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Impaired TCR signal transduction, but normal antigen presentation, in a patient with common variable immunodeficiency
Author(s) -
Fischer Michael B.,
Hauber Ilona,
Wolf Hermann M.,
Vogel Erich,
Mannhalter Josef W.,
Eibl Martha M.
Publication year - 1994
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1994.tb05068.x
Subject(s) - common variable immunodeficiency , superantigen , antigen , immunology , t cell receptor , t cell , biology , medicine , immune system , antibody
Summary. We describe a 27‐year‐old white man with common variable immunodeficiency (CVID) who has two healthy histoidentical brothers and one IgA‐deficient sister who shares one HLA haplotype with the patient. T cells from the patient with CVID showed an impaired response to recall antigens (tetanus toxoid, E. coli ), whereas his IgA‐deficient sister and his two healthy histoidentical brothers responded normally. Cross‐mixing experiments using isolated monocytes and T cells from the CVID patient and one histoidentical brother revealed that the patient's monocytes were fully functional in processing and presenting antigen to resting T cells of his brother, and provided normal accessory cell function for superantigen‐induced activation of his brother's resting T cells. In contrast, the patient's T cells were unable to respond to antigen presented by the brother's monocytes and failed to respond with an increase in intracellular free Ca ++ to stimulation with superantigen, which is known to bind to the TCR Vβ‐chain outside the antigen‐binding groove. However, stimulation with a combination of PMA and IM, directly activating protein kinase C and increasing intracellular free Ca ++ by bypassing membrane receptors, induced normal Ca ++ flux. These data indicate that the patient with CVID has a defect in TCR‐mediated signalling at the level of the T cells which is not present in his histoidentical healthy brothers or in his haploidentical IgA‐deficient sister.