Browsing by Author "Roszik, Jason"
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Item Beyond Autoantibodies: Biologic Roles of Human Autoreactive B Cells in Rheumatoid Arthritis Revealed by RNA?Sequencing(Arthritis and Rheumatism, 2017-06) Mahendra, Ankit; Yang, Xingyu; Abnouf, Shaza; Adolacion, Jay R.T.; Park, Daechan; Soomro, Sanam; Roszik, Jason; Coarfa, Cristian; Romain, Gabrielle; Wanzeck, Keith; Bridges, Louis Jr. S.; Aggarwal, Amita; Qiu, Peng; Agarwal, Sandeep K.; Mohan, Chandra; Varadarajan, NavinObjective:To obtain the comprehensive transcriptome profile of human citrulline?specific B cells from patients with rheumatoid arthritis (RA). Methods:Citrulline? and hemagglutinin?specific B cells were sorted by flow cytometry using peptide–streptavidin conjugates from the peripheral blood of RA patients and healthy individuals. The transcriptome profile of the sorted cells was obtained by RNA?sequencing, and expression of key protein molecules was evaluated by aptamer?based SOMAscan assay and flow cytometry. The ability of these proteins to effect differentiation of osteoclasts and proliferation and migration of synoviocytes was examined by in vitro functional assays. Results:Citrulline?specific B cells, in comparison to citrulline?negative B cells, from patients with RA differentially expressed the interleukin?15 receptor ? (IL?15R?) gene as well as genes related to protein citrullination and cyclic AMP signaling. In analyses of an independent cohort of cyclic citrullinated peptide–seropositive RA patients, the expression of IL?15R? protein was enriched in citrulline?specific B cells from the patients’ peripheral blood, and surprisingly, all B cells from RA patients were capable of producing the epidermal growth factor ligand amphiregulin (AREG). Production of AREG directly led to increased migration and proliferation of fibroblast?like synoviocytes, and, in combination with anti–citrullinated protein antibodies, led to the increased differentiation of osteoclasts. Conclusion:To the best of our knowledge, this is the first study to document the whole transcriptome profile of autoreactive B cells in any autoimmune disease. These data identify several genes and pathways that may be targeted by repurposing several US Food and Drug Administration–approved drugs, and could serve as the foundation for the comparative assessment of B cell profiles in other autoimmune diseases.Item Multifaceted role of BTLA in the control of CD8+ T cell fate after antigen encounter(Clinical Cancer Research, 2018-10) Ritthipichai, Krit; Haymaker, Cara L.; Martinez-Paniagua, Melisa A.; Aschenbrenner, Andrew; Yi, Xiaohui; Zhang, Minying; Kale, Charuta; Vence, Luis M.; Roszik, Jason; Hailemichael, Yared; Overwijk, William W.; Varadarajan, Navin; Nurieva, Roza; Radvanyi, Laszlo G.; Hwu, Patrick; Bernatchez, ChantalePurpose: Adoptive T-cell therapy using autologous tumor-infiltrating lymphocytes (TIL) has shown an overall clinical response rate 40%–50% in metastatic melanoma patients. BTLA (B-and-T lymphocyte associated) expression on transferred CD8+ TILs was associated with better clinical outcome. The suppressive function of the ITIM and ITSM motifs of BTLA is well described. Here, we sought to determine the functional characteristics of the CD8+BTLA+TIL subset and define the contribution of the Grb2 motif of BTLA in T-cell costimulation. Experimental Design: We determined the functional role and downstream signal of BTLA in both human CD8+ TILs and mouse CD8+ T cells. Functional assays were used including single-cell analysis, reverse-phase protein array (RPPA), antigen-specific vaccination models with adoptively transferred TCR-transgenic T cells as well as patient-derived xenograft (PDX) model using immunodeficient NOD-scid IL2Rgammanull (NSG) tumor-bearing mice treated with autologous TILs. Results: CD8+BTLA? TILs could not control tumor growth in vivo as well as their BTLA+ counterpart and antigen-specific CD8+BTLA? T cells had impaired recall response to a vaccine. However, CD8+BTLA+ TILs displayed improved survival following the killing of a tumor target and heightened “serial killing” capacity. Using mutants of BTLA signaling motifs, we uncovered a costimulatory function mediated by Grb2 through enhancing the secretion of IL-2 and the activation of Src after TCR stimulation. Conclusions: Our data portrays BTLA as a molecule with the singular ability to provide both costimulatory and coinhibitory signals to activated CD8+ T cells, resulting in extended survival, improved tumor control, and the development of a functional recall response. Clin Cancer Res; 23(20); 6151–64. ©2017 AACR.Item Quantitative High-Throughput Single-Cell Cytotoxicity Assay for T cells(Journal of Visualized Experiments, 2013) Liadi, Ivan; Roszik, Jason; Romain, Gabrielle; Cooper, Laurence J.N.; Varadarajan, NavinCancer immunotherapy can harness the specificity of immune response to target and eliminate tumors. Adoptive cell therapy (ACT) based on the adoptive transfer of T cells genetically modified to express a chimeric antigen receptor (CAR) has shown considerable promise in clinical trials1-4. There are several advantages to using CAR+ T cells for the treatment of cancers including the ability to target non-MHC restricted antigens and to functionalize the T cells for optimal survival, homing and persistence within the host; and finally to induce apoptosis of CAR+ T cells in the event of host toxicity5. Delineating the optimal functions of CAR+ T cells associated with clinical benefit is essential for designing the next generation of clinical trials. Recent advances in live animal imaging like multiphoton microscopy have revolutionized the study of immune cell function in vivo6,7. While these studies have advanced our understanding of T-cell functions in vivo, T-cell based ACT in clinical trials requires the need to link molecular and functional features of T-cell preparations pre-infusion with clinical efficacy post-infusion, by utilizing in vitro assays monitoring T-cell functions like, cytotoxicity and cytokine secretion. Standard flow-cytometry based assays have been developed that determine the overall functioning of populations of T cells at the single-cell level but these are not suitable for monitoring conjugate formation and lifetimes or the ability of the same cell to kill multiple targets8. Microfabricated arrays designed in biocompatible polymers like polydimethylsiloxane (PDMS) are a particularly attractive method to spatially confine effectors and targets in small volumes9. In combination with automated time-lapse fluorescence microscopy, thousands of effector-target interactions can be monitored simultaneously by imaging individual wells of a nanowell array. We present here a high-throughput methodology for monitoring T-cell mediated cytotoxicity at the single-cell level that can be broadly applied to studying the cytolytic functionality of T cells.