Control of early <i>Salmonella typhimurium</i> growth in innately <i>Salmonella</i>-resistant mice does not require functional T lymphocytes.

Abstract

Abstract Previous studies have shown that mice that survive infection with a virulent strain of Salmonella typhimurium are able to control the initial net multiplication of the bacterium within tissues of the reticuloendothelial cell system (RES). Such mice carry the Chromosome 1 resistance allele Ityr (for “immunity to typhimurium”). Inbred mice that cannot contain early salmonella multiplication are homozygous for the susceptibility allele, designated Itys. Although evidence from several investigations indicates that the macrophage is one of the effector cells that controls the expression of innate salmonella resistance, the role of other cells types such as the Τ lymphocyte in immunity during the early stages of S. typhimurium infection has not been determined. To address this issue, the kinetics of microbial growth were compared in the spleens and livers of Ityr euthymic nu/+ and athymic nu/nu mice. In this comparative study, no differences in net bacterial growth in these RES organs were observed between nu/+ and nu/nu mice for the first 13 days of infection. These results strongly suggest that Ityr-regulated resistance to S. typhimurium does not require Τ cell participation.