T regulatory cells are markedly diminished in diseased salivary glands of patients with primary Sjögren's syndrome.
OBJECTIVE
To investigate the abnormalities of T regulatory cells (Treg) in salivary glands and peripheral blood in patients with primary Sjögren's syndrome (pSS).


METHODS
Levels of CD4+CD25+ high T cells of the peripheral blood of 52 patients with pSS were measured by flow-cytometric assay. Lower lip salivary gland biopsies were examined by immunohistochemistry, using monoclonal mouse anti-human antibodies [CD25, CD4, CD8, CD68, forkhead transcription factor (Foxp3)] in 30 patients with pSS. Using real-time polymerase chain reaction, Foxp3 messenger RNA expression was assessed in the salivary glands and CD4+ T cells from peripheral blood.


RESULTS
Many inflammatory cells, predominantly CD4+ and CD8+ T cells and macrophages, were found in salivary glands of patients with SS, but CD4+CD25+ Treg numbers and Foxp3 expression were markedly reduced in those biopsy samples. Levels of CD4+CD25+ high T cells and Foxp3 expression in peripheral blood of patients with pSS were significantly lower than in healthy controls. However, the inhibitory function of CD4+CD25+ T cells in pSS was unchanged compared to that of controls. Peripheral CD4+CD25+ high T cell numbers in pSS did not correlate with Schirmer's test and salivary flow rate, or with the presence or absence of anti-SSA/SSB antibodies and immunoglobulin level.


CONCLUSIONS
The remarkable reduction of Treg numbers in salivary glands and reduction of CD4+CD25+ high T cells in peripheral blood suggests a possible role for absence of Treg in the pathogenesis of salivary gland destruction in pSS.
Department of Rheumatology and Immunology, Anhui Medical University Affiliated Provincial Hospital, Hefei, Anhui Province, China. Lixiaomei1@medmail.com.cn
Xiaomei
X
Li
Xiangpei
X
Li
Long
L
Qian
Guosheng
G
Wang
Hong
H
Zhang
Xiaoqiu
X
Wang
Ke
K
Chen
Zhimin
Z
Zhai
Qing
Q
Li
Yiping
Y
Wang
David C H
DC
Harris
D000328:Adult; D001707:Biopsy, Needle; D015704:CD4 Antigens / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000096:biosynthesis; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000097:blood; D008297:Male; D008875:Middle Aged; D012469:Salivary Glands / Q000473:pathology*; D012859:Sjogren's Syndrome / Q000097:blood / Q000473:pathology*; D016176:T-Lymphocyte Subsets; D050378:T-Lymphocytes, Regulatory
D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit