Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Very low immunoglobulin secretion occurs in pokeweed mitogen (PWM) stimulated cord blood mononuclear cells (MNC) and has been attributed to an 'immaturity' of both T and B cells of the newborn. The cord blood T cells are phenotypically 'naive' cells, in which suppressor activity for B cell function appears to dominate over helper activity. The cord blood B cells, in spite of their expression of different membrane immunoglobulin isotypes, secrete almost no IgG and IgA in the various B cell assays so far compared. We found that cord blood B cells are as competent as B cells from adults to generate clonal IgM, IgG and IgA responses in a culture system in which a cell contact with mutant EL-4 thymoma cells in conjunction with T cell supernatant leads to strong B cell activity. As regarding the possible causes of the low cord blood PWM response, we studied the role of transforming growth factor-beta 1 (TGF-beta 1), a potent inhibitor of lymphocyte functions. TGF-beta 1 sensitivity of B cells and TGF-beta 1 mRNA levels in MNC were found to be similar for adult and cord blood cells. A neutralizing anti-TGF-beta 1 antibody enhance the adult PWM response, but the immunoglobulin secretion in cord MNC remained very low. We conclude that suppression by endogenous TGF-beta 1 occurs in the PWM system but is not responsible for the low immunoglobulin response of cord blood MNC and that the newborn's B cell 'immaturity' can be overcome with potent T cell signals in vitro. This is consistent with the newborn's capacity to generate a T-dependent B cell response in vivo.
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PMID:Are cord blood B cells functionally mature? 204 18

Human thymoma, which is occasionally associated with autoimmune disease, is a thymic epithelial cell tumor and often contains a large number of lymphocytes. In a previous study, we have shown that a proportion of CD4 single positive T cells in human thymomas lack CD3, suggesting immaturity. In this study, we focused on the rest of the CD4 single positive T cells in thymomas that expressed CD3/TcR alpha beta and investigated the maturity of single positive T cells by analyzing lymphocyte surface antigens and the cells' proliferative response to a mitogen. CD4 single positive cells that expressed CD3 or TcR alpha beta also expressed CD69 and had probably undergone positive selection in the tumor. Further, isolated CD4 or CD8 single positive cells from the thymomas responsed to a mitogen although at lower levels than the corresponding single positive cells in the peripheral blood. These results indicate that thymomas contain single positive T cells which have mature phenotype and proliferative ability, and suggest that T cells may differentiate in thymoma.
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PMID:Mature CD4 single positive thymocytes in human Thymoma: T cells may differentiate in the thymic epithelial cell tumor. 939 46