Production and characterization of a human antisperm monoclonal antibody against CD52g for topical contraception in women.

BACKGROUND: Approximately 40% of human pregnancies are unintended, indicating a need for more acceptable effective contraception methods. New antibody production systems make it possible to manufacture reagent-grade human monoclonal antibodies (mAbs) for clinical use. We used the Nicotiana platform to produce a human antisperm mAb and tested its efficacy for on-demand topical contraception. METHODS: Heavy and light chain variable region DNA sequences of a human IgM antisperm antibody derived from an infertile woman were inserted with human IgG1 constant region sequences into an agrobacterium and transfected into Nicotiana benthamiana. The product, an IgG1 mAb ["Human Contraception Antibody" (HCA)], was purified on Protein A columns, and QC was performed using the LabChip GXII Touch protein characterization system and SEC-HPLC. HCA was tested for antigen specificity by immunofluorescence and western blot assays, antisperm activity by sperm agglutination and complement dependent sperm immobilization assays, and safety in a human vaginal tissue (EpiVaginal™) model. FINDINGS: HCA was obtained at concentrations ranging from 0.4 to 4 mg/ml and consisted of > 90% IgG monomers. The mAb specifically reacted with a glycan epitope on CD52g, a glycoprotein produced in the male reproductive tract and found in abundance on sperm. HCA potently agglutinated sperm under a variety of relevant physiological conditions at concentrations ≥ 6.25 µg/ml, and mediated complement-dependent sperm immobilization at concentrations ≥ 1 µg/ml. HCA and its immune complexes did not induce inflammation in EpiVaginal™ tissue. INTERPRETATION: HCA, an IgG1 mAb with potent sperm agglutination and immobilization activity and a good safety profile, is a promising candidate for female contraception. FUNDING: This research was supported by grants R01 HD095630 and P50HD096957 from the National Institutes of Health.

Chlamydia trachomatis Infection, when Treated during Pregnancy, Is Not Associated with Preterm Birth in an Urban Safety-Net Hospital.

Preterm birth is a major public health problem, occurring in more than half a million births per year in the United States. A number of maternal conditions have been recognized as risk factors for preterm birth, but for the majority of cases, the etiology is not completely understood. Chlamydia trachomatis is one of the most prevalent sexually transmitted infections in the world. However, its role in adverse pregnancy outcome in women is still debated. In order to determine if genitourinary tract infection with C. trachomatis during pregnancy was associated with preterm birth, we conducted a case-control study on women who delivered at Boston Medical Center, an urban "safety-net" hospital that serves a socioeconomically disadvantaged and racially diverse population. Women with known risk factors for preterm birth or immune suppression were excluded. Variables collected on enrolled subjects included demographics; diagnosis of C. trachomatis during or prior to pregnancy; tobacco, alcohol, and illicit substance use; gestational age; and birthweight and gender of the newborn. We also collected urine for chlamydia testing at the time of delivery and placental biopsies for nucleic acid amplification and histological studies. A total of 305 subjects were enrolled: 100 who delivered preterm and 205 who delivered full term. Among those subjects, we identified 19 cases of pregnancy-associated C. trachomatis infection: 6/100 preterm and 13/205 full term, a difference which was not statistically significant. Only two cases of untreated chlamydia infection were identified postpartum, and both occurred in women who delivered at term. We conclude that genitourinary tract infection with C. trachomatis during pregnancy, when appropriately treated, is not associated with preterm birth.

Condylomata Acuminata (Anogenital Warts) Contain Accumulations of HIV-1 Target Cells That May Provide Portals for HIV Transmission.

Background: Condylomata acuminata (anogenital warts [AGWs]) are prevalent in human immunodeficiency virus (HIV)-infected individuals and sexually active populations at risk for HIV acquisition and have been associated with HIV transmission. We compared AGW specimens to control tissue specimens for abundance, types, and location of HIV target cells and for susceptibility to HIV infection in vitro, to provide biologic evidence that AGWs facilitate HIV transmission. Methods: We used immunohistologic staining to identify HIV target cells in AGW and control specimens. We also inoculated HIV in vitro into AGW and control specimens from HIV-negative men and assessed infection by means of TZM-bl and p24 assays. Results: CD1a+ dendritic cells, CD4+ T cells, and macrophages were significantly more abundant in the epidermis of AGW specimens than control specimens. These HIV target cells also often appeared in large focal accumulations in the dermis of AGW specimens. Two of 8 AGW specimens versus 0 of 8 control specimens showed robust infection with HIV in vitro. Conclusions: Compared with normal skin, AGWs contain significantly higher concentrations of HIV target cells that may be susceptible to HIV infection. Condylomata may thus promote HIV transmission, especially in the setting of typical lesion vascularity and friability. Prevention or treatment of AGWs may decrease the sexual transmission of HIV.

