Document Detail


Antigen-dependent selection of T cells that are able to efficiently regulate free cytoplasmic Ca2+ levels.
MedLine Citation:
PMID:  8027538     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In T helper cells, the process of memory acquisition is reflected in the expression of phenotypic markers. However, little is known regarding the functional changes that occurred in T helper cells selected after a primary Ag-specific response. We now present data that indicate that such T helper cells acquire the ability to down-regulate high concentrations of free cytoplasmic Ca2+. This property renders them resistant to intense inductive stimuli, such as high concentrations of ionomycin. The accumulation of cells that display this ability parallels the progressive proliferative enrichment of Ag-specific T cells and correlates with the surface expression of the CD45RB(low) isoform. As previously shown, persistent high levels of cytoplasmic Ca2+ are responsible for death via apoptosis in virgin T cells. In contrast, the ability to regulate cytosolic Ca2+ allows survival and clonal expansion. We suggest that memory T cells behave differently from virgin T cells when interacting with Ag-presenting B cells (as reported by others) because they have acquired this new physiologic property. Ag-presenting B cells deliver an intense stimulatory signal to T cells because of a high multiplicity of cognate interactions. Thus, Ag-driven T cell proliferation results in the selection of "resistant" T helper cells that can be successfully stimulated by memory B cells. In contrast, naive T cells, which cannot modulate high levels of cytosolic Ca2+, are deleted as a consequence of Ag presentation by B cells.
Authors:
R Rajasekar; A Augustin
Related Documents :
20380478 - Micro-raman detection of nuclear membrane lipid fluctuations in senescent epithelial br...
19695678 - Polycomb group protein bmi1 is overexpressed and essential in anchorage-independent col...
20352028 - Cellular senescence is a common characteristic shared by preneoplasic and osteo-arthrit...
20043098 - Fibroblasts from werner syndrome patients: cancer cells derived by experimental introdu...
6771298 - Epidermal growth factor and thyrotropin-releasing hormone act similarly on a clonal pit...
15032398 - Induction of inflammatory cell accumulation using human mast cell tryptases.
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of immunology (Baltimore, Md. : 1950)     Volume:  153     ISSN:  0022-1767     ISO Abbreviation:  J. Immunol.     Publication Date:  1994 Aug 
Date Detail:
Created Date:  1994-08-09     Completed Date:  1994-08-09     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985117R     Medline TA:  J Immunol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1037-45     Citation Subset:  AIM; IM    
Affiliation:
Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Antigens / immunology
Calcium / metabolism*
Cytosol / metabolism
Immunologic Memory*
Ionomycin / pharmacology
Mice
Mice, Inbred BALB C
Mice, Inbred C57BL
Ovalbumin / immunology
Receptors, Nicotinic / immunology
T-Lymphocytes / metabolism*
T-Lymphocytes, Helper-Inducer / immunology*
Chemical
Reg. No./Substance:
0/Antigens; 0/Receptors, Nicotinic; 56092-81-0/Ionomycin; 7440-70-2/Calcium; 9006-59-1/Ovalbumin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Immunohistochemical detection of the androgen receptor with monoclonal antibody F39.4 in routinely p...
Next Document:  Glycosyl phosphatidylinositol membrane anchor is not required for T cell activation through CD73.