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Mahendra, A.

Publications and source records attributed to Mahendra, A..

2 recordsLinked to original sources

Multidimensional single-cell analysis identifies a role of CD2-CD58 interactions for clinical antitumor T cell responses

The in vivo persistence of adoptively transferred T cells is predictive of anti-tumor response. Identifying functional properties of infused T cells that lead to in vivo persistence and tumor eradication has remained elusive. We profiled CD19-specific CAR T cells that comprise the infusion products used to treat large B cell lymphomas using high-throughput single-cell technologies based on Timelapse Imaging Microscopy In Nanowell Grids (TIMING) that integrates killing, cytokine secretion, and transcriptional profiling. Our results show that the directional migration of CD19-specific CAR T cells is correlated with polyfunctionality. We identified that CD2 on T cells is associated with directional migration and that the interaction between CD2 on T cells and CD58 on lymphoma cells accelerates killing and serial killing. Consistent with this, we observed elevated CD58 expression on pre-treatment tumor samples in patients with relapsed or refractory large B cell lymphomas treated with CD19-specific CAR T cell therapy was associated with complete clinical response and survival. These results highlight the importance of studying dynamic T-cell tumor cell interactions in identifying optimal antitumor responses. KEY POINTS- Profiling patient infusion products revealed that polyfunctional CAR T cells show directional migration, which is associated with higher CD2 expression - The ligand for CD2, CD58 is expressed at higher levels in the tumors of lymphoma patients who respond better to CAR T cell treatment

immunology↗

Beyond Autoantibodies: Biological Roles Of Human Autoreactive B Cells In Rheumatoid Arthritis Revealed By Whole Transcriptome Profiling

Although the contribution of B-cell derived autoreactive antibodies to rheumatoid arthritis (RA) has been studied extensively, the autoantibody-independent roles of B cells in the progression of the disease is not well-defined. Here we present the first comprehensive transcriptome profile of human autoreactive B cells in an autoimmune disease by performing RNA-sequencing of citrulline-specific B cells from RA patients. In order to facilitate a comprehensive understanding of the profile of these citrulline-specific (RA-CCPPOS) B cells, we performed comparative analyses to both citrulline-negative (RA-CCPNEG) B cells from the same donors, and identified 431 differentially expressed genes (DEGs); and hemagglutinin-specific (HA) B cells from healthy individuals and identified 1658 DEGs. Three-way comparisons of these B cell populations demonstrated that RA-CCPPOS B cells, in comparison to the RA-CCPNEG B cells, demonstrate a potential role in protein citrullination and inflammation; RA-CCPPOS B cells in comparison to HA-specific B cells demonstrate RA-specific signatures like the expression of pro-inflammatory cytokines, chemokines, costimulatory molecules and B-cell activation cascades; and all B cells from RA patients demonstrated a significant impact of the multitude of TNF signaling pathways. Furthermore, transcription factor profiling suggested that cyclic AMP (cAMP) related pathways and downstream signaling molecules are selectively enriched in RA-CCPPOS cells in comparison to the other two B cell subsets. We advanced the understanding of the citrulline reactive B cells in RA pathophysiology by documenting and validating two novel observations in independent cohorts of patients: (1) the expression of IL15R is restricted to citrulline-specific cells within RA patients and the concentration of soluble IL15R is elevated in the sera of RA patients, (2) B cells from RA patients are capable of producing epidermal growth factor ligand, amphiregulin (AREG) which in turn has a direct impact on the mechanistic effectors of RA, osteoclasts and fibroblastlike synoviocytes (FLS). Overall, our comprehensive dataset identifies several existing FDA-approved drugs that can potentially be repurposed for RA and can serve as a foundation for studying the multi-faceted roles of B cells in other autoimmune diseases.

immunology↗