WC1⁺ γδ T cell memory population is induced by killed bacterial vaccine

Abstract

Limited studies have addressed the ability of cd T cells to become memory populations. We previously demonstrated that WC1.1 + cd T cells from ruminants vaccinated with killed Leptospira borgpetersenii proliferate and produce IFN-c in recall responses. Here we show that this response is dependent upon antigen-responsive CD4 T cells, at least across transwell membranes; this requirement cannot be replaced by IL-2. The response was also dependent upon in vivo priming, since cd T cells from leptospira vaccine-naive animals did not respond to antigen even when co-cultured across membranes from antigen-responsive PBMC. cd T cells were the major antigen-responding T cell population for the first 4 wks following vaccination and replicated more rapidly than CD4 T cells. Primed WC1 + cd T cells circulated as CD62L hi /CD45RO int /CD44 lo , characteristics of T CM cells. When stimulated with antigen, they decreased CD62L, increased CD44 and CD25, and had no change in CD45RO expression. These changes paralleled those of the leptospira antigen-responsive CD4 T cells but differed from those of cd T cells proliferating to mitogen stimulation. This system for in vivo cd T cell priming is unique, since it relies on a killed antigen to induce memory and may be pertinent to designing vaccines that require type 1 pro-inflammatory cytokines.

Gamma-Delta T-Cell Responses During SubcutaneousMycobacterium aviumSubspeciesparatuberculosisChallenge in Sensitized or Naïve Calves Using Matrix Biopolymers

“…Though in our study this difference was not statistically significant, the data are similar to a study by Blumerman et al suggesting that memory WC1þ cells can be induced by killed bacterin. 2 A lack of antigenic specificity in naive gd T cells of cattle is consistent with previous reports. gd T cells are nonmajor histocompatibility restricted and thus directly respond to pathogen-associated molecular patterns.…”

A Leptospira borgpetersenii Serovar Hardjo Vaccine Induces a Th1 Response, Activates NK Cells, and Reduces Renal Colonization

“…2) Lymphocyte proliferation in response to antigen. Lymphocytes were stimulated ex vivo with antigen prepared from highpassage L. borgpetersenii serovar Hardjo strain RZ33, providing uniformity with previous studies (3,4,9,18,19) and consistency within this experiment; RZ33 was used to prepare the Mono2 reference vaccine in this study and previous studies. PBMCs obtained from Mono1-vaccinated animals mounted a significantly higher proliferation response after exposure to antigen than either Mono2-vaccinated or control animals (Fig.…”

Rapid and Transient Activation of γδ T Cells to IFN-γ Production, NK Cell-Like Killing, and Antigen Processing during Acute Virus Infection

“…Others have reported that it has been difficult to generate Agspecific gd T cells following vaccination (42). Reports of gd T cell memory induction in the bovine (13,43) may indicate that, in this species, specific Ag-dependent stimulation of gd T cells may exist. It cannot be ruled out that gd T cell responses at such an early stage as reported in this study result from nonspecific stimulation by endogenously derived ligands.…”