Even though the prevalence of Chlamydial infection is similar

in male and female, the amount of information currently available

about the pathogenesis and immunity to C. trachomatis

infection in males is scarce. We have previously demonstrated

using an in vivo male genital tract model of Chlamydial infection

that the inoculation of Chlamydia muridarum (Cm) within meatus

urethra results in an ascending infection with a special tropism

for the prostate gland. The presence of the bacteria in the

prostate gland was sustained at late time point after inoculation

(90dpi) and was accompanied by infiltration of the gland. In the

present work we analyze the composition of the infiltrate using

immune-histochemical assays. We detected few CD11b+, CD3+,

CD4+ and CD8+ cells in prostate glands of control rats. Prostate

gland infiltration observed in infected rats was composed

mostly by CD3 cells, with high staining for CD8 and CD4 cells.

No differences between infected and control glands were observed

when CD11b+ cells were analyzed. We also investigated

the presence of antibodies against male genital tract antigens in

infected and control serum obtained at day 90pi. A high proportion

of serum from infected animals showed immune- reactivity

against bladder (85%), prostate (100%) and testis (75%) extracts.

However, no immune-reactivity was observed when urethra

and seminal vesicle extracts were used. Our results prompt us

to speculate that during the course of Cm male urogenital tract

infection, the special tropism of this bacteria for the prostate

gland and its continuous presence together with the production

of cytokines and quemokines would induce a chronic inflammation

with the release of prostate and other male genital antigens

that, in turn, would evolve in the break of tolerance and the

onset of an autoimmune process within the male genital tract.