Novel autoantibodies directed against the common tertiary configuration of transfer RNA in a patient with interstitial lung disease.
OBJECTIVE
To identify and characterize a novel autoantibody, anti-WS, that binds total transfer RNA (tRNA).


METHODS
Serum from patient WS, who had polyarthritis, Sjögren's syndrome, Raynaud's phenomenon, and interstitial pulmonary fibrosis, was used in this study. Characteristics of anti-WS and antibody-reactive determinants of tRNA were investigated by 32P immunoprecipitation using HeLa cell RNA and deletion mutants of tRNA transcribed in vitro.


RESULTS
WS serum produced nucleolar and cytoplasmic staining on indirect immunofluorescence. 32P immunoprecipitation assays demonstrated that this serum immunoprecipitated total tRNAs and 5.8S and 5S ribosomal RNAs from 32P-labeled HeLa cell extract. When deproteinized RNA was used as antigen source, total tRNAs were still precipitated by WS serum. An immunoprecipitation study, using various deletion mutants of Escherichia coli tRNA, demonstrated that both D and T psi C loops were needed for antibody binding. Substitution of nucleotide 18G with 18A of E coli tRNA(Trp), which is essential in the formation of the tertiary "L" shape of tRNA, inhibited binding by anti-WS antibodies.


CONCLUSIONS
Anti-WS antibodies are novel autoantibodies directed against tRNAs. The antibody binding site is the common L-shaped tertiary structure conformed by the D loop and T psi C loop of tRNA, suggesting that the antibodies are induced by a conserved sequence among all species. Furthermore, these antibodies could be a marker for a newly recognized subset of connective tissue disease.
Matsumura
M
M
Keio University School of Medicine, Tokyo, Japan.
Ohosone
Y
Y
Miyachi
K
K
Akizuki
M
M
Matsuoka
Y
Y
Irimajiri
S
S
Shimizu
M
M
Mimori
T
T
D001323:Autoantibodies / Q000032:analysis*; D004926:Escherichia coli / Q000737:chemistry; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D017353:Gene Deletion; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000276:immunology*; D008875:Middle Aged; D016296:Mutagenesis / Q000276:immunology; D010761:Phosphorus Radioisotopes; D011233:Precipitin Tests; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D012349:RNA, Transfer, Asp / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D012354:RNA, Transfer, His / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D012362:RNA, Transfer, Ser / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D012364:RNA, Transfer, Trp / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D012366:RNA, Transfer, Val / Q000737:chemistry / Q000235:genetics / Q000276:immunology
D001323:Autoantibodies; D010761:Phosphorus Radioisotopes; D012349:RNA, Transfer, Asp; D012354:RNA, Transfer, His; D012362:RNA, Transfer, Ser; D012364:RNA, Transfer, Trp; D012366:RNA, Transfer, Val; D012343:RNA, Transfer