RNF121 Inhibits Angiogenic Growth Factor Signaling by Restricting Cell Surface Expression of VEGFR-2.

Ligand stimulation promotes downregulation of RTKs, a mechanism by which RTKs, through the ubiquitination pathway are removed from the cell surface, causing a temporary termination of RTK signaling. The molecular mechanisms governing RTK trafficking and maturation in the endoplasmic reticulum (ER)/Golgi compartments are poorly understood. Vascular endothelial growth factor receptor-2 (VEGFR-2) is a prototypic RTK that plays a critical role in physiologic and pathologic angiogenesis. Here we demonstrate that Ring Finger Protein 121 (RNF121), an ER ubiquitin E3 ligase, is expressed in endothelial cells and regulates maturation of VEGFR-2. RNF121 recognizes newly synthesized VEGFR-2 in the ER and controls its trafficking and maturation. Over-expression of RNF121 promoted ubiquitination of VEGFR-2, inhibited its maturation and resulted a significantly reduced VEGFR-2 presence at the cell surface. Conversely, the shRNA-mediated knockdown of RNF121 in primary endothelial cells reduced VEGFR-2 ubiquitination and increased its cell surface level. The RING Finger domain of RNF121 is required for its activity toward VEGFR-2, as its deletion significantly reduced the effect of RNF121 on VEGFR-2. Additionally, RNF121 inhibited VEGF-induced endothelial cell proliferation and angiogenesis. Taken together, these data identify RNF121 as a key determinant of angiogenic signaling that restricts VEGFR-2 cell surface presence and its angiogenic signaling.

Characterization of a Hormone-Responsive Organotypic Human Vaginal Tissue Model: Morphologic and Immunologic Effects.

Estrogen and progesterone regulate proliferation and differentiation of epithelial cells in the female genital tract. We investigated the effects of these hormones on reconstructed human organotypic vaginal epithelial tissue models (EpiVaginal). We ascertained that epithelial cells in the tissue models express estrogen and progesterone receptors. Treatment with estradiol-17ß (E(2)) significantly increased epithelium thickness and transepithelial electrical resistance (TEER), whereas progesterone (P) treatment resulted in thinning of the epithelium and decreased TEER when compared with untreated controls. Exposure to E(2) increased (1) the expression of the progesterone receptor B (PR-B), (2) accumulation of glycogen in suprabasal cells, (3) epithelial differentiation, and (4) the expression of a number of gene pathways associated with innate immunity, epithelial differentiation, wound healing, and antiviral responses. These findings indicate that EpiVaginal tissues are hormone responsive and can be used to study the role of female reproductive hormones in innate immune responses, microbial infection, and drug delivery in the vaginal mucosa.

The Neonatal Fc receptor (FcRn) enhances human immunodeficiency virus type 1 (HIV-1) transcytosis across epithelial cells.

The mechanisms by which human immunodeficiency virus type 1 (HIV-1) crosses mucosal surfaces to establish infection are unknown. Acidic genital secretions of HIV-1-infected women contain HIV-1 likely coated by antibody. We found that the combination of acidic pH and Env-specific IgG, including that from cervicovaginal and seminal fluids of HIV-1-infected individuals, augmented transcytosis across epithelial cells as much as 20-fold compared with Env-specific IgG at neutral pH or non-specific IgG at either pH. Enhanced transcytosis was observed with clinical HIV-1 isolates, including transmitted/founder strains, and was eliminated in Fc neonatal receptor (FcRn)-knockdown epithelial cells. Non-neutralizing antibodies allowed similar or less transcytosis than neutralizing antibodies. However, the ratio of total:infectious virus was higher for neutralizing antibodies, indicating that they allowed transcytosis while blocking infectivity of transcytosed virus. Immunocytochemistry revealed abundant FcRn expression in columnar epithelia lining the human endocervix and penile urethra. Acidity and Env-specific IgG enhance transcytosis of virus across epithelial cells via FcRn and could facilitate translocation of virus to susceptible target cells following sexual exposure.

A quantitative glycogen assay to verify use of self-administered vaginal swabs.

