Model of immunomodulation study in bovines: expression of MHC class 1b in trophoblastic and mesenchymal cells in cloned conceptuses and natural placenta

• Grant number: 09/06702-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2009
• End date: July 31, 2011
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Flávio Vieira Meirelles
• Grantee: Rodrigo da Silva Nunes Barreto
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

During bovine placentation a strict trophoblastic invasion occurs trigged by trophoblastic giant cells (TGC) which fusion with uterine epithelial cells, ending in hybrids cells. This cells are them degradated or absorbed by the trophoblast or delivery substances and free-fetal DNA (fDNA) in maternal blood flow, likewise in human cytotophoblast. fDNA identification in maternal serum effectively proved the migration, that occurs with minor NK cells intervention, indicating a immunemodulation in this cells, probably due to MHC class Ib molecule, a possible functional homologous of murine PED and human HLA-G gene, known to be involved in embryo development and protection of maternal NK cells action. This immunemodulation in TGCs may be extrapolate for mesenchymal cells that it inhibit lymphocytic function by suppression of CD4+ and CD8+ T cells and are important in cellular therapy studies. Therefore the aim of this study is characterize PED/HLAG homologue, in bovines trophoblastic and amniotic mesenchymal cells. For it will be used bovine cloned conceptuses that express green fluorescent protein (GFP) and control gestations (obtained in slaughterhouse) with 60 and 90 days of gestation. Placentomes, amnion and maternal serum will be collected. Part of samples (placentomes) will be fixed and include in paraffin for immunohistochemistry for GFP and PED/HLAG homologue study, part will be frozen in liquid nitrogen (placentomes, amnion and maternal serum) for mRNA extraction and verification of PED/HLAG homologue expression; amnion will be used for mesenchymal cells culture for immunocytochemistry and the maternal serum for fDNA identification by PCR. Results will be compared between bovines cloned conceptus and natural matting gestation for characterization of immunemodulation in TGCs and amniotic mesenchymal cells. Homologue PED/HLAG identification in bovines TGCs and amniotic mesenchymal cells are of great importance for bovine placentation and mesenchymal cell therapy studies.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

BARRETO, Rodrigo da Silva Nunes. Occurrence and mechanisms of fetal microchimerism in bovines pregnancies. 2011. Master's Dissertation - Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) São Paulo.