InVivoMAb anti-human MHC Class I (HLA-A, HLA-B, HLA-C)
Product Description
Specifications
| Isotype | Mouse IgG2a, κ |
|---|---|
| Recommended Isotype Control(s) | InVivoMAb mouse IgG2a isotype control, unknown specificity |
| Recommended Dilution Buffer | InVivoPure pH 6.5 Dilution Buffer |
| Conjugation | This product is unconjugated. Conjugation is available via our Antibody Conjugation Services. |
| Immunogen | Human tonsil cell membrane |
| Reported Applications |
Functional assays in vitro Organoids/Organ-on-Chip Immunopeptidomics Immunoprecipitation Immunofluorescence Flow cytometry ELISA |
| Formulation |
PBS, pH 6.5 Contains no stabilizers or preservatives |
| Endotoxin |
≤1EU/mg (≤0.001EU/μg) Determined by LAL assay |
| Purity |
≥95% Determined by SDS-PAGE |
| Sterility | 0.2 µm filtration |
| Production | Purified from cell culture supernatant in an animal-free facility |
| Purification | Protein G |
| RRID | AB_1107730 |
| Molecular Weight | 150 kDa |
| Storage | The antibody solution should be stored at the stock concentration at 4°C. Do not freeze. |
| Need a Custom Formulation? | See All Antibody Customization Options |
Application References
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Valenzuela, N. M., et al (2013). "Blockade of p-selectin is sufficient to reduce MHC I antibody-elicited monocyte recruitment in vitro and in vivo" Am J Transplant 13(2): 299-311.
PubMed
Donor-specific HLA antibodies significantly lower allograft survival, but as yet there are no satisfactory therapies for prevention of antibody-mediated rejection. Intracapillary macrophage infiltration is a hallmark of antibody-mediated rejection, and macrophages are important in both acute and chronic rejection. The purpose of this study was to investigate the Fc-independent effect of HLA I antibodies on endothelial cell activation, leading to monocyte recruitment. We used an in vitro model to assess monocyte binding to endothelial cells in response to HLA I antibodies. We confirmed our results in a mouse model of antibody-mediated rejection, in which B6.RAG1(-/-) recipients of BALB/c cardiac allografts were passively transferred with donor-specific MHC I antibodies. Our findings demonstrate that HLA I antibodies rapidly increase intracellular calcium and endothelial presentation of P-selectin, which supports monocyte binding. In the experimental model, donor-specific MHC I antibodies significantly increased macrophage accumulation in the allograft. Concurrent administration of rPSGL-1-Ig abolished antibody-induced monocyte infiltration in the allograft, but had little effect on antibody-induced endothelial injury. Our data suggest that antagonism of P-selectin may ameliorate accumulation of macrophages in the allograft during antibody-mediated rejection.
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Valenzuela, N. M., et al (2013). "HLA class I antibodies trigger increased adherence of monocytes to endothelial cells by eliciting an increase in endothelial P-selectin and, depending on subclass, by engaging FcgammaRs" J Immunol 190(12): 6635-6650.
PubMed
Ab-mediated rejection (AMR) of solid organ transplants is characterized by intragraft macrophages. It is incompletely understood how donor-specific Ab binding to graft endothelium promotes monocyte adhesion, and what, if any, contribution is made by the Fc region of the Ab. We investigated the mechanisms underlying monocyte recruitment by HLA class I (HLA I) Ab-activated endothelium. We used a panel of murine mAbs of different subclasses to crosslink HLA I on human aortic, venous, and microvascular endothelial cells and measured the binding of human monocytic cell lines and peripheral blood monocytes. Both anti-HLA I murine (m)IgG1 and mIgG2a induced endothelial P-selectin, which was required for monocyte adhesion to endothelium irrespective of subclass. mIgG2a but not mIgG1 could bind human FcgammaRs. Accordingly, HLA I mIgG2a but not mIgG1 treatment of endothelial cells significantly augmented recruitment, predominantly through FcgammaRI, and, to a lesser extent, FcgammaRIIa. Moreover, HLA I mIgG2a promoted firm adhesion of monocytes to ICAM-1 through Mac-1, which may explain the prominence of monocytes during AMR. We confirmed these observations using human HLA allele-specific mAbs and IgG purified from transplant patient sera. HLA I Abs universally elicit endothelial exocytosis leading to monocyte adherence, implying that P-selectin is a putative therapeutic target to prevent macrophage infiltration during AMR. Importantly, the subclass of donor-specific Ab may influence its pathogenesis. These results imply that human IgG1 and human IgG3 should have a greater capacity to trigger monocyte infiltration into the graft than IgG2 or IgG4 due to enhancement by FcgammaR interactions.
