Hypoxia promotes BCMA loss and a suppressive secretome thereby hindering CAR T cell therapy in multiple myeloma
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PROVIDER: PRJNA1315189 | ENA |
REPOSITORIES: ENA
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Project description:Multiple myeloma (MM) develops in a hypoxic bone marrow (BM) microenvironment, which alters tumor behavior and immune responses. While hypoxia is known to directly suppress immune function, its effect on immunotherapy-relevant antigen expression and the MM secretome remains underexplored. Here, we investigated how hypoxia affects BCMA expression and BCMA-targeted CAR T cell responses. MM cells cultured under hypoxia (1% O₂) showed reduced BCMA surface and total protein expression, resulting in reduced CAR-mediated signaling. Importantly, the hypoxic tumor secretome further reduced BCMA levels and significantly impaired CAR T cell killing and cytokine production, which was partially reversible by γ-secretase inhibition. To dissect the suppressive nature of the hypoxic secretome, we identified an increase in small extracellular vesicle (sEV) release under hypoxia. RNA profiling of sEVs revealed a hypoxia-induced RNA signature with potential immunomodulatory roles. In conclusion, hypoxia diminishes BCMA expression and enhances secretion of immunosuppressive factors, including sEVs, thereby limiting the efficacy of BCMA CAR T cell therapy in MM.
2025-09-11 | GSE307311 | GEO
Project description: Not available
| S-EPMC12781295 | biostudies-literature
Project description:Chimeric antigen receptor T-cells (CAR-T) targeting B-cell-maturating-antigen (TNRFSF17, BCMA) show unprecedented overall response rates of up to 100% in heavily pretreated relapsed-refractory Multiple Myeloma (RRMM). However, the efficiency of the treatment is hindered by the rapid emergence of tumor-intrinsic mechanisms of resistance. We herein describe a patient with RRMM and extramedullary disease (EMD) who underwent Idecabtagene vicleucel BCMA CAR-T therapy. The patient rapidly achieved very good partial response including full resolution of EMD, but aggressively relapsed 5 months after CAR T cell infusion. Single cell RNA sequencing and immunohistochemistry on the re-emerging tumor cells demonstrated loss of target expression on mRNA and protein levels, and whole genome sequencing revealed the homozygous deletion of Chr 16p1313, including the BCMA locus. Clonal heterogeneity of BCMA could be observed in 32 RRMM patients from our institution. In three of them heterozygous deletion of BCMA could be confirmed, with none of them having underwent prior anti-BCMA therapy. Thus, our report not only provides first evidence of BCMA loss as the underlying mechanism of disease relapse following BCMA targeted immunotherapy in MM. It furthermore identifies a subset of patients at risk to develop biallelic BCMA inactivation thus linking genomic instability in MM to relapse from targeted immunotherapies.
2020-12-30 | GSE143317 | GEO
Project description:Despite the acknowledged effectiveness of BCMA chimeric antigen receptor T (CAR-T) cells in killing multiple myeloma (MM) cells, predicting treatment responsivity to BCMA CAR-T therapy remains a challenge. In this study, we demonstrated that the best overall responses (BORs) of patients over the 15-month follow-up are positively correlated with the abundance and targeted cytotoxic activity of CD8+ effector CAR-T cells on day 28 after CAR-T cell infusion. Additionally, favorable responses are associated with attenuated immunosuppression mediated by regulatory T cells (Tregs), enhanced CD8+ effector T cell cytotoxic activity, and elevated type 1 conventional dendritic cell (cDC1) antigen presentation ability. Our study sheds light on MM microenvironment dynamics after BCMA CAR-T therapy, offering clues for predicting treatment responsivity.
2024-07-10 | GSE271915 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. B cell maturation antigen (BCMA) target loss is considered to be a rare event that mediates multiple myeloma (MM) resistance to anti-BCMA chimeric antigen receptor T cell (CAR T) or bispecific T cell engager (TCE) therapies. Emerging data report that downregulation of G protein coupled receptor family C group 5 member D (GPRC5D) protein often occurs at relapse after anti-GPRC5D CAR T. To examine the tumor intrinsic factors that promote MM antigen escape, we performed combined bulk and single cell whole genome sequencing/ copy number variation analysis of 30 patients treated with anti-BCMA and/ or -GPRC5D CAR T/ TCE. In two cases, MM relapse post TCE/ CAR T was driven by BCMA negative clones harboring focal biallelic deletions at the TNFRSF17 locus at relapse or by selective expansion of pre-existing subclones with biallelic TNFRSF17 loss. In another five cases of relapse, newly detected non-truncating missense mutations or in-frame deletions in the extracellular domain of BCMA negated the efficacies of anti-BCMA TCEs, despite detectable surface BCMA protein expression. Here, we also report the first four cases of MM relapse with biallelic mutations of GPRC5D following anti-GPRC5D TCE, including two cases with convergent evolution where multiple subclones lost GPRC5D through somatic events. Immunoselection of BCMA or GPRC5D negative or mutant clones is an important tumor intrinsic driver of relapse post targeted therapies. Mutational events on BCMA confer distinct sensitivities towards different anti-BCMA therapies, underscoring the importance of considering the tumor antigen landscape for optimal design and selection of targeted immunotherapies in MM.
2023-06-29 | GSE226336 | GEO
Project description:Mass spectrometric analysis of MM cell-purified B-cell maturation antigen (BCMA) protein to identify ubiquitylation sites.
