Peritoneal and testicular macrophage mrna expression after exposure to UPEC CFT073

ABSTRACT: Ascending bacterial infections of the male genitourinary tract by Escherichia coli are an important cause of male infertility. Thus understanding mechanisms by which immunocompetent cells such as testicular macrophages (TM) respond to infection and how bacterial pathogens manipulate defense pathways is of great relevance. Following infection with uropathogenic E. coli (UPEC) whole genome expression profiling revealed induction of the calcium-dependent nuclear factor of activated T cells (NFAT) signaling pathway in TM as well as in peritoneal macrophages (PM) that were used in comparison. UPEC-dependent NFAT activation was confirmed in cultured TM and in TM using an in vivo infection model. Elevated expression of NFATC2-regulated anti-inflammatory cytokines was found in TM (IL-4, IL-13) and PM (IL-3, IL-4, IL-13). NFATC2 is activated by a rapid influx of calcium caused by the UPEC pore forming toxin alpha-hemolysin. Mutant analysis identified alpha-hemolysin as the main virulent factor responsible for UPEC-dependant suppression of IL-6 and TNF-a cytokine release from PM. Alpha-hemolysin caused differential activation of MAP kinase and AP-1 signaling pathways in TM and PM leading to differential expression profiles of key pro-inflammatory cytokines in PM (IL-1a, IL-1b and IL-6 downregulated) and TM (IL-1b and IL-6 upregulated). In contrast to PM, treatment with lipopolysaccharide did not result in activation of the NFkB pathway in TM as shown by lack of degradation of IkBa and lack of pro-inflammatory cytokine secretion (IL-6, TNF-a). In conclusion, these results propose a mechanism how TM can defend against microbes, while at the same time they are able to maintain the immune privileged status of the testis.

ORGANISM(S): Rattus norvegicus

PROVIDER: GSE24780 | GEO | 2010/10/20

SECONDARY ACCESSION(S): PRJNA132225

REPOSITORIES: GEO