Tissue concentrations of eosinophils in the bovine oviduct and uterus at different stages of the oestrous cycle

Tissue distribution of some immune cells in bovine reproductive tract during follicular and luteal phase

More recent studies indicate that immune cells which secrete their secretory products or cytokines play an important role in reproductive system. In our study, immune cell populations (CD8⁺ T lymphocytes, CD68⁺ macrophages, plasma cells, siderophages, eosinophils) and expression of major histocompatibility complex (MHC) class I and class II were examined in female reproductive tract during follicular (n = 13) and luteal phase (n = 10). Plasma cells and eosinophil granulocytes are present in few numbers in luminal epithelium, but abundant in longitudinal muscle layer of uterus, whereas siderophages are the dominant cell type in stroma. Moreover, MHC-I and -II⁺ cells are expressed by individual cells in organ layers, while CD8⁺ T cells and CD68⁺ macrophages are dominant in epithelium and muscle layer, respectively. In conclusion, we did not found significant changes in immune cells according to follicular and luteal phases, but localization and numbers in each organ have changed according to both organ and layers. These results indicate that these factors may play a crucial role not only to generate an immune response but also to have a role in regulation of physiological functions in female reproductive organs.

Uterine Mast Cells and Immunoglobulin-E Antibody Responses During Clearance of Tritrichomonas foetus

We showed earlier that Tritrichomonas foetus-specific bovine immunoglobulin (Ig)G1 and IgA antibodies in uterine and vaginal secretions are correlated with clearance of this sexually transmitted infection. Eosinophils have been noted in previous studies of bovine trichomoniasis but the role of mast cells and IgE responses have not been reported. The hypothesis that IgE and mast cell degranulation play a role in clearance was tested in 25 virgin heifers inseminated experimentally and infected intravaginally with T. foetus strain D1 at estrus and cultured weekly. Groups were euthanatized at 3, 6, 9, or 12 weeks, when tissues were fixed and secretions were collected for culture and antibody analysis. Immunohistochemistry using a monoclonal antibody to a soluble lipophosphoglycan (LPG)-containing surface antigen (TF1.17) demonstrated antigen uptake by uterine epithelial cells. Lymphoid nodules were detected below antigen-positive epithelium. Little IgG2 antibody was detected but IgG1, IgA, IgM, and IgE T. foetus-specific antibodies increased in uterine secretions at weeks 6 and 9 after infection. This was inversely proportional to subepithelial mast cells numbers and most animals cleared the infection by the sampling time after the lowest mast cell count. Furthermore, soluble antigen was found in uterine epithelium above inductive sites (lymphoid nodules). Cross-linking of IgE on mast cells by antigen and perhaps LPG triggering appears to have resulted in degranulation. Released cytokines may account for production of predominantly Th2 (IgG1 and IgE) and IgA antibody responses, which are related to clearance of the infection.

Pituitary-ovary-spleen axis in ovulation

Leukocytes are rapidly recruited to the preovulatory ovary and play a crucial role as facilitators of ovulation and luteal formation. In this article, recent findings on leukocyte trafficking to the ovary, as well as the physiological role of leukocytes in the ovary, will be summarized and discussed. We then explore the novel hypothesis that the hypothalamus-pituitary-ovary (HPO) axis might include the spleen as a reservoir of leukocytes by summarizing recent reports on this topic, both in the fields of immunology and reproductive biology.

Distribution of eosinophil granulocytes and mast cells in the reproductive tract of female goats in the preimplantation phase

