InVivoMAb polyclonal Syrian hamster IgG
Product Details
The polyclonal Syrian hamster IgG is purified from Syrian hamster serum. It is ideal for use as a non-reactive control IgG for Syrian hamster antibodies in most in vivo and in vitro applications.Specifications
| Isotype | Syrian hamster IgG |
|---|---|
| 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 |
| Purification | Protein G |
| RRID | AB_1107782 |
| Molecular Weight | 150 kDa |
| Murine Pathogen Tests |
Ectromelia/Mousepox Virus: Negative Hantavirus: Negative K Virus: Negative Lactate Dehydrogenase-Elevating Virus: Negative Lymphocytic Choriomeningitis virus: Negative Mouse Adenovirus: Negative Mouse Cytomegalovirus: Negative Mouse Hepatitis Virus: Negative Mouse Minute Virus: Negative Mouse Norovirus: Negative Mouse Parvovirus: Negative Mouse Rotavirus: Negative Mycoplasma Pulmonis: Negative Pneumonia Virus of Mice: Negative Polyoma Virus: Negative Reovirus Screen: Negative Sendai Virus: Negative Theilerās Murine Encephalomyelitis: Negative |
| Storage | The antibody solution should be stored at the stock concentration at 4Ā°C. Do not freeze. |
Additional Formats
Recommended Products
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Recommended Dilution Buffer
InVivoPure pH 7.0 Dilution Buffer
Bradley, T., et al. (2020). "Immune checkpoint modulation enhances HIV-1 antibody induction" Nat Commun 11(1): 948. PubMed
Eliciting protective titers of HIV-1 broadly neutralizing antibodies (bnAbs) is a goal of HIV-1 vaccine development, but current vaccine strategies have yet to induce bnAbs in humans. Many bnAbs isolated from HIV-1-infected individuals are encoded by immunoglobulin gene rearrangments with infrequent naive B cell precursors and with unusual genetic features that may be subject to host regulatory control. Here, we administer antibodies targeting immune cell regulatory receptors CTLA-4, PD-1 or OX40 along with HIV envelope (Env) vaccines to rhesus macaques and bnAb immunoglobulin knock-in (KI) mice expressing diverse precursors of CD4 binding site HIV-1 bnAbs. CTLA-4 blockade augments HIV-1 Env antibody responses in macaques, and in a bnAb-precursor mouse model, CTLA-4 blocking or OX40 agonist antibodies increase germinal center B and T follicular helper cells and plasma neutralizing antibodies. Thus, modulation of CTLA-4 or OX40 immune checkpoints during vaccination can promote germinal center activity and enhance HIV-1 Env antibody responses.
Klepsch, V., et al. (2020). "Targeting the orphan nuclear receptor NR2F6 in T cells primes tumors for immune checkpoint therapy" Cell Commun Signal 18(1): 8. PubMed
BACKGROUND: NR2F6 has been proposed as an alternative cancer immune checkpoint in the effector T cell compartment. However, a realistic assessment of the in vivo therapeutic potential of NR2F6 requires acute depletion. METHODS: Employing primary T cells isolated from Cas9-transgenic mice for electroporation of chemically synthesized sgRNA, we established a CRISPR/Cas9-mediated acute knockout protocol of Nr2f6 in primary mouse T cells. RESULTS: Analyzing these Nr2f6(CRISPR/Cas9 knockout) T cells, we reproducibly observed a hyper-reactive effector phenotype upon CD3/CD28 stimulation in vitro, highly reminiscent to Nr2f6(-/-) T cells. Importantly, CRISPR/Cas9-mediated Nr2f6 ablation prior to adoptive cell therapy (ACT) of autologous polyclonal T cells into wild-type tumor-bearing recipient mice in combination with PD-L1 or CTLA-4 tumor immune checkpoint blockade significantly delayed MC38 tumor progression and induced superior survival, thus further validating a T cell-inhibitory function of NR2F6 during tumor progression. CONCLUSIONS: These findings indicate that Nr2f6(CRISPR/Cas9 knockout) T cells are comparable to germline Nr2f6(-/-) T cells, a result providing an independent confirmation of the immune checkpoint function of lymphatic NR2F6. Taken together, CRISPR/Cas9-mediated acute Nr2f6 gene ablation in primary mouse T cells prior to ACT appeared feasible for potentiating established PD-L1 and CTLA-4 blockade therapies, thereby pioneering NR2F6 inhibition as a sensitizing target for augmented tumor regression. Video abstract.
Wang, Q., et al. (2019). "Single-cell profiling guided combinatorial immunotherapy for fast-evolving CDK4/6 inhibitor-resistant HER2-positive breast cancer" Nat Commun 10(1): 3817. PubMed
Acquired resistance to targeted cancer therapy is a significant clinical challenge. In parallel with clinical trials combining CDK4/6 inhibitors to treat HER2+ breast cancer, we sought to prospectively model tumor evolution in response to this regimen in vivo and identify a clinically actionable strategy to combat drug resistance. Despite a promising initial response, acquired resistance emerges rapidly to the combination of anti-HER2/neu antibody and CDK4/6 inhibitor Palbociclib. Using high-throughput single-cell profiling over the course of treatments, we reveal a distinct immunosuppressive immature myeloid cell (IMC) population to infiltrate the resistant tumors. Guided by single-cell transcriptome analysis, we demonstrate that combination of IMC-targeting tyrosine kinase inhibitor cabozantinib and immune checkpoint blockade enhances anti-tumor immunity, and overcomes the resistance. Furthermore, sequential combinatorial immunotherapy enables a sustained control of the fast-evolving CDK4/6 inhibitor-resistant tumors. Our study demonstrates a translational framework for treating rapidly evolving tumors through preclinical modeling and single-cell analyses.
