It is generally accepted that the tingible bodies (Körper) of Flemming (7) found in lymphatic tissue germinal centers represent phagocytized nuclear debris of small lymphocytes (1, 2, 6, 7, 11, and others) or both lymphocyte and erythrocyte debris (15) . Several ideas about the significance of tingible bodies assume that they are small lymphocytes . The "graveyard theory" emphasizes the phagocy...

Intercellular channels called gap junctions enable multicellular organisms to exchange information rapidly between cells. Though gap junctions are held to be ubiquitous in solid tissues, we have only recently found them in the lymphoid organs. Functional direct cell-cell communication has now been confirmed by us and other groups in bone marrow, thymus, and in secondary lymphoid tissues. What f...

744 INSIGHTS | The Journal of Experimental Medicine In this issue, two independent groups show that the transcription factor ZBTB20 is required for the maintenance of long-lived plasma cells following immunization with the commonly used adjuvant, alum. Intriguingly, one group found that ZBTB20 was dispensable for plasma cell survival when they used adjuvants that activate Toll-like receptors (T...

The sequence of morphological changes in the rat spleen following SRBC injection associated with hemolysin production has been correlated with estimates of proliferative activity by splenic lymphatic tissue. Formation of new, reactive germinal centers containing macrophages which engulf nuclear debris is a prominent feature of the response. This is prevented by pretreatment of the animal with c...

Lifelong antibody responses to vaccination require reorganization of lymphoid tissue and dynamic intercellular communication called the germinal center reaction. B lymphocytes undergo cellular polarization during antigen stimulation, acquisition, and presentation, which are critical steps for initiating humoral immunity. Here, we show that germinal center B lymphocytes asymmetrically segregate ...

The fine structure of tritiated thymidine-labeled cells in antigen-stimulated mouse spleen germinal centers is described. In studies on the ultrastructural level, two labeled cell types found in germinal centers are observed. Large lymphocytes are characterized by their very numerous free ribosomes, a paucity of endoplasmic reticulum, relatively few mitochondria, and a poorly developed Golgi re...

TLR7 enhances germinal center maturation and migration of B cells to the dark zone where proliferation and somatic hypermutation occur. Our goal was to determine how Tlr7 dose influences selection of the autoreactive B cell repertoire in NZW/BXSB. Yaa mice bearing the site-directed heavy chain transgene 3H9 that encodes for the TLR7 regulated anti-CL response. To create a physiologic setting in...

Background: The varicocele (VCL) impacts the testicular tissue both by enhancing tissue inflammation and by down-regulating the antioxidant status. On the other hand, in varicocele patient the critical role of Hsp70 in spermiogenesis is identified. Therefore present study was estimated to evaluate the protective effect of testosterone and vitamin E on VCL-decreased Hsp70 expression and on VCL-i...