.
Immunotherapy targeting negative immune checkpoint regulators to enhance the anti-tumour immune response holds promise in the treatment of TNBC. V-domain Ig suppressor of T-cell activation (VISTA) is an immune checkpoint molecule, known to be upregulated and involved in modulating tumour immunity in TNBC. However, how VISTA affects immune response and its therapeutic potential in TNBC remains unclear. Here, we examined VISTA expression and cellular distribution in TNBC patients' samples and pre-clinical TNBC mouse model. Functional assays were performed to assess the impact of VISTA blockade on macrophage phenotypes, CD8ā+āT cell infiltration and activation, and overall anti-tumour immune response. In this study we show that VISTA expression levels are increased in TNBC patients' samples and pre-clinical mouse models compared to non-involved breast tissue and VISTA is mainly expressed on tumour infiltrating macrophages and neutrophils. Blocking VISTA reverts macrophages immunosuppressive phenotypes, increases CD8ā+āT cell infiltration and activation, and enhances an anti-tumour immune response. Mechanistically, we show that neutralising VISTA on macrophages enhances their immune-stimulatory functions and inhibits the suppressive effect of macrophages on CD8ā+āT cells activation. These findings provide the rationale for the development of anti-VISTA targeting strategies in the treatment of TNBC. Ā© 2025. The Author(s).
- Cancer Research,
- Immunology and Microbiology
Development of PVTX-405 as a potent and highly selective molecular glue degrader of IKZF2 for cancer immunotherapy.
In Nature Communications on 1 May 2025 by Chen, Z., Dhruv, H., et al.
IKZF2 (Helios) is a transcription factor that is selectively expressed by Tregs and is essential for preserving the function and stability of Tregs in the tumor microenvironment (TME), where it suppresses the anti-tumor immune response. Targeted IKZF2 degradation by small molecules represents a promising strategy for the development of a new class of cancer immunotherapy. Herein, we describe the discovery of PVTX-405, a potent, effective, highly selective, and orally efficacious IKZF2 molecular glue degrader. PVTX-405 degrades IKZF2 (DC50ā=ā0.7ānM and Dmaxā=ā91%) while sparing other CRBN neo-substrates. Degradation of IKZF2 by PVTX-405 increases production of inflammatory cytokine IL-2 and reduces the suppressive activity of Tregs, leading to an increase in Teff cell proliferation. Once-daily oral administration of PVTX-405 as single agent significantly delays the growth of MC38 tumors in a syngeneic tumor model using humanized CRBN mice. PVTX-405 in combination with anti-PD1 or anti-LAG3 significantly increases animal survival compared to anti-PD1 or anti-LAG3 alone. Together, these results demonstrate that PVTX-405 is a promising IKZF2 degrader for clinical development for the treatment of human cancers. Ā© 2025. The Author(s).
- Immunology and Microbiology
B cells modulate lung antiviral inflammatory responses via the neurotransmitter acetylcholine.
In Nature Immunology on 1 May 2025 by Cembellin-Prieto, A., Luo, Z., et al.
The rapid onset of innate immune defenses is critical for early control of viral replication in an infected host and yet it can also lead to irreversible tissue damage, especially in the respiratory tract. Sensitive regulators must exist that modulate inflammation, while controlling the infection. In the present study, we identified acetylcholine (ACh)-producing B cells as such early regulators. B cells are the most prevalent ACh-producing leukocyte population in the respiratory tract demonstrated with choline acetyltransferase (ChAT)-green fluorescent protein (GFP) reporter mice, both before and after infection with influenza A virus. Mice lacking ChAT in B cells, disabling their ability to generate ACh (ChatBKO), but not those lacking ChAT in T cells, significantly, selectively and directly suppressed Ī±7-nicotinic-ACh receptor-expressing interstitial, but not alveolar, macrophage activation and their ability to secrete tumor necrosis factor (TNF), while better controlling virus replication at 1ād postinfection. Conversely, TNF blockade via monoclonal antibody treatment increased viral loads at that time. By day 10 of infection, ChatBKO mice showed increased local and systemic inflammation and reduced signs of lung epithelial repair despite similar viral loads and viral clearance. Thus, B cells are key participants of an immediate early regulatory cascade that controls lung tissue damage after viral infection, shifting the balance toward reduced inflammation at the cost of enhanced early viral replication. Ā© 2025. The Author(s).
