title: High molecular weight basic and acidic immunosuppressive protein components in uterine secretions of pregnant cows.
abstract: Immunosuppressive proteinaceous components were determined in bovine uterine milk (UTM) collected during late pregnancy. Crude UTM was separated by ion-exchange (carboxymethylcellulose-CMC) and gel filtration (Sephacryl S-200 and Sepharose CL-6B) chromatography. Basic (CMC+) and acidic (CMC-) protein molecular weight (Mr) components were tested for immunosuppressive activity in an in vitro mitogen (phytohemagglutinin-PHA)-treated lymphocyte blastogenesis assay. For most experiments, cultures containing 1 x 10(5) lymphocytes were incubated with 0.08 micrograms PHA and varying concentrations of test protein in RPMI-1640 with supplements. At 48 +/- 1 h, 0.1 microCi of [3H]thymidine was added to cultures and [3H]DNA was quantified at 60 +/- 1 h of culture. Results were expressed as percentage of control values. Crude UTM, CMC+, and CMC- components exhibited immunosuppressive activity. For immunosuppressive Sephacryl S-200 fractions, activity was greater (p less than 0.05-0.01) for CMC+, S-200 fraction I (greater than or equal to 250,000 Mr, void volume [Vo]) than for CMC-, S-200 fractions I (Vo) and III combined for protein concentrations of 20, 40, and 50 micrograms/ml. For the high Mr Sepharose CL-6B protein components, CMC+, CL-6B fraction I (greater than or equal to 4 x 10(6) Mr, Vo) exhibited greater (p less than 0.05-0.005) activity than CMC-, CL-6B fractions I (greater than or equal to 4 x 10(6) Mr, Vo) and II (2.8 x 10(6) Mr) combined at protein concentrations ranging from 20 to 80 micrograms/ml. In summary, bovine UTM contains basic and acidic immunosuppressive protein components, with the greatest activity being associated with a high Mr, basic component.
authors.affiliation: Department of Animal Science, North Carolina A&T State University, Greensboro 27411.
authors.forename: E C
authors.initials: EC
authors.lastname: Segerson
authors.forename: F W
authors.initials: FW
authors.lastname: Bazer
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D005260:Female; D006023:Glycoproteins; D007166:Immunosuppressive Agents / Q000032:analysis* / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D011506:Proteins / Q000032:analysis* / Q000276:immunology / Q000494:pharmacology; D015843:Serpins; D014599:Uterus / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D007166:Immunosuppressive Agents; D011506:Proteins; D015843:Serpins; C029708:uterine luminal fluid proteins