Programmed cell death 1 positive lymphocytes at palate tonsils in the elder patients with chronic tonsillitis

• Main Authors: Yuki Fujihara, Koji Yamanegi, Yasuyuki Nagasawa, Ayu Yoshida, Yukako Goto, Shunsuke Kumanishi, Hiroyuki Futani, Shigeo Fukunishi, Shinichi Yoshiya, Hiroshi Nishiura
• Format: Article
• Language: English
• Published: Elsevier 2021-03-01
• Series: Biochemistry and Biophysics Reports
• Subjects: Chronic tonsillitis; GPR56; Lymphocytes; Marginal zone; PD-1
• Online Access: http://www.sciencedirect.com/science/article/pii/S2405580820302089

Circulating lymphocytes infiltrate into local foci at the inflammatory phase of acute wound healing for activation of the immune system and express an immune checkpoint protein programmed cell death 1 (PD-1) at the resolution phase for inactivation of the immune system. Conversely, the PD-1 expression was still found even on circulating lymphocytes of the elder patients with chronic tonsillitis at the palliative stage. Recently, an adhesion G protein coupled receptor 56 (GPR56) was reported to at least work as a proliferation factor for infiltrated lymphocytes into local foci at the resolution phase of acute wound healing. To preliminary examine a similar role of PD-1 and GPR56 at local foci at chronic inflammation, palate tonsils were prepared from small amounts of patients with chronic tonsillitis and tonsillar hypertrophy. A positive relationship of RNA expression might be observed between PD-1 and GPR56 in the elder patients with chronic tonsillitis. In regard to immunohistopathological findings, there were huge and small amounts of PD-1 and GPR56 expression at the marginal zone of lymphoid follicles of palate tonsils with chronic tonsillitis. Moreover, the positive relationship of RNA expression between PD-1 and GPR56 confirmed in large numbers of the elder patients with chronic tonsillitis. Probably, GPR56 participates in a supplement of PD-1+ lymphocytes to circulating bloods of the elder patients with chronic tonsillitis through a lymphocyte cell maintenance system at the marginal zone of the lymphoid follicles of palate tonsils.