- In Vivo,
- Mus musculus (House mouse),
- Cancer Research
Resistance to anti-LAG-3 plus anti-PD-1 therapy in head and neck cancer is mediated by Sox9+ tumor cells interaction with Fpr1+ neutrophils.
In Nature Communications on 28 April 2025 by Wang, X., Cheng, M., et al.
Relatlimab and nivolumab combination therapy shows significant efficacy in treating various types of cancer. Current research on the molecular mechanisms of this treatment is abundant, but in-depth investigations into post-treatment resistance remain notably lacking. In this study, we identify significant enrichment of SRY (sex determining region Y)-box 9 (Sox9)+ tumor cells in resistant samples using single cell RNA sequencing (scRNAseq) in a head and neck squamous cell carcinoma (HNSCC) mouse model. In addition, Sox9 directly regulates the expression of annexin A1 (Anxa1), mediating apoptosis of formyl peptide receptor 1 (Fpr1)+ neutrophils through the Anxa1-Fpr1 axis, which promotes mitochondrial fission, inhibits mitophagy by downregulating BCL2/adenovirus E1B interacting protein 3 (Bnip3) expression and ultimately prevents the accumulation of neutrophils in tumor tissues. The reduction of Fpr1+ neutrophils impairs the infiltration and tumor cell-killing ability of cytotoxic Cd8 T and Ī³Ī“T cells within the tumor microenvironment, thereby leading to the development of resistance to the combination therapy. We further validate these findings using various transgenic mouse models. Overall, this study comprehensively explains the mechanisms underlying resistance to the anti-LAG-3 plus anti-PD-1 combination therapy and identifies potential therapeutic targets to overcome this resistance. Ā© 2025. The Author(s).
- In Vivo,
- Mus musculus (House mouse)
Myelopoiesis is temporally dynamic and is regulated by lifestyle to modify multiple sclerosis.
In Nature Communications on 17 April 2025 by Yates, A. G., Khamhoung, A., et al.
Monocytes and neutrophils from the myeloid lineage contribute to multiple sclerosis (MS), but the dynamics of myelopoiesis during MS are unclear. Here we uncover a disease stage-specific relationship between lifestyle, myelopoiesis and neuroinflammation. In mice with relapsing-remitting experimental autoimmune encephalomyelitis (RR-EAE), myelopoiesis in the femur, vertebrae and spleen is elevated prior to disease onset and during remission, preceding the peaks of clinical disability and neuroinflammation. In progressive EAE (P-EAE), vertebral myelopoiesis rises steadily throughout disease, while femur and splenic myelopoiesis is elevated early before waning later during disease height. In parallel, sleep disruption or hyperlipidemia and cardiometabolic syndrome augment M-CSF generation and multi-organ myelopoiesis to worsen P-EAE clinical symptoms, neuroinflammation, and spinal cord demyelination, with M-CSF blockade abrogating these symptoms. Lastly, results from a previous trial show that Mediterranean diet restrains myelopoietic activity and myeloid lineage progenitor skewing and improves clinical symptomology of MS. Together, our data suggest that myelopoiesis in MS is dynamic and dependent on disease stage and location, and that lifestyle factors modulate disease by influencing M-CSF-mediated myelopoiesis. Ā© 2025. The Author(s).
Targeted labeling and depletion of alveolar macrophages using VeDTR mouse technology.
In IScience on 21 March 2025 by Nakayama, Y., Sasai, M., et al.
Alveolar macrophages (AMs) are essential for maintaining lung homeostasis. However, their roles in respiratory infections have been controversial because the methods of depleting them have often suffered from poor cell selectivity. To resolve this problem, we here used VeDTR technology to generate a transgenic mouse line in which AMs can be specifically depleted using diphtheria toxin. When various respiratory infections were examined using this system, we found that AMs prevented the proliferation of Mycobacterium abscessus. This result differed from previous findings using clodronate liposomes to deplete macrophages. We also revealed that the disappearance of AMs contributes to the reduction of bacterial load in the lungs and that AMs are indispensable for GM-CSF-mediated defense against M.Ā abscessus infection. Taken together, the development of an AM-specific depletion system has provided an opportunity to study the roles of AMs in various respiratory infections from a different perspective. Ā© 2025 The Author(s).
