Prostate epithelial cells express TLR4 intracellularly and respond to lps activating NF-KB

GATTI, G; MOTRICH, RD; RIVERO, VE; MACCIONI, M

Cordoba

Congreso; VII Latin American Congress of Immunology; 2005

Asociacion Latinoamericana de Inmunologia

Despite the prevalence of prostate disease, very little is known about the immunobiology of the prostate and its contribution to disease. Due to the expanding body of literature suggesting a link between chronic inflammation and cancer, it seems important to investigate how prostate epithelial cells (PE) deal with inflammatory stimuli. To this aim, we stimulated a rat PE cell line (MAT-LU) or rat primary PE cells with lipopolysaccharide (LPS). We show, by RT-PCR, that PE constitutively express significant levels of TLR4 and CD14 mRNA. TLR4 and CD14 proteins were also detected, although not at the cell surface but intracellularly (flow cytometry and confocal microscopy). An increase in the percentage of cells expressing TLR4 as well as an increase in the levels of expression of this receptor were seen after 24 hours of treatment with LPS (basal: 34.3 %, MFC: 16.80 ; 24h: 46.6%, MFC: 22.44 48h: 35.8%, MFC: 18.24). LPS-stimulated MAT-LU cells activate NF-KB transcription factor, induce the expression of iNOS and secrete NO and TNF-alpha. Evenmore, numerous chemokine genes are either up-regulated or induced in the cell line as well as in normal primary PE cells.
Our results clearly demonstrate, that PE are fully competent to respond. The fact that they express TLR4 intracellularly suggest the presence of regulatory mechanisms, that once overcome, it could turn these cells into active players of the innate immunity.