Secretory IGA differentially promotes adherence of type 1-piliated Escherichia coli to immortalized vaginal epithelial cell lines

Vaginal Product Formulation Alters the Innate Antiviral Activity and Glycome of Cervicovaginal Fluids with Implications for Viral Susceptibility

Glycosylated proteins (i.e., mucins, IgG) are important mediators of innate antiviral immunity in the vagina; however, our current knowledge of the role that glycan themselves play in genital immunity is relatively low. Herein, we evaluate the relationship between innate antiviral immunity and glycomic composition in cervicovaginal lavage fluid (CVL) collected as part of a Phase I clinical trial testing the impact of two distinct formulations of the antiretroviral drug dapivirine. Using lectin microarray technology, we discovered that formulation (hydrogel- versus film-based delivery) impacted the CVL glycome, with hydrogel formulations inducing more changes, including a loss of high-mannose. The loss of this epitope correlated to a loss of anti-HIV-1 activity. Glycoproteomic identification of high-mannose proteins revealed a cohort of antiproteases shown to be important in HIV-1 resistance, whose expression covaried with the high-mannose signature. Our data strongly suggests high-mannose as a marker for secreted proteins mediating innate antiviral immunity in vaginal fluids and that drug formulation may impact this activity as reflected in the glycome.

Studying the effects of reproductive hormones and bacterial vaginosis on the glycome of lavage samples from the cervicovaginal cavity

The cervicovaginal fluid (CVF) coating the vaginal epithelium is an important immunological mediator, providing a barrier to infection. Glycosylation of CVF proteins, such as mucins, IgG and S-IgA, plays a critical role in their immunological functions. Although multiple factors, such as hormones and microflora, may influence glycosylation of the CVF, few studies have examined their impact on this important immunological fluid. Herein we analyzed the glycosylation of cervicovaginal lavage (CVL) samples collected from 165 women under different hormonal conditions including: (1) no contraceptive, post-menopausal, (2) no contraceptive, days 1-14 of the menstrual cycle, (3) no contraceptive, days 15-28 of the menstrual cycle, (4) combined-oral contraceptive pills for at least 6 months, (5) depo-medroxyprogesterone acetate (Depo-Provera) injections for at least 6 months, (6) levonorgestrel IUD for at least 1 month. Glycomic profiling was obtained using our lectin microarray system, a rapid method to analyze carbohydrate composition. Although some small effects were observed due to hormone levels, the major influence on the glycome was the presence of an altered bacterial cohort due to bacterial vaginosis (BV). Compared to normal women, samples from women with BV contained lower levels of sialic acid and high-mannose glycans in their CVL. The change in high mannose levels was unexpected and may be related to the increased risk of HIV-infection observed in women with BV, as high mannose receptors are a viral entry pathway. Changes in the glycome were also observed with hormonal contraceptive use, in a contraceptive-dependent manner. Overall, microflora had a greater impact on the glycome than hormonal levels, and both of these effects should be more closely examined in future studies given the importance of glycans in the innate immune system.

The impact of decreasing urinary IgA levels on decreased bacteriuria in a rat model of ileal augmented bladder

PURPOSE

Bacteriuria is frequently observed in patients with urinary tract reconstruction using intestinal segments. These patients have higher urinary IgA levels than those with a normal bladder. We examined the relationship between bacterial adherence and urinary IgA in a rat ileal augmented bladder model.

MATERIALS AND METHODS

Rat ileal augmented bladder models were divided into groups 3 months and 1 year after surgery. Experimental cystitis was induced in the 2 groups by transurethral inoculation of Escherichia coli. At 14 days after inoculation the rats were sacrificed, and cfu/mg tissue of the bladder and ileal patch was measured. Rats with negative urine culture in the 2 groups were sacrificed, and urine specimens and augmented bladder tissue were collected. Urinary IgA levels were determined and immunohistochemistry staining of the tissue was done with anti-rat IgA antibody.

RESULTS

In rats with experimental cystitis E. coli significantly adhered to the bladder and ileal patch in the 3-month group but not in the 1-year group. Urinary IgA levels in the 3-month group were significantly higher than in the 1-year group. On immunohistochemistry the number of IgA immunoreactive cells in the ileal patch decreased in the 1-year group compared to that in the 3-month group.

CONCLUSIONS

These results suggest that increased urinary IgA may be the cause of the higher incidence of bacteriuria in patients with urinary reconstruction using intestinal segments. Therefore, the decrease in IgA production in the inserted intestinal segments may contribute to a spontaneous decrease in of bacteriuria with time.