- Cancer Research
Inhibitors of oncogenic Kras specifically prime CTLA4 blockade to transcriptionally reprogram Tregs and overcome resistance to suppress pancreas cancer
Preprint on BioRxiv : the Preprint Server for Biology on 4 March 2025 by Mahadevan, K. K., Maldonado, A. S., et al.
Lack of sustained response to oncogenic Kras (Kras*) inhibition in preclinical models and patients with pancreatic ductal adenocarcinoma (PDAC) emphasizes the need to identify impactful synergistic combination therapies to achieve robust clinical benefit. Kras* targeting results in an influx of global T cell infiltrates including Tregs, effector CD8 + T cells and exhausted CD8 + T cells expressing several immune checkpoint molecules in PDAC. Here, we probe whether the T cell influx induced by diverse Kras* inhibitors open a therapeutic window to target the adaptive immune response in PDAC. We show a specific synergy of anti-CTLA4 immune checkpoint blockade with Kras* targeting primed by Kras G12D allele specific inhibitor, MRTX1133 and multi-selective pan-RAS inhibitor, RMC-6236, both currently in clinical testing phase. In contrast, attempted therapeutic combination following Kras* targeting with multiple checkpoint inhibitors, including anti-PD1, anti-Tim3, anti-Lag3, anti-Vista and anti-4-1BB agonist antibody failed due to compensatory mechanisms mediated by other checkpoints on exhausted CD8 + T cells. Anti-CTLA4 therapy in Kras* targeted PDAC transcriptionally reprograms effector T regs to a naĆÆve phenotype, reverses CD8 + T cell exhaustion and is associated with recruitment of tertiary lymphoid structures (TLS) containing interferon (IFN)-stimulated/ activated B cells and germinal center B cells to enable immunotherapy efficacy and overcome resistance with long-term survival. Single cell ATAC sequencing analysis revealed that transcriptional reprogramming of Tregs is epigenetically regulated by downregulation of AP-1 family of transcription factors including Fos, Fos-b, Jun-b, Jun-d in the IL-35 promoter region. This study reveals an actionable vulnerability in the adaptive immune response in Kras* targeted PDAC with important clinical implications. Graphical abstract
- Biochemistry and Molecular biology,
- Cell Biology,
- Immunology and Microbiology
Maresin-1 promotes neuroprotection and modulates metabolic and inflammatory responses in disease-associated cell types in preclinical models of multiple sclerosis.
In The Journal of Biological Chemistry on 1 March 2025 by Zahoor, I., Nematullah, M., et al.
Multiple sclerosis (MS) is a prevalent inflammatory neurodegenerative disease in young people, causing neurological abnormalities and impairment. To investigate a novel therapeutic agent for MS, we observed the impact of maresin 1 (MaR1) on disease progression in a well-known, relapsing-remitting experimental autoimmune encephalomyelitis mouse model. Treatment with MaR1 accelerated inflammation resolution, reduced neurological impairment, and delayed disease development by reducing immune cell infiltration (CD4+IL-17+ and CD4+IFNĪ³+) into the central nervous system. Furthermore, MaR1 administration enhanced IL-10 production, primarily in macrophages and CD4+ cells. However, neutralizing IL-10 with an anti-IL-10 antibody eliminated the protective impact by MaR1 in relapsing-remitting experimental autoimmune encephalomyelitis model, implying the significance of IL-10 in MaR1 treatment. Metabolism has been recognized as a critical mediator of effector activity in many types of immune cells. In our investigation, MaR1 administration significantly repaired metabolic dysregulation in CD4+ cells, macrophages, and microglia in EAE mice. Furthermore, MaR1 treatment restored defective efferocytosis in treated macrophages and microglia. MaR1 also preserved myelin in EAE mice and regulated O4+ oligodendrocyte metabolism by reversing metabolic dysregulation via increased mitochondrial activity and decreased glycolysis. Overall, in a preclinical MS animal model, MaR1 therapy has anti-inflammatory and neuroprotective properties. It also induced metabolic reprogramming in disease-associated cell types, increased efferocytosis, and maintained myelination. Moreover, our data on patient-derived peripheral blood mononuclear cells substantiated the protective role of MaR1, expanding the therapeutic spectrum of specialized proresolving lipid mediators. Altogether, these findings suggest the potential of MaR1 as a novel therapeutic agent for MS and other autoimmune diseases. Copyright Ā© 2025 The Authors. Published by Elsevier Inc. All rights reserved.
