Defining trained immunity in female genital tract neutrophils. - PROJECT SUMMARY/ABSTRACT Human immunodeficiency virus (HIV) is contracted through sexual acquisition in women of all ages. Yet, the low rate of HIV transmission per sexual act (0.08%), indicates that local mechanisms, such as epithelial barriers, mucus, secreted immune mediators and innate immune cells, contribute to the prevention of HIV infection in women. Adaptive responses have been described as “too little too late” and therefore indicates a need for pre- existing innate immune protection to prevent infection. These protective mechanisms, however, are poorly characterized in the female genital tract (FGT) and the potential contribution of innate immune memory, also known as trained immunity, to this process is completely unknown. Trained immunity is the functional modification of innate immune cells after initial stimulation that generates heightened innate immune responses to heterologous secondary stimulations. It can be induced by pathogen, antigen, or cytokine stimulation, and leads to long-lasting epigenetic modifications in hematopoietic stem cell progenitors. Specific transcriptional, epigenetic, and functional changes have been used to characterize trained immunity in animal models and in human blood cells, but the contribution of trained immunity to immune protection in human mucosal surfaces is completely unknown. Neutrophils mediate initial recognition and responses to HIV in the FGT and can be targeted for the induction of trained immunity. Neutrophils are amongst the first cells to encounter HIV in the FGT and rapidly release neutrophil extracellular traps and cytokines in response to HIV exposure. This proposal will test the hypothesis that genital neutrophils protect against HIV acquisition through trained innate immune responses. This hypothesis will be tested utilizing single cell assay for transposase accessible chromatin with whole transcriptome analysis, spectral flow cytometry, Luminex analysis, and HIV infection assays. This study will define for the first time the existence of trained immune cells in the FGT, and how trained neutrophils may contribute to protection against HIV acquisition. The results of this study will significantly impact women’s health by identifying mechanisms and cells that can be targeted for novel prevention strategies against HIV acquisition in women. This research will be conducted in the Wayne State University School of Medicine C.S. Mott Center for Human Growth and Development, a specialized center housing world-renowned reproductive immunologists and reproductive biologists. The candidate will receive enhanced training in molecular biology techniques, bioinformatics, responsible conduct of research, grantsmanship, scientific dissemination, networking, and mentoring through formal and informal programs to prepare for an independent research career.