-
Valenzuela, N. M., et al (2013). "Blockade of p-selectin is sufficient to reduce MHC I antibody-elicited monocyte recruitment in vitro and in vivo" Am J Transplant 13(2): 299-311.
PubMed
Donor-specific HLA antibodies significantly lower allograft survival, but as yet there are no satisfactory therapies for prevention of antibody-mediated rejection. Intracapillary macrophage infiltration is a hallmark of antibody-mediated rejection, and macrophages are important in both acute and chronic rejection. The purpose of this study was to investigate the Fc-independent effect of HLA I antibodies on endothelial cell activation, leading to monocyte recruitment. We used an in vitro model to assess monocyte binding to endothelial cells in response to HLA I antibodies. We confirmed our results in a mouse model of antibody-mediated rejection, in which B6.RAG1(-/-) recipients of BALB/c cardiac allografts were passively transferred with donor-specific MHC I antibodies. Our findings demonstrate that HLA I antibodies rapidly increase intracellular calcium and endothelial presentation of P-selectin, which supports monocyte binding. In the experimental model, donor-specific MHC I antibodies significantly increased macrophage accumulation in the allograft. Concurrent administration of rPSGL-1-Ig abolished antibody-induced monocyte infiltration in the allograft, but had little effect on antibody-induced endothelial injury. Our data suggest that antagonism of P-selectin may ameliorate accumulation of macrophages in the allograft during antibody-mediated rejection.
-
Valenzuela, N. M., et al (2013). "HLA class I antibodies trigger increased adherence of monocytes to endothelial cells by eliciting an increase in endothelial P-selectin and, depending on subclass, by engaging FcgammaRs" J Immunol 190(12): 6635-6650.
PubMed
Ab-mediated rejection (AMR) of solid organ transplants is characterized by intragraft macrophages. It is incompletely understood how donor-specific Ab binding to graft endothelium promotes monocyte adhesion, and what, if any, contribution is made by the Fc region of the Ab. We investigated the mechanisms underlying monocyte recruitment by HLA class I (HLA I) Ab-activated endothelium. We used a panel of murine mAbs of different subclasses to crosslink HLA I on human aortic, venous, and microvascular endothelial cells and measured the binding of human monocytic cell lines and peripheral blood monocytes. Both anti-HLA I murine (m)IgG1 and mIgG2a induced endothelial P-selectin, which was required for monocyte adhesion to endothelium irrespective of subclass. mIgG2a but not mIgG1 could bind human FcgammaRs. Accordingly, HLA I mIgG2a but not mIgG1 treatment of endothelial cells significantly augmented recruitment, predominantly through FcgammaRI, and, to a lesser extent, FcgammaRIIa. Moreover, HLA I mIgG2a promoted firm adhesion of monocytes to ICAM-1 through Mac-1, which may explain the prominence of monocytes during AMR. We confirmed these observations using human HLA allele-specific mAbs and IgG purified from transplant patient sera. HLA I Abs universally elicit endothelial exocytosis leading to monocyte adherence, implying that P-selectin is a putative therapeutic target to prevent macrophage infiltration during AMR. Importantly, the subclass of donor-specific Ab may influence its pathogenesis. These results imply that human IgG1 and human IgG3 should have a greater capacity to trigger monocyte infiltration into the graft than IgG2 or IgG4 due to enhancement by FcgammaR interactions.
Product Citations
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The GF-NEO discovery platform unveils a [KQE][DG] sequence motif within fusion neoantigens in pediatric cancer.
