Evidence for Expression of Both Classical and Non-Classical Major Histocompatibility Complex Class I Genes in Bovine Trophoblast Cells

Authors

  • Christopher J. Davies,

    1. Department of Veterinary Microbiology and Pathology & Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA;
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  • Jennifer A. Eldridge,

    1. Department of Veterinary Microbiology and Pathology & Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA;
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  • Patricia J. Fisher,

    1. Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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  • Donald H. Schlafer

    1. Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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Christopher J. Davies, Department of Veterinary Microbiology and Pathology, Washington State University, PO Box 647040, Pullman, WA 99164-7040, USA.
E-mail: cdavies@vetmed.wsu.edu

Abstract

Problem

During the third trimester of pregnancy bovine trophoblast cells in the interplacentomal and arcade regions of the placenta express major histocompatibility complex class I (MHC-I) antigens. At parturition immunological recognition of MHC-I antigens appears to contribute to normal placental release. Therefore, we hypothesized that during late pregnancy bovine trophoblast cells express polymorphic, classical MHC-I antigens.

Method of study

Cloning, microarray screening and sequencing of cDNA were used to study transcription of MHC-I genes in peripheral blood mononuclear cells (PBMC) and interplacentomal, trophoblast cells. Real-time reverse transcription, polymerase chain reaction (RT-PCR) was used to compare the abundance of MHC-I transcripts in PBMC and trophoblast cells.

Results

Screening of cloned MHC-I cDNA on MHC-I microarrays indicated that in PBMC 90–98% of MHC-I transcripts were encoded by classical MHC-I genes with the remainder encoded by non-classical MHC-I genes. In contrast, 21–66% of MHC-I transcripts from interplacentomal trophoblast cells were from classical genes and 34–79% were from non-classical genes. Transcripts from four non-classical MHC-I loci were identified by sequence analysis. Real-time RT-PCR indicated that the overall levels of MHC-I gene expression in PBMC and trophoblast were similar.

Conclusion

Bovine interplacentomal trophoblast cells express both classical and non-classical MHC-I genes, but the relative level of expression varies considerably.

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