- Cancer Research,
- Genetics,
- Immunology and Microbiology
Histone lactylation-driven B7-H3 expression promotes tumor immune evasion.
In Theranostics on 24 February 2025 by Ma, Z., Yang, J., et al.
Rationale: Tumor cells possess sophisticated strategies to circumvent immune detection, including the modulation of endogenous immune checkpoints, particularly those within the B7 family. Elucidating the mechanisms that govern the induction of B7 family molecules is crucial for the advancement of immunotherapy. Lysine lactylation (Kla), a newly identified epigenetic modification, is suggested may play a role in reshaping the tumor microenvironment and facilitating immune evasion. Methods: We analyzed the glycolysis pathway's enrichment in patients with immune-evading tumors and assessed the impact of lactate treatment on the antitumor immunity of CD8+ T cells in the tumor microenvironment. We interrupted glycolysis using lactate dehydrogenase A (LDHA) knockdown and sodium oxamate, and evaluated its effects on CD8+ T cell cytotoxicity. Additionally, we investigated the correlation between B7-H3 expression and the glycolysis pathway, and explored the molecular mechanisms underlying lactate-induced B7-H3 expression. Results: Our findings revealed that the glycolysis pathway was highly enriched in immune-evading tumors. Lactate treatment inhibited the antitumor immunity of CD8+ T cells, whereas interruption of glycolysis via LDHA knockdown or treatment with sodium oxamate augmented the cytotoxicity of CD8+ T cells, effectively counteracting tumor immune evasion. B7-H3 expression was found to be closely linked with the glycolysis pathway. Mechanistically, lactate-upregulated H3K18la directly bound to the B7-H3 promoter in conjunction with the transcription factor Creb1 and its co-activator Ep300, leading to increased B7-H3 expression and contributing to tumor progression by compromising the proportion and cytotoxicity of tumor-infiltrating CD8+ T cells. In mouse tumor bearing models, inhibiting glycolysis and B7-H3 expression suppressed tumor cell growth, activated tumor-infiltrating CD8+ T cells, and demonstrated potent anti-tumor efficacy. Furthermore, this approach enhanced the efficacy of anti-PD-1 treatment. Conclusions: This study uncovers a novel mechanism by which lactate modulates the immune microenvironment through the glycolysis pathway and B7-H3 expression, providing new avenues for lactate metabolism-targeted tumor immunotherapy. Ā© The author(s).
- Immunology and Microbiology
RGS2 is an innate immune checkpoint for suppressing GĪ±q-mediated IFNĪ³ generation and lung injury.
In IScience on 21 February 2025 by Joshi, J. C., Joshi, B., et al.
Interferon gamma (IFNĪ³), a type II interferon, augments tissue inflammation following infections, leading to lethal acute lung injury (ALI), yet the mechanisms controlling IFNĪ³ generation in the lungs remain elusive. Here, we identified regulator of G protein signaling 2 (RGS2) as a gatekeeper of the lung's IFNĪ³ levels during infections. Deletion of RGS2 sustained an increase in IFNĪ³ levels in macrophages, leading to unresolvable inflammatory lung injury. This response was not seen in RGS2 null chimeric mice receiving wild-type (WT) bone marrow or the RGS2 gene in alveolar macrophages (AMs) or IFNĪ³-blocking antibody. RGS2 functioned by suppressing GĪ±q-mediated IFNĪ³ generation and AM inflammatory signaling. Thus, the inhibition of GĪ±q blocked IFNĪ³ generation in AMs and rewired AM transcriptomes from an inflammatory to a reparative phenotype in RGS2 null mice, pointing to the RGS2-GĪ±q axis as a potential target for suppressing inflammatory injury. Ā© 2025 The Author(s).
- Immunology and Microbiology
Dietary cysteine enhances intestinal stemness via CD8+T cell-derived IL-22
Preprint on BioRxiv : the Preprint Server for Biology on 16 February 2025 by Chi, F., Zhang, Q., et al.
