Immune-mediated migration of neutrophils into the uterine lumen of guinea pigs

Novel immunocontraceptive targets in mammals: uterine secretions and the conceptus; a marsupial approach

We report the first immunocontraceptive trial in mammals using a uterine-secreted protein, the marsupial shell coat protein 4 (CP4). The marsupial shell coat, which surrounds the conceptus for 60–80% of gestation, is secreted by the uterine epithelium. Following immunization against glutathione S-transferase (GST)-CP4, the fertility of female common brushtail possums (n=6) was significantly reduced (P=0.000), and this reduction in fertility was positively correlated with the maximum GST-CP4 humoral immune response (P=0.025). Ultrastructural examination of the reproductive tract indicated that the cell-mediated immune response against GST-CP4 targeted the shell coat, the shell-free conceptus and the uterine glandular epithelium, thus preventing normal conceptus development and uterine secretion of shell coat proteins and nutrients. These results show that uterine-secreted proteins are promising immunocontraceptive targets, especially in pest mammal species, e.g. possum, rabbit and horse, that have uterine-secreted additions to embryonic coats, or that have late implantation requiring uterine nutrient provisioning from secretions.

Specific antibody to Haemophilus somnus in the bovine uterus following intramuscular immunization

Sources of anti-Haemophilus somnus antibody in bovine uterine secretions following intramuscular immunization and subsequent intrauterine inoculation of killed H. somnus were investigated. Holstein cattle (n = 21) were immunized with a 270-kDa outer membrane protein from H. somnus (omp-270) by intramuscular injection. At estrus, the cattle were given an intrauterine inoculum of a heat-killed suspension of a homologous strain of H. somnus containing omp-270 (n = 7), a heterologous strain of H. somnus lacking omp-270 (n = 7), or phosphate-buffered saline (n = 7). Uterine secretions were sampled by saline lavage immediately prior to inoculation and at 6, 24, 48, 72, 96, and 120 h after inoculation. Immunoglobulin G subclass I (IgG1) and IgG2 antibody specific for omp-270 were detectable in estrous uterine secretions of all systemically immunized cattle from which an adequate sample was obtained. IgM antibody specific for omp-270 was detected in serum following immunization but was not consistently detected in the uterine secretions of any animal. IgA antibody specific for omp-270 was not detectable in either serum or uterine secretions following immunization or intrauterine inoculation. Ratios of antibody to immunoglobulin and ratios of immunoglobulin to albumin in serum and uterine secretions indicated that about half the IgG1 and essentially all the IgG2 in secretions originated in the serum. Relative titers of IgG1 and IgG2 omp-270-specific antibodies in the uterine lumen and serum gave no evidence for selective transport of either subclass from serum into local secretions. Neither heterologous nor homologous intrauterine inocula detectably altered the serum contribution to antibody in uterine secretions within the sampling period. On the basis of these results, development of a systemic IgG2 antibody response may provide the basis for local immunological protection in the bovine reproductive tract.

The phagocytic activity of polymorphonuclear leucocytes isolated from normal uterus and that with experimentally induced inflammation in cows

The purpose of the study was the determination of the activity of the neutrophils isolated from a physiologically sound (non-inflamed) uterus 2 days after ovulation, and comparison of this activity with that of the polymorphonuclear leucocytes (PMNs) obtained from an uterus which had undergone experimentally induced specific or non-specific inflammatory reaction. The study was carried out on 20 cows between the 2nd and the 8th day after ovulation. Activity of PMNs was determined on the basis of the per cent of these cells with Fc receptors for IgG on their surface, and on the basis of assessment of the phagocytic activity. The Fc receptors were determined by the rosette test. The phagocytic activity of PMNs was determined in relation to two standard strains of S. aureus Smith which were phagocytized by mediation of Fc receptors and S. aureus 305 phagocytized by mediation of the "non-immunological" receptors. The study showed that the inflammatory process in the uterus caused intensive migration of large numbers of PMNs into the lumen. These PMNs have their properties altered: there is a significantly lower per cent of cells with Fc receptors in this cell population and lower Fc-dependent phagocytic activity. A significant rise in the phagocytic activity mediated by non-immunological receptors occurs at the same time in this cell population.

