CYTOKINE MESSENGER-RNA PROFILE OF MYELIN BASIC-PROTEIN REACTIVE T-CELL CLONES IN PATIENTS WITH MULTIPLE-SCLEROSIS

Autoimmune mechanisms involving T-cell responses to (a) myelin autoant igen(s), such as myelin basic protein (MBP), are thought to contribute to the pathogenesis of multiple sclerosis (MS), Cytokines may play a central role in the regulation of the pathogenic autoimmune responses in MS and the mediation of tissue damage in the disease. To study the cytokine expression of myelin reactive T-cells in MS, we determined th e cytokine mRNA levels in a panel of blood derived MBP-specific T-cell clones derived from MS patients (33 clones) and normal controls (21 c lones), using a novel quantitative RT-PCR method. Our results demonstr ate that MBP-specific T-cells, both from MS patients and control subje cts, predominantly display a Th1- or Th0-like cytokine pattern. Althou gh MS clones express higher levels of TNF alpha and IL-10 mRNA, these differences do not reach statistical significance, Interestingly, sign ificantly increased TNF alpha and IFN gamma mRNA levels were observed among clones derived from HLA-DR2 positive versus HLA-DR2 negative MS patients. This HLA halpotype is known to be associated with MS. The hi gh levels of TNF alpha and IFN gamma mRNA observed in MBP-reactive T-c ell clones from MS patients indicate an important role of these cytoki nes in the disease process. Our data lend further support to the patho genic role of MBP-reactive T-cells in MS.