A critical question in physiology is understanding how tissues adapt and alter their cellular composition in response to dietary cues. The mammalian small intestine, a vital digestive organ that absorbs nutrients, is maintained by rapidly renewing Lgr5 + intestinal stem cells (ISCs) at the intestinal crypt base. While Lgr5 + ISCs drive intestinal adaptation by altering self-renewal and differentiation divisions in response to diverse diets such as high-fat diets and fasting regimens, little is known about how micronutrients, particularly amino acids, instruct Lgr5 + ISC fate decisions to control intestinal homeostasis and repair after injury. Here, we demonstrate that cysteine, an essential amino acid, enhances the ability of Lgr5 + ISCs to repair intestinal injury. Mechanistically, the effects of cysteine on ISC-driven repair are mediated by elevated IL-22 from intraepithelial CD8Ī±Ī² + T cells. These findings highlight how coupled cysteine metabolism between ISCs and CD8 + T cells augments intestinal stemness, providing a dietary approach that exploits ISC and immune cell crosstalk for ameliorating intestinal damage.
- Immunology and Microbiology
The AURKA inhibitor alters the immune microenvironment and enhances targeting B7-H3 immunotherapy in glioblastoma.
In JCI Insight on 10 February 2025 by Liu, J., Deng, Y., et al.
Glioblastoma (GBM) is one of the most lethal adult brain tumors with limited effective therapeutic options. Immunotherapy targeting B7-H3 (CD276) has shown promising efficacy in the treatment of gliomas. However, the response to this treatment varies among glioma patients due to individual differences. It's necessary to find an effective strategy to improve the efficacy of targeting B7-H3 immunotherapy for nonresponders. In this study, we demonstrated a strong correlation between aurora kinase A (AURKA) and CD276 expression in glioma tissue samples. Additionally, both AURKA knockdown and overexpression resulted in parallel changes in B7-H3 expression levels in glioma cells. Mechanistically, AURKA elevated B7-H3 expression by promoting epidermal growth factor receptor (EGFR) phosphorylation, which was validated in glioma cell lines and primary GBM cells. What's more, the combination of AURKA inhibitor (alisertib) and anti-B7-H3 antibody markedly reduced tumor size and promoted CD8+ T cell infiltration and activation in mouse orthotopic syngeneic glioma models. To our knowledge, this study is the first to demonstrate AURKA-mediated B7-H3 upregulation in glioma cells; moreover, it proposes a promising therapeutic strategy combining the AURKA inhibitor alisertib with B7-H3-specific blocking mAbs.
- Cancer Research,
- Immunology and Microbiology
Neoadjuvant anti-4-1BB confers protection against spontaneous metastasis through low-affinity intratumor CD8+T cells in triple-negative breast cancer
Preprint on BioRxiv : the Preprint Server for Biology on 2 February 2025 by Lim, B. J. W., Liu, M., et al.
ABSTRACT Neoadjuvant immunotherapy seeks to harness the primary tumor as a source of relevant tumor antigens to enhance systemic anti-tumor immunity through improved immunological surveillance. Despite having revolutionized the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC), a significant portion of patients remain unresponsive and succumb to metastatic recurrence post-treatment. Here, we found that optimally scheduled neoadjuvant administration of anti-4-1BB monotherapy was able to counteract metastases and prolong survival following surgical resection. Phenotypic and transcriptional profiling revealed enhanced 4-1BB expression on tumor-infiltrating intermediate (T int ), relative to progenitor (T prog ) and terminally exhausted (T term ) T cells. Furthermore, T int was enriched in low-affinity T cells. Treatment with anti-4-1BB drove clonal expansion of T int , with reduced expression of tissue-retention marker CD103 in T prog . This was accompanied by increased TCR clonotype sharing between paired tumors and pre-metastatic lungs. Further interrogation of sorted intratumor T cells confirmed enhanced T cell egress into circulation following anti-4-1BB treatment. In addition, gene signature extracted from anti-4-1BB treated T int was consistently associated with improved clinical outcomes in BRCA patients. Combinatorial neoadjuvant anti-4-1BB and ablation of tumor-derived CXCL16 resulted in enhanced therapeutic effect. These findings illustrate the intratumor changes underpinning the efficacy of neoadjuvant anti-4-1BB, highlighting the reciprocity between local tissue-retention and distant immunologic fortification, suggesting treatment can reverse the siphoning of intratumor T cells to primary tumor, enabling redistribution to distant tissues and subsequent protection against metastases.
