The Differential Expression and Function of the Inflammatory Chemokine Receptor CXCR5 in Benign Prostatic Hyperplasia and Prostate Cancer

An analysis of single-cell data reveals therapeutic effects of AMG487 in experimental autoimmune uveitis

Uveitis, an ocular autoimmune disease that poses a significant threat to vision, is caused by immune cells erroneously attacking retinal cells and currently lacks specific and effective therapeutic interventions. The CXC chemokine receptor 3 (CXCR3) facilitates the migration of immune cells to sites of inflammation. AMG487, a CXCR3 antagonist, holds potential for treating autoimmune diseases by blocking immunes cells chemotaxis. However, its effects and mechanisms in uveitis remain unclear. Using single-cell assay for transposase-accessible chromatin sequencing and RNA sequencing, we observed increased expression of CXCR3 and chemotactic pathways in peripheral blood of Vogt-Koyanagi-Harada patients and cervical lymph nodes of experimental autoimmune uveitis mice. AMG487 treatment in experimental autoimmune uveitis was shown to be therapeutically effective. Analysis of flow cytometry and single-cell RNA sequencing in AMG487-treated mice revealed reduced expression of inflammatory genes in immune cells. Specifically, AMG487 decreased the proportion of plasma cell in B cells, restored the ratio between effector T cells and regulatory T cells, and diminished T helper (Th) 17 cell pathogenicity by suppressing highly inflammatory granulocyte-macrophage colony-stimulating factor-producing Th17 cells while enhancing anti-inflammatory interleukin-10-producing Th17 cells. Our study presents an exhaustive single-cell transcriptional analysis of immune cells under AMG487 treatment, thereby elucidating potential mechanisms and providing a potential reference for the development of novel therapeutic strategies for autoimmune diseases.

CXCR3 antagonist AMG487 ameliorates experimental autoimmune prostatitis by diminishing Th1 cell differentiation and inhibiting macrophage M1 phenotypic activation

BACKGROUND

Chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS) is an inflammatory immune disease that is characterized by infiltrating inflammatory cells in the prostate and pelvic or by perineal pain. Receptor CXCR3modulates immune and inflammatory responses; however, the effects of CXCR3 antagonist AMG487 in the context of CP/CPPS are unknown. Therefore, we investigated the effect of AMG487 in experimental autoimmune prostatitis (EAP) mice and explored the potential functional mechanisms.

METHODS

The EAP model was induced by intradermally injecting a mixture of prostate antigens and complete Freund's adjuvant on Days 0 and 28. To evaluate the effect of AMG487 on EAP mice, treatment with AMG487 and vehicle solution was conducted for the indicated period. Then, procedures were performed, including behavioral test, to evaluate the pain response to stimulation before the mice were killed and a histological assessment to evaluate the inflammation after the mice were killed. Immunofluorescence, flow cytometry, and Western blot assay were used to analyze the functional phenotype and regulation mechanism of AMG487 on T helper type 1 (Th1) cells and macrophages.

RESULTS

We found high expression of CXCR3 in human benign prostate tissues with inflammation and EAP mice. The elevated CXCR3 in prostate tissues correlates with the severity of inflammation. CXCR3 antagonist AMG487 treatment ameliorated the inflammatory changes and the pelvic pain of EAP mice. AMG487 inhibits Th1 cell differentiation through the IL-12/STAT4pathway and inhibits pro-inflammatory M1 macrophages through the lipopolysaccharide/NF-κB p65signaling. AMG487 could inhibit the secretion of inflammatory mediators in EAP mice.

CONCLUSION

CXCR3 antagonist AMG487 could ameliorate the inflammatory changes and the pelvic pain of EAP mice by diminishing Th1 cell differentiation and inhibiting macrophage M1 phenotypic activation. Thus, the results imply that AMG487 has the potential as an effective therapeutic agent in the prevention and treatment of EAP.

CXCL13 Signaling in the Tumor Microenvironment

Chemokines have emerged as important players in tumorigenic process. An extensive body of literature generated over the last two or three decades strongly implicate abnormally activated or functionally disrupted chemokine signaling in liaising most-if not all-hallmark processes of cancer. It is well-known that chemokine signaling networks within the tumor microenvironment are highly versatile and context-dependent: exert both pro-tumoral and antitumoral activities. The C-X-C motif chemokine ligand 13 (CXCL13), and its cognate receptor CXCR5, represents an emerging example of chemokine signaling axes, which express the ability to modulate tumor growth and progression in either way. Collateral evidence indicate that CXCL13-CXCR5 axis may directly modulate tumor growth by inducing proliferation of cancer cells, as well as promoting invasive phenotypes and preventing their apoptosis. In addition, CXCL13-CXCR5 axis may also indirectly modulate tumor growth by regulating noncancerous cells, particularly the immune cells, within the tumor microenvironment. Here, we review the role of CXCL13, together with CXCR5, in the human tumor microenvironment. We first elaborate their patterns of expression, regulation, and biological functions in normal physiology. We then consider how their aberrant activity, as a result of differential overexpression or co-expression, may directly or indirectly modulate the growth of tumors through effects on both cancerous and noncancerous cells.