Cells antibody-synthesizing

B lymphocytes, B cells or bone marrow-derived lymphocytes are formed in humans in the bone marrow by stem cells. On antigenic stimulation they develop into plasma cells and synthesize and secrete circulating antibodies. 

IL-13 is a recently described cytokine secreted by different human T cell subsets and is a potent modulator of human monocyte and B cell function (Minty et al., 1993). Both CDT" and CDB" T cell clones synthesize IL-13 in response to antigen-specific or polyclonal stimuli (Zurawski and De Vries, 1994). IL-13 has profound effects on human monocyte morphology, surface antigen expression, antibody-dependent cellular toxicity and cytokine synthesis (Minty et al., 1993 McKenzie et al., 1993). In human monocytes stimulated by LPS, the production of proinflammatory cytokines, chemokines... 

Perfusion MBRs have been introduced for the production of monoclonal antibodies. The mammalian cells that synthesize them are grown in the extracapillary space between the fibers in the module. Nutrients are supplied through the fibers, which also extract the metabolites continuously. The high cell concentrations between the fibers initiate high antibody harvests. These MBRs are also being investigated as an alternative concept for bioartificial organs such as liver and pancreas. 

In the newborn infant, resistance to infectious agents is first achieved by maternal antibodies that cross the placenta during fetal development or antibodies from mammary gland secretions transferred to a nursing infant. Subsequent antibody-mediated protection is provided by antibodies synthesized by the B cells of the individual as described above. Following this natural sequence, the focus on molecules and how molecular structures account for biological function begins with antibody structure. 

Fig. 5.1. Two pathways in normal cells to synthesize DNA precursors. The mutant myeloma cell line, which has the capacity to grow indeflnitely in vitro and can confer this property on antibody-producing lymphocytes through cell fusion, lacks the salvage pathway (no thymidine kinase (TK) or hypoxanthine-guanine phosphori-bosyl transferase (HGPRT)). This cell line would, therefore, not grow in the presence of folic acid antagonists. Fused cells, however, may grow since the antibody-producing cells contribute the salvage pathway.

It would also appear that several other cells may synthesize ONN-associated epitopes in one assessment, fibroblasts, vascular pericytes, endothelia, chondrocytes, selected epithelial cells, and nerves were also immunoreactive for this determinant. Overall, a sensitivity of 90% and a specificity of 54% has been reported for ONN relative to the diagnosis of osteoblastic neoplasms. Again, because of potential problems concerning cross-reactivity of available antisera to this marker, 746-248 monoclonal antibodies should be used diagnostically. Even then, since ONN does not demonstrate the selectivity of expression that is associated with OCN, it must be used only as part of... 

Plasma cell A large lymphocyte differentiated from a B cell that synthesizes and releases antibodies like those on the B cell surface. 

We have thus far explored the possibilities that the impairment of antibody production in the vitamin deficiencies might be linked either to a faulty processing of the antigen or to a disturbance in the integrity of the antibody-synthesizing cells. There is also the distinct likelihood that the vitamins, by virtue of their close interrelationships with various enzyme systems, function directly in the enzymatic reactions involved in antibody synthesis. Our complete ignorance of these reactions constitutes an effective barrier against any attempt to implicate the vitamins in specific enzymatic mechanisms. However, certain points of interest are worthy of discussion. 

Spleen macrophages and that their antigens persist in these cells since no significant amounts of antigen could be demonstrated in antibody synthesizing cells ... 

In response to antigenic challenge, they differentiate into plasma cells and synthesize specific antibody. Their characteristics and functions are shown in Table 4.. ... 

The term uncommitted cell is ambiguous. For opponents of the precommitment hypothesis it may mean a pluripotential or totipotential cell which may gain its antibody-synthesizing capacity as a consequence of contact with antigen. Proponents of the precommitment hypothesis accept that immature uncommitted cells do exist, but they postulate that uncommitted cells cannot be triggered by antigen. 

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