BACKGROUND: Self-administered swabs are used to sample vaginal contents for a variety of clinical purposes including detection of sexually transmitted infections, condom breakage, and vaginal product use. The goal of this study was to determine whether a quantitative glycogen assay can be used to assess whether a swab has been exposed to the vagina to assure study compliance. STUDY DESIGN: Buccal, skin, or vaginal samples were tested to determine whether a commercial quantitative glycogen assay can differentiate vaginal specimens. In addition, archived remnant de-identified vaginal swabs from clinical trials were tested. Periodic acid-Schiff stain was used to identify glycogen-positive cells as a confirmation test. RESULTS: Glycogen concentrations in eluates of vaginal swabs from reproductive-aged women were significantly higher than those from unused swabs (mean ± SE, 964 ± 135 µg/mL vs. 14.7 ± 2.5 µg/mL, P < 0.001) and swabs exposed to buccal and finger/hand epithelia (40.3 ± 4.8 and 18.5 ± 5.4 µg/mL, P < 0.001). Glycogen concentrations were lower and more variable in vaginal swabs from older perimenopausal/menopausal women (mean ± SE, 235 ± 123, P < 0.01). Semen and sample storage longer than 1 year did not affect glycogen detection. Using a cutoff of 100 µg/mL of glycogen, 30 of 30 vaginal swabs from reproductive-aged women versus 0 of 28 control swabs were positive, for an assay sensitivity of 1 (95% confidence interval, 0.86-1) and specificity of 1 (95% confidence interval, 0.85-1). Periodic acid-Schiff stain correlated with soluble glycogen results but was less specific. CONCLUSIONS: The quantitative glycogen assay provides a simple and inexpensive method to validate the use of self-administered swabs for sampling vaginal contents in clinical studies.

Expression of toll-like receptors in genital tract tissues from normal and HIV-infected men.

PROBLEM: cells of the innate immune system use Toll-like receptors (TLRs) to recognize and respond to invading pathogens. This study was carried out to characterize TLR expression in the human male genital tract, an initial infection site for several sexually transmitted pathogens. METHOD OF STUDY: immunohistochemistry was used to detect expression of TLRs 1-9 in genital tract tissues from HIV(-) and HIV(+) men. RESULTS: in HIV(-) men, TLR1(+) leukocytes were detected throughout the genital tract. Leukocytes in the penile urethra also expressed TLRs2, 3, 5, 7 and 9. Epithelial cells in most tissues did not express TLRs; exceptions were the prostate, where TLRs3 and 8 were observed on the apical surface of luminal epithelial cells, and the penile urethra, where epithelial cells expressed TLR9. In genital tissues from HIV(+) men with AIDS, few TLR(+) cells were detected. CONCLUSION: cells in the male genital tract can express a variety of TLRs. The penile urethra contained the highest number of TLR(+) cells, indicating that this tissue plays a major role in the innate immune defense of the male genital tract. Overall, TLR expression was reduced in genital tissues from HIV(+) men.

Mucin gene expression in human male urogenital tract epithelia.

BACKGROUND: Mucins are large, hydrophilic glycoproteins that protect wet-surfaced epithelia from pathogen invasion as well as provide lubrication. At least 17 mucin genes have been cloned to date. This study sought to determine the mucin gene expression profile of the human male urogenital tract epithelia, to determine if mucins are present in seminal fluid and to assess the effect of androgens on mucin expression. METHODS AND RESULTS: Testis, epididymis, vas deferens, seminal vesicle, prostate, bladder, urethra and foreskin were assessed for mucin expression by RT-PCR (for 14 mucin genes) and immunohistochemistry (nine antibodies for five mucins). Epithelia of the vas deferens, prostate and urethra expressed the greatest number of mucins, each with mRNA for between 5 and 8 mucins. Except for MUC20 in epididymis, mRNA for MUC1 and MUC20, both membrane-associated mucins, was detected in all tissues analysed. By comparison, MUC6 was more restricted in expression, being primarily detected in seminal vesicle. MUC1, MUC5B and MUC6 were detected in seminal fluid samples by immunoblot analysis. Androgens had no effect on mucin expression in cultured human prostatic epithelial cells. CONCLUSIONS: Each region of urogenital tract epithelium expressed a unique mucin gene repertoire. Secretory mucins are present in seminal fluid, and androgens do not appear to regulate mucin gene expression in prostatic epithelial cells in culture.