[show abstract][hide abstract] ABSTRACT: Despite intensive efforts, the general rules for gamma delta T cell recognition remain undefined. Here, we take advantage of the detailed knowledge of the molecular structure and biosynthetic pathways of major histocompatibility complex (MHC) molecules to analyze the recognition properties of the gamma delta T cell clones LBK5 (specific for the class II MHC, IEk) and G8 (specific for the nonclassical class I MHC, TL10b). We find that the activation of these clones requires neither class I nor class II antigen-processing and that peptides do not confer specificity. Epitope mapping also shows that the topology of gamma delta T cell receptor interaction with the MHC is distinct from that of alpha beta T cells. These results suggest that the molecular nature of gamma delta T cell recognition is fundamentally different than that of alpha beta T cells.
[show abstract][hide abstract] ABSTRACT: Peripheral blood T lymphocytes from healthy donors were stimulated with Mycobacterium tuberculosis in vitro and afterward analyzed phenotypically. Marked expansion of the gamma/delta T cell population (3- to 21-fold) was observed in 15/21 donors 7 to 10 days after stimulation. In addition to M. tuberculosis, Mycobacterium leprae (six of eight) as well as the gram-positive bacteria, Staphylococcus aureus (two of six), group A streptococci (seven of nine), and Listeria monocytogenes (four of eight) augmented gamma/delta TCR expression in peripheral blood T cells of many donors. gamma/delta T lymphocytes expressed IL-2R and secreted IL-2 upon restimulation with M. tuberculosis. Stimulation with M. tuberculosis evoked specific cytolytic activities in gamma/delta T lymphocytes because: gamma/delta T cells lysed M. tuberculosis pulsed but not unpulsed targets; high concentrations of TCR delta 1 mAb facilitated killing of unpulsed target cells; and low doses of anti-TCR delta 1 mAb blocked killing of pulsed targets. Furthermore, gamma/delta T cells from four donors, after activation with M. tuberculosis or with group A streptococci, respectively, only lysed targets pulsed with the homologous agents, whereas in other donors some cross-reactivity was observed. We conclude that, upon contact with mycobacteria and perhaps other microorganisms, gamma/delta T cells are activated which contribute to immunity against infection via IL-2 secretion and specific target cell lysis.
The Journal of Immunology 11/1990; 145(8):2434-9. · 5.52 Impact Factor
[show abstract][hide abstract] ABSTRACT: Alterations of the cerebrospinal fluid (CSF) protein contents and the blood brain barrier (BBB) in schizophrenia have been observed by several authors but no relationship to clinical characteristics like psychopathology, the course or the duration of the disease could be described until now. We have studied 27 schizophrenic patients upon each of whom a lumbar punction had been carried out for clinical reasons. The average values of the patients were within the normal range. Nine patients (33%) showed the total protein content to be > 45 mg% and 6 (22%) > 50 mg%. In the latter 6 patients an impaired BBB (raised albumin CSF/serum quotient) and in 4 patients (15%) a raised CSF immunoglobulin (IgG) were observed. No relation to the patient's age and the duration of the disease was found but correlations with the Scale for the Assessment of Negative Symptoms (SANS) showed significant results in the subscores "affective flattening/affective blunting", "alogia/paralogia" as well as in the total score with respect to the CSF contents of albumin and IgG (p = 0.009-0.02). These correlations suggest that the CSF albumin and the CSF IgG are related to the negative symptomatology in schizophrenia and that patients with these CSF alterations may have a higher risk of developing negative symptoms.
Schizophrenia Research 02/1995; 14(3):223-8. · 4.59 Impact Factor
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