Polymorphonuclear neutrophils are necessary for the recruitment of CD8(+) T cells in the liver in a pregnant mouse model of Chlamydophila abortus (Chlamydia psittaci serotype 1) infection

The role of polymorphonuclear neutrophils (PMNs) in the development of the specific immune response against Chlamydophila abortus (Chlamydia psittaci serotype I) infection,vas studied in a pregnant mouse model involving treat ment with RB6-8C5 monoclonal antibody. PMN depletion significantly affected the immune response in the liver, in which the T-lymphocyte and F4/80(+) c ell populations decreased, particularly the CD8(+) T-cell population. A Th1 -like response, characterized by high levels of gamma interferon without de tectable levels of interleukin 4 (IL-4) in serum, was observed in both depl eted and nondepleted mice, although an increased production of IL-10 was de tected in the depleted group. Our results suggest that PMNs play a very imp ortant role in the recruitment of other leukocyte populations to the inflam matory foci but have little influence in the polarization of the immune spe cific response toward a Th1-like response.