Su, W., et al. (2019). "The Polycomb Repressor Complex 1 Drives Double-Negative Prostate Cancer Metastasis by Coordinating Stemness and Immune Suppression" Cancer Cell 36(2): 139-155.e110. PubMed
The mechanisms that enable immune evasion at metastatic sites are poorly understood. We show that the Polycomb Repressor Complex 1 (PRC1) drives colonization of the bones and visceral organs in double-negative prostate cancer (DNPC). In vivo genetic screening identifies CCL2 as the top prometastatic gene induced by PRC1. CCL2 governs self-renewal and induces the recruitment of M2-like tumor-associated macrophages and regulatory T cells, thus coordinating metastasis initiation with immune suppression and neoangiogenesis. A catalytic inhibitor of PRC1 cooperates with immune checkpoint therapy to reverse these processes and suppress metastasis in genetically engineered mouse transplantation models of DNPC. These results reveal that PRC1 coordinates stemness with immune evasion and neoangiogenesis and point to the potential clinical utility of targeting PRC1 in DNPC.
Binnewies, M., et al. (2019). "Unleashing Type-2 Dendritic Cells to Drive Protective Antitumor CD4(+) T Cell Immunity" Cell 177(3): 556-571.e516. PubMed
Differentiation of proinflammatory CD4(+) conventional T cells (T(conv)) is critical for productive antitumor responses yet their elicitation remains poorly understood. We comprehensively characterized myeloid cells in tumor draining lymph nodes (tdLN) of mice and identified two subsets of conventional type-2 dendritic cells (cDC2) that traffic from tumor to tdLN and present tumor-derived antigens to CD4(+) T(conv), but then fail to support antitumor CD4(+) T(conv) differentiation. Regulatory T cell (T(reg)) depletion enhanced their capacity to elicit strong CD4(+) T(conv) responses and ensuing antitumor protection. Analogous cDC2 populations were identified in patients, and as in mice, their abundance relative to T(reg) predicts protective ICOS(+) PD-1(lo) CD4(+) T(conv) phenotypes and survival. Further, in melanoma patients with low T(reg) abundance, intratumoral cDC2 density alone correlates with abundant CD4(+) T(conv) and with responsiveness to anti-PD-1 therapy. Together, this highlights a pathway that restrains cDC2 and whose reversal enhances CD4(+) T(conv) abundance and controls tumor growth.
- Immunology and Microbiology,
Characterisation of an autochthonous mouse ccRCC model of immune checkpoint inhibitor therapy resistance.
In Scientific Reports on 5 June 2025 by Peighambari, A., Huang, H., et al.
Many metastatic clear cell renal cell carcinomas (ccRCC) are resistant to immune checkpoint inhibitor therapies, however the mechanisms underlying sensitivity or resistance remain incompletely characterised. We demonstrate that ccRCCs in the Vhl/Trp53/Rb1 mutant mouse model are resistant to combined anti-PD-1/anti-CTLA-4 therapy alone and in combination with additional therapeutic agents that reflect current ccRCC clinical trials. However, in some animals in vivo checkpoint therapy allowed isolated splenic T cells to recognise cultured ccRCC cells from the same animal, implicating the tumour microenvironment in suppression of T cell activation. We identified putative immunosuppressive myeloid cell populations with features similar to myeloid cells in the microenvironment of human ccRCC. The expression patterns of immune checkpoint ligands in both the mouse model and in human ccRCC suggests that several checkpoint systems other than PD-1 and CTLA-4 are likely to represent the dominant T cell suppressive forces in ccRCC. Our findings characterise an autochthonous mouse ccRCC model of immune checkpoint inhibitor therapy resistance and pave the way for a systematic functional dissection of the identified potential molecular barriers to effective immune therapy of ccRCC. Ā© 2025. The Author(s).
- Cancer Research,
- Immunology and Microbiology
Antigen-presenting cancer-associated fibroblasts in murine pancreatic tumors differentially control regulatory T cell phenotype and function via CXCL9 and CCL22
Preprint on BioRxiv : the Preprint Server for Biology on 1 April 2025 by Maru, S. Y., Wetzel, M., et al.
Pancreatic ductal adenocarcinoma (PDAC) is characterized by a complex tumor microenvironment (TME) including stromal cells that influence resistance to therapy. Recent studies have revealed that stromal cancer-associated fibroblasts (CAFs) are heterogeneous in origin, gene expression, and function. Antigen-presenting CAFs (apCAFs), are defined by major histocompatibility complex (MHC)-II expression and can activate effector CD4 + T cells that have the potential to contribute to the anti-cancer immune response, but also can induce regulatory T cell (Treg) differentiation. Whether apCAFs promote or restrain the antitumor response remains uncertain. Using tumor clones of the KPC murine PDAC model differing in sensitivity to immune checkpoint blockade (ICB), we found that immunosensitive (sKPC) tumors were characterized by higher immune cell and apCAF infiltration than resistant (rKPC) tumors. IMC analysis showed proximity of apCAFs and CD4 + T cells in both sKPC and rKPC tumors implicating interaction within the TME. apCAF-depleted sKPC tumor-bearing mice had diminished sensitivity to ICB. apCAFs from both sKPC and rKPC tumors activated tumor-infiltrating CD4 + T cells and induced Treg differentiation. However, transcriptomic analysis showed that Tregs induced by apCAFs were overexpressed for immunosuppressive genes in rKPCs relative to sKPCs, and that this is associated with differential chemokine signaling from apCAFs depending on tumor origin. Together these data implicate apCAFs as important mediators of the antitumor immune response, modulation of which could facilitate the development of more effective anti-tumor immune based approaches for PDAC patients.
