Pathogen-specific regulatory T cells delay the arrival of effector T cells in the lung during early tuberculosis.
The ability of the adaptive immune system to restrict Mycobacterium tuberculosis (Mtb) is impeded by activated Foxp3(+) regulatory T (T reg) cells. The importance of pathogen-specific T reg cells in this process has not been addressed. We show that T reg cell expansion after aerosol Mtb infection does not occur until Mtb is transported to the pulmonary lymph node (pLN), and Mtb-specific T reg cells have an increased propensity to proliferate. Even small numbers of Mtb-specific T reg cells are capable of delaying the priming of effector CD4(+) and CD8(+) T cells in the pLN and their subsequent accumulation in the lung, the primary site of infection. This delay likely prolongs the initial phase of bacterial expansion and explains the higher bacterial burden observed in these mice. Thus, T reg cells recognizing Mtb-derived antigens specifically and potently restrict protective immune responses during tuberculosis.
Shafiani
Shahin
S
Department of Pediatrics, University of Washington, Seattle, WA 98195, USA.
Tucker-Heard
Glady's
G
Kariyone
Ai
A
Takatsu
Kiyoshi
K
Urdahl
Kevin B
KB
D000336:Aerosols; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D049109:Cell Proliferation; D051858:Forkhead Transcription Factors / Q000276:immunology; D007109:Immunity / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis; D008168:Lung / Q000276:immunology* / Q000382:microbiology* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D013045:Species Specificity; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000276:immunology / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000276:immunology* / Q000382:microbiology* / Q000473:pathology
D000336:Aerosols; D000942:Antigens, Bacterial; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D007371:Interferon-gamma