[HTML][HTML] CXCR3 enables recruitment and site-specific bystander activation of memory CD8+ T cells

NJ Maurice, MJ McElrath, E Andersen-Nissen… - Nature …, 2019 - nature.com
NJ Maurice, MJ McElrath, E Andersen-Nissen, N Frahm, M Prlic
Nature communications, 2019nature.com
Bystander activation of memory T cells occurs in the absence of cognate antigen during
infections that elicit strong systemic inflammatory responses, which subsequently affect host
immune responses. Here we report that memory T cell bystander activation is not limited to
induction by systemic inflammation. We initially observe potential T cell bystander activation
in a cohort of human vaccine recipients. Using a mouse model system, we then find that
memory CD8+ T cells are specifically recruited to sites with activated antigen-presenting …
Abstract
Bystander activation of memory T cells occurs in the absence of cognate antigen during infections that elicit strong systemic inflammatory responses, which subsequently affect host immune responses. Here we report that memory T cell bystander activation is not limited to induction by systemic inflammation. We initially observe potential T cell bystander activation in a cohort of human vaccine recipients. Using a mouse model system, we then find that memory CD8+ T cells are specifically recruited to sites with activated antigen-presenting cells (APCs) in a CXCR3-dependent manner. In addition, CXCR3 is also necessary for T cell clustering around APCs and T cell bystander activation, which temporospatially overlaps with the subsequent antigen-specific T cell response. Our data thus suggest that bystander activation is part of the initial localized immune response, and is mediated by a site-specific recruitment process of memory T cells.
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