DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.48120#0045
Abstracts
27
(mAbs) appeared to cross-react with proteins A and B" (and thus with U1 and
U2 snRNPs) whereas one exclusivley recognized protein B" (and consequently
reacted only with U2 snRNPs). Epitope mapping employing a DNase I fragment
library of the B" cDNA showed that the three mAb-reactive regions were discon-
tinuous and that they substantially overlapped. All three mAb-reactive epitopes
comprised the epitope 2 analogue of protein B". Competition experiments with
anti-(Ul, U2)RNP patients sera showed that all three monoclonal antibodies
defined autoimmune reactive sites.
From the above findings it is concluded that the anti-snRNP immune response
in patients with connective tissue diseases is polyclonal and most probably an-
tigen-driven.
References
1. HABETS, W. J., SlLLEKENS, P.T.G., HOET, M.H., SCHALKEN, J. A., ROEBROEK, A. J.M.
Leunissen, J.A.M., Van De Ven, W. J. M., Van Venrooij, W. J. (1987): Analysis of
a cDNA clone expressing a human autoimmune antigen: full-lenght sequence of the U2
small nuclear RNA-associated B" antigen. Proc. Natl. Acad. Sci. USA 84, 2421-2425
2. Sillekens, P.T.G., Habets, W. J.A., Beijer R. P, Van Venrooij, W. J. (1987): cDNA
cloning of the human U1 snRNA associated A protein: Extensive homology between
U1 and U2 snRNP specific proteins. EMBO J. 6, 3841-3848
3. Habets, W. J., Sillekens, P.T. G., Hoet, M.H., McAllister, G., Lerner, M.R.,
Van Venrooij, W. J.: B cell autoepitopes of the human U1 snRNP-specific A protein
are immunologically conserved in small nuclear ribonucleoproteins. Proc. Natl. Acad.
Sci. USA in press
Clinical Significances of Rare Autoantibodies to Small Nuclear and
Cytoplasmic Ribonucleoproteins
N. Hama, T. Mimori, M. Akizuki, and M. Homma
Keio University School of Medicine, Tokyo, Japan
This study attempts to clarify the clinical significances of infrequent autoan-
tibodies reactive with small nuclear and cytoplasmic ribonucleoproteins.
405 sera from patients with connective tissue diseases were screened by protein
A-facilitated immunoprecipitation (Lerner-Steitz assay) using 32P-labeled
HeLa cell extracts as antigen sources. Immunoprecipitated RNAs were frac-
27
(mAbs) appeared to cross-react with proteins A and B" (and thus with U1 and
U2 snRNPs) whereas one exclusivley recognized protein B" (and consequently
reacted only with U2 snRNPs). Epitope mapping employing a DNase I fragment
library of the B" cDNA showed that the three mAb-reactive regions were discon-
tinuous and that they substantially overlapped. All three mAb-reactive epitopes
comprised the epitope 2 analogue of protein B". Competition experiments with
anti-(Ul, U2)RNP patients sera showed that all three monoclonal antibodies
defined autoimmune reactive sites.
From the above findings it is concluded that the anti-snRNP immune response
in patients with connective tissue diseases is polyclonal and most probably an-
tigen-driven.
References
1. HABETS, W. J., SlLLEKENS, P.T.G., HOET, M.H., SCHALKEN, J. A., ROEBROEK, A. J.M.
Leunissen, J.A.M., Van De Ven, W. J. M., Van Venrooij, W. J. (1987): Analysis of
a cDNA clone expressing a human autoimmune antigen: full-lenght sequence of the U2
small nuclear RNA-associated B" antigen. Proc. Natl. Acad. Sci. USA 84, 2421-2425
2. Sillekens, P.T.G., Habets, W. J.A., Beijer R. P, Van Venrooij, W. J. (1987): cDNA
cloning of the human U1 snRNA associated A protein: Extensive homology between
U1 and U2 snRNP specific proteins. EMBO J. 6, 3841-3848
3. Habets, W. J., Sillekens, P.T. G., Hoet, M.H., McAllister, G., Lerner, M.R.,
Van Venrooij, W. J.: B cell autoepitopes of the human U1 snRNP-specific A protein
are immunologically conserved in small nuclear ribonucleoproteins. Proc. Natl. Acad.
Sci. USA in press
Clinical Significances of Rare Autoantibodies to Small Nuclear and
Cytoplasmic Ribonucleoproteins
N. Hama, T. Mimori, M. Akizuki, and M. Homma
Keio University School of Medicine, Tokyo, Japan
This study attempts to clarify the clinical significances of infrequent autoan-
tibodies reactive with small nuclear and cytoplasmic ribonucleoproteins.
405 sera from patients with connective tissue diseases were screened by protein
A-facilitated immunoprecipitation (Lerner-Steitz assay) using 32P-labeled
HeLa cell extracts as antigen sources. Immunoprecipitated RNAs were frac-