Changes in eosinophil granulocytes and mast cells post-insemination may affect conceptus implantation, but information regarding the numbers of such cells in the mammalian reproductive tract is limited. This study investigated the preimplantation distribution of eosinophil granulocytes and mast cells (MCs) in the reproductive tract organs of female goats. Uterus, uterine cervix and uterine tubes samples were obtained at slaughter. Cornu uteri were washed in phosphate buffer solution (each animal contained at least one embryo). Tissues were fixed in 10% neutral buffered formol, Carnoy solution and Mota's fixative (basic lead acetate) for 48 h and embedded in paraffin. Six-micrometre-thick sections were stained with Congo red (for eosinophil granulocytes) and toluidine blue in 1% aqueous solution at pH 1.0 for 5 min (for MCs). In the uterus, MCs occurred in highest numbers in the myometrium. Higher MC numbers were observed in uterus, uterine and uterine tubes in the preimplantation (experimental) group (cycle synchronised through 7 days intravaginal sponge with 0.3 g P(4)) compared with the control group (P < 0.05). Eosinophil granulocyte numbers were significantly higher in the experimental group than in the control group (P < 0.05). These results indicate preimplantation-related changes in numbers of eosinophil granulocytes and MCs in goat reproductive tract organs.

Vaginal and Cervical Dilatation Intrapartum is Associated with Eosinophilic Infiltration in the Cow but not in the Sheep

During parturition maximal dilatation of the vagina and cervix is necessary for expulsion of the neonate. The aim of the present study was to characterize the cell infiltration of the vagina and cervix that is associated with this event in cows and sheep. For this purpose, vaginal and cervical tissue were removed from four pluriparous cows and four sheep immediately after delivery of the neonate by biopsy under visual control (group 1), and the eosinophilic granulocytes were stained selectively. Four cows that were in interoestrus were used for control (group 2). In a third group of cows (n=10), blood samples were taken to determine the concentration of eosinophilic granulocytes from the fifth day antepartum up to the sixth day postpartum (group 3). A high degree of infiltration with eosinophilic granulocytes was detected in the bovine vagina and cervix intrapartum but not during interoestrus and in the ovine tissue intrapartum (p <0.001). In the bovine tissue, the cell density was higher in the vagina than in the cervix (p <0.05). The intrapartal tissue infiltration was associated with a short-term blood eosinopenia. In conclusion, this investigation demonstrates eosinophilic infiltration in the bovine vagina and cervix intrapartum, which differs from the situation in sheep. We suggest that this difference can be explained by the fact that cows deliver at high oestrogen and low progesterone values, but sheep show relatively high intrapartal P4 levels, which might suppress tissue infiltration with eosinophilic granulocytes.

Corrigendum to "The sow endometrium at different stages of the oestrus cycle: studies on morphological changes and infiltration by cells of the immune system." [Anim. Reprod. Sci. 65 (2001) 95-114]

The aim of this study was to investigate the distribution of leukocytes and the morphological changes of the sow endometrium throughout the oestrous cycle. Fifteen crossbred multiparous sows (Swedish Landrace x Swedish Yorkshire), with an average parity number of 3.4+/-0.7 (mean+/-S.D.) were used. Blood samples were collected from the jugular vein 1 h before slaughter for analyses of oestradiol-17beta and progesterone levels. Uterine samples from the mesometrial side of both horns, taken immediately after slaughter at late dioestrus, prooestrus, oestrus, early dioestrus and dioestrus, were fixed, embedded in plastic resin and stained with toluidine blue. The surface and glandular epithelium as well as subepithelial and glandular connective tissue layers were examined by light microscopy (LM). The significantly highest surface and the glandular epithelium were observed at oestrus and dioestrus, respectively. The largest number of capillaries (underneath the surface epithelium) was found at oestrus. In the surface epithelium, the largest number of intraepithelial lymphocytes (IELs, round nucleus) was found at early dioestrus. The largest number of lymphocytes and macrophages within the glandular epithelium were found at early dioestrus and oestrus, respectively. In the subepithelial connective tissue layer, the most common type of leukocytes during all stages was the lymphocyte. The largest numbers of lymphocytes and neutrophils were found at oestrus while the largest number of eosinophils was found at dioestrus. The dominating cells of the immune system in the connective tissue of the glandular layer were lymphocytes and macrophages. The significantly largest numbers of lymphocytes and plasma cells were found at early dioestrus and dioestrus, respectively. The number of lymphocytes in the connective tissue of the glandular layer and the number of plasma cells in the subepithelial layer were positively correlated with the plasma level of progesterone (P < or = 0.05). The numbers of capillaries and neutrophils in the subepithelial layer underneath the surface epithelium as well as the number of macrophages in both surface and glandular epithelium were positively correlated with the plasma level of oestradiol-17beta (P < or = 0.05). In conclusion, the present study showed a variation om the infiltration and distrobution of lymphocytes, neutrophils, eosinophils, macrophages, mast cells, and plasma cells in the sow endometrium during different stages of the oestrous cycle. Also morphological parameters (e.g. height of surface and glandular epithelium, capillaries density and degree of oedema) varied throughout the oestrous cycle.

