Secondary lymphoid organs

NF-kB is also crucial for the proper functioning of the adaptive immune system not only by acting on the immune cells themselves but also by participating in the development and organization of the secondary lymphoid organs (lymph nodes, spleen, and Peyer s patches), in which both B and T lymphocytes undergo maturation and activation. NF-kB proteins have an important role in lymphocyte development and... 

The cells that make up the immune system are distributed throughout the body but are found mainly in the lymphoreticular organs, which may be divided into the primary lymphoid organs, i.e. the thymus and bone marrow, and the secondary or peripheral... 

Central memory (TCM) CCR7 Used to define these cells and allows entry into secondary lymphoid organs... 

Effector memory (Tem) CCR7 (absent) Lack CCR7 and are thereby excluded from noninflamed secondary lymphoid organs... 

Secondary lymphoid organs CCR7 Entry and localization in T-cell zones... 

Forster R, Schubel A, Breitfeld D, et al. CCR7 coordinates the primary immune response by establishing functional microenvironments in secondary lymphoid organs. Cell 1999 99 23-33. 

Carramolino L, Zaballos A, Kremer L, et al. Expression of CCR9 beta-chemokine receptor is modulated in thymocyte differentiation and is selectively maintained in CD8(+) T cells from secondary lymphoid organs. Blood 2001 97(4) 850-857. 

Ohl L, Henning G, Krautwald S, et al. Cooperating mechanisms of CXCR5 and CCR7 in development and organization of secondary lymphoid organs. J Exp Med 2003 197 1199-1204. 

Cyster JG. Chemokines and cell migration in secondary lymphoid organs. Science 1999 286(5447) 2098-2102. 

There are literally hundreds of markers that are currently available for the mouse and human than can be used to characterize lymphoid and myeloid cells and subsets in primary and secondary lymphoid organs. Many of the markers expressed in mammals are highly conserved across species and have been designated as genetic clusters of differentiation (CD). CDs can be identified with fluorescently labeled monoclonal antibodies. As presented previously, when combined with other fluorescent probes, important information on intracellular biochemistry and cell function can be obtained. Many of the biochemical markers used by immunotoxicologists are common to other... 

Atrophy of lymphoid organs (spleen and thymus) and lymphoid hyperplasia in bronchial and mediastinal lymph nodes were observed in rats and mice exposed 6 hours/day for 12 of 16 days to 1.6 mg nickel/m as nickel sulfate, 3.6 mg nickel/id as nickel subsulfide, and 23.6 mg nickel as nickel oxide (Benson et al. 1987, 1988 Dunnick et al. 1988). The atrophy of the lymphoid organs was considered secondary to the decrease in body weight (Benson et al. 1987, 1988 Dunnick et al. 1988). According to the series of 16-day and 13-week studies by Haley et al. (1990), Benson et al. (1987,... 

Thus, human exposure to PCBs in Japan (Yusho accident) and China has been associated with increased respiratory infections and decreased levels of immunoglobulins in serum. In animals exposed to these compounds, there is atrophy of both primary and secondary lymphoid organs, lower circulating immunoglobulins, and decreased antibody responses after exposure to antigens. Similarly, the exposure of both humans and farm animals to polybrominated biphenyls, which occurred in Michigan in 1973, resulted in depressed immune responses. 

---