- Immunology and Microbiology
KRASG12D-Specific Targeting with Engineered Exosomes Reprograms the Immune Microenvironment to Enable Efficacy of Immune Checkpoint Therapy in PDAC Patients
Preprint on MedRxiv : the Preprint Server for Health Sciences on 6 March 2025 by LeBleu, V. S., Smaglo, B. G., et al.
Oncogenic KRAS drives initiation and maintenance of pancreatic ductal adenocarcinoma (PDAC). Here, we show that engineered exosomes with Kras G12D specific siRNA (iExoKras G12D ) reveal impressive biodistribution in pancreas with negligible toxicity in preclinical studies in mice and Rhesus macaques. Clinical testing of iExoKras G12D in the iEXPLORE (iExoKras G12D in Pancreatic Cancer) Phase I study employed a classical 3+3 dose escalation design (Phase Ia), followed by an accelerated titration design (Phase Ib) ( NCT03608631 ). Patients with advanced metastatic disease were enrolled after failure of multiple lines of therapy. iExoKras G12D therapy was well-tolerated with no reported dose-limiting toxicity with some cases of stable disease response, and maximum tolerated infusion was not reached even at the highest dose. Downregulation of KRAS G12D DNA and suppression of phopho-Erk was documented with increased intratumoral in CD8 + T cell infiltration in patient samples upon treatment. The CD8 + T cell recruitment priming by iExoKras G12D informed on potential efficacy of immune checkpoint therapy and lead to validation testing in preclinical PDAC models. Combination therapy of iExoKras G12D and anti-CTLA-4 antibodies, but not anti-PD1, revealed robust anti-tumor efficacy via FAS mediated CD8 + T cell anti-tumor activity. This first-in-human, precision medicine clinical trial offers new insights into priming of immunotherapy by oncogenic Kras inhibitor and an opportunistic combination therapy for PDAC patients.
- 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
- In Vivo,
- Mus musculus (House mouse),
- Immunology and Microbiology
Molecular control of PDPNhi macrophage subset induction by ADAP as a host defense in sepsis.
In JCI Insight on 4 February 2025 by Zhang, P., Wang, X., et al.
Induction of podoplanin (PDPN) expression is a critical response of macrophages to LPS stimulation or bacterial infection in sepsis, but how this key process of TLR4-stimulated PDPN upregulation is regulated and the effect of PDPN expression on macrophage function remain elusive. Here, we determined how this process is regulated in vitro and in vivo. PDPN failed to be upregulated in TLR4-stimulated macrophages deficient in adhesion and degranulation-promoting adapter protein (ADAP), which could be rescued by the reconstitution of ADAP. A distinct PDPNhi peritoneal macrophage (PM) subset, which exhibited an M2-like phenotype and enhanced phagocytic activity, was generated in WT but not in ADAP-deficient septic mice. The blockade of PDPNhi PMs mimicked the effect of ADAP deficiency, which exacerbated sepsis. Mechanistically, Bruton's tyrosine kinase-mediated (BTK-mediated) tyrosine phosphorylation of ADAP at Y571 worked together with mTOR to converge on STAT3 activation for the transactivation of the PDPN promoter. Moreover, agonist activation of STAT3 profoundly potentiated the PDPNhi PM subset generation and alleviated sepsis severity in mice. Together, our findings reveal a mechanism whereby ADAP resets macrophage function by controlling the TLR4-induced upregulation of PDPN as a host innate immune defense during sepsis.
- Cancer Research
CDK8 remodels the tumor microenvironment to resist the therapeutic efficacy of targeted KRASG12Dinhibition in pancreatic ductal adenocarcinoma
Preprint on BioRxiv : the Preprint Server for Biology on 2 February 2025 by McAndrews, K. M., Mahadevan, K. K., et al.
Mutations in KRAS are a dominant driver of pancreatic ductal adenocarcinoma (PDAC), with over 40% of PDAC patients presenting with KRAS G12D mutations. The recent development of small molecule inhibitors targeting KRAS G12D has enabled targeting of mutant KRAS signaling and suppression of PDAC; however, the contribution of the tumor microenvironment (TME) to the sustained therapeutic efficacy of KRAS G12D inhibition and mechanism/s of resistance to KRAS G12D suppression remain to be elucidated. Here, we employed spatial transcriptomics, single cell RNA sequencing, and CODEX-based spatial proteomics to evaluate cancer cell intrinsic and extrinsic responses to KRAS G12D inhibition with MRTX1133. While KRAS G12D inhibition initially increases CD11c + cells with impactful T cell infiltration within proximity to cancer cells, long-term treatment with MRTX1133 resulted in reversal of the immune responses leading to KRAS G12D therapy resistance promoted by CDK8, a multiprotein mediator complex associated kinase. CDK8 imparts resistance in part through induction of downstream CXCL2 chemokine secretion, inhibition of FAS expression, and remodeling of the TME to promote immune evasion. Targeting CDK8 by itself and in combination with Ī±CTLA-4 immunotherapy overcomes resistance to KRAS G12D inhibition with prolonged survival with translational implications.
