Deborah J. Anderson

Monoclonal antibodies to human trophoblast and sperm antigens: Report of two WHO-sponsored workshops, June 30, 1986—Toronto, Canada☆

Two WHO-sponsored workshops were recently held to obtain a consensus view from researchers active in the field of reproductive immunology on the current status of the application of monoclonal antibodies to studies of molecular events underlying reproduction and to determine the feasibility of using this approach to identify trophoblast- or sperm-specific antigens that might represent suitable candidates for the development of antifertility vaccines. A total of 66 mouse monoclonal antibodies reacting with human sperm and 45 monoclonal antibodies reacting with human trophoblast membrane components were submitted by 29 laboratories. These were evaluated in coded form by 42 laboratories with the appropriate expertise in biochemistry, immunohistology and tests of reproductive cell function. The majority of both anti-sperm and anti-trophoblast monoclonal antibodies cross-reacted with cellular elements in non-reproductive tissues. However, at least five monoclonal antibodies (two anti-trophoblast and three anti-sperm) appeared to demonstrate sufficient specificity to warrant further investigation as reagents for the identification of antifertility vaccine candidates.

Effects of products of activated leukocytes (lymphokines and monokines) on the growth of malignant trophoblast cells in vitro

Supernatants from activated leukocyte cultures and individual lymphokines and monokines were added to cultures of JEG-3 human gestational choriocarcinoma cells in vitro, and effects on cell proliferation were measured. Activated leukocyte culture supernatants, recombinant gamma-interferon, tumor necrosis factor, and colony-stimulating factor significantly inhibited JEG-3 proliferation. In contrast, high doses of both interleukin 1 and 2 stimulated JEG-3 proliferation. Low doses of B cell growth factor stimulated JEG-3 proliferation, whereas the highest dose was inhibitory. Further understanding of the effects of lymphokines and monokines on trophoblastic growth may provide important insights into immunologic mechanisms affecting early pregnancy development and tumor-host interactions in gestational trophoblastic neoplasia.

The impact of the ovulatory cycle on cytokine production: evaluation of systemic, cervicovaginal, and salivary compartments.

To understand the impact of the menstrual cycle on immunologic parameters, we measured the level of cytokines and chemokines from plasma, cervicovaginal lavage (CVL), and saliva samples of 6 premenopausal women during the follicular and luteal phases of the ovulatory cycle. We demonstrate that the level of plasma interleukin-8 (IL-8) was 4-fold higher during the follicular phase than the luteal phase (p = 0.004), whereas plasma IL-1beta, IL-4, IL-6, IL-10, interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-1alpha (MIP-1alpha), and TNF receptor II (TNFR II) were not altered during the ovulatory cycle. In the vaginal compartment, as measured from CVL samples, the levels of IL-6 and IL-1beta were both 5-fold higher in the follicular than the luteal phase (p = 0.0002 and 0.03, respectively). Salivary cytokine and chemokine samples were similar when measured during the luteal and the follicular phases. Additional analysis of lymphocyte subsets for phenotypic and functional markers indicated that they were not influenced by the ovulatory cycle. Collectively, these data suggest that IL-6, IL-8, and IL-1beta are differentially regulated during the ovulatory cycle.

Selective suppression of monocyte chemoattractant protein-1 expression by human papillomavirus E6 and E7 oncoproteins in human cervical epithelial and epidermal cells.

Infection of cervical keratinocytes by high‐risk HPV is involved in the etiology of cervical carcinoma. Since viral products are immunogenic, development of cancer may require suppression of immune responses directed against infected epithelial cells. Many markers of host immune effector responses decrease as cervical intraepithelial neoplasia progresses. Among these is epithelial cell expression of the chemokine MCP‐1, though the mechanism for its suppression is unclear. Here, we show that the E6 and E7 viral oncogenes from high‐risk HPV, individually and together, suppress MCP‐1 expression in primary epithelial cells derived from the female genital tract. This is not a consequence of global suppression of chemokine expression since other chemokines, including IP‐10, IL‐8 and RANTES, were less affected. Furthermore, 4 of 6 HPV‐positive cervical carcinoma cell lines did not express MCP‐1. Our data indicate that suppression of MCP‐1 expression is part of the program of high‐risk HPV E6/E7‐induced transformation of primary epithelial cells. These observations are consistent with a model in which MCP‐1 expression by infected keratinocytes, which would stimulate an immune attack on HPV‐transformed cells, is suppressed for invasive cervical cancer to appear.

