Effect of menstrual cycle on mucosal immunity to SHIV within the reproductive tract of baboons (Papio anubis): preliminary findings

Hormonal synchronization of the menstrual cycles of pigtail macaques to facilitate biomedical research including modeling HIV susceptibility

BACKGROUND

Menstrual cycle synchronization of female pigtail macaques could prove an invaluable resource in studies of the reproductive tract, associated infections, and other potential research fields. We tested whether use of an oral progesterone and estradiol combination tablet could synchronize menstrual cycles following treatment discontinuation.

METHODS

Daily desogestrel 0.075 mg and ethinyl estradiol 0.01 mg were administered orally to three pigtail macaques at visual onset of perineal sex swelling and were continued until all animals had received it for at least 45 days. The hormones were discontinued, and these three macaques and three controls were observed for menstruation and had blood progesterone and estrogen measured over an additional 2-month period.

RESULTS

All treatment animals showed spontaneous menstrual cycle synchronization for 2 months after menstrual cycling resumed.

CONCLUSION

Progesterone and estradiol combination therapy can be used in pigtail macaques to induce synchronized cycling that persists in the absence of on-going hormone treatments.

The effect of progesterone levels and pregnancy on HIV-1 coreceptor expression

The upregulation of HIV-1 co-receptor expression during certain clinical settings may explain the predisposition of individuals to enhanced HIV-1 acquisition. We sought to determine the effect of estrogen and progesterone on the HIV-1 coreceptors, CCR5 and CXCR4. Co-receptor expression on CD3- and CD14-positive cells obtained systemically and locally (genital tissue in women) was determined in men, pre- and post-menopausal women, pregnant women in each trimester and in labor. CCR5 on both CD3- and CD14-positive cells was highest in pregnant women, and increased as gestation advanced ( P < .01 and P < .001, respectively). Progesterone levels were significantly associated with CCR5 expression on PBMCs ( P < .03 for CD3-positive, and P < .002 for CD14-positive cells) and from cells isolated from tissue ( P < .001).CCR5 mRNA expression correlated with the cell surface marker expression from blood and tissue. These findings suggest that pregnancy and other high progesterone states may predispose women to HIV-1 acquisition.

Nonoxynol-9 Induces Apoptosis of Endometrial Explants by Both Caspase-Dependent and -Independent Apoptotic Pathways1

Contraceptive microbicides formulated as vaginal gels offer the possibility of women-controlled contraception and prevention of HIV infection. The effects of these gels on the upper reproductive tract are largely unknown. The purpose of this study was to determine whether nonoxynol-9 (N-9) induces apoptosis in human endometrium using endometrial explant as a model. Apoptosis was determined by gel electrophoresis for the detection of DNA fragmentation and by immunohistochemistry using the M30 CytoDEATH and anti-cleaved caspase-3 (CASP3) antibodies for the detection of caspase activity. The ability of the broad-spectrum caspase inhibitor and CASP3-specific inhibitor to prevent N-9-induced cell death was measured. Expression of apoptosis-related genes such as BCL2, BAX, Fas receptor (FAS), and Fas ligand (FASLG) was quantified using real-time polymerase chain reaction (PCR) analysis. This study demonstrated that N-9 induced DNA fragmentation and caspase activity in endometrial explants in a dose- and time-dependent manner. Caspase inhibitors did not fully prevent the N-9-induced DNA fragmentation. Real-time PCR analysis revealed that FAS and FASLG were largely increased following N-9 treatment. Together, these results suggested that apoptosis triggered by N-9 in endometrial explants is mediated upstream via FAS and FASLG, followed by CASP3 activation leading to final cell death. It appears that other factors besides caspases are also involved in the N-9-induced apoptosis.

Myocarditis susceptibility in female mice depends upon ovarian cycle phase at infection

Female BALB/c mice were infected with coxsackievirus B3 in the diestrus, proestrus, estrus, or metestrus phases of the ovarian cycle. Cycle stage was determined by vaginal smear. All mice were killed 7 days after infection. Females infected in the diestrus and especially the proestrus phases developed myocarditis. CD4+ T cells expressing interferon-gamma (IFNgamma) infiltrate the myocardium in these two phases, whereas CD4+ T cells expressing IL-4 are more frequent during estrus. Cardiac virus titers were determined 15 h and 7 days after infection. No differences in virus titer were seen at 7 days. These studies show that natural hormone variations can have substantial effects on viral pathogenicity presumably due to hormone effects on the immune system.

The effect of nonoxynol-9 on human endometrium

Contraceptive microbicides formulated as vaginal gels offer the possibility of women-controlled contraception and prevention of HIV infection. However, the effects of these gels on the upper reproductive tract is largely unknown. The purpose of this study was to determine the effects of nonoxynol-9 (N-9) on human endometrium. Human endometrial biopsies were cultured and incubated with various dosages of N-9 for 6 or 24 h. Endometrial histology was assessed by light microscopy using hematoxylin and eosin. Inflammatory response was determined by analyzing proinflammatory cytokines with enzyme-linked immunosorbent assay. Endometrial mucin was assessed by immunohistochemistry and real-time polymerase chain reaction. Histological changes consistent with focal coagulative necrosis were seen after 6 and 24 h of culture. All cytokines (interleukin 1beta, tumor necrosis factor alpha and interleukin 8) decreased at all concentrations of N-9 after 24 h of incubation. The expression of Mucin1 (MUC-1) was inhibited in a dose-dependent manner at both the protein and messenger RNA levels. These results demonstrate for the first time that N-9 has multiple, potential deleterious effects on the human endometrium characterized by necrosis, alteration of proinflammatory cytokines and inhibition of MUC-1 expression. Taken together, these in vitro findings suggest that N-9 can interrupt the functional barrier provided by the endometrium and, thus, facilitate infection with HIV and other pathogens.