- Cancer Research,
- Immunology and Microbiology
Development of Syngeneic Murine Glioma Models with Somatic Mismatch Repair Deficiency to Study Therapeutic Responses to Alkylating Agents and Immunotherapy.
In Current Protocols on 1 February 2025 by Bhatt, D., Sundaram, R. K., et al.
Glioblastoma (GBM) carries a dismal prognosis, with a median survival of less than 15 months. Temozolomide (TMZ), the standard frontline chemotherapeutic for GBM, is an alkylating agent that generates DNA O6-methylguanine (O6MeG) lesions. Without O6MeG-methyltransferase (MGMT), this lesion triggers the mismatch repair (MMR) pathway and leads to cytotoxicity via futile cycling. TMZ resistance frequently arises via the somatic acquisition of MMR deficiency (MMRd). Moreover, DNA-damaging agents have been shown capable of increasing tumor immunogenicity and improving response to immune checkpoint blockade (ICB), which has had limited success in glioma. The study of how alkylating chemotherapy such as TMZ impacts antitumor immunity in glioma has been hindered by a lack of immunocompetent models that incorporate relevant DNA repair genotypes. Here, we used CRISPR/Cas9 to generate models isogenic for knockout (KO) of Mlh1 in the syngeneic SB28 murine glioma cell line. MMR KO models readily formed intracranial tumors and exhibited in vitro and in vivo resistance to TMZ. In contrast, MMR KO cells maintained sensitivity to KL-50, a newly developed alkylating compound that exerts MGMT-dependent, MMR-independent cytotoxicity. Lastly, MMR KO tumors remained resistant to ICB, mirroring the lack of response seen in patients with somatic MMRd GBM. The development of syngeneic, immunologically cold glioma models with somatic loss of MMR will facilitate future studies on the immunomodulatory effects of alkylating agents in relevant DNA repair contexts, which will be vital for optimizing combinations with ICB. Ā© 2025 Wiley Periodicals LLC. Basic Protocol 1: Validation of mismatch repair knockouts and in vitro sensitivity to alkylating agents Basic Protocol 2: Stereotaxic injection of isogenic SB28 cells in female C57BL/6J mice and in vivo treatment. Ā© 2025 Wiley Periodicals LLC.
- Mus musculus (House mouse),
- Immunology and Microbiology
Targeting the NLRP3 inflammasome abrogates cardiotoxicity of immune checkpoint blockers.
In Journal for Immunotherapy of Cancer on 7 January 2025 by Lu, Y., Gao, J., et al.
Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many malignant tumors. However, ICI-induced hyper-immune activation causes cardiotoxicity. Traditional treatments such as glucocorticoids and immunosuppressants have limited effectiveness and may even accelerate tumor growth. This study aimed to identify approaches that effectively reduce cardiotoxicity and simultaneously preserve or enhance the antitumor immunity of ICI therapy. ICI injection in melanoma-bearing C57BL/6J female mice was used to simulate cardiotoxicity in patients with tumor undergoing immune therapy. MCC950 was used to block nod-like receptor protein 3 (NLRP3) inflammasome activity. Echocardiography, immunofluorescence, flow cytometry, and reverse transcription quantitative polymerase chain reaction were used to assess cardiac function, immune cell populations, and inflammatory factor levels. Bulk and single-cell RNA sequencing was used to detect the changes in cardiac transcriptome and immunological network. NLRP3 inhibition reduced inflammatory response and improved cardiac function. Notably, NLRP3 inhibition also resulted in a pronounced suppression of tumor growth. Single-cell RNA sequencing elucidated that MCC950 treatment reduced the cardiac infiltration of pathogenic macrophages, cytotoxic T cells, activated T cells, and their production of inflammatory cytokines, while enhancing the presence of reparative macrophages and naive T cells. In addition, MCC950 attenuated cardiotoxicity induced by dual programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) immunotherapy and promoted tumor regression, and showed efficacy in treating established cardiotoxicity. Our findings provide a promising clinical approach for preventing and treating cardiotoxicity induced by ICIs, dissociating the antitumor efficacy of ICI-based therapies from their cardiotoxic side effects. Ā© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.
CTLA4 blockade abrogates KEAP1/STK11-related resistance to PD-(L)1 inhibitors.
In Nature on 1 November 2024 by Skoulidis, F., AraĆŗjo, H. A., et al.
