Identification of guinea pig gd T cells and characterization during pulmonary tuberculosis

Guinea pigs are an alternative small animal model for many disease studies. Here we describe a pan-gd monoclonal antibody (anti-TCRd1) specific for the constant region of human T cell receptor delta chains that cross-reacts with a subpopulation of guinea pig (Cavia porcellus) lymphocytes. The phenotype and distribution of this subpopulation is consistent with the guinea pig gd T cell subset. FACS analysis of fresh PBMC and splenocytes from naı̈ve guinea pigs revealed the presence of a subset of cells that stained with the anti-TCRd1 mAb. The relative percentage of anti-TCRd1 positive cells in PBMC and tissues is similar to that described for gd T cells in other species. Immunohistochemistry of tissues also revealed a distribution of anti-TCRd1 positive cells consistent with gd T cells. These data are further supported by staining of a polyclonal guinea pig T cell line that became progressively CD4 and CD8 negative in long-term culture. Analysis of PBMC from guinea pigs following aerosol infection with virulent Mycobacterium tuberculosis revealed no apparent changes in the steady-state percentage of blood gd T cells. Taken together, these data suggest that the anti-TCRd1 antibody recognizes the gd T cell subset in guinea pigs. This reagent may be useful for examining gd T cells in various disease models where the guinea pig is a more desirable model for study. # 2004 Elsevier B.V. All rights reserved.