title: Factors of tonsillar involution: age-dependent changes in B-cell activation and Langerhans' cell density.
abstract: Incorporation of radioactive thymidine as well as morphological and autoradiographical investigations performed with isolated B and T lymphocytes of the tonsil show that first of all B cells are activated or proliferating. The combination of autoradiography with cytochemistry was the only means of detecting a few activated T cells. With increasing age the number of activated B cells decreases. A reduced number of Langerhans' cells acting as antigen receptors in the epithelium of the crypt is assumed to be one cause of this phenomenon. Tonsillar involution originates from both a decline in the antigen receptors and in the depletion of B-cell activation. Malfunctions in these processes give rises to pathogenic factors in chronic tonsillitis.
mesh_terms: D000328:Adult; D000917:Antibody Formation; D001345:Autoradiography; D001402:B-Lymphocytes / Q000166:cytology*; D002648:Child; D002675:Child, Preschool; D004247:DNA / Q000096:biosynthesis; D004847:Epithelial Cells; D006801:Humans; D007801:Langerhans Cells / Q000166:cytology*; D007958:Leukocyte Count; D008875:Middle Aged; D008938:Mitosis; D014066:Palatine Tonsil / Q000166:cytology*; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000166:cytology; D013936:Thymidine / Q000378:metabolism
chemical_list: D004247:DNA; D013936:Thymidine