Peripheral blood granulocyte activity following contact sensitization of rats with dinitrochlorobenzene

Contact hypersensitivity (CHS) reaction is a classic example of a cell-medi ated reaction. As the afferent phase of the reaction includes inflammation, CHS is a suitable model for investigating non-specific immunity. Some aspe cts of granulocyte activity in the afferent phase of experimentally induced CHS to dinitrochlorobenzene (DNCB) in two genetically different rat strain s, AO and DA were examined in this study. A shift in the ratio of granulocy tes to lymphocytes in favour of granulocytes and an increase in granulocyte survival were noted in DA rats. Granulocytes from both strains demonstrate d increased levels of NBT reduction and an increase in their adhesion to pl astic. Decreased granulocyte adhesion in the presence of monoclonal antibod ies to beta (2) integrins (anti-CD11b/c acid anti-CD18) points to the contr ibution of these molecules to granulocyte adhesiveness during the sensitiza tion phase of CHS. Stimulation of adhesion in the presence of anti-CD11a an tibody, points to a differential modulation of adhesion molecule activity d uring the afferent phase of CHS. Changes in functional activity of granuloc ytes demonstrated in this study might contribute to the development of CHS in rats. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.