2025-07-29 | PXD056372 | Pride
Project description:Multiple myeloma (MM) immune escape resulting from B cell maturation antigen (BCMA) target loss is considered to be a rare event that mediates MM resistance to anti-BCMA chimeric antigen receptor T cell (CAR T) or bispecific T cell engager (TCE) therapies. Emerging clinical data also suggests that downregulation of G protein coupled receptor family C group 5 member D (GPRC5D), another promising target antigen expressed on MM cells, is observed in patients at relapse post anti-GPRC5D CAR T, but the genomic mechanisms that underlie GPRC5D loss has not been described. In order to examine the tumor intrinsic factors that promote MM antigen escape, we performed combined bulk whole genome sequencing and single cell copy number variation analysis on CD138+ cells from bone marrow aspirates of patients before and after relapse from anti-BCMA or -GPRC5D CAR T/ TCE. We describe five cases with distinct biallelic events on TNFRSF17 at MM relapse after CAR T/ TCE. In addition to focal biallelic deletions at the TNFRSF17 locus acquired at relapse, BCMA negative clones can emerge from the selective expansion of subclones with homozygous TNFRSF17 loss that exist prior to any anti-BCMA therapy exposure. Furthermore, we corroborate with functional data to demonstrate that three different non-truncating mutations in the extracellular domain of BCMA negates the efficacies of BCMA directed TCEs and mediate disease relapse in patients. With respect to GPRC5D, we report four cases of MM relapse with biallelic loss of GPRC5D following anti-GPRC5DxCD3ε. Our data support that immunoselection of BCMA negative or mutant clones post anti-BCMA therapies may be more frequent than currently accepted in the field, and that an all or none screening approach for BCMA expression is inadequate to detect pertinent mutations that affect patient response to targeted therapies. We also highlight the importance of developing immunotherapies targeting novel and non-redundant epitopes or antigens in MM
2023-06-29 | GSE226327 | GEO
Project description:Multiple myeloma (MM) immune escape resulting from B cell maturation antigen (BCMA) target loss is considered to be a rare event that mediates MM resistance to anti-BCMA chimeric antigen receptor T cell (CAR T) or bispecific T cell engager (TCE) therapies. Emerging clinical data also suggests that downregulation of G protein coupled receptor family C group 5 member D (GPRC5D), another promising target antigen expressed on MM cells, is observed in patients at relapse post anti-GPRC5D CAR T, but the genomic mechanisms that underlie GPRC5D loss has not been described. In order to examine the tumor intrinsic factors that promote MM antigen escape, we performed combined bulk whole genome sequencing and single cell copy number variation analysis on CD138+ cells from bone marrow aspirates of patients before and after relapse from anti-BCMA or -GPRC5D CAR T/ TCE. We describe five cases with distinct biallelic events on TNFRSF17 at MM relapse after CAR T/ TCE. In addition to focal biallelic deletions at the TNFRSF17 locus acquired at relapse, BCMA negative clones can emerge from the selective expansion of subclones with homozygous TNFRSF17 loss that exist prior to any anti-BCMA therapy exposure. Furthermore, we corroborate with functional data to demonstrate that three different non-truncating mutations in the extracellular domain of BCMA negates the efficacies of BCMA directed TCEs and mediate disease relapse in patients. With respect to GPRC5D, we report four cases of MM relapse with biallelic loss of GPRC5D following anti-GPRC5DxCD3ε. Our data support that immunoselection of BCMA negative or mutant clones post anti-BCMA therapies may be more frequent than currently accepted in the field, and that an all or none screening approach for BCMA expression is inadequate to detect pertinent mutations that affect patient response to targeted therapies. We also highlight the importance of developing immunotherapies targeting novel and non-redundant epitopes or antigens in MM
2023-06-29 | GSE226335 | GEO
Project description:BCMA targeting chimeric antigen receptor (CAR) T cell therapy have shown deep and durable responses in multiple myeloma. However, relapse following therapy is frequently observed, and mechanisms of resistance remain ill-defined. We performed single cell genomic characterization of longitudinal samples from a patient who relapsed after initial CAR T cell treatment with lack of response to retreatment.
2021-01-11 | GSE164551 | GEO
Project description:BCMA is the main target for CAR-T cells in multiple myeloma (MM), demonstrating promising outcomes. However, unlike what happens with CART19 in lymphoblastic leukemia and non-hodgkin lymphoma, a high proportion of patients will relapse after CART BCMA therapy due to insufficient antigen expression, low CAR-T cell persistence and/or T-cell exhaustion. CD28 transmembrane domains (CD28-TMD) in CAR receptors promote dimerization with CD28, forming CAR-CD28 heterodimers that enhance sensitivity to low-abundance antigens. In other B cell malignancies, second-generation anti-CD19 4-1BB CARs with CD28-TMD have shown high efficacy and a favorable toxicity profile. We have developed a second-generation CD8α-TMD BCMA-4-1BBζ CAR-T product, ARI0002h (ARI2h; cesni-cel) for patients with relapsed/refractory MM. We hypothesized that replacing the TMD of ARI0002h with a CD28-TMD could increase efficacy and reduce tumor escape while maintaining a tolerable toxicity profile. We generated CAR-T cells using T-cells isolated from buffy coats and evaluated the efficacy and fitness of CAR-Ts at day 8-10 of expansion against several MM cell lines. In vitro analyses included cytotoxicity, proliferation, cytokine secretion, T-cell subset markers, activation and exhaustion profiling, metabolomic assays, and RNA-seq after multiple tumor challenges. In in vivo xenograft studies using NSG mice, with tumor cells expressing GFP-ffLuc, disease progression was monitored weekly via bioluminescence imaging.
2026-03-11 | GSE289423 | GEO