Programmed death (PD)-1:PD-ligand 1/PD-ligand 2 pathway inhibits T cell effector functions during human tuberculosis.
Protective immunity against Mycobacterium tuberculosis requires the generation of cell-mediated immunity. We investigated the expression and role of programmed death 1 (PD-1) and its ligands, molecules known to modulate T cell activation, in the regulation of IFN-gamma production and lytic degranulation during human tuberculosis. We demonstrated that specific Ag-stimulation increased CD3+PD-1+ lymphocytes in peripheral blood and pleural fluid from tuberculosis patients in direct correlation with IFN-gamma production from these individuals. Moreover, M. tuberculosis-induced IFN-gamma participated in the up-regulation of PD-1 expression. Blockage of PD-1 or PD-1 and its ligands (PD-Ls: PD-L1, PD-L2) enhanced the specific degranulation of CD8+ T cells and the percentage of specific IFN-gamma-producing lymphocytes against the pathogen, demonstrating that the PD-1:PD-Ls pathway inhibits T cell effector functions during active M. tuberculosis infection. Furthermore, the simultaneous blockage of the inhibitory receptor PD-1 together with the activation of the costimulatory protein signaling lymphocytic activation molecule led to the promotion of protective IFN-gamma responses to M. tuberculosis, even in patients with weak cell-mediated immunity against the bacteria. Together, we demonstrated that PD-1 interferes with T cell effector functions against M. tuberculosis, suggesting that PD-1 has a key regulatory role during the immune response of the host to the pathogen.
Department of Biological Chemistry, School of Sciences, University of Buenos Aires, Buenos Aires, Argentina.
Javier O
JO
Jurado
Ivana B
IB
Alvarez
Virginia
V
Pasquinelli
Gustavo J
GJ
Martínez
María F
MF
Quiroga
Eduardo
E
Abbate
Rosa M
RM
Musella
H Eduardo
HE
Chuluyan
Verónica E
VE
García
D000941:Antigens / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology* / Q000378:metabolism; D051017:Apoptosis Regulatory Proteins / Q000276:immunology*; D060890:B7-H1 Antigen; D002478:Cells, Cultured; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000276:immunology*; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D009169:Mycobacterium tuberculosis / Q000276:immunology; D061027:Programmed Cell Death 1 Ligand 2 Protein; D061026:Programmed Cell Death 1 Receptor; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology*; D000071177:Signaling Lymphocytic Activation Molecule Family Member 1; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014376:Tuberculosis / Q000276:immunology* / Q000378:metabolism
D000941:Antigens; D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; D060890:B7-H1 Antigen; C423236:CD274 protein, human; D036341:Intercellular Signaling Peptides and Proteins; C105992:PDCD1 protein, human; C556977:PDCD1LG2 protein, human; D061027:Programmed Cell Death 1 Ligand 2 Protein; D061026:Programmed Cell Death 1 Receptor; D011956:Receptors, Cell Surface; D000071177:Signaling Lymphocytic Activation Molecule Family Member 1; D007371:Interferon-gamma