Sunday, May 29, 2016

Tissue retention of antigen-specific resident memory T cells

In recent years research in memory T cell response showed that secondary response to peripheral antigen challenge is driven mostly by locally-residing, tissue resident memory T cells (TRM). Such studies are important to understand how vaccines affect development of TRM (previously, main focus was on memory T cells residing in lymphoid tissues, such as spleen and lymph nodes).

Few studies suggested that virus induced TRM cells could migrate out and reside in tissues not directly affected by virus [i.e. Ag-independent manner]. However, immune response to different viruses can differ fundamentally from each other. For example, new report in Journal of Experimental Medicine (JEM) showed that skin infection with vaccinia virus (VacV, a benign relative of smallpox) instructs development and retention of local TRM in an antigen-specific manner.

In mice, infection with VacV by skin scarification produces local infection and induction of virus antigen-specific T cell response is local as well.

Importantly, accumulation of CD8 T cells within infected tissue was indeed antigen-specific, and not driven by local virus-induced inflammation per se.

Secondary antigenic challenge confirmed that TRM response was restricted to local tissue previously infected with virus carrying the same antigen.

In summary, this study showed that in case of VacV infection tissue retention of TRM cells was antigen-dependent and occurred locally at the site of primary viral challenge.

David Usharauli

No comments:

Post a Comment