Showing papers by "Marco Salvetti published in 1993"

Predominant and stable T cell responses to regions of myelin basic protein can be detected in individual patients with multiple sclerosis.

Abstract: T lymphocytes from patients with multiple sclerosis (MS) recognize multiple myelin basic protein (MBP) epitopes. This situation complicates the design of specific immunotherapies. We investigated to which extent the T cell response to MBP is heterogeneous in single subjects in terms of preferentially recognized regions of the molecule, major histocompatibility complex (MHC) restriction, and stability over time. From each of nine patients with MS, a minimum of six MBP-specific T lymphocyte lines (TLL) were assayed for the proliferative response to a panel of overlapping peptides, encompassing the whole MBP. Predominant Tcell recognitions of distinct MBP regions were present in three patients, all HLA-DR2+, independently of the clinical features of their disease. Tcell reactivity was preferentially directed to residues 16-38 in one patient. In this case the response was also stable over time, during different phases of the disease. Predominant reactivity to residues 86-99 was detected in the two other DR2+ patients. In each of the patients with other HLA-DR haplotypes (DR2−), as well as in three DR2+ non-MS donors, the Tcell response to MBP appeared to be considerably more heterogeneous. The HLA restriction element varied among TLL recognizing the same MBP region, even when raised from the same individual. The genomic HLA typing, performed on the DRB1 and DRB5 genes in the DR2+ subjects, showed no obvious correspondence between preferential responses to regions of MBP and HLA-DR2 subtypes. In this context, a simple, new method for the genomic typing of the HLA-DRB1 gene in individuals with the HLA-DR2 serological specificity is also described. We conclude that predominant and stable T cell responses to a single MBP region can be detected in some patients with MS. In these individuals, the MHC restriction of the T cell recognition of predominant regions appears to be variable. Polymorphisms of the HLA-DR2 gene products alone do not account for the selection of the dominant MBP Tcell epitope.

Target epitopes of myelin basic protein specific T cell lines in multiple sclerosis

Abstract: A highly efficient new method for the generation of antigen specific T cell lines (TCL) is now available. By this method we established 134 myelin basic protein (MBP) TCL from the peripheral blood of 9 patients with definite multiple sclerosis (n=69) and 8 healthy donors (n=65). The yield of MBP reactive TCL in the two groups was comparable. So far 22 MBP specific TCL from 7 patients and 24 from 7 healthy individuals have been tested for their proliferative response to a panel of four synthetic peptides representing MBP residues 7–26, 80–99, 139–153 and 148–162. Although the peptide sequences did not encompass the whole MBP, the pattern of reactivity to these peptides in patients and controls seems to be similar. Further, when multiple TCL from the same donor were analysed, no dominant recognition emerged.