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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Ely ZA, Kulstad ZJ, Gunaydin G, Addepalli S, Verzani EK, Casarrubios M, Clauser KR, Wang X, Lippincott IE, Louvet C, Schmitt T, Kapner KS, Agus MP, Hennessey CJ, Cleary JM, Hadrup SR, Klaeger S, Su J, Jaeger AM, Wolpin BM, Raghavan S, Smith EL, Green
PubMed
Translation of the noncoding genome in cancer can generate cryptic (noncanonical) peptides capable of presentation by human leukocyte antigen class I (HLA-I); however, the cancer specificity and immunogenicity of noncanonical HLA-I-bound peptides (ncHLAp) are incompletely understood. Using high-resolution immunopeptidomics, we discovered that cryptic peptides are abundant in the pancreatic cancer immunopeptidome. Approximately 30% of ncHLAp exhibited cancer-restricted translation, and a substantial subset were shared among patients. Cancer-restricted ncHLAp displayed robust immunogenic potential in a sensitive ex vivo T cell priming platform. ncHLAp-reactive, T cell receptor-redirected T cells exhibited tumoricidal activity against patient-derived pancreatic cancer organoids. These findings demonstrate that pancreatic cancer harbors cancer-restricted ncHLAp that can be recognized by cytotoxic T cells. Future therapeutic strategies for pancreatic cancer, and potentially other solid tumors, may include targeting cryptic antigens.
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Ely ZA, Kulstad ZJ, Gunaydin G, Addepalli S, Verzani EK, Casarrubios M, Clauser KR, Wang X, Lippincott IE, Louvet C, Schmitt T, Kapner KS, Agus MP, Hennessey CJ, Cleary JM, Hadrup SR, Klaeger S, Su J, Jaeger AM, Wolpin BM, Raghavan S, Smith EL, Green
PubMed
Translation of the noncoding genome in cancer can generate cryptic (noncanonical) peptides capable of presentation by human leukocyte antigen class I (HLA-I); however, the cancer specificity and immunogenicity of noncanonical HLA-I-bound peptides (ncHLAp) are incompletely understood. Using high-resolution immunopeptidomics, we discovered that cryptic peptides are abundant in the pancreatic cancer immunopeptidome. Approximately 30% of ncHLAp exhibited cancer-restricted translation, and a substantial subset were shared among patients. Cancer-restricted ncHLAp displayed robust immunogenic potential in a sensitive ex vivo T cell priming platform. ncHLAp-reactive, T cell receptor-redirected T cells exhibited tumoricidal activity against patient-derived pancreatic cancer organoids. These findings demonstrate that pancreatic cancer harbors cancer-restricted ncHLAp that can be recognized by cytotoxic T cells. Future therapeutic strategies for pancreatic cancer, and potentially other solid tumors, may include targeting cryptic antigens.
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Lazear MR, Remsberg JR, Jaeger MG, Rothamel K, Her HL, DeMeester KE, Njomen E, Hogg SJ, Rahman J, Whitby LR, Won SJ, Schafroth MA, Ogasawara D, Yokoyama M, Lindsey GL, Li H, Germain J, Barbas S, Vaughan J, Hanigan TW, Vartabedian VF, Reinhardt CJ, Di
PubMed
Most human proteins lack chemical probes, and several large-scale and generalizable small-molecule binding assays have been introduced to address this problem. How compounds discovered in such "binding-first" assays affect protein function, nonetheless, often remains unclear. Here, we describe a "function-first" proteomic strategy that uses size exclusion chromatography (SEC) to assess the global impact of electrophilic compounds on protein complexes in human cells. Integrating the SEC data with cysteine-directed activity-based protein profiling identifies changes in protein-protein interactions that are caused by site-specific liganding events, including the stereoselective engagement of cysteines in PSME1 and SF3B1 that disrupt the PA28 proteasome regulatory complex and stabilize a dynamic state of the spliceosome, respectively. Our findings thus show how multidimensional proteomic analysis of focused libraries of electrophilic compounds can expedite the discovery of chemical probes with site-specific functional effects on protein complexes in human cells.
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Bourne CM, Mun SS, Dao T, Aretz ZEH, Molvi Z, Gejman RS, Daman A, Takata K, Steidl C, Klatt MG, Scheinberg DA (2022). "Unmasking the suppressed immunopeptidome of EZH2-mutated diffuse large B-cell lymphomas through combination drug treatment" Blood A
PubMed
Exploring the repertoire of peptides presented on major histocompatibility complexes (MHCs) helps identify targets for immunotherapy in many hematologic malignancies. However, there is a paucity of such data for diffuse large B-cell lymphomas (DLBCLs), which might be explained by the profound downregulation of MHC expression in many DLBCLs, and in particular in the enhancer of zeste homolog 2 (EZH2)-mutated subgroup. Epigenetic drug treatment, especially in the context of interferon-γ (IFN-γ), restored MHC expression in DLBCL. In DLBCL, peptides presented on MHCs were identified via mass spectrometry after treatment with tazemetostat or decitabine alone or in combination with IFN-γ. Such treatment synergistically increased the expression of MHC class I surface proteins up to 50-fold and the expression of class II surface proteins up to threefold. Peptides presented on MHCs increased to a similar extent for both class I and class II MHCs. Overall, these treatments restored the diversity of the immunopeptidome to levels described in healthy B cells for 2 of 3 cell lines and allowed the systematic search for new targets for immunotherapy. Consequently, we identified multiple MHC ligands from the regulator of G protein signaling 13 (RGS13) and E2F transcription factor 8 (E2F8) on different MHC alleles, none of which have been described in healthy tissues and therefore represent tumor-specific MHC ligands that are unmasked only after drug treatment. Overall, our results show that EZH2 inhibition in combination with decitabine and IFN-γ can expand the repertoire of MHC ligands presented on DLBCLs by revealing suppressed epitopes, thus allowing the systematic analysis and identification of new potential immunotherapy targets.
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.