ENTRANCE AND SURVIVAL OF SALMONELLA-TYPHIMURIUM AND YERSINIA-ENTEROCOLITICA WITHIN HUMAN B-CELL AND T-CELL LINES

Lymphocytes, located within the Peyer's patches, might be involved in the dissemination of enteropathogenic Salmonella typhimurium and Yersi nia enterocolitica bacteria. To test this hypothesis, we have investig ated the susceptibility of human B- and T-cell lines to bacterial adhe sion and invasion. The two S. typhimurium strains analyzed were highly invasive, while the two Y. enterocolitica (0:8) strains adhered to th e B- and T-cell lines but did not enter the cell lines in significant amounts. We hypothesize that the incapability of the Y. enterocolitica (0:8) strains to enter the human B- and T-cell lines is most probably due to the bacterial inability to induce the internalization process upon adhesion to both cell lines. Although immortalized B- and T-cell lines were used in this study, the results presented suggest the possi bility that both cell types could play a role in the dissemination of intracellularly residing S. typhimurium in vivo.