To Investigate the significance of Intercellular adhesion molecule-1 (ICAM-1) and leukocyte function-associated antlgen-1 (LFA-1) In host defense against infection with Intracellular parasites, we examined the effects of In vivo pretreatment with mAbs to ICAM-1 (1A29) and LFA-1α (WT-1) on the protection against Infection with Listeria monocytogenesIn Fisher F344/N rats. Expression of ICAM-1 and LFA-1α molecules on T cells In spleen, liver and peritoneal cavity of rats was down-regulated after i.p. administration with daily doses of 300 μg of either 1A29 or WT-1 for 10 days. The survival rate of rats inoculated with viable Listeria was significantly reduced byIn vivo pretreatment with 1A29 together with WT-1 for 10 days but not by In vivo pretreatment with control mAb. The numbers of bacteria In the spleen In rats pretreated with both 1A29 and WT-1 were significantly increased on day 3 and day 6 after Infection with 1 × 107 of viable Listeria corresponding to 1/30 of LD50 to normal rats. Thus, the resistance against llsterial Infection was severely Impaired by combinational pretreatment with mAbs In ICAM-1 and LFA-1α. As shown In our previous report, the early appearance of CD3+TCRαβ- T cells, presumably TCR αδ cells, was evident In the peritoneal cavity and liver of control rats at the early stage after llsterial Infection, while this was suppressed at this stage in rats pretreated with both 1A29 and WT1. These results suggest that the ICAM-1 and LFA-1 adhesion pathway may be critically involved in protectlve roles of CD3+TCRαβ- T cells at the early stage of rat listeriosis.
All Science Journal Classification (ASJC) codes
- Immunology and Allergy