Immune cell populations in the equine corpus luteum throughout the oestrous cycle and early pregnancy: an immunohistochemical and flow cytometric study.
Abstract: Recent evidence indicates that the cells of the immune system and their large network of secretory products, or cytokines, play an active role in the ovary throughout the oestrous cycle. In the present study, immune cell populations (T and B lymphocytes, macrophages, granulocytes and eosinophils) and expression of major histocompatibility complex (MHC) class II were investigated in corpora lutea from mares in early (days 2-4), mid- (days 7-10) and late (days 12-14) dioestrus, the post-luteolytic phase (days 16-17) and early pregnancy. The number of T lymphocytes within the corpus luteum increased in the late luteal phase. CD4+ cells did not increase until day 16, whereas the number of CD8+ cells increased before functional luteolysis; an apparently selective luteal infiltration of CD8+ cells was observed. MHC class II expression by non-steroidogenic cells was increased in samples from days 16-17, as was the number of infiltrating macrophages. Flow cytometry revealed very low expression of MHC class II by large luteal cells at all stages of the oestrous cycle. In early pregnancy, the number of CD4+ and CD8+ cells and macrophages decreased, as did MHC class II expression, compared with mid-dioestrous samples. B cells were present in very small numbers in all samples examined. Eosinophils were similarly sparsely distributed and numbers decreased further in pregnancy. After exogenous PGF2 alpha administration, populations of CD4+ cells and non-specific esterase staining cells were significantly smaller than after natural luteolysis, whereas eosinophil numbers were increased compared with samples from days 16-17. However, the number of CD8+ and CD5+ cells and MHC class II expression were not significantly different from those observed after natural luteolysis. These findings indicate that populations of immune cells in the equine corpus luteum vary during its lifespan. The selective increase in CD8+ cells before functional luteolysis indicates that they have a physiological role in the regression of the corpus luteum.
Publication Date: 2000-02-26 PubMed ID: 10690195DOI: 10.1530/jrf.0.1170281Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research article is about studying the presence and variance in immune cell populations in the corpus luteum of horses through their oestrous cycle and early pregnancy. It explores the correlation between different immune cells and the process of luteolysis – the regression of the corpus luteum.
Objective and Methodology
- The study aimed to understand the role of immune cell populations, such as T and B lymphocytes, macrophages, granulocytes, and eosinophils, in the ovarian cycles and early pregnancy of mares.
- Through immunohistochemistry and flow cytometry, the researchers examined the expression of the major histocompatibility complex (MHC) class II and the numerous immune cell populations in corpora lutea in varying phases.
Findings
- The research found that during the late luteal phase (days 12-14), the number of T lymphocytes within the corpus luteum increased. Also, two types of T cells, CD4+ cells and CD8+ cells, behave differently during this phase. CD4+ cells increased only by day 16, whereas CD8+ cells increased before functional luteolysis.
- Macrophages were also found in higher numbers in samples from days 16-17, along with an increase in MHC class II expression from non-steroidogenic cells. Big luteal cells showed very low expression of MHC class II throughout the oestrous cycle from the flow cytometry analysis.
- The presence of B cells and eosinophils was comparatively low in all samples, with their numbers decreasing further during pregnancy. Eosinophil numbers increased compared to samples from days 16-17 after introducing exogenous PGF2 alpha.
- In early pregnancy, the count of CD4+ and CD8+ cells and macrophages had decreased, along with the MHC class II expression, compared to the mid-dioestrous samples.
Conclusions
- The study concludes that immune cell populations within the equine corpus luteum vary during different stages of the oestrous cycle and early pregnancy.
- It also suggests a possible physiological role for the CD8+ cells in the regression of the corpus luteum, as shown by their selective increase before functional luteolysis. The understanding of immune cell function in the ovarian cycle might be crucial for reproductive health and management in equines.
Cite This Article
APA
Lawler DF, Hopkins J, Watson ED.
(2000).
Immune cell populations in the equine corpus luteum throughout the oestrous cycle and early pregnancy: an immunohistochemical and flow cytometric study.
J Reprod Fertil, 117(2), 281-290.
https://doi.org/10.1530/jrf.0.1170281 Publication
Researcher Affiliations
- Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, Easter Bush Veterinary Centre, Midlothian, UK.
MeSH Terms
- Animals
- B-Lymphocytes / immunology
- CD4-Positive T-Lymphocytes / immunology
- CD8-Positive T-Lymphocytes / immunology
- Cell Count / drug effects
- Corpus Luteum / drug effects
- Corpus Luteum / immunology
- Dinoprost / pharmacology
- Eosinophils / immunology
- Estrus / immunology
- Female
- Flow Cytometry
- Histocompatibility Antigens Class II / metabolism
- Horses / immunology
- Immunohistochemistry
- Macrophages / immunology
- Pregnancy
- Pregnancy, Animal / immunology
- T-Lymphocyte Subsets / immunology
Citations
This article has been cited 7 times.- Abdulrahman N, Fair T. Contribution of the immune system to follicle differentiation, ovulation and early corpus luteum formation. Anim Reprod 2019 Oct 23;16(3):440-448.
- Galvão AM, Ferreira-Dias G, Skarzynski DJ. Cytokines and angiogenesis in the corpus luteum. Mediators Inflamm 2013;2013:420186.
- Luo W, Diaz FJ, Wiltbank MC. Induction of mRNA for chemokines and chemokine receptors by prostaglandin F2α is dependent upon stage of the porcine corpus luteum and intraluteal progesterone. Endocrinology 2011 Jul;152(7):2797-805.
- Cannon MJ, Davis JS, Pate JL. Expression of costimulatory molecules in the bovine corpus luteum. Reprod Biol Endocrinol 2007 Jan 31;5:5.
- Cannon MJ, Pate JL. The role of major histocompatibility complex molecules in luteal function. Reprod Biol Endocrinol 2003 Nov 10;1:93.
- Townson DH, Liptak AR. Chemokines in the corpus luteum: implications of leukocyte chemotaxis. Reprod Biol Endocrinol 2003 Nov 10;1:94.
- Chaves MA, Ferst JG, Fiorenza MF, Vit FF, da Silveira JC. The Influence of Ovarian-Derived Extracellular Vesicles in Reproduction. Adv Anat Embryol Cell Biol 2026;241:123-146.
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