A new look at antifertility vaccines

This article reviews new advances in biochemistry, biotechnology, and immunology relevant to antifertility vaccine development and evaluates the current status and future prospects of contraceptive vaccines and other immunologic approaches to fertility regulation. Contraceptive vaccine candidates include human chorionic gonadotropin, human luteinizing hormone and luteinizing hormone releasing hormone, and reproductive steroid hormones. Sperm enzymes are attractive for a contraceptive vaccine; among the sperm antigens studied are antibodies to hyaluronidase, acrosin, and lactate dehydrogenase-C4. Several laboratories have developed monoclonal antibodies to a variety of sperm antigens and are using them to identify and characterize new sperm proteins and their roles in fertility. Considerable progress has been made toward biochemical characterization of unique glycoproteins constituting the zona pellucida. Zona pellucida antigens are good candidates because antizona antibodies may block both fertilization and implantation, and low amounts of antibody would be sufficient because of the small number of mature eggs with zona present at any time. Studies are underway to identify human embryonic antigens through examination of the protein profile of human teratocarcinoma cell lines at various stages of differentiation and through analysis of antibodies in human pregnancy and infertility sera. Placental and extraembryonic membranes produce several tissue-specific antigens that have been considered for antifertility vaccines, but concern that they could produce late or incomplete abortion has prevented their serioud consideration. Because of possibly serious systemic side effects, presence of the blood-testis barrier, and large number of sperm produced daily, it is unlikely that sperm vaccines can be safely administered to men. Nautural protective mechanisms will probably render some immunocontraceptive approaches ineffective. The possibility of serious pathogenic side effects of contraceptive vaccines demands vaccines demands a cautious approach to their development.

Comparative In Vitro Sensitivities of Human Immune Cell Lines, Vaginal and Cervical Epithelial Cell Lines, and Primary Cells to Candidate Microbicides Nonoxynol 9, C31G, and Sodium Dodecyl Sulfate

ABSTRACT In experiments to assess the in vitro impact of the candidate microbicides nonoxynol 9 (N-9), C31G, and sodium dodecyl sulfate (SDS) on human immune and epithelial cell viability, cell lines and primary cell populations of lymphocytic and monocytic origin were generally shown to be equally sensitive to exposures ranging from 10 min to 48 h. However, U-937 cells were more sensitive to N-9 and C31G after 48 h than were primary monocyte-derived macrophages. Cytokine activation of monocytes and lymphocytes had no effect on cell viability following exposure to these microbicidal compounds. Primary and passaged vaginal epithelial cultures and cell lines differed in sensitivity to N-9 and C31G but not SDS. These studies provide a foundation for in vitro experiments in which cell lines of human immune and epithelial origin can be used as suitable surrogates for primary cells to further investigate the effects of microbicides on cell metabolism, membrane composition, and integrity and the effects of cell type, proliferation, and differentiation on microbicide sensitivity.

