Visualization of myelin basic protein (MBP) T cell epitopes in multiple sclerosis lesions using a monoclonal antibody specific for the human histocompatibility leukocyte antigen (HLA)-DR2-MBP 85-99 complex.
Susceptibility to multiple sclerosis (MS) is associated with the human histocompatibility leukocyte antigen (HLA)-DR2 haplotype, suggesting that major histocompatibility complex class II-restricted presentation of central nervous system-derived antigens is important in the disease process. Antibodies specific for defined HLA-DR2-peptide complexes may therefore be valuable tools for studying antigen presentation in MS. We have used phage display technology to select HLA-DR2-peptide-specific antibodies from HLA-DR2-transgenic mice immunized with HLA-DR2 molecules complexed with an immunodominant myelin basic protein (MBP) peptide (residues 85-99). Detailed characterization of one clone (MK16) demonstrated that both DR2 and the MBP peptide were required for recognition. Furthermore, MK16 labeled intra- and extracellular HLA-DR2-MBP peptide complexes when antigen-presenting cells (APCs) were pulsed with recombinant MBP. In addition, MK16 inhibited interleukin 2 secretion by two transfectants that expressed human MBP-specific T cell receptors. Analysis of the structural requirement for MK16 binding demonstrated that the two major HLA-DR2 anchor residues of MBP 85-99 and the COOH-terminal part of the peptide, in particular residues Val-96, Pro-98, and Arg-99, were important for binding. Based on these results, the antibody was used to determine if the HLA-DR2-MBP peptide complex is presented in MS lesions. The antibody stained APCs in MS lesions, in particular microglia/macrophages but also in some cases hypertrophic astrocytes. Staining of APCs was only observed in MS cases with the HLA-DR2 haplotype but not in cases that carried other haplotypes. These results demonstrate that HLA-DR2 molecules in MS lesions present a myelin-derived self-peptide and suggest that microglia/macrophages rather than astrocytes are the predominant APCs in these lesions.
Krogsgaard
M
M
Department of Pharmacology, Royal Danish School of Pharmacy, DK-2100 Copenhagen, Denmark.
Wucherpfennig
K W
KW
Cannella
B
B
Hansen
B E
BE
Svejgaard
A
A
Pyrdol
J
J
Ditzel
H
H
Raine
C
C
Engberg
J
J
Fugger
L
L
Canella
B
B
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D004331:Drosophila melanogaster; D015802:HLA-DR2 Antigen / Q000378:metabolism*; D006801:Humans; D016056:Immunodominant Epitopes / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009103:Multiple Sclerosis / Q000235:genetics / Q000276:immunology*; D004676:Myelin Basic Protein / Q000235:genetics / Q000276:immunology*; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology
D000911:Antibodies, Monoclonal; D015802:HLA-DR2 Antigen; D016056:Immunodominant Epitopes; D004676:Myelin Basic Protein; D010446:Peptide Fragments; D011994:Recombinant Proteins