[The correlation between dendritic cell-specific ICAM-3 grabbing nonintegrin expression and Mycobacterium tuberculosis in humans].

To investigate the correlation between dendritic cell-specific ICAM-3 grabbing nonintegrin (DC-SIGN) expression and Mycobacterium tuberculosis in humans. The peripheral blood mononuclear cells were obtained respectively from 25 patients with tuberculosis, 25 patients with pneumonia and 25 healthy individuals, and were cultured in medium with GM-CSF and IL-4. Five days later, expression of CD(11c), CD(86), HLA-DR and DC-SIGN were detected by flow cytometry. The expression of DC-SIGN mRNA was detected by RT-PCR. The levels of IL-12 and IL-10 in the supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Proliferation induction of T lymphocytes dendritic cells (DCs) was measured by mixed lymphocyte reaction (MLR). The expression of CD(86) on DCs in the tuberculosis patients [(72 +/- 11)%] was significantly lower than those in the other 2 groups [(87 +/- 16)%, (92 +/- 6)%] (F = 11.97, P < 0.01). In patients with tuberculosis, the expression of DC-SIGN on DCs [(85 +/- 8)%] was significantly higher than the other 2 groups [(60 +/- 28)%, (62 +/- 13)%] (F = 8.27, P < 0.01), and so was the DC-SIGN mRNA level (F = 3.99, P < 0.05). The levels of IL-10 secreted by DCs in the tuberculosis patients [(98 +/- 31) ng/L] were significantly higher than those in the other 2 groups [(74 +/- 38) ng/L and (66 +/- 27) ng/L] (F = 4.19, P < 0.05). MLR showed lower potency of proliferation induction of T lymphocytes in the tuberculosis patients (1858 +/- 628) than the other 2 groups (3066 +/- 1389), (3383 +/- 1163) (F = 7.92, P < 0.01). Expression of CD(11c) and HLA-DR on DCs and IL-12 levels were not significantly different among the 3 groups (P > 0.05). The decreased DC maturity, elevated IL-10 secretion by DCs, decreased proliferation induction of T lymphocytes and impaired immune response may be due to overexpression of DC-SIGN in patients with tuberculosis.