Role Played by the Programmed Death-1-Programmed Death Ligand Pathway during Innate Immunity against Mycobacterium tuberculosis

IB Alvarez, V Pasquinelli, JO Jurado… - The Journal of …, 2010 - academic.oup.com
IB Alvarez, V Pasquinelli, JO Jurado, E Abbate, RM Musella, SS de la Barrera, VE García
The Journal of infectious diseases, 2010academic.oup.com
Tuberculous pleurisy allows the study of specific cells at the site of Mycobacterium
tuberculosis infection. Among pleural lymphocytes, natural killer (NK) cells are a major
source of interferon γ (IFN-γ), and their functions are regulated by activating and inhibitory
receptors. Programmed death-1 (PD-1), programmed death ligand 1 (PD-L1), and
programmed death ligand 2 (PD-L2) are recognized inhibitory receptors in adaptive
immunity, but their role during innate immunity remains poorly understood. We investigated …
Abstract
Tuberculous pleurisy allows the study of specific cells at the site of Mycobacterium tuberculosis infection. Among pleural lymphocytes, natural killer (NK) cells are a major source of interferon γ (IFN-γ), and their functions are regulated by activating and inhibitory receptors. Programmed death-1 (PD-1), programmed death ligand 1 (PD-L1), and programmed death ligand 2 (PD-L2) are recognized inhibitory receptors in adaptive immunity, but their role during innate immunity remains poorly understood. We investigated the PD-1:PDL1/PD-L2 pathway on NK cell effector functions in peripheral blood and pleural fluid from patients with tuberculosis. M. tuberculosis stimulation significantly up-regulated PD-1, PD-L1, and PD-L2 levels on NK cells. Interestingly, a direct correlation between PD-1 and IFN-γ expression on NK cells was observed. Moreover, blockade of the PD-1 pathway markedly augmented lytic degranulation and IFN-γ production of NK cells against M. tuberculosis. Furthermore, PD-1+ NK cells displayed a diminished IFN-γ mean fluorescence intensity, denoting the relevance of PD-1 on IFN-γ regulation. Together, we described a novel inhibitory role played by PD-1:PD-L interactions in innate immunity in tuberculosis.
Oxford University Press