AUTHOR=Basile Juan I. , Liu Ruining , Mou Wenjun , Gao Yu , Carow Berit , Rottenberg Martin E. 

TITLE=Mycobacteria-Specific T Cells Are Generated in the Lung During Mucosal BCG Immunization or Infection With Mycobacterium tuberculosis

JOURNAL=Frontiers in Immunology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.566319

DOI=10.3389/fimmu.2020.566319

ISSN=1664-3224

ABSTRACT=<p>Specific T cell responses are central for protection against infection with <italic>M. tuberculosis</italic>. Here we show that mycobacteria-specific CD4 and CD8 T cells accumulated in the lung but not in the mediastinal lymph node (MLN) at different time points after <italic>M. tuberculosis</italic> infection or BCG immunization. Proliferating specific T cells were found in the lung after infection and immunization. Pulmonary, but not MLN-derived CD4 and CD8 T cells, from <italic>M. tuberculosis</italic>-infected mice secreted IFN-γ after stimulation with different mycobacterial peptides. Mycobacteria-specific resident memory CD4 and CD8 T cells (TRM) expressing PD-1 accumulated in the lung after aerosol infection and intratracheal (i.t.) -but not subcutaneous (s.c.)- BCG immunization. Chemical inhibition of recirculation indicated that TRM were generated in the lung after BCG i.t. immunization. In summary, mycobacteria specific-TRM accumulate in the lung during i.t. but not s.c. immunization or <italic>M. tuberculosis</italic> infection. Collectively our data suggests that priming, accumulation and/or expansion of specific T cells during BCG immunization and <italic>M. tuberculosis</italic> infection occurs in the lung.</p>