To search for a potential role of T cell antigen receptor (TcR) γ/β‐bearing cells in host‐defense against Listeria monocytogenes, we analyzed the sequential appearance of γ/δ and α/β T cell in the peritoneal exudate cells (PEC) during an i.p. infection with sublethal dose (2 × 103) of viable Listeria organisms in mice. The PEC on day 1 after the infection consisted of 48% macrophages and 50% lymphocytes, most of which were surface IgM+ (B) cells. The number of PEC increased to the maximal level by day 3. The PEC at this stage contained an appreciable number of CD3+ T cells in addition to a large number of macrophages. Of the CD3+ cells, the proportion of CD4−CD8− cells, most of which expressed no TcR α/β, increased to the maximal level on day 3 after the infection. In correlation with an increased number of CD3+CD4−CD8−TcR α/β− cells, high level of TcR γ/δ chain gene messages was detected in the nonadherent population of the PEC on this stage. On the other hand, the PEC on day 8 contained an increased number of CD4+CD8− and CD4−CD8+ cells which expressed TcR α/β chain on their surface. These results suggest that the γ/δ T cells precede the α/β T cells in appearance during listerial infection. The γ/β T cells may be involved at the first line of the host‐defense against Listeria.
All Science Journal Classification (ASJC) codes
- Immunology and Allergy