Abstract: 85

H ANTIGEN EXPRESSION BY OVINE ENDOMETRIAL CELLS.

GR Newton^{1 2 *}, S Woldesenbet¹ , T Green¹ , H Powell¹ , K Sonnier¹ , GA Johnson^{2 *}
Cooperative Agricultural Research Center, Prairie View A&M University, Prairie View, TX ¹
Center for Animal Biotechnology and Genomics, Texas A&M University System Health Science Center, College Station, TX ²

Blood group H antigen is a marker for uterine receptivity in goats (Capra hircus) and may play a role in blastocyst - uterine epithelial (UE) cell adhesion. Our objectives were to determine if this carbohydrate antigen is also expressed by ovine endometrial epithelial cells. Uterine tissues were obtained from sheep on Day (D) 1, 11, 13, 15, 17 and 19 of pregnancy (n=4 ewes/group). Immunofluorescent microscopy of frozen tissue sections revealed intense staining on the apical surface of glandular (G) UE cells from D11 - 19 of pregnancy. Light punctate staining of luminal (L) UE cells was present from D15 - 19 of pregnancy. Areas of intense staining were observed on LUE cells only on D15 of pregnancy. Transformed sheep (ts) LUE cells were used to determine if estradiol (E; 10^-9M), progesterone (P; 10^-7M) or E+P, with or without interferon tau (IFNt; 10,000 antiviral U/ml), regulates H antigen expression in vitro. Intermittent punctate surface staining was observed on tsLUE cells independent of steroid treatment. Treatment with IFNt increased H antigen expression (P<.01) and resulted in large aggregates of punctate staining. Domain specific biotinylation and Western bloting of cell lysates from primary cultures of polarized (p) caprine (c) LUE and tsLUE cells were used to identify proteins carrying the H antigen. For both cell types, major immunoreactive apical membrane proteins were detected at 31, 33, 42, 55, 60 and 70 kDa. Therefore, the H antigen is expressed on ovine LE and GE during pregnancy recognition in utero, up-regulated by IFNt on tsLUE and carried by similar proteins on pcLUE and tsLUE cells. The H-antigen may be a valid marker for uterine receptivity in sheep. (Supported by NIH-MBRS 2S06GM08094 to GRN)

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