The emerging fungal pathogenCandida aurisinduces IFNĪ³ to colonize mammalian hair follicles
Preprint on BioRxiv : the Preprint Server for Biology on 18 January 2025 by Merrill, E. D., Prudent, V., et al.
Public health alarm concerning the emerging fungus Candida auris is fueled by its antifungal drug resistance and propensity to cause deadly outbreaks. Persistent skin colonization drives transmission and lethal sepsis although its basis remains mysterious. We compared the skin colonization dynamics of C. auris with its relative C. albicans , quantifying skin fungal persistence and distribution and immune composition and positioning. C. auris displayed a higher propensity to colonize hair follicles and avidly bound to human hair. While C. albicans triggered an effective sterilizing type 3/17 antifungal immune response driven by IL-17A/F-producing lymphocytes, C. auris triggered a type 1, IFNĪ³-driven immune response targeting hair follicles. Rather than promoting fungal clearance, IFNĪ³ enhanced C. auris skin colonization by acting directly on keratinocytes impairing epithelial barrier integrity and repressing antifungal defense programs. C. auris exploits focal skin immune responses to create a niche for persistence in hair follicles.
- Immunology and Microbiology
T cell-derived IFN-Ī³ Suppresses T Follicular Helper Cell Differentiation and Antibody Responses
Preprint on BioRxiv : the Preprint Server for Biology on 1 January 2025 by Sala, E., Nelli, M., et al.
CD4 + T cells play a critical role in antiviral humoral and cellular immune responses. We have previously reported that subcutaneous lymphocytic choriomeningitis virus (s.c. LCMV) infection is characterized by a stark compartmentalization of CD4 + T cells, leading to strong T H 1 polarization but virtually absent T follicular helper (T FH ) cells, a key driver of humoral immunity. Here, we investigated the mechanisms responsible for this impaired T FH differentiation. We found that T-bet + cells induced by s.c. LCMV infection encompass a T H 1 subset expressing Granzyme-B (GzmB) and a Tcf-1 + subset that retains the potential for T FH differentiation without expressing mature T FH markers. Interestingly, IFN-Ī³ blockade enables full differentiation of Tcf-1 + cells into T FH , formation of germinal centers and increased antibody production. Of note, the suppression of T FH cells by IFN-Ī³ is not directly mediated through CD4 + T cells but rather involves another cell type, likely dendritic cells (DCs). Our study provides novel insights into the mechanisms directing early CD4 + T cell polarization and affecting humoral responses to viruses, laying a foundation for the development of effective vaccine strategies.
- Immunology and Microbiology
Dynamics of tissue repair regulatory T cells and damage in acute Trypanosoma cruzi infection.
In PLoS Pathogens on 1 January 2025 by Boccardo, S., Rodriguez, C., et al.
Tissue-repair regulatory T cells (trTregs) comprise a specialized cell subset essential for tissue homeostasis and repair. While well-studied in sterile injury models, their role in infection-induced tissue damage and antimicrobial immunity is less understood. We investigated trTreg dynamics during acute Trypanosoma cruzi infection, marked by extensive tissue damage and strong CD8+ immunity. Unlike sterile injury models, trTregs significantly declined in secondary lymphoid organs and non-lymphoid target tissues during infection, correlating with systemic and local tissue damage, and downregulation of function-associated genes in skeletal muscle. This decline was linked to decreased systemic IL-33 levels, a key trTreg growth factor, and promoted by the Th1 cytokine IFN-Ī³. Early recombinant IL-33 treatment increased trTregs, type 2 innate lymphoid cells, and parasite-specific CD8+ cells at specific time points after infection, leading to reduced tissue damage, lower parasite burden, and improved disease outcome. Our findings not only provide novel insights into trTregs during infection but also highlight the potential of optimizing immune balance by modulating trTreg responses to promote tissue repair while maintaining effective pathogen control during infection-induced injury. Copyright: Ā© 2025 Boccardo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Immunology and Microbiology
Pathobiont-induced suppressive immune imprints thwart T cell vaccine responses.
