IL-17–Producing innate and pathogen-specific tissue resident memory γδ T cells expand in the lungs of Bordetella pertussis–infected mice

A Misiak, MM Wilk, M Raverdeau… - The Journal of …, 2017 - journals.aai.org
A Misiak, MM Wilk, M Raverdeau, KHG Mills
The Journal of Immunology, 2017journals.aai.org
Abstract γδ T cells play a role in protective immunity to infection at mucosal surface, but also
mediate pathology in certain autoimmune diseases through innate IL-17 production. Recent
reports have suggested that γδ T cells can have memory analogous to conventional αβ T
cells. In this study we have examined the role of γδ T cells in immunity to the respiratory
pathogen Bordetella pertussis. γδ T cells, predominantly Vγ4− γ1− cells, produced IL-17 in
the lungs as early as 2 h after infection. The bacterial burden during primary infection was …
Abstract
γδ T cells play a role in protective immunity to infection at mucosal surface, but also mediate pathology in certain autoimmune diseases through innate IL-17 production. Recent reports have suggested that γδ T cells can have memory analogous to conventional αβ T cells. In this study we have examined the role of γδ T cells in immunity to the respiratory pathogen Bordetella pertussis. γδ T cells, predominantly Vγ4− γ1− cells, produced IL-17 in the lungs as early as 2 h after infection. The bacterial burden during primary infection was significantly enhanced and the induction of antimicrobial peptides was reduced in the absence of early IL-17. A second peak of γδ T cells is detected in the lungs 7–14 d after challenge and these γδ T cells were pathogen specific. γδ T cells, exclusively Vγ4, from the lungs of infected but not naive mice produced IL-17 in response to heat-killed B. pertussis in the presence of APC. Furthermore, γδ T cells from the lungs of mice reinfected with B. pertussis produced significantly more IL-17 than γδ T cells from infected unprimed mice. γδ T cells with a tissue resident memory T cell phenotype (CD69+ CD103+) were expanded in the lungs during infection with B. pertussis and proliferated rapidly after rechallenge of convalescent mice. Our findings demonstrate that lung γδ T cells provide an early source of innate IL-17, which promotes antimicrobial peptide production, whereas pathogen-specific Vγ4 cells function in adaptive immunological memory against B. pertussis.
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