BRONCHIAL GAMMA-DELTA T-LYMPHOCYTES AND EXPRESSION OF HEAT-SHOCK PROTEINS IN MILD ASTHMA

Heat shock proteins (HSPs), which are important targets for gamma delt a T-lymphocytes, are thought to play a role in inflammatory and immune diseases. The purpose of this study was to characterize, in asthma, t he presence and distribution of alpha beta and gamma delta T-lymphocyt es and of hsp60, hsp70 and hsp90 in bronchial biopsies, and to seek fo r a co-localization of gamma delta T-cells and HSPs. Ten subjects with mild atopic asthma and nine control subjects underwent fibreoptic bro nchoscopy and bronchial biopsies, to which specific monoclonal antibod ies and immunohistochemical techniques were applied. T-lymphocytes pre sent in bronchi both of asthmatic and control subjects were predominan tly of the alpha beta T-cell receptor phenotype (median 632 cells . mm (-2) (range 85-1,510 cells . mm(-2)), and 855 cells . mm(-2) (286-2,42 4 cells . mm(-2)), respectively), whereas, gamma delta T-lymphocytes w ere always rare (median 26 cells . mm(-2) (range 0-114 cells . mm(-2)) , and 0 cells . mm(-2) (0-57 cells . mm(-2)), respectively). Both in a sthmatic and control subjects, bronchial epithelium was positive for h sp60, hsp70 and hsp90. There was no significant difference in the perc entages of positive epithelial cells between asthmatic and control sub jects. No co-localization of HSPs and gamma delta T-cells was observed . Our findings do not support the hypothesis that heat shock proteins and gamma delta T-cells play an important role in inflammatory and imm une responses in mild asthma.