For patients with advanced non-small-cell lung cancer (NSCLC), dual immune checkpoint blockade (ICB) with CTLA4 inhibitors and PD-1 or PD-L1 inhibitors (hereafter, PD-(L)1 inhibitors) is associated with higher rates of anti-tumour activity and immune-related toxicities, when compared with treatment with PD-(L)1 inhibitors alone. However, there are currently no validated biomarkers to identify which patients willĀ benefit from dual ICB1,2. Here we show that patients with NSCLC who have mutations in the STK11 and/or KEAP1 tumour suppressor genes derived clinical benefit from dual ICB with the PD-L1 inhibitor durvalumab and the CTLA4 inhibitor tremelimumab, but not from durvalumab alone, when added to chemotherapy in the randomized phase III POSEIDON trial3. Unbiased genetic screens identified loss of both of these tumour suppressor genes as independent drivers of resistance to PD-(L)1 inhibition, and showed that loss of Keap1 was the strongest genomic predictor of dual ICB efficacy-a finding that was confirmed in several mouse models of Kras-driven NSCLC. In both mouse models and patients, KEAP1 and STK11 alterations were associated with an adverse tumour microenvironment, which was characterized by a preponderance of suppressive myeloid cells and the depletion of CD8+ cytotoxic T cells, but relative sparing of CD4+ effector subsets. Dual ICB potently engaged CD4+ effector cells and reprogrammed the tumour myeloid cell compartment towards inducible nitric oxide synthase (iNOS)-expressing tumoricidal phenotypes that-together with CD4+ and CD8+ T cells-contributed to anti-tumour efficacy. These data support the use of chemo-immunotherapy with dual ICB to mitigate resistance to PD-(L)1 inhibition in patients with NSCLC who have STK11 and/or KEAP1 alterations. Ā© 2024. The Author(s).
- Biochemistry and Molecular biology,
- Cancer Research
CDK12 loss drives prostate cancer progression, transcription-replication conflicts, and synthetic lethality with paralog CDK13.
In Cell Reports Medicine on 15 October 2024 by Tien, J. C., Luo, J., et al.
Biallelic loss of cyclin-dependent kinase 12 (CDK12) defines a metastatic castration-resistant prostate cancer (mCRPC) subtype. It remains unclear, however, whether CDK12 loss drives prostate cancer (PCa) development or uncovers pharmacologic vulnerabilities. Here, we show Cdk12 ablation in murine prostate epithelium is sufficient to induce preneoplastic lesions with lymphocytic infiltration. In allograft-based CRISPR screening, Cdk12 loss associates positively with Trp53 inactivation but negatively with Pten inactivation. Moreover, concurrent Cdk12/Trp53 ablation promotes proliferation of prostate-derived organoids, while Cdk12 knockout in Pten-null mice abrogates prostate tumor growth. In syngeneic systems, Cdk12/Trp53-null allografts exhibit luminal morphology and immune checkpoint blockade sensitivity. Mechanistically, Cdk12 inactivation mediates genomic instability by inducing transcription-replication conflicts. Strikingly, CDK12-mutant organoids and patient-derived xenografts are sensitive to inhibition or degradation of the paralog kinase, CDK13. We therein establish CDK12 as a bona fide tumor suppressor, mechanistically define how CDK12 inactivation causes genomic instability, and advance a therapeutic strategy for CDK12-mutant mCRPC. Copyright Ā© 2024 The Author(s). Published by Elsevier Inc. All rights reserved.
TCF-1 and TOX regulate the memory formation of intestinal group 2 innate lymphoid cells in asthma.
In Nature Communications on 8 September 2024 by Bao, K., Gu, X., et al.
Immune memory has been expanded to group 2 innate lymphoid cells (ILC2s), but the cellular and molecular bases remain incompletely understood. Based on house dust mite (HDM)-induced mice asthma models and human samples, we applied flow cytometry, parabiosis, in vivo imaging and adoptive transplantation to confirm the persistence, migration and function of CD45+lineage-CD90.2+NK1.1-NKp46-ST2-KLRG1+IL-17RB+ memory-like ILC2s (ml-ILC2s). Regulated by CCR9/CCL25 and S1P signaling, ml-ILC2s reside in the lamina propria of small intestines (siLP) in asthma remission, and subsequently move to airway upon re-encountering antigens or alarmins. Furthermore, ml-ILC2s possess properties of longevity, potential of rapid proliferation and producing IL-13, and display transcriptional characteristics with up-regulation of Tox and Tcf-7. ml-ILC2s transplantation restore the asthmatic changes abrogated by Tox and Tcf7 knockdown. Our data identify siLP ml-ILC2s as a memory-like subset, which promotes asthma relapse. Targeting TCF-1 and TOX might be promising for preventing asthma recurrence. Ā© 2024. The Author(s).
- Immunology and Microbiology
Transcriptomic, clonal, and functional analyses reveal Liver tissue-imprinted immuno-profile of circulating autoreactive CD4 T cells in autoimmune liver diseases
Preprint on BioRxiv : the Preprint Server for Biology on 29 March 2024 by Cardon, A., GuinebretiĆØre, T., et al.
