title: Effects of desensitization on different kinds of in vitro PPD-induced response of lymph node lymphocytes from tuberculin-sensitive guinea pigs.
abstract: Guinea pigs rendered hypersensitive to tuberculin 2 to 3 weeks (early stage) or 10 to 14 weeks (late stage) after sensitization with complete Freund's adjuvant could be completely desensitized by a single or double injections of a sufficient amount of PPD (purified protein derivative). Lymph node cells from such desensitized animals 48 to 72 hr after the challenge showed a considerable reduction of the ability to produce blastogenic factor and skin reactive factor upon PPD-stimulation, whereas the macrophage migration inhibitory factor activity remained still unaffected. As regards antigen-induced 3H-thymidine incorporation in vitro, lymph node cells from animals desensitized in the late stage after sensitization showed no substantial reduction in the degree of enhanced DNA synthesis upon PPD-stimulation, although the desensitization in the early stage resulted in a significant loss of this activity. These results suggest the possibility that desensitizing challenge does not bring about a uniform and regular effect on every lymphocyte subpopulations relevant to different functions and, in addition, indicate that there are some exceptions to the compartmentalization concept of antigen-reactive lymphocytes.
mesh_terms: D000818:Animals; D003888:Desensitization, Immunologic; D005260:Female; D006168:Guinea Pigs; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D008198:Lymph Nodes; D008214:Lymphocytes / Q000276:immunology*; D008263:Macrophage Migration-Inhibitory Factors / Q000276:immunology; D013936:Thymidine; D014373:Tuberculin / Q000276:immunology*
chemical_list: D008263:Macrophage Migration-Inhibitory Factors; D014373:Tuberculin; D013936:Thymidine