ABSTRACT: B cells are highly abundant lymphocytes and central players in humoral immunity. Although T cells are well known to support humoral responses, how B cells influence T cell responses is less understood. Here, we show that B cells are critical for CD8(+) T cell responses to chronic, but not acute, viral infections. In the absence of B cells, T cells responding to chronic infection exhibited severely impaired effector differentiation. This dependency on B cell help was dictated by high antigen loads and strong T cell receptor (TCR) stimulation. Loss of either B cells or interferon-I (IFN-I) signaling led to severe functional deficits in exhausted T cells, implicating B cells as key producers of IFN-I. The IFN-I-dependent T cell response to strong TCR stimulation is mediated, in part, by the transcription factor IRF1. Therefore, during chronic infection, we uncover an important role for B cell-derived IFN-I in modulating T cell responses to strong TCR stimulation.
Author Info: (1) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (2) Department of Microbi
Author Info: (1) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (2) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (3) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (4) Institute of Molecular Medicine and Experimental Immunology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany. (5) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia; Institute of Molecular Medicine and Experimental Immunology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany. (6) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (7) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (8) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (9) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (10) Institute for Immunology, University Hospital Heidelberg, Heidelberg, Germany. (11) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (12) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (13) Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia. (14) Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, VIC, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC, Australia. (15) Institute for Immunology, University Hospital Heidelberg, Heidelberg, Germany. (16) Department of Medicine II (Gastroenterology, Hepatology, Endocrinology, and Infectious Diseases), Medical Center, University of Freiburg, Baden-Wrttemberg, Germany. (17) Department of Medicine II (Gastroenterology, Hepatology, Endocrinology, and Infectious Diseases), Medical Center, University of Freiburg, Baden-Wrttemberg, Germany. (18) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (19) Institute of Molecular Medicine and Experimental Immunology, University Hospital Bonn, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany. (20) Computational Sciences Initiative (CSI), the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (21) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. (22) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. Electronic address: yannick.alexandre@unimelb.edu.au. (23) Department of Microbiology and Immunology, the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia. Electronic address: daniel.utzschneider@unimelb.edu.au.
