Single cell and tissue-transcriptomic analysis of murine bladders reveals age- and TNFα-dependent but microbiota-independent tertiary lymphoid tissue formation

Abstract

Aging has multifaceted effects on the immune system, but how aging affects tissue-specific immunity is not well-defined. Bladder diseases characterized by chronic inflammation are highly prevalent in older women, but mechanisms by which aging promotes these pathologies remain unknown. Tissue transcriptomics of unperturbed, young and aged bladders identified a highly altered immune landscape as a fundamental feature of the aging female bladder. Detailed mapping of immune cells using single cell RNA-sequencing revealed novel subsets of macrophages and dendritic cells and unique changes to the immune repertoire in the aged bladder. B and T cells are highly enriched in aged bladders and spontaneously form organized bladder tertiary lymphoid tissues (bTLTs). Naïve, activated, and germinal center B cells and IgA + plasma cells are found within bTLT and associated with increased urinary IgA concentrations. bTLTs form with increasing age and their formation is dependent on TNFα. Microbiota are not required to form bTLT form, as aged germfree mice harbor them. Thus, bTLTs require age-dependent TNFα but are independent of the microbiota. Our results indicate that chronic, age-associated inflammation underlies a fundamental alteration to the bladder and establishes a resource for further investigation of the bladder immune system in homeostasis, aging, and disease.

A Cellular Reference Resource for the Mouse Urinary Bladder

“…Additionally, large groups of contiguous spots positive for the plasma cell marker Jchain were identified in ST data. Specifically these large clusters of contiguous spots were present in aged but not mature sections (contiguous spots Aged=462, Young=3, Fig.S6) which is in line with a recent report 49 wherein tertiary lymphoid structures, which are highly populated with plasma cells, were more prevalent in aged bladder sections.…”

The influence of age and sex on the pre-treatment immune microenvironment of a carcinogen induced murine model of bladder cancer

“…While this confirmed the unique bladder transcriptome profiles of the groups under study, many of the top upregulated genes revealed shifts in immune-associated genes with increasing age, suggesting that fundamental changes in the aged murine bladder tissue microenvironment were immune-related. These findings are in concordance with the previous report by Ligon et al, 16 where such changes were reported in female mice.…”

“…Such induced TLSs generally provide heterologous humoral immune protection at mucosal sites. 25 As widely reported, TLSs in the bladder also form during the course of normal aging due to increased systemic levels of TNF-α 16 , chronic inflammatory conditions of the urogenital tract such as those observed in interstitial cystitis associated Hunner lesions and bladder cancer. 26-29…”

“…13-15 Simultaneous to changes in peripheral immune profiles, significant alterations within the mucosae also occur with biological aging and were recently reported in the context of healthy female murine bladder. 16…”

Female chronic posterior urethritis is underestimated in patients with lower urinary tract symptoms

“…The cause and pathogenic factors of female chronic posterior lesions are not yet completely known. It has been suggested that many factors, including non-specific infection, urethral obstruction, urethral-hymenal fusion, senile atrophy, traumatic causes, inflamm-ageing, and estrogen deficiency, may be implicated in its pathogenesis (4,12,17,18). Urethritis is classified as gonococcal or nongonococcal urethritis (NGU) based on its causative organisms that may be sexually and non-sexually transmitted.…”