Autoimmune liver diseases (AILD) are immune-mediated disorders in which CD4 T cells may play a central role. However, self-antigen-specific CD4 T cells are mainly characterized in the bloodstream, and the link with the immune response in the targeted tissue is a difficult and under-studied task in AILD. We hypothesize that circulating self-antigen-specific CD4 T cells contain dominant hepatic CD4 T cell clonotypes and represent liver-derived autoreactive CD4 T cells. Single cell transcriptomic analysis of circulating self-antigen-specific CD4 T cells reveal a specific B-helper and immuno-exhausted transcriptional profile, which is conserved for different autoantigens, but distinct from several other types of foreign antigen specificities. The dominant hepatic CD4 T cell clones shared a similar transcriptomic signature and were enriched in the circulating PD1+ TIGIT+ HLA-DR+ CD4 T cell subset. In liver biopsy, PD1+ CD4 T cells were present in tertiary lymphoid structure, reinforcing the hypothesis of a pathogenic role of these cells. Using a mouse model, we demonstrated antigen-specific CD4 T cells acquired the immuno-exhausted transcriptional profile when they accumulated in the liver after local antigen reactivity. Inhibition of immune checkpoint molecules contributed to increased hepatic damages in a CD4 T cell dependent manner. This study reveals the origin of liver-autoreactive CD4 T cells in the blood of AILD patients that are imprinted by the liver environment and recirculate from the damaged tissue during the active phase of the disease. In addition, this study also shows how immune checkpoint molecules contribute to local antigen-specific tolerance in the liver, which may be dysregulated in AILD and immunotherapy-induced acute hepatitis. Finally, our study enables tracking and isolating liver autoreactive CD4 T cells in future diagnostic and therapeutic purposes.
- Cancer Research
CDK12Loss Promotes Prostate Cancer Development While Exposing Vulnerabilities to Paralog-Based Synthetic Lethality
Preprint on BioRxiv : the Preprint Server for Biology on 21 March 2024 by Tien, J. C., Chang, Y., et al.
SUMMARY Biallelic loss of cyclin-dependent kinase 12 ( CDK12 ) defines a unique molecular subtype of metastatic castration-resistant prostate cancer (mCRPC). It remains unclear, however, whether CDK12 loss per se is sufficient to drive prostate cancer developmentāeither alone, or in the context of other genetic alterationsāand whether CDK12 -mutant tumors exhibit sensitivity to specific pharmacotherapies. Here, we demonstrate that tissue-specific Cdk12 ablation is sufficient to induce preneoplastic lesions and robust T cell infiltration in the mouse prostate. Allograft-based CRISPR screening demonstrated that Cdk12 loss is positively associated with Trp53 inactivation but negatively associated with Pten inactivationāakin to what is observed in human mCRPC. Consistent with this, ablation of Cdk12 in prostate organoids with concurrent Trp53 loss promotes their proliferation and ability to form tumors in mice, while Cdk12 knockout in the Pten -null prostate cancer mouse model abrogates tumor growth. Bigenic Cdk12 and Trp53 loss allografts represent a new syngeneic model for the study of androgen receptor (AR)-positive, luminal prostate cancer. Notably, Cdk12/Trp53 loss prostate tumors are sensitive to immune checkpoint blockade. Cdk12 -null organoids (either with or without Trp53 co-ablation) and patient-derived xenografts from tumors with CDK12 inactivation are highly sensitive to inhibition or degradation of its paralog kinase, CDK13. Together, these data identify CDK12 as a bona fide tumor suppressor gene with impact on tumor progression and lends support to paralog-based synthetic lethality as a promising strategy for treating CDK12- mutant mCRPC.
- Cancer Research,
- Immunology and Microbiology
Antitumor Effect by Either FLASH or Conventional Dose Rate Irradiation Involves Equivalent Immune Responses.
In International Journal of Radiation Oncology, Biology, Physics on 15 March 2024 by Almeida, A., Godfroid, C., et al.
The capability of ultrahigh dose rate FLASH radiation therapy to generate the FLASH effect has opened the possibility to enhance the therapeutic index of radiation therapy. The contribution of the immune response has frequently been hypothesized to account for a certain fraction of the antitumor efficacy and tumor kill of FLASH but has yet to be rigorously evaluated. To investigate the immune response as a potentially important mechanism of the antitumor effect of FLASH, various murine tumor models were grafted either subcutaneously or orthotopically into immunocompetent mice or in moderately and severely immunocompromised mice. Mice were locally irradiated with single dose (20 Gy) or hypofractionated regimens (3 Ć 8 or 2 Ć 6 Gy) using FLASH (ā„2000 Gy/s) and conventional (CONV) dose rates (0.1 Gy/s), with/without anti-CTLA-4. Tumor growth was monitored over time and immune profiling performed. FLASH and CONV 20 Gy were isoeffective in delaying tumor growth in immunocompetent and moderately immunodeficient hosts and increased tumor doubling time to >14 days versus >7 days in control animals. Similar observations were obtained with a hypofractionated scheme, regardless of the microenvironment (subcutaneous flank vs ortho lungs). Interestingly, in profoundly immunocompromised mice, 20 Gy FLASH retained antitumor activity and significantly increased tumor doubling time to >14 days versus >8 days in control animals, suggesting a possible antitumor mechanism independent of the immune response. Analysis of the tumor microenvironment showed similar immune profiles after both irradiation modalities with significant decrease of lymphoid cells by ā¼40% and a corresponding increase of myeloid cells. In addition, FLASH and CONV did not increase transforming growth factor-Ī²1 levels in tumors compared with unirradiated control animals. Furthermore, when a complete and long-lasting antitumor response was obtained (>140 days), both modalities of irradiation were able to generate a long-term immunologic memory response. The present results clearly document that the tumor responses across multiple immunocompetent and immunodeficient mouse models are largely dose rate independent and simultaneously contradict a major role of the immune response in the antitumor efficacy of FLASH. Therefore, our study indicates that FLASH is as potent as CONV in modulating antitumor immune response and can be used as an immunomodulatory agent. Copyright Ā© 2023 The Authors. Published by Elsevier Inc. All rights reserved.
