B cell activation in the cecal patches during the development of an experimental colitis model

• Published in: Biochemical and biophysical research communications 2018-02, Vol.496 (2), p.367-373
• Main Authors: Watabe, Taro, Nagaishi, Takashi, Tsugawa, Naoya, Kojima, Yudai, Jose, Nisha, Hosoya, Akinori, Onizawa, Michio, Nemoto, Yasuhiro, Oshima, Shigeru, Nakamura, Tetsuya, Karasuyama, Hajime, Adachi, Takahiro, Watanabe, Mamoru
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; B cells; CALCIUM IONS; Cecal patches; Colitis; INFLAMMATION; Intravital imaging; LARGE INTESTINE; MICE; Oxazolone
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2018.01.053

Although previous studies have suggested that appendix seems to be involved in the colitis, the role of this in the pathogenesis remains unclear. In this study, we assessed the importance of appendiceal lymphoid follicles, specifically the cecal patches (CP) in mice, using an experimental colitis model. Treatment with oxazolone resulted in ulcerations particularly at CP with follicular expansion as well as colitis. The colitis was attenuated by either appendectomy or the absence of mature B cells. We therefore established an intravital imaging system accompanied by the fluorescence resonance energy transfer technology to analyze the dynamic immune response of CP B cells. Our observation revealed frequent Ca2+ signaling in CP B cells during the early phase of colitis development. These findings suggested that the CP B cells may be involved in the pathogenesis of colitis including inflammatory bowel diseases in humans. •Cecal patch (CP) ulcerations are seen in the oxazolone colitis model.•Th1, Th2 and Th17 responses in the colon are induced by oxazolone treatment.•Appendectomy attenuates colitis along with decrease in these Th responses.•Colitis and CP ulcerations are also attenuated by the absence of mature B cells.•Intravital imaging shows B cell activation in CP in the setting of colitis.