CLONAL EXPANSION OF T-CELLS IN MEASLES

Some autoimmune complications such as postinfectious encephalomyelitis are associated with immunologic abnormalities induced by measles viru s infection. To address the superantigenic stimulation in measles whic h might be related with autoimmune complications, T-cells bearing the TCRBV5S2 or TCRBV8 chains and the expression of activation markers wer e analyzed by monoclonal antibodies. To estimate clonal expansions, th e CDR3 length profile in T-cells bearing the TCRBVSS2 or TCRBV8 chains was analyzed by two-stage PCR. Results showed that the expression of DR molecules in CD3(+) cells was increased significantly in measles pa tients (19.6 +/- 20.7%) compared to healthy children (2.9 +/- 1.4%). T he mean percentage (7.1 +/- 4.4%) of T-cells bearing the TCRBV8 chain was increased in measles patients compared to healthy children (5.6 +/ - 3.1%). The percentage of T-cells bearing the TCRBVSS2 chain in measl es patients (3.0 +/- 1.2%) was similar to that in healthy children (2. 7 +/- 0.6%). By analysis of the CDR3 length we found that there was no evidence of clonal expansions in T-cells bearing the TCRBV8 chain and that there were clonal expansions in T-cells bearing the TCRBV5S2 cha in. These data suggest a conventional antigenic stimulation with T-cel ls bearing the TCRBVSS2 chain and a superantigenic stimulation with T- cells bearing the TCRBV8 chain may occur in the acute stage of measles infection. (C) 1998 Elsevier Science B.V. All rights reserved.