In Nature Communications on 16 December 2024 by Hajam, I. A., Tsai, C. M., et al.
Pathobionts have evolved many strategies to coexist with the host, but how immune evasion mechanisms contribute to the difficulty of developing vaccines against pathobionts is unclear. Meanwhile, Staphylococcus aureus (SA) has resisted human vaccine development to date. Here we show that prior SA exposure induces non-protective CD4+ T cell imprints, leading to the blunting of protective IsdB vaccine responses. Mechanistically, these SA-experienced CD4+ T cells express IL-10, which is further amplified by vaccination and impedes vaccine protection by binding with IL-10RĪ± on CD4+ T cell and inhibit IL-17A production. IL-10 also mediates cross-suppression of IsdB and sdrE multi-antigen vaccine. By contrast, the inefficiency of SA IsdB, IsdA and MntC vaccines can be overcome by co-treatment with adjuvants that promote IL-17A and IFN-Ī³ responses. We thus propose that IL-10 secreting, SA-experienced CD4+ T cell imprints represent a staphylococcal immune escaping mechanism that needs to be taken into consideration for future vaccine development. Ā© 2024. The Author(s).
- Cancer Research,
- Immunology and Microbiology
Sorafenib-induced macrophage extracellular traps via ARHGDIG/IL4/PADI4 axis confer drug resistance through inhibiting ferroptosis in hepatocellular carcinoma.
In Biology Direct on 11 November 2024 by Huang, X., Yi, N., et al.
Hepatocellular carcinoma (HCC) is one of the most common as well as leading causes of mortality worldwide, and sorafenib is the first-line treatment in HCC patients. Unfortunately, drug resistance to sorafenib often develops. However, the underlying mechanism remains unclear. Here, we reveal the important role of macrophage extracellular traps (METs)-mediated crosstalk between macrophages and tumor cells in sorafenib resistance. METs in HCC tumor tissues were detected using immunofluorescence. The concentrations of MPO-DNA, elastase and cytokines were measured using ELISA. The mRNA expression levels of genes were confirmed by qRT-PCR. The siRNAs were conducted to knock ARHGDIG in Hepa1-6 and Hep3B cells. Western Blot assay was performed to determine protein expression of Rho GDP dissociation inhibitor gamma (ARHGDIG, or RHOGDI-3), PADI2, and PADI4. Cell viability and migration were evaluated by CCK-8 assay and transwell assay, respectively. Cell ferroptosis was assessed by measurement of Fe2+ concentration, flow cytometry assay of lipid ROS, and western blot assay of GPX4. The functions of sorafenib, DNase I, IL4 neutralization antibody and GPX4 in tumor growth were explored through in vivo experiments. Sorafenib induced MET formation in M2 macrophages rather than M1 macrophages derived from both human and mice. In Hepa1-6 HCC mice, METs clearance by DNase I improved response to sorafenib therapy, detected by tumor weight, tumor growth curve, tumor volume, and survival. By screening candidate cytokines that affect macrophage function, we found that sorafenib-promoting IL4 secretion by HCC cells plays a crucial role in sorafenib-induced MET formation. Understanding the critical role of IL4 in sorafenib-induced MET formation led us to find that IL4 neutralization significantly improved the efficiency of sorafenib in HCC models. Mechanistically, we discovered that sorafenib increased the expression of ARHGDIG in HCC cells, which led to the release of IL4. In M2 macrophages, IL4 triggered MET formation by elevating the mRNA and protein expression of peptidyl arginine deiminase 4 (PADI4) rather than PADI2. In HCC models, GSK484 inhibition of PADI4 could consistently weaken sorafenib resistance and improve sorafenib efficiency. Importantly, we discovered that METs contribute to sorafenib resistance by inhibiting the ferroptosis of HCC cells. Meanwhile, PADI4 inhibition or DNase I could reverse the sorafenib resistance caused by METs-inhibiting ferroptosis of HCC cells. Our study concludes that sorafenib-induced METs inhibit the ferroptosis of tumor cells, suggesting that targeting the IL4/PADI4/METs axis in HCC could reduce or prevent sorafenib resistance. Ā© 2024. The Author(s).
