Suppressor activity of bone marrow cells and localization of fluorescent-labeled bone marrow cells within ovine endometrial tissue.
Numbers of fluorescein isothiocyanate (FITC)-labeled bone marrow (BM) cells of donor lambs were quantified within endometrial cell suspensions following their administration to ovariectomized (OVX; control-and estradiol-17beta-treated) and intact (estrus, d-14 cyclic and pregnant) ewes. The numbers of fluorescent BM cells were greater (P < .05) for the estrous and d-14 cyclic ewes than for both groups of OVX ewes. Fractionation of the endometrial cells with Percoll revealed that the majority of fluorescent cells were low-density (1.002 to 1.056 g/mL) cells. In coculture experiments, low-density cells from lamb BM not only suppressed the incorporation of thymidine into phytohemagglutinin-treated peripheral blood lymphocytes, but the cells also released suppressor factor into the culture medium. Suppressor activity tended to be reversed (P < .1) by a pan-specific neutralization antibody to transforming growth factor-beta (TGF-beta); however, the activity was unaffected by a neutralization antibody to TGF-beta2. These findings suggest that ovine endometrial suppressor cells may represent a population of low-density BM-derived natural suppressor cells, and their trafficking and localization patterns may depend on an ovarian factor(s). Further, suppressor activity does not seem to be mediated by TGF-beta2.
Segerson
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EC
Department of Animal Science, North Carolina A&T State University, Greensboro 27411, USA. segerson@ncat.edu
Beetham
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PK
D000818:Animals; D001854:Bone Marrow Cells / Q000276:immunology*; D002458:Cell Fractionation; D002469:Cell Separation / Q000662:veterinary; D002478:Cells, Cultured; D018920:Coculture Techniques / Q000662:veterinary; D003470:Culture Media; D004717:Endometrium / Q000166:cytology*; D005260:Female; D005456:Fluorescent Dyes; D008214:Lymphocytes / Q000187:drug effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D011247:Pregnancy; D012756:Sheep / Q000276:immunology*; D013491:Suppressor Factors, Immunologic; D016212:Transforming Growth Factor beta / Q000378:metabolism
D003470:Culture Media; D005456:Fluorescent Dyes; D010835:Phytohemagglutinins; D013491:Suppressor Factors, Immunologic; D016212:Transforming Growth Factor beta