title: A porcine intrauterine 4-mda component with transforming growth factor-beta activity suppresses natural killer cell responses.
abstract: A 4-MDa component, recovered from uterine luminal secretions of gilts on d 15 of pregnancy, was assessed for suppression of the lytic responses from natural killer (NK) and lymphokine-activated killer (LAK) effector cells. Each cell type originated from preparations of peripheral blood lymphocytes (PBL), and the LAK cells were generated from the incubation of PBL with interleukin-2. The PBL and LAK cells were cultured for 5 d with and without the 4-MDa component. Following culture, the cells were incubated (22 h) with NK-sensitive K-562 target cells at varying effector:target cell ratios (25:1 to 200:1). Lytic activity was assessed with the chromium-51 release assay. Additional experiments were conducted in order to determine whether suppressor activity of the 4-MDa component was time-dependent and associated with transforming growth factor-beta2 (TGF-beta2). For effector:target cell ratios combined, the 4-MDa component suppressed the lytic activity of PBL but failed to affect the LAK cells. Suppression of NK-mediated lysis occurred by d 3 of the 5-d culture period. In addition, suppressor activity of the 4-MDa component was reversed by a neutralization antibody to TGF-beta2. In conclusion, the 4-MDa component with TGF-beta2 activity suppressed the lytic responses of porcine NK cells.
authors.affiliation: Department of Animal Science, North Carolina A&T State University, Greensboro 27411, USA. segerson@ncat.edu
authors.forename: E C
authors.initials: EC
authors.lastname: Segerson
authors.forename: P K
authors.initials: PK
authors.lastname: Beetham
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000302:isolation & purification / Q000494:pharmacology; D002478:Cells, Cultured; D002850:Chromatography, Gel / Q000662:veterinary; D005260:Female; D015979:Killer Cells, Lymphokine-Activated / Q000187:drug effects; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D008970:Molecular Weight; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000276:immunology*; D013552:Swine / Q000276:immunology*; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014599:Uterus / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D016212:Transforming Growth Factor beta