- Cancer Research
Somatic mouse models of gastric cancer reveal genotype-specific features of metastatic disease.
In Nature Cancer on 1 February 2024 by Leibold, J., Tsanov, K. M., et al.
Metastatic gastric carcinoma is a highly lethal cancer that responds poorly to conventional and molecularly targeted therapies. Despite its clinical relevance, the mechanisms underlying the behavior and therapeutic response of this disease are poorly understood owing, in part, to a paucity of tractable models. Here we developed methods to somatically introduce different oncogenic lesions directly into the murine gastric epithelium. Genotypic configurations observed in patients produced metastatic gastric cancers that recapitulated the histological, molecular and clinical features of all nonviral molecular subtypes of the human disease. Applying this platform to both wild-type and immunodeficient mice revealed previously unappreciated links between the genotype, organotropism and immune surveillance of metastatic cells, which produced distinct patterns of metastasis that were mirrored in patients. Our results establish a highly portable platform for generating autochthonous cancer models with flexible genotypes and host backgrounds, which can unravel mechanisms of gastric tumorigenesis or test new therapeutic concepts. Ā© 2024. The Author(s).
- Mus musculus (House mouse),
- Cancer Research,
- Immunology and Microbiology
CD4 T cell-activating neoantigens enhance personalized cancer vaccine efficacy.
In JCI Insight on 8 December 2023 by Huff, A. L., Longway, G., et al.
PubMed
Personalized cancer vaccines aim to activate and expand cytotoxic antitumor CD8+ T cells to recognize and kill tumor cells. However, the role of CD4+ T cell activation in the clinical benefit of these vaccines is not well defined. We previously established a personalized neoantigen vaccine (PancVAX) for the pancreatic cancer cell line Panc02, which activates tumor-specific CD8+ T cells but required combinatorial checkpoint modulators to achieve therapeutic efficacy. To determine the effects of neoantigen-specific CD4+ T cell activation, we generated a vaccine (PancVAX2) targeting both major histocompatibility complex class I- (MHCI-) and MHCII-specific neoantigens. Tumor-bearing mice vaccinated with PancVAX2 had significantly improved control of tumor growth and long-term survival benefit without concurrent administration of checkpoint inhibitors. PancVAX2 significantly enhanced priming and recruitment of neoantigen-specific CD8+ T cells into the tumor with lower PD-1 expression after reactivation compared with the CD8+ vaccine alone. Vaccine-induced neoantigen-specific Th1 CD4+ T cells in the tumor were associated with decreased Tregs. Consistent with this, PancVAX2 was associated with more proimmune myeloid-derived suppressor cells and M1-like macrophages in the tumor, demonstrating a less immunosuppressive tumor microenvironment. This study demonstrates the biological importance of prioritizing and including CD4+ T cell-specific neoantigens for personalized cancer vaccine modalities.
- Cancer Research,
- Immunology and Microbiology
Differential requirements for CD4+ T cells in the efficacy of the anti-PD-1+LAG-3 and anti-PD-1+CTLA-4 combinations in melanoma flank and brain metastasis models.
In Journal for Immunotherapy of Cancer on 6 December 2023 by Phadke, M. S., Li, J., et al.
PubMed
Although the anti-PD-1+LAG-3 and the anti-PD-1+CTLA-4 combinations are effective in advanced melanoma, it remains unclear whether their mechanisms of action overlap. We used single cell (sc) RNA-seq, flow cytometry and IHC analysis of responding SM1, D4M-UV2 and B16 melanoma flank tumors and SM1 brain metastases to explore the mechanism of action of the anti-PD-1+LAG-3 and the anti-PD-1+CTLA-4 combination. CD4+ andāCD8+ Tācell depletion, tetramer binding assays and ELISPOT assays were used to demonstrate the unique role of CD4+Tācell help in the antitumor effects of the anti-PD-1+LAG-3 combination. The anti-PD-1+CTLA-4 combination was associated with the infiltration of FOXP3+regulatoryāCD4+ cells (Tregs), fewer activated CD4+T cells and the accumulation of a subset of IFNĪ³ secreting cytotoxic CD8+T cells, whereas the anti-PD-1+LAG-3 combination led to the accumulation of CD4+T helper cells that expressed CXCR4, TNFSF8, IL21R and a subset of CD8+T cells with reduced expression of cytotoxic markers. T cell depletion studies showed a requirement for CD4+T cells for the anti-PD-1+LAG-3 combination, but not the PD-1-CTLA-4 combination at both flank and brain tumor sites. In anti-PD-1+LAG-3 treated tumors, CD4+Tācell depletion was associated with fewer activated (CD69+) CD8+T cells and impaired IFNĪ³ release but, conversely, increased numbers of activated CD8+T cells and IFNĪ³ release in anti-PD-1+CTLA-4 treated tumors. Together these studies suggest that these two clinically relevant immune checkpoint inhibitor (ICI) combinations have differential effects on CD4+Tācell polarization, which in turn, impacted cytotoxic CD8+Tācell function. Further insights into the mechanisms of action/resistance of these clinically-relevant ICI combinations will allow therapy to be further personalized. Ā© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
- Mus musculus (House mouse),
- Immunology and Microbiology
Local and distant response to intratumoral immunotherapy assessed by immunoPET in mice.