Immunological induction of endometritis-model investigations in cows

The course of the inflammatory reaction in the uterus after local or systemic administration of specific or non-specific antigens was studied. The study was carried out on 40 cows, 10-11 weeks after labour and between 6 and 8 days after ovulation. A specific cell-mediated type of reaction was induced by intrauterine challenge with PPD in cows previously vaccinated with M. bovis subcutaneously or by intrauterine administration. A specific inflammatory process of the type of Arthus reaction was induced by intrauterine challenge with C. fetus ssp. veneralis in animals immunized with these bacteria subcutaneously or by intrauterine instillation of these bacteria. A non-specific inflammatory process in the uterus was initiated by one instillation of lipopolysaccharide (LPS) into the left uterine horn. The cells were washed out from the uterus before and 6, 24, 48 and 72 hours after initiation of the specific or non-specific inflammatory process. The per cent proportions of various cell types were determined. It was demonstrated that intrauterine instillation of specific or non-specific antigens in cows caused a significant rise in PMNs per cent in relation to the control group.

Ia antigen expression in the rat uterus

Using indirect immunofluorescence and monoclonal antibodies, we have determined the distribution of Ia+ cells in the non-pregnant rat uterus. In cycling animals, Ia+ cells, most of dendritic shape and non-specific esterase negative, were abundant in the connective tissue of the myometrium and throughout the endometrium, especially adjacent to the luminal and glandular epithelia. In contrast, the number of T lymphocytes was very much less and few of these cells expressed Ia antigen. Stromal Ia+ cells were more numerous during estrus than in any other phase of the cycle. Only a few Ia+ cells were seen in neonatal uterine samples, but the numbers increased to approximately adult levels by 32 days of age. Prepubertal glands were consistently negative, but epithelial expression of Ia antigens in adult uteri showed interesting variations. The luminal epithelium was always negative, whereas the glandular epithelial cells often were positive. Glandular staining was quite heterogeneous in individual samples, but most gland profiles were negative or weakly positive during proestrus and estrus and positive during diestrus. Ovariectomized females given different steroid supplements revealed significant hormonal effects. Estrogen alone dramatically increased the numbers of Ia+ stromal cells compared with control samples, but progesterone alone had no effect. However, progesterone given with estrogen abrogated the estrogenic influence. Progesterone alone caused decreased expression of Ia antigens by the glandular epithelium. If the highly-Ia/ cells in the stroma are capable of antigen presentation, these results indicate a significant potential for local antigen processing with the uterine endometrium.

Systemic immunity developing from intrauterine antigen exposure in the nonpregnant rat

This report provides a simplified model for investigating the antigen handling mechanisms of the mammalian uterus. The effectiveness of the uterus as a site for systemic immunization has been studied using a hapten-protein conjugate (DNP-BGG) as antigen in nonpregnant virgin rats. The data indicate that although the uterus is inefficient as an antigen delivery site, strong systemic immune responses can be generated under appropriate conditions. Intrauterine (i.u.) immunization with alum-precipitated DNP-BGG did not induce significant antibody activity but primed the females so that vigorous anamnestic responses were produced after a second exposure to (soluble) antigen. The following results were obtained: (1) The optimal immunization dose was 100-2000 micrograms. (2) Alum-precipitation of the immunizing antigen was necessary in order to sensitize the female, while inclusion of killed Bordetella pertussis organisms was not. (3) The site of challenge after i.u. immunization affected the level of serum antibody activity. (4) Retention of antigen within the uterus for as little as 1 day sensitized the females as effectively as 28 days' exposure. (5) The presence or absence of ovarian hormones had no apparent effect in this system.