[Abnormal interferon-inducible protein-10 expression in the labial glands of patients with Sjogren's syndrome].
OBJECTIVE
To investigate whether interferon-inducible protein 10 (IP-10) is involved in the inflammatory process of the labial gland of patients with Sjogren's Syndrome (SS).


METHODS
Forty-nine patients performed labial gland biopsy, the number of lymphocytes in the biopsy tissues was calculated and the IP-10 was detected by the methods as following: 39 biopsied labial tissues were examined by RT-PCR, among them, 21 were from primary SS, 5 from secondary SS and 13 from other diseases. With RT-PCR, the IP-10 and beta-actin were co-amplified with specific primers. The gel-fractioned and ethidium bromide amplification products were then analyzed by densitometry. The expression of IP-10 was semi-quantificated by IP-10/beta-actin ratio. Twenty-one samples were examined by immunohistochemistry with specific goat anti-IP-10 antibody, 10 of them from primary SS, 3 from secondary SS, 8 from other diseases. 11 out of 21 samples were examined by both RT-PCR and immunohistochemistry.


RESULTS
The expression of IP-10 mRNA was significantly up-regulated in labial glands of patients with SS compared with other diseases (IP-10/beta-actin ratio was 0.329 +/- 0.157 vs 0.099 +/- 0.059, P < 0.01). The number of lymphocyte infiltration foci in labial glands of patients with SS correlated to the IP-10/beta-actin ratio (r = 0.657, P < 0.05). Ductal epithelial cells and some of the infiltrating lymphocytes were stained by anti-IP-10 antibody by immunohistochemistry in 8 of the primary SS (8/10), all of the secondary SS (3/3) and one with primary biliary sclerosis (1/8). The expression of IP-10 protein detected by immunohistochemistry was consistent with that of mRNA detected by RT-PCR.


CONCLUSIONS
IP-10 is abnormally highly expressed in the labial glands of patients with SS and positively relates to the lymphocyte infiltration. It thus suggests chemokine IP-10 may be one of the important molecules attracting the lymphocytes to the minor salivary glands to form the lymphocytic foci of Sjogren's Syndrome.
Zhou
Wei
W
Department of Rheumatology and Clinical Immunology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China.
Dong
Yi
Y
Zhao
Yan
Y
Tang
Fu-lin
FL
D000328:Adult; D054357:Chemokine CXCL10; D019743:Chemokines, CXC / Q000096:biosynthesis* / Q000235:genetics; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008046:Lip / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012470:Salivary Glands, Minor / Q000378:metabolism*; D012859:Sjogren's Syndrome / Q000378:metabolism*; D015854:Up-Regulation
D054357:Chemokine CXCL10; D019743:Chemokines, CXC; D012333:RNA, Messenger