The impact of biological sex and menopause on the bladder immunological landscape and transcriptome

Proposal Summary/Abstract As major drivers of sexual dimorphism, it is hypothesized that sex hormones modulate the immunological landscape of the lower urinary tract and contribute to functional changes observed across the lifespan. For example, females have a higher incidence of urinary tract infection (UTI) and UTI risk increases in elderly individuals of both sexes. There is also a disproportionate burden of recurrent UTI (rUTI) in women after the onset of menopause and the associated decline in estrogen. Bladder tertiary lymphoid tissues (bTLTs) are frequently found in the bladders of women with rUTI, are associated increased rUTI risk, and have been shown to be increase in size and prevalence with aging in female mice. Our exciting preliminary single cell RNA sequencing (scRNA-seq) suggest a link between bTLT-resident T-cells and T-cell exhaustion. Our preliminary data also suggest that bTLTs form in men and may be associated with BPH due to urinary voiding dysfunction. I hypothesize that the incidence of bTLTs increases across the lifespan in both men and women and that bTLT- resident T-cells express markers of T-cell exhaustion. I also hypothesize that T-cell exhaustion is a characteristic of T-cell populations within bTLTs found in rUTI and BPH patients and that androgens mediate T-cell exhaustion. To begin to address these hypotheses and achieve my scientific training goals, I will leverage access to an extensive human bladder tissue repository and expertise in single-cell RNA sequencing (scRNA-seq) to investigate the incidence, composition and functional profile of bladder tertiary lymphoid tissues over the lifespan in both men and women. Under the mentorship of my sponsor Dr. Nicole De Nisco and co-sponsor Dr. Douglas Strand, I will define the incidence and transcriptional profile of bTLTs across the lifespan and will extend existing mouse studies to determine if bTLTs are also associated with aging in human women (Aim 1A). Based on exciting preliminary scRNA-seq data, I will specifically test the hypothesis that bTLTs are proportionally enriched for T-cells expressing markers of T-cell exhaustion (Aim 1B) and using patient biopsies I will determine if T-cell exhaustion also characterizes bTLTs found in women with rUTI (Aim 1C). I will then determine if bTLTs, which we have observed in male samples, are similarly associated with aging in men (Aim 2A) and if T-cells associated with male bTLTs also express markers of T-cell exhaustion (Aim 2B). Finally, I will utilize a unique set of biobanked bladder tissue from men with benign prostatic hyperplasia undergoing 5ARI therapy or not to specifically test the hypothesis that androgens are associated with T-cell exhaustion phenotypes in the male bladder. This fellowship proposal aims to provide the extensive, mentored training needed to complete my doctoral work in the pursuit of my future as an independent academic scientist studying benign urology. The completion of these aims will provide me training in cutting-edge experimental techniques and is necessary for my development into an independent academic scientist studying host-microbe and immune interactions in benign urology.