concanavalin-a and Ataxia-Telangiectasia

Two sisters with ataxia-telangiectasia (A-T) and their parents were investigated for some parameters related to immunological functions. We found a decrease of total mature T lymphocytes, a decrease of OKT4+ helper-inducer T subset, and normal values of OKT8+ suppressor-cytotoxic T subset; a normal decrease of E rosette formation after incubation in vitro with theophylline, with a lowered E rosette capacity in one patient. The responses to phytohemagglutinin (PHA)and concanavalin A (ConA) were lowered. In addition we observed a reduction of basal capping of B lymphocytes in one patient and in her parents: this phenomenon could be related to cytoskeletal disorders, possibly involved in the pathogenesis of the disease.

Topics: Adolescent; Antibodies, Monoclonal; Ataxia Telangiectasia; Child; Concanavalin A; Female; Humans; Lymphocyte Activation; Phytohemagglutinins; Rosette Formation; Theophylline; Time Factors

The current concepts of the mechanisms of initiation and regulation of the proliferative response of lymphoid cells underlie a series of research performed by the authors. Using the modern methods an attempt was made to analyze comprehensively the causes of its lowering in patients with congenital immune deficiency (ataxia-telangiectasia, the Louis-Bar syndrome). It was established that irresponsiveness of the patients' cells to mitogens is not associated with the inability of these cells to interact with mitogen, to produce the growth factor of T cells or adsorb it on their membrane. It is suggested that the derangement is likely to be connected with the blockade of the postmembrane component of the proliferation trigger. It is also assumed that the analysis of the low proliferative response employed by the authors can be successfully used for other pathologies.

Topics: Ataxia Telangiectasia; Concanavalin A; Drug Combinations; Humans; Interleukin-1; Interleukin-2; Lymphocyte Activation; Phytohemagglutinins; Sulfones; Uracil

It has been shown that suppressor T lymphocytes can be activated by plant mitogens as Con A. In order to see if there is any change in lymphocyte surface markers in addition to functional activity, lymphocyte subpopulations (E, EA gamma, EAC rosette forming cells) were determined in 18 healthy controls and 16 patients with ataxia-telangiectasia (AT) after 18-24 hour incubation of lymphocytes with or without Con A (10 micrograms/ml per 2 x 10(6) lymphocytes). Without any incubation, the percentage of EA gamma-RFC was higher and E-RFC was lower in AT patients than in controls. In healthy controls the percentage of EA gamma-RFC significantly increased after incubation with Con A, while the patient group did not show any significant difference. In contrast, the percentage of E-RFC cells in AT group showed significant increase after Con A incubation, while this difference was not significant in healthy controls. There was no significant difference in percentage of EAC-RFC with or without Con A incubation in healthy controls and AT patients. These differences between patient and control groups can be explained by the different features in circulating lymphocyte subpopulations.

Topics: Ataxia Telangiectasia; Concanavalin A; Humans; Lymphocytes; Surface Properties; T-Lymphocytes

Topics: Adenoviridae Infections; Agglutination; Animals; Ataxia Telangiectasia; Carcinoma; Cell Transformation, Neoplastic; Chromosome Aberrations; Chromosome Disorders; Chromosome Mapping; Chromosomes; Colonic Neoplasms; Concanavalin A; Culture Techniques; Humans; Immunoglobulin A; Immunoglobulin E; Nucleic Acid Hybridization; Rats