Immunomodulator expression in trophoblasts from the feline immunodeficiency virus (FIV)-infected cat as a contributor to placental immunopathology and reproductive failure at early- and late-term pregnancy
Mississippi State University
Coats, S. Karen
Downer, N. Donald
Wise, A. Dwayne
Nelson, D. Phillip
Other Advisors or Committee Members
Burgess, C. Shane
Date of Degree
Dissertation - Open Access
College of Arts and Sciences
Department of Biological Sciences
Mother-to-child transmission (MTCT) of HIV accounts for more than 90% of pediatric infections worldwide, yet the mechanism of vertical transfer remains unknown. The feline immunodeficiency virus (FIV)-infected cat is a cost-effective, small-animal model of HIV pathogenesis and MTCT, which produces a high rate of reproductive failure and fetal infection in litters delivered at early- and late-term gestation. Our previous data suggest that FIV infection may dysregulate placental cytokines and compromise pregnancy. We hypothesized that FIV-infection may cause dysregulation of placental cytokine expression, and aberrant expression of these cytokines may potentiate inflammation and transplacental infections. The purpose of this project was to evaluate feline placental immunopathology at the whole and cellular levels during early- and late-term gestation to understand how lentiviruses may perturb placental immune parameters. To determine whether placentas were vulnerable to FIV infection, we quantified the expression of the FIV receptors, CD134 and CXCR4, in RNA extracted from late-term placental tissue. We found higher expression of CD134 and CXCR4 in placentas from successful pregnancies. To evaluate relative cytokine expression in randomly-sampled, whole placental specimens, we quantified representative pro- and anti-inflammatory cytokines and a chemokine. IL-6 and IL-12p35 were increased in early-gestation, FIV-infected queens; IL-6 was increased in late-gestation, FIV-infected queens. To evaluate placental immunopathology at the cellular level, we developed a novel immunohistochemistry method to identify trophoblastic cells selectively. Trophoblasts were collected using laser capture microdissection, and RNA was extracted from captured cells. We detected expression of several anti- and pro-inflammatory cytokines and the chemokine receptor CXCR4 (the FIV co-receptor) in trophoblasts at both stages of gestation. However, we failed to detect expression of other cytokines and CD134, the FIV primary receptor. FIV infection slightly lowered expression of all cytokines at both early and late pregnancy, although only the decrease in IL-5, from early pregnancy, and IL-4 and IL-12p35, from late pregnancy, reached significant levels. Fetal non-viability was associated with decreased trophoblast expression of IL-4, IL-6, IL-12p35, and CXCR4 at early gestation and decreased expression of IL-4, IL-12p35, IL-12p40 at late gestation. Collectively, these data indicate that FIV infection negatively impacts pregnancy outcome and alters placental immunomodulation.
Scott, Veronica Lynn, "Immunomodulator expression in trophoblasts from the feline immunodeficiency virus (FIV)-infected cat as a contributor to placental immunopathology and reproductive failure at early- and late-term pregnancy" (2010). Theses and Dissertations. 2578.