Identification of Ro(SSA) 52 kDa reactive T cells in labial salivary glands from patients with Sjögren's syndrome.
OBJECTIVE
To identify the self-antigens recognized by autoreactive T cells in labial salivary glands from patients with Sjõgren's syndrome (SS).


METHODS
T cells lines were established from infiltrating T cells in the labial salivary glands from 6 patients with SS, using interleukin 2 and phytohemagglutinin. Bulk cultured T cells and T cell lines were examined for the proliferative response to recombinant Ro(SSA) 52 kDa and SSB proteins. The usage of T cell receptor (TCR) V beta and V alpha genes from Ro(SSA) 52kDa reactive T cells was analyzed by family polymerase chain reaction. The sequences of complementary determining region 3 of TCR V beta genes were also examined.


RESULTS
Three of 6 bulk cultured T cells and 4 of 16 T cell lines showed a significant proliferative response to Ro(SSA) 52 kDa protein. All T cell lines represented CD4+ alpha beta T cells by flow cytometry analysis. All 4 RO(SSA) 52 kDa reactive T cell lines utilized the V beta 2 gene and 3 lines used the V beta 13 gene, suggesting preferential usage of the V beta 2 and the V beta 13 genes in Ro(SSA) 52 kDa reactive T cells. Junctional sequences of TCR V beta genes from Ro(SSA) 52 kDa reactive T cell lines showed the conserved amino acid sequences in CDR3 region.


CONCLUSIONS
These findings support the notion that Ro(SSA) 52 kDa is a possible autoantigen recognized by autoreactive T cells and that limited epitope is present on the Ro(SSA) 52 kDa antigen.
Namekawa
T
T
Second Department of Internal Medicine, School of Medicine, Chiba University, Japan.
Kuroda
K
K
Kato
T
T
Yamamoto
K
K
Murata
H
H
Sakamaki
T
T
Nishioka
K
K
Iwamoto
I
I
Saitoh
Y
Y
Sumida
T
T
D000595:Amino Acid Sequence; D001324:Autoantigens / Q000276:immunology*; D001483:Base Sequence; D015704:CD4 Antigens / Q000276:immunology; D002455:Cell Division; D002460:Cell Line; D005796:Genes; D006801:Humans; D008046:Lip; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D020733:RNA, Small Cytoplasmic; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology; D012261:Ribonucleoproteins / Q000276:immunology*; D012469:Salivary Glands / Q000276:immunology*; D012859:Sjogren's Syndrome / Q000276:immunology* / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D000099207:SS-A Antigen
D001324:Autoantigens; D015704:CD4 Antigens; D015335:Molecular Probes; D020733:RNA, Small Cytoplasmic; D016693:Receptors, Antigen, T-Cell, alpha-beta; D012261:Ribonucleoproteins; D000099207:SS-A Antigen; C116006:RO60 protein, human