Abstract |
Systemic lupus erythematosus is characterized by the presence of high titers of autoantibodies reacting with various components of the U1 small nuclear ribonucleoprotein particle ( snRNP). It has been suggested that these antibodies are produced by an antigen-driven mechanism under the dependence of antigen-specific T cells. To investigate the role of T cell help in this process, we sought, with 20 overlapping peptides, the Th epitopes on the U1-70K snRNP in unprimed H-2(k) MRL / lpr lupus mice and immunized CBA normal mice. The peptide 131 - 151 was recognized by both IgG autoantibodies and CD4(+) T cells from 7 - 9-week-old MRL / lpr mice. In this test, antigen-presenting cells (APC) from MRL / lpr mice were required; APC from naive CBA mice failed to stimulate CD4(+) cells from MRL / lpr mice. The potential role of MRL / lpr B cells as APC, the expression of MHC class II molecules at their surface and their activation state (expression of CD69, CD80 / B7-1 and CD86 / B7-2 molecules) were studied. Peptide 131 - 151 bound both I-A(k) and I-E(k) class II molecules and favored an IL-2-positive T cell response but not IFN-gamma, IL-6 and IL-10 secretion. Segment 131 - 151 is localized within the RNP80 motif and contains residues that are highly conserved in many nuclear, nucleolar and cytoplasmic RNA binding proteins.
|
Authors | F Monneaux, J P Briand, S Muller |
Journal | European journal of immunology
(Eur J Immunol)
Vol. 30
Issue 8
Pg. 2191-200
(Aug 2000)
ISSN: 0014-2980 [Print] Germany |
PMID | 10940910
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Epitopes, T-Lymphocyte
- Peptide Fragments
- Ribonucleoprotein, U1 Small Nuclear
|
Topics |
- Amino Acid Motifs
- Animals
- Antigen-Presenting Cells
(physiology)
- Autoimmunity
- B-Lymphocytes
(immunology)
- CD4-Positive T-Lymphocytes
(immunology)
- Epitopes, T-Lymphocyte
- Female
- Lupus Vulgaris
(immunology)
- Lymphocyte Activation
- Mice
- Mice, Inbred BALB C
- Mice, Inbred CBA
- Mice, Inbred MRL lpr
- Peptide Fragments
(immunology)
- Ribonucleoprotein, U1 Small Nuclear
(immunology)
|