Potential Roles of a Special CD8αα+ Cell Population and CC Chemokine Thymus-Expressed Chemokine in Ovulation Related Inflammation

Abstract

It is well known that ovulation may be an inflammatory process. However, it remains elusive how immune cells participate in this process. We have identified a novel CD8αα+ population, which resembles tissue dendritic cells, in the theca of antral follicles. We further observed a dramatic influx of the CD8αα+cells into the ovulating follicles. This CD8αα+population was absent in the ovary of estradiol-induced anovulatory C31F1 mice and subfertile athymic nude mice. Expression of a CC chemokine thymus-expressed chemokine (TECK) has previously been found in the ovary; we further demonstrated that TECK attracted CD8αα+cells into the ovary. Anti-TECK Ab, elicited in the female mice by active immunization, depleted the ovarian CD8αα+ cells in vivo. Mice with a high titer of TECK Ab failed to ovulate after superovulation induction. More importantly, the immunized mice had greatly reduced fertility, which was positively correlated with the Ab titers. Ovarian TECK expression was normal in anovulatory C31F1 mice, suggesting that infertility in the immunized mice is due to a block of CD8αα+ cell migration. Finally, the origin of ovarian CD8αα+ cells was explored. Upon being transferred, thymic CD8α+ cells were able to home to the theca of follicles in the recipients. Thus, ovarian CD8αα+ cells, which participate in the ovulation-related inflammation, may originate in the thymus.

Preferential Replication of Vaccinia Virus in the Ovaries is Independent of Immune Regulation Through IL-10 and TGF-β

“…It has been reported that macrophages and neutrophils dramatically infiltrate the ovaries during the ovulatory process, likely in response to a luteinizing hormone surge (33), and an equally important influx of monocytes into the corpus luteum occurs at the late post-ovulatory phase (34). In another study, a novel CD8aa + cell population was further observed to influx into ovulating follicles (15). These data suggest that there is a dynamic immune environment within the ovaries that is associated with ovarian function.…”

“…Similarly to MCMV, VACV possesses a wide range of immune evasion strategies it uses in order to survive. Although ovarian immunity generated during VACV infection has yet to be studied, recent data have suggested that there are correlations between ovarian immune cells and infection or inflammation (14,15). We therefore sought to investigate whether VACV may employ the ovaries as a target for immune evasion through the induction of an organ-specific immune-suppressive environment.…”

Ovarian phagocyte subsets and their distinct tissue distribution patterns

“…Thus, it is possible that some subsets, which may be related to important ovarian functions such as ovulation, may have been missed. For example, we have identified a CD8aa C phagocyte-like population (Zhou et al 2009). This phagocyte-like population invades mature follicles during super-ovulation.…”

“…The mice is maintained in the animal facility at The University of Texas Health Science Center at Houston and allowed to acclimate for a minimum of 7 days. For analysis of ovarian cells, four pairs of ovaries from same-aged animals were used for isolation of ovarian cells following our previously published method (Zhou et al 2009). The experiments were repeated at least three times for each age.…”

“…Dead cells were further removed by Ficoll gradient (density 1.119) centrifugation. As controls, peripheral blood leukocytes (PBLs) or splenocytes were isolated following our previously published method (Zhou et al 2009). The isolated cells were used for flow cytometry immediately or for immunofluorescence after an overnight culture.…”