Daudi Langat, Ph.D.

Research Assistant Professor

B.Sc (Moi University, Eldoret, Kenya)

M.Sc, Ph.D. (University of Nairobi, Kenya)

Post-Doctoral Training: Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS.

email: dlangat@kumc.edu

Research Description
My research is focused on analyzing expression and regulation of major histocompatibility complex antigens in the placenta, using the baboon as a model. Previous work in our laboratory (and others) showed that the human placenta tightly regulates expression of transplantation antigens by down-regulating the expression of polymorphic class Ia and class II HLA genes while up-regulating expression of the relatively monomorphic class Ib genes, HLA-E and HLA-G. It has been proposed that HLA-G may play an important role in human pregnancy, and failure of expression may be involved in pathological conditions in pregnancy such as pre-eclampsia. My research focus is to identify an animal model that maybe used for in vivo functional studies of HLA-G. So far, we have identified a potential functional homologue of HLA-G (termed Paan-AG) in the olive baboon. This molecule has properties similar to those of HLA-G, and the messages and protein are expressed in the placenta and decidua but not in other tissues. We are currently analyzing this gene further to confirm whether it has any functional role at the maternal-fetal interface in the baboon. This will enable us determine whether the olive baboon can serve as a model for in vivo HLA-G functional studies.

Representative Publications

Book Chapter

• Langat DK, Fazleabas AT, Hunt JS. Methods for evaluating histocompatability antigen gene expression in the baboon. In: Soares M, Hunt, JS (Eds). Placental and Trophoblast Methods and Protocols: Methods in Molecular Medicine 2006; 122:165-180.

Review Papers

• Hunt JS, Morales PJ, Pace JL, Fazleabas AT, Langat DK. A commentary on gestational programming and functions of HLA-G in pregnancy. Placenta. 2007, 28 Suppl A:S57-63.
• Hunt JS, Langat DK, McIntire R, Morales PJ. The immunology of human pregnancy: an overview. Reproductive Biology Online, 2006;4 Suppl 1:S10
• Langat, DK, Hunt JS. Do non-human primates provide appropriate animal models for studies on the function of HLA-G? Biology of Reproduction 2002; 67(5):1367-1374.

Research Papers

• Langat DK, Wheaton DA, Platt JS, Sifers T, Hunt JS. Signaling Pathways for BAFF (B Cell Activating Factor) and APRIL (a Proliferation-Inducing Ligand) in Human Placentas. American Journal of Pathology,2008, In Press.
• Morales PJ, Pace JL, Platt JS, Langat DK, Hunt JS. Synthesis of beta(2)-microglobulin-free, disulphide-linked HLA-G5 homodimers in human placental villous cytotrophoblast cells. Immunology 2007, 122(2):179-88.
• Langat DK, Platt SJ, Tawfik O, Fazleabas AT, Hunt JS. Differential expression of human leukocyte antigen-G (HLA-G) messenger RNAs and proteins in normal human prostate and prostatic adenocarcinoma. Journal of Reproductive Immunology 2006; 71(1):75-86.
• Mwenda JM, Owuor RA, Kyama CM, Wango EO, M'arimi M, Langat DK. Khat (Catha edulis) up-regulates testosterone and decreases prolactin and cortisol levels in the baboon. Journal of Ethnopharmacology 2006; 103:379-384.
• Langat DK, Morales PJ, Fazleabas AT, Hunt JS. Potential regulatory sequences in the untranslated regions of the baboon MHC class Ib gene, Paan-AG, more closely resemble those in the human MHC class Ia genes than those in the class Ib gene, HLA-G. Immunogenetics. 2004, 56(9):657-66.
• Langat DK, Morales PJ, Fazleabas AT, Mwenda JM, Hunt JS. The olive baboon (Papio anubis): a potential animal model to study the function of human leukocyte antigen-G (HLA-G). Gynecol Obstet Invest. 2004;57(1):33-6.
• Langat DK, Morales PJ, Fazleabas AT, Mwenda JM, Hunt JS. Baboon placentas express soluble and membrane-bound Paan-AG proteins encoded by alternatively spliced transcripts of the class Ib major histocompatibility complex gene, Paan-AG. Immunogenetics. 2002, 54(3):164-73.