ROLE OF LYSOSOMES IN CELLULAR LYTIC PROCESSES .4. ULTRASTRUCTURAL AND HISTOCHEMICAL CHANGES IN LYMPHOID TISSUE OF THYMECTOMIZED MICE WITH WASTING DISEASE

Lymphoid tissues obtained from mice with wasting disease resulting from neonatal thymectomy were examined by histochemical and electron microscopical techniques. The lymphoid organs showed loss of architecture, depletion of lymphocytes, and marked infiltration of macrophages. Plasma cells, however, were numerous. Macrophages were frequently engaged in the phagocytosis of altered lymphocytes, and their degradation within the phagocytic vacuoles appeared to be due to hydrolytic enzymes derived from macrophage lysosomes. Stages in the maturation of myeloid cells, including the development of lysosomes in the Golgi apparatus, were readily detected in the spleen. Neither bacteria nor viruses were detected in the lymphoid tissues, and a possible role of lymphocytic phagocytosis in the depletion of lymphocytes is suggested. © 1969 Academic Press, Inc.