In iScience on 20 February 2026 by Savoie, C., Wu, Z., et al.
PubMed
Gene fusions (GFs) are critical events in pediatric oncology, often serving as oncogenic drivers. However, fusion proteins and their derived neoantigens (GF-NEOs) remain underexplored for targeted immunotherapy. We developed ProteoFusioNEO, a computational tool for the in silico translation of transcriptomic data, analyzing 5,190 pediatric patients with cancer and 935 cell lines, yielding 382 and 446 fusion proteins. We highlight that GFs generate multiple translational outcomes, with 97% being in-frame in patients. Fusion junctions exhibit the sequence motif [KQE][DG], which partly reflects the nature of exon-exon junctions, albeit with additional hydrophilicity. Moreover, GF-NEOs' abundance may be shaped by the motif, offering insights into fusion protein biology. Finally, a multipronged validation strategy using in vitro and in vivo systems confirms the GF-NEOs presentation through mass spectrometry-based proteomics and immunopeptidomics. Multiple GF-NEOs encoded by two versions of the ETV6-RUNX1 fusion were validated, paving the way for targeted immunotherapy development.
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C/EBPβ-induced alternative splicing of RCAN1 generates a potent TCR-T target in mesenchymal glioblastoma.
In Cell Mol Immunol on 1 January 2026 by Xiong, Z., Kong, Q., et al.
PubMed
Glioblastoma (GBM) is an aggressive brain tumor with limited treatment options and a dismal prognosis. While immunotherapy has shown promise in treating some solid tumors, the treatment of GBM has been mostly unsuccessful because of a lack of targetable tumor antigens and high tumor heterogeneity. Here, we report RCAN1-4 as a novel tumor antigen derived from alternative splicing induced by the transcription factor C/EBPβ. Both C/EBPβ and RCAN1-4 are highly expressed in GBM and glioma stem cells as mesenchymal subtype hallmarks. We report an immunogenic HLA-A24-specific splicing junction epitope within exon 4 and exon 5 that is unique to RCAN1-4. This epitope was validated for its ability to stimulate T cell responses in HLA-A24+ donors and GBM patients, leading us to identify RCAN1-4-reactive T cell receptors (TCRs) for the construction of TCR-engineered T cells (TCR-T cells). Functional studies of TCR-Ts demonstrated the in vitro and in vivo killing of RCAN1-4pos GBM tumor cells, highlighting its potential as an immunotherapeutic target in mesenchymal GBM.
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Malignant cell MHC-II immunopeptidomes reveal the evolution of tumor-host interactions
In Research Square on 18 December 2025 by Jaeger, A., Deonarine, A., et al.
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Engineered antibodies that stabilize drug-modified KRASG12C neoantigens enable selective and potent cross-HLA immunotherapy.
In Nat Commun on 17 December 2025 by Maso, L., Mosure, S. A., et al.
PubMed
Covalent inhibitors of oncoprotein KRAS have initial efficacy, but responses lack durability. Covalently modified oncoproteins are presented as MHC-restricted hapten-peptides (p*MHC) on the cancer cell surface, enabling combination of targeted therapy with immunotherapy to overcome drug resistance. Building on indirect evidence of KRASG12C-derived p*MHCs, we use immunopeptidomics to identify and directly quantify these synthetic neoantigens. To address challenges by their low copy number, we develop AETX-R114, a T cell engaging bispecific antibody with picomolar affinity for MHC-restricted sotorasib-modified KRASG12C peptides presented by three HLA-A3 supertype alleles. AETX-R114 dramatically increases the half-life and thereby the number of presented p*MHCs, enabling selective and potent killing of resistant cancer cells both in vitro and in vivo. To broaden the therapeutic potential of creating and targeting synthetic neoantigens, we further develop AETX-R302, which recognizes divarasib-modified KRASG12C peptides presented on alleles from the HLA-A2 and A3 supertypes. Cryo-EM structure determination reveals the molecular basis for breaking HLA supertype restriction. Collectively, our study illustrates how engineered antibodies can transform synthetic neoantigens into actionable cancer immunotherapy targets.