Expansion of T follicular helper cells is associated with disease progression in rat experimental membranous nephropathy model

Background.T follicular helper (Tfh) cells drive humoral immunity by facilitating B cell responses, but the functional role of Tfh cells in the pathogenesis of idiopathic membranous nephropathy (IMN) remains unclear.Objectives.This study aimed to establish a rat experimental membranous nephropathy model, investigate the phenotypic characteristics of Tfh cells, and analyze a clinically significant correlation between Tfh cells. Materials and methods.Passive Heymann nephritis (PHN) rats were induced by immunizing Sprague Dawley rats with anti-Fx1A serum.The frequency of Tfh and B cell subsets was analyzed with flow cytometry (FC).The serum concentration of interleukin-21 (IL-21), the relative mRNA expression levels of IL-21 and B cell lymphoma 6 (Bcl-6) in spleen mononuclear cells (MNCs), and the kidney infiltration of CD4 + T cells and IL-21 were assessed.The potential correlations among these measures were analyzed. Results.In comparison with the control group, significantly increased percentages of Tfh cells, inducible T cell co-stimulator-positive (ICOS + ) Tfh cells, and mRNA expression of Bcl-6 were detected in the spleen of PHN rats.Elevated IL-21 expression was detected in the serum and kidneys.Remarkably, the percentage of splenic ICOS + Tfh cells was positively correlated with 24 h urine protein concentrations (r = 0.676, p = 0.011) in PHN rats.Conclusions.These data indicate that ICOS + Tfh cells contribute to development of IMN, and they might be potential therapeutic targets for IMN.