The sow endometrium at different stages of the oestrous cycle: studies on morphological changes and infiltration by cells of the immune system

The aim of this study was to investigate the distribution of leukocytes and the morphological changes of the sow endometrium throughout the oestrous cycle. Fifteen crossbred multiparous sows (Swedish Landrace x Swedish Yorkshire), with an average parity number of 3.4 +/- 0.7 (mean +/- S.D.) were used. Blood samples were collected from the jugular vein 1h before slaughter for analyses of oestradiol-17beta and progesterone levels. Uterine samples from the mesometrial side of both horns, taken immediately after slaughter at late dioestrus, prooestrus, oestrus, early dioestrus and dioestrus, were fixed, embedded in plastic resin and stained with toluidine blue. The surface and glandular epithelium as well as subepithelial and glandular connective tissue layers were examined by light microscopy. The significantly highest surface and the glandular epithelium were observed at oestrus and dioestrus, respectively. The largest number of capillaries (underneath the surface epithelium) was found at oestrus. In the surface epithelium, the largest number of intraepithelial lymphocytes (IELs, round nucleus) was found at early dioestrus. The largest number of lymphocytes and macrophages within the glandular epithelium were found at early dioestrus and oestrus, respectively. In the subepithelial connective tissue layer, the most common type of leukocytes during all stages was the lymphocyte. The largest numbers of lymphocytes and neutrophils were found at oestrus while the largest number of eosinophils was found at dioestrus. The dominating cells of the immune system in the connective tissue of the glandular layer were lymphocytes and macrophages. The significantly largest numbers of lymphocytes and plasma cells were found at early dioestrus and dioestrus, respectively. The number of lymphocytes in the connective tissue of the glandular layer and the number of plasma cells in the subepithelial layer were positively correlated with the plasma level of progesterone (P < or = 0.05). The numbers of capillaries and neutrophils in the subepithelial layer underneath the surface epithelium as well as the number of macrophages in both surface and glandular epithelium were positively correlated with the plasma level of oestradiol-17beta (P < or = 0.05). In conclusion, the present study showed a variation in the infiltration and distribution of lymphocytes, neutrophils, eosinophils, macrophages, mast cells and plasma cells in the sow endometrium during different stages of the oestrous cycle. Also morphological parameters (e.g. height of surface and glandular epithelium, capillaries density and degree of oedema) varied throughout the oestrous cycle.

Fibroblasts and eosinophils in normal fibroplasia of ferret vulval skin, shown by light and electron microscopy; with special reference to eosinophil degranulation

In order to compare aspects of normal fibroplasia with reports for pathologically fibrotic tissue, light and electron microscopic observations were made on ferret vulval skin, which proliferates markedly with the onset of estrus and regresses equally fast after mating. Estrous tissue, which contained hypertrophied fibroblasts, new collagen, elastic fibers and ground substance, was invaded by numerous eosinophils with extensive release of granules. Eosinophil degranulation was both extra- and intracellular; some cells, completely disintegrated, had released all contents into the extracellular matrix. Extruded granules reacted positively for major basic protein. In regression, diminished fibroblasts incorporated collagen fibrils. Many of the features seen in this normal fibroplasia in ferret vulval skin are similar to those in pathologic situations. Thus, in particular, the presence of degranulating eosinophils in pathologic fibrosis does not necessarily indicate that they are the cause of the disease. Our information and that from other sources implies a role for eosinophils in connective tissue change.