PhD, University of Cincinnati, 2020, Medicine: Immunology

A complication that can occur during pregnancy is placenta inflammation, referred to as chorioamnionitis (chorio). Exposure to this inflammatory condition has been associated with several post-natal morbidities. Chorio, particularly severe chorio leads to the increased production of various inflammatory mediators in the amniotic fluid. This inflamed amniotic fluid encounters the fetus, resulting in systemic and mucosal immune responses. However, a full understanding of the fetal responses to the inflammatory milieu created by chorio and the contribution of inflammatory cytokines like IL-1 and TNFa to these responses remains limited. The work presented here examined and characterized the fetal systemic and mucosal immune response to chorio exposure in humans and in a non-human primate (NHP) animal model. Our NHP model in which using intra-amniotic (IA) LPS in the Rhesus macaque, phenocopies severe chorio and allowed us to evaluate the impact of chorio exposure on the fetus. Systemically we found that IA LPS leads to a decreased frequency of CD4+FoxP3+ regulatory T cells (Tregs). However, while CD4+FoxP3+ Tregs are reduced in the context of chorio, they markedly upregulate production of IL-17, becoming the most significant source of this cytokine in inflammatory conditions. A similar, but milder phenotype was found in the cord blood as well. We later found that the Th17-like response was partially controlled by IL-1 or TNFa signaling, but the frequency of CD4+FoxP3+ did not recover after blockade IL-1 or TNF. The presence of a chorio induced Th17-like signature was also found in human cord blood of severe chorio exposed fetuses with sustained elevation of RORC and RORC/FOXP3 mRNA ratio. These findings point to a regulatory/inflammatory disbalance in the fetal systemic response to chorio exposure that particularly impacts regulatory T cells. In our NHP Rhesus macaque model, we also conducted an in-depth analysis of the chorio-induced fetal mucosal immune response in (open full item for complete abstract)

Committee: Claire Chougnet Ph.D. (Committee Chair); David Hildeman Ph.D. (Committee Member); Edith Janssen Ph.D. (Committee Member); Alan Jobe M.D. (Committee Member); Ian Lewkowich Ph.D. (Committee Member) Subjects: Immunology

MS, University of Cincinnati, 2020, Medicine: Immunology

Chorioamnionitis (chorio) occurs in 10% of all preterm births (<37weeks) and around 40% of very preterm births (<32 weeks). There is a massive increase in the concentration of inflammatory cytokine in the amniotic fluid during chorio. Although the fetal lung and all mucosal tissues are directly exposed to this inflammatory environment, the innate response induced in the fetus is not well understood. We use an experimental model of chorio with lipopolysaccharide (LPS) injection intra-amniotic (IA) given to pregnant rhesus macaque to stimulate an inflammatory response similar to human chorio. The amniotic fluid cytokines (IL-1, IL-6, TNF-a) were increased by more than one log. Previous data suggest that one of the immune e populations affected in the fetal lung was the mucosal-associated invariant T cell (MAIT). Using immunofluorescence we established a massive increase in MAIT cells in lung, expressing TCR Va7.2 and co-expressing CD161, IL-12R and IL-18R. MAIT cells increased 10x after 16hr and 48hr IA exposure compared to controls, and began to decrease 120hr post LPS. The absence of Ki67 but high expression of CCR5 suggested they migrated to the lung. Corresponding analysis of fetal peripheral blood polynuclear cells (PBMC) showed the frequency of blood CCR5+ MAIT cells decreased significantly following LPS exposure. MAIT cells are known for being activated through their TCR or through cytokine alone so we next looked at expression of these cytokines in the lung of IA LPS animals. We found significant increases in both IL-12p40 and IL-18 mRNA in lung MAIT cells. In accordance, IA LPS animals appeared activated because of their high rate of expression of their functional markers granzyme B and PD-1. We next looked at the role of IL-1 and TNFa signaling in the accrual of MAIT cells. IL-1ß injection caused increased amount of MAIT cells into fetal lung similar to LPS IA. Lastly, we tried to block the effects of LPS with treatments of subcutaneous and IA IL-1RA and ant (open full item for complete abstract)

Committee: Claire Chougnet Ph.D. (Committee Chair); Jonathan Katz Ph.D. (Committee Member); Ian Lewkowich Ph.D. (Committee Member) Subjects: Immunology

PhD, University of Cincinnati, 2017, Medicine: Neuroscience/Medical Science Scholars Interdisciplinary

Intrauterine inflammation (IUI) is a prevalent health concern that impacts approximately 10-15% of births annually. This clinical condition is termed chorioamnionitis, and it is characterized by inflammation of the uterus and uterus-associated tissue along with the developing offspring. Despite the prevalence of chorioamnionitis, testing for IUI is not routinely monitored nor are treatment measures well-researched. In humans, chorioamnionitis is associated with a number of psychiatric and developmental disorders, such as cerebral palsy, learning disabilities, schizophrenia and attention-deficit/hyperactivity disorder. Exposure to brain inflammation during early life development is thought to be linked to abnormal behavioral or developmental phenotypes later in life, but the consequences of IUI on brain development remain poorly understood. The objective of this dissertation research is to better characterize the behavioral and neurological effects of IUI exposure. Chapter one will outline the interactions between the brain and the immune system, as well as introduce our model of IUI. Along with the role of microglia and myelinating cells, the behavioral impact of brain inflammation will also be discussed. Chapter two will investigate the hypothesis that IUI exposure negatively alters developmental programming of the immune system and establishment of brain myelination. Specifically, findings discussed will include assessment in the immune response to a “second-hit” acute immune stimulation and changes in the expression of genes and proteins linked to myelin synthesis and inflammation in both neonatal and adult mice. Chapters three and four will explore the effects of IUI exposure on cognition and behavior, as well as changes in gene expression in adult mice. Findings discussed will include modifications in responses to tests designed to assess generalized anxiety, motivation, working memory, locomotion, impulsive-like behaviors and changes in gene expressio (open full item for complete abstract)

Committee: Matia| Solomon Ph.D. (Committee Chair); James Herman Ph.D. (Committee Member); Teresa Reyes Ph.D. (Committee Member); Renu Sah Ph.D. (Committee Member); Kim Seroogy Ph.D. (Committee Member) Subjects: Neurology