Hormonal Levels among HIV-1-Seropositive Women Compared with High-Risk HIV-Seronegative Women during the Menstrual Cycle

There is a paucity of normative data on hormonal levels among HIV-infected women. Hormonal levels may influence fertility and HIV-related immunological and virological factors. The objective of this study was to determine progesterone and estradiol levels during the menstrual cycle in HIV-seropositive women compared with high-risk seronegative women. The study enrolled 55 HIV-infected and 10 high-risk uninfected women with self-reported regular menstrual cycles (25-30-day cycles). Progesterone and estradiol levels were determined on a weekly basis for 8 weeks. The analysis included evaluations from the first complete menstrual cycle for the 54 HIV-infected and 9 uninfected women who had at least one complete cycle. The median age was 35 years for HIV-infected women and 36 years for uninfected women. The median CD4+ count for HIV-seropositive women was 210 cells/mm3. The median menstrual cycle length was 28 days (range 22-49 days) for HIV-infected women and 25 days (range 24-44 days) for uninfected women. The maximum progesterone level during the luteal phase was normal (>3.0 ng/ml) for 52 (96%) of 54 HIV-seropositive women and 7 (78%) of 9 HIV-seronegative women (p = 0.09, Fishers exact test). The median maximum progesterone level was 12.2 ng/ml in HIV-seropositive women and 7.2 ng/ml in HIV-seronegative women (p = 0.07, Wilcoxon test). The median maximum estradiol value during the follicular phase was 148 pg/ml for HIV-seropositive women and 111 pg/ml for HIV-seronegative women (p = 0.04, Wilcoxon test). Among HIV-infected women, there were no significant differences in progesterone and estradiol levels by antiretroviral therapy, baseline plasma viral load, or median CD4+ cell count. We conclude that HIV-infected women with self-reported normal menstrual cycles have normal levels of progesterone and estradiol during the menstrual cycle.

Low erythrocyte complement receptor type 1 (CR1, CD35) expression in preeclamptic gestations

Erythrocyte complement receptor type 1 (E‐CR1) is the main immune complex clearance mechanism in humans. Decreased E‐CR1 expression is noted in certain inflammatory disorders. Recent evidence implicates inflammation in the pathogenesis of preeclampsia. We investigated whether E‐CR1 is decreased in preeclampsia.

Cell-Mediated Immune Mechanisms in Recurrent Spontaneous Abortion

Approximately 20% of all conceptions end in detectable spontaneous abortion. Recurrent abortion is a common and important clinical problem affecting approximately 1 in 300pregnancies (14). The risks for recurrent abortion have been calculated by Warburton and Frazier (54) to be 24% after one abortion, 26% after two abortions, and 32% after three consecutive pregnancy losses before 20 weeks gestation. Many instances of recurrent spontaneous abortion have identifiable etiologies such as chromosomal (5), mullerian (38), endocrinological (26,55), and infectious (12,29) abnormalities. However, recurrent abortion was unexplained in as many as 40% of couples studied (52). An immunologic etiology is suspected in women with subclinical autoimmune disease such as systemic lupus erythematosus, who have an increased incidence of otherwise unexplained recurrent abortion (11,13,15,39). The transplacental passage of maternal immunoglobulins that are cytotoxic to trophoblastic or fetal tissue is presumed to be a pathologic mechanism for abortion in such cases (32). Recurrent abortion is also associated with immunity to allogenic (husband’s) lymphocytes, sperm, and trophoblast antigens (3,25,33). Our current evidence indicates that the mechanisms of immunologic abortion in women may not only be antibody mediated (humoral response) but could also be cellularly mediated (cellular response) due to cytotoxic effects of lymphokines and monokines released by reproductive antigen (sperm and/or trophoblast) or other foreign (i.e., microbial) antigensensitized lymphocytes and macrophages in reproductive tissues.

Antigenic heterogeneity in human ovarian cancer

Primary and metastatic tumor tissues from 21 patients with ovarian epithelial cancer were studied with a panel of 8 monoclonal antibodies. Primary tumors reacted with 1 to 7 antibodies (mean, 3.5). Heterogeneity was observed even within histologic subtypes. Comparison of metastases (including ascites) with their respective primaries revealed differences in antigen profile in each of 10 cases studied. In one patient variable antigen expression was observed in five ascites samples collected over a 12-month period. These observations of antigenic heterogeneity and modulation with respect to site and time suggest that single monoclonal antibody immunotherapy would not be appropriate for all patients or even for a single patient over time.