The immunobiological properties expressed in vitro and in vivo of Salmonella enteritidis-induced murine T cell lines

Abstract

Splenic T lymphocytes from two strains of mice, BALB/c and B10.BR, infected with an attenuated strain of Salmonella enteritidis were cloned by the double-layer soft agar technique in the presence of interleukin 2 (IL 2), formalin-killed S. enteritidis (FKS) and syngeneic feeder cells. One Salmonella-reactive T cell line was established from each strain of mice. Both T cell lines bore Thy-1+, Lyt-1+ and L3T4+ surface markers as demonstrated by cytofluorography. Biological properties of the T cell lines were studied with respect to their ability to proliferate and produce lymphokines such as IL 2 and gamma-interferon (IFN-gamma) in response to Salmonella antigens, and to transfer adoptively protection against infection and delayed-type hypersensitivity (DTH). As the result of the present study, the T cell lines were proliferated specifically against several Salmonella and other bacteria, which belong to species of Enterobacteriaceae. Their proliferation required the presence of the specific antigen(s) and the compatibility in the I-A region of the H-2 complex between the T cell lines and feeder cells. The T cell lines could be proliferated with resultant production of IL 2 and IFN-gamma by in vitro culture in the presence of syngeneic feeder cells and Salmonella antigens. The protective activity assessed by the number of recoverable bacteria in spleens and livers after challenge with virulent S. enteritidis and DTH reactions to Salmonella antigen were exhibited by the T cell lines when transferred adoptively to naive syngeneic mice. These results suggested that different biological functions of cell-mediated immunity to Salmonella could be mediated by a single phenotype of T cell population.