To investigate the effect of secondary lymphoid tissue chemokine (SLTC) and its receptor CCL21/CCR7 on chemotaxis of peripheral blood lymphocytes in the patients with Sjögren's syndrome (SS) and explore their roles in the SS pathogenesis.
Thirty-one SS patients were selected, including 18 primary SS patients (pSS) and 13 secondary SS (sSS) patients. In addition, 20 healthy persons were selected as normal controls. Peripheral blood lymphocytes were isolated from all the SS patients and normal controls. The cell trans-membrane test with 24-well transwells was used to detect the effect of CCL21/CCR7 on the lymphocyte migration.
In the presence of CCL21, the chemotactic indexes (CIs) of lymphocytes from pSS and sSS patients were 2.92±0.12 and 2.80±0.28, respectively. Both of them were significantly higher than that of normal controls (CI=1.32±0.11, P<0.01), while there was no difference between pSS and sSS patients. After anti-CCR7 mAb pretreatment, the lymphocyte CIs of pSS and sSS patients respectively, decreased significantly to 1.04±0.05 and 1.03±0.08 as compared with untreated controls.
CCR7 is the one of the important factors resulting in lymphocyte migration. CCL21/CCR7 interaction mediates the migration of peripheral lymphocytes in SS patients and may be involved in the gland damage due to the infiltration of massive lymphocytes in exocrine glands in SS patients.