In Journal for Immunotherapy of Cancer on 1 November 2023 by Meyblum, L., Chevaleyre, C., et al.
PubMed
Despite the promising efficacy of immune checkpoint blockers (ICB), tumor resistance and immune-related adverse events hinder their success in cancer treatment. To address these challenges, intratumoral delivery of immunotherapies has emerged as a potential solution, aiming to mitigate side effects through reduced systemic exposure while increasing effectiveness by enhancing local bioavailability. However, a comprehensive understanding of the local and systemic distribution of ICBs following intratumoral administration, as well as their impact on distant tumors, remains crucial for optimizing their therapeutic potential.To comprehensively investigate the distribution patterns following the intratumoral and intravenous administration of radiolabeled anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and to assess its corresponding efficacy in both injected and non-injected tumors, we conducted an immunoPET imaging study. CT26 and MC38 syngeneic colorectal tumor cells were implanted subcutaneously on both flanks of Balb/c and C57Bl/6 mice, respectively. Hamster anti-mouse CTLA-4 antibody (9H10) labeled with zirconium-89 ([89Zr]9H10) was intratumorally or intravenously administered. Whole-body distribution of the antibody was monitored by immunoPET imaging (n=12 CT26 Balb/c mice, n=10 MC38 C57Bl/6 mice). Tumorous responses to injected doses (1-10āmg/kg) were correlated with specific uptake of [89Zr]9H10 (n=24). Impacts on the tumor microenvironment were assessed by immunofluorescence and flow cytometry. Half of the dose was cleared into the blood 1āhour after intratumoral administration. Despite this, 7ādays post-injection, 6-8% of the dose remained in the intratumoral-injected tumors. CT26 tumors with prolonged ICB exposure demonstrated complete responses. Seven days post-injection, the contralateral non-injected tumor uptake of the ICB was comparable to the one achieved through intravenous administration (7.5Ā±1.7%āID.cm-3 and 7.6Ā±2.1%āID.cm-3, respectively) at the same dose in the CT26 model. This observation was confirmed in the MC38 model. Consistent intratumoral pharmacodynamic effects were observed in both intratumoral and intravenous treatment groups, as evidenced by a notable increase in CD8+T cells within the CT26 tumors following treatment. ImmunoPET-derived pharmacokinetics supports intratumoral injection of ICBs to decrease systemic exposure while maintaining efficacy compared with intravenous. Intratumoral-ICBs lead to high local drug exposure while maintaining significant therapeutic exposure in non-injected tumors. This immunoPET approach is applicable for clinical practice to support evidence-based drug development. Ā© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
- Cancer Research,
- Immunology and Microbiology
KRASG12D inhibition reprograms the microenvironment of early and advanced pancreatic cancer to promote FAS-mediated killing by CD8+ TĀ cells.
In Cancer Cell on 11 September 2023 by Mahadevan, K. K., McAndrews, K. M., et al.
The KRASG12D mutation is present in nearly half of pancreatic adenocarcinomas (PDAC). We investigated the effects of inhibiting the KRASG12D mutant protein with MRTX1133, a non-covalent small molecule inhibitor of KRASG12D, on early and advanced PDAC and its influence on the tumor microenvironment. Employing 16 different models of KRASG12D-driven PDAC, we demonstrate that MRTX1133 reverses early PDAC growth, increases intratumoral CD8+ effector TĀ cells, decreases myeloid infiltration, and reprograms cancer-associated fibroblasts. MRTX1133 leads to regression of both established PanINs and advanced PDAC. Regression of advanced PDAC requires CD8+ TĀ cells and immune checkpoint blockade (ICB) synergizes with MRTX1133 to eradicate PDAC and prolong overall survival. Mechanistically, inhibition of KRASG12D in advanced PDAC and human patient derived organoids induces FAS expression in cancer cells and facilitates CD8+ TĀ cell-mediated death. Collectively, this study provides a rationale for a synergistic combination of MRTX1133 with ICB in clinical trials. Copyright Ā© 2023 Elsevier Inc. All rights reserved.
- Cancer Research,
- Immunology and Microbiology
The GPCR-GĪ±s-PKA signaling axis promotes T cell dysfunction and cancer immunotherapy failure.
In Nature Immunology on 1 August 2023 by Wu, V. H., Yung, B. S., et al.
PubMed
Immune checkpoint blockade (ICB) targeting PD-1 and CTLA-4 has revolutionized cancer treatment. However, many cancers do not respond to ICB, prompting the search for additional strategies to achieve durable responses. G-protein-coupled receptors (GPCRs) are the most intensively studied drug targets but are underexplored in immuno-oncology. Here, we cross-integrated large singe-cell RNA-sequencing datasets from CD8+ T cells covering 19 distinct cancer types and identified an enrichment of GĪ±s-coupled GPCRs on exhausted CD8+ T cells. These include EP2, EP4, A2AR, Ī²1AR and Ī²2AR, all of which promote T cell dysfunction. We also developed transgenic mice expressing a chemogenetic CD8-restricted GĪ±s-DREADD to activate CD8-restricted GĪ±s signaling and show that a GĪ±s-PKA signaling axis promotes CD8+ T cell dysfunction and immunotherapy failure. These data indicate that GĪ±s-GPCRs are druggable immune checkpoints that might be targeted to enhance the response to ICB immunotherapies. Ā© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.
