M F Kramer1, B Mack, G Rasp. 1. Department of Oto-Rhino-Laryngology/Head and Neck Surgery, Ludwig-Maximilians-University, Klinikum Grosshadern, Marchioninistr.15, 81377 Munich, Germany. mkramer@hno.med.uni-muenchen.de
Abstract
BACKGROUND: Interleukin 16 (IL-16) acts highly chemotactic on CD4-bearing cells. Besides chemotaxis, IL-16 has numerous immunomodulatory effects, and not only on T cells. OBJECTIVE: To determine IL-16 expression in human tonsils. METHODS: Tonsillar follicles were immunohistologically characterized to elicit a possible cellular source of IL-16 expression. RESULTS: The mantle zone of immature and mature B cells was CD22 immunoreactive (ir), whereas the germinal center of activated B cells was CD23-ir. Plasma cells that were CD38-ir were observed extrafollicularly beneath the epithelium and within the germinal center. T cells were found most frequently in the extrafollicular space, with a majority of CD4 cells. CD68-ir macrophages were predominantly found within the germinal center. Immunostaining of anti-IL-16 revealed strong cytoplasmatic reactivity of extrafollicular cells and of cells at the outer rim of the mantle zone. Numerous cells adherent to the stratified squamous epithelium were IL-16-ir as well. Double immunostaining identified CD4(+) T cells as the major cellular source of IL-16 expression. Furthermore, a population of CD22(+) B cells at the outer rim of the mantle zone expressed IL-16 as well. CONCLUSIONS: Interleukin 16 was mainly expressed in a typical CD4-like pattern in human tonsils. Our data strongly suggest that CD4(+) lymphocytes constitute the major cellular source for IL-16. We hypothesize that the double-immunostained CD4-ir and IL-16-ir cells represent activated T cells. Because CD22(+) B cells at the outer rim of the mantle zone expressed IL-16 as well, we conclude that this area might constitute the locus of IL-16-mediated B-cell differentiation.
BACKGROUND:Interleukin 16 (IL-16) acts highly chemotactic on CD4-bearing cells. Besides chemotaxis, IL-16 has numerous immunomodulatory effects, and not only on T cells. OBJECTIVE: To determine IL-16 expression in human tonsils. METHODS: Tonsillar follicles were immunohistologically characterized to elicit a possible cellular source of IL-16 expression. RESULTS: The mantle zone of immature and mature B cells was CD22 immunoreactive (ir), whereas the germinal center of activated B cells was CD23-ir. Plasma cells that were CD38-ir were observed extrafollicularly beneath the epithelium and within the germinal center. T cells were found most frequently in the extrafollicular space, with a majority of CD4 cells. CD68-ir macrophages were predominantly found within the germinal center. Immunostaining of anti-IL-16 revealed strong cytoplasmatic reactivity of extrafollicular cells and of cells at the outer rim of the mantle zone. Numerous cells adherent to the stratified squamous epithelium were IL-16-ir as well. Double immunostaining identified CD4(+) T cells as the major cellular source of IL-16 expression. Furthermore, a population of CD22(+) B cells at the outer rim of the mantle zone expressed IL-16 as well. CONCLUSIONS:Interleukin 16 was mainly expressed in a typical CD4-like pattern in human tonsils. Our data strongly suggest that CD4(+) lymphocytes constitute the major cellular source for IL-16. We hypothesize that the double-immunostained CD4-ir and IL-16-ir cells represent activated T cells. Because CD22(+) B cells at the outer rim of the mantle zone expressed IL-16 as well, we conclude that this area might constitute the locus of IL-16-mediated B-cell differentiation.
Authors: Barbara L Andersen; Neha Godiwala Goyal; David M Weiss; Travis D Westbrook; Kami J Maddocks; John C Byrd; Amy J Johnson Journal: Cancer Date: 2018-05-14 Impact factor: 6.860
Authors: A Andersson; I Qvarfordt; M Laan; M Sjostrand; C Malmhall; G C Riise; L-O Cardell; A Linden Journal: Clin Exp Immunol Date: 2004-10 Impact factor: 4.330