Publications

The prevalence of HIV is exceptionally high among Jamaican men who have sex with men (JMSM) compared to similar populations within the Caribbean. A noticeable gap in the literature is the impact of childhood sexual abuse (CSA) and sexual assault on the state of the epidemic among this population. This study focused on JMSM's experiences with CSA and sexual assault and how these domains relate to HIV prevention. We analyzed qualitative data from 20 semi-structured in-depth interviews and focus group discussions with 10 men. Common themes emerged that highlight the patterns and nature of the abuse, the characteristics of the perpetrators, and the ways in which participants engage agency and resiliency as a basis to reclaim personal power. These findings serve as a catalyst for understanding how experiences with CSA and sexual assault affect the lives of young JMSM; how those experiences may impact attitudes and behaviors regarding HIV testing, engagement in care; and have implications for shaping legal policy, clinical, and mental health services for JMSM survivors.

Epithelial surfaces form critical barriers to the outside world and are continuously renewed by adult stem cells. Whereas dynamics of epithelial stem cells during homeostasis are increasingly well understood, how stem cells are redirected from a tissue-maintenance program to initiate repair after injury remains unclear. Here we examined infection by Heligmosomoides polygyrus, a co-evolved pathosymbiont of mice, to assess the epithelial response to disruption of the mucosal barrier. H. polygyrus disrupts tissue integrity by penetrating the duodenal mucosa, where it develops while surrounded by a multicellular granulomatous infiltrate. Crypts overlying larvae-associated granulomas did not express intestinal stem cell markers, including Lgr5, in spite of continued epithelial proliferation. Granuloma-associated Lgr5 crypt epithelium activated an interferon-gamma (IFN-γ)-dependent transcriptional program, highlighted by Sca-1 expression, and IFN-γ-producing immune cells were found in granulomas. A similar epithelial response accompanied systemic activation of immune cells, intestinal irradiation, or ablation of Lgr5 intestinal stem cells. When cultured in vitro, granuloma-associated crypt cells formed spheroids similar to those formed by fetal epithelium, and a sub-population of H. polygyrus-induced cells activated a fetal-like transcriptional program, demonstrating that adult intestinal tissues can repurpose aspects of fetal development. Therefore, re-initiation of the developmental program represents a fundamental mechanism by which the intestinal crypt can remodel itself to sustain function after injury.

Chitin, one of the most abundant biopolymers on Earth, is bound and degraded by chitinases, specialized enzymes that are similarly widespread in nature. Chitin catabolism affects global carbon and nitrogen cycles through a host of diverse biological processes, but recent work has focused attention on systems of chitin recognition and degradation conserved in mammals, connecting an ancient pathway of polysaccharide processing to human diseases influenced by persistent immune triggering. Here we review current advances in our understanding of how chitin-chitinase interactions affect mucosal immune feedback mechanisms essential to maintaining homeostasis and organ health.