IGF1R Promotes Th17/Treg Cell Development in Experimental Autoimmune Prostatitis

Chronic prostatitis is a common urological disorder in young and middle-aged men, characterized by frequent relapses and an unknown etiology. We investigated the potential function of insulin-like growth factor 1 (IGF1) -related ligands in chronic prostatitis in the current study.

In this study, we established the chronic experimental autoimmune prostatitis mouse model H&E staining was used to assess immune cell infiltration in prostate tissue, while RT-qPCR and Western blot analyses were performed to validate gene and protein expression differences across groups, respectively. Immunofluorescence staining was utilized to determine the spatial distribution of key proteins. Flow cytometry was conducted to analyze the proportions of immune cell populations in different experimental groups. Adeno-associated virus (AAV) was employed to knock down Igflr, and ELISA was used to measure cytokine levels in the peripheral blood of mice. Statistical significance was defined as P < 0.05, and all tests were conducted as two-tailed. Data analysis was performed using R software (version 4.2.2).

We successful established the EAP model and discovered that the expression of IGF1R, content of IGF1-related ligands, was highest in prostate tissue and CD4⁺ T cell subset. Furthermore, protein expression levels of IGF1R were also validated that upregulated in mouse prostate tissue. Colocalization of immunofluorescence suggested that IGF1R protein is highly expressed on CD4⁺ T cells. Stimulation with desIGF1, a truncated analogue of IGF1, resulted in the significantly increased prostate inflammation and pain scores observed in the EAP+desIGF1 group mouse compared to other groups In vitro study further suggested that desIGF1 could increase the proportion of Th17 cells while decreasing the proportion of Treg cells. In the EAP+AAV-shIgf1r group, the knock down function of igf1r led to the alleviative prostate inflammation and response frequency of pain behavior test. We found that calcium ion associated pathways are active in EAP by bioinformatics, and further validated that PKC-β protein with significantly increased expression noted in the EAP+desIGF1 group, and decreased in the EAP+AAV-shIgf1r group. We also found that the proportion of Th17 cells increased after activation of PKC- β by flow cytometry.

These findings support that PKC-β associated pathways mediated by IGF1/IGF1R axis may impact Th17 cell differentiation and exacerbating prostate inflammation in EAP mouse, providing new molecular targets for the clinical therapeutic strategy.