Analysis of NKT cells and related cytokines in peripheral blood of the patients with primary biliary cirrhosis / 中华检验医学杂志

ABSTRACT

Objective To analyze and evaluate the changes of quantity and function of TCBVα24+ Vβ11+ NKT in PBMC of the patients with PBC and its relationship with the occurrence of PBC. Methods Flow cytometry was utilized to count TCRVα24+ Vβ11+ NKT cells in PBMC in 60 cases of PBC and 60 cases of age-matched and gender-matched controls. NKT cells were activated and expanded by α-galcer and IL-2 in vitro. The percentages of positive NKT cells expressing IL-4 and IFN-γ were determined by ICS-FC. The levels of serum IL-4 and IFN-γ were tested by ELSIA. The numbers of cells secreting IFN-γ and IL-4 were detected by ELISpot. Results The ratios of NKT cells in PBC group were [0. 16(0. 11-0. 26) ]% before expansion and [0. 82 (0. 61-0. 89) ]% after expansion, significantly lower than control group [(0.33 (0.27-0.38) ]% and [27.40 (23.52-33.87) ]%, respectively, (Z=6.563, 7.707, P<0. 01 ). Seven days after expansion by α-galcer and IL-2, the expansion folds of NKT cells were 96. 05 (80.50-100.27) in PBC group and 134.65 (121.60-142. 13) in control group, respectively (Z =6.462,P < 0. 01 ). At the same time, the ratio of IFN-γ+ and TCRVα24+ Vβ11+ NKT detected by ICS-FC in PBC group was significantly higher than that in control group [ 38. 98 ( 36.73-42. 98 ) ]% vs [ 34. 56 ( 30. 12-36. 78 ) ] %, Z = 3. 158, P < 0. 05, while the ratio of IL-4+ and TCRVα24 + Vβ11+ NKT cells in PBC group was significantly lower than that in control group[0. 193(0. 179-0. 218) ]% vs [34. 36 (30. 93-38. 77) ]%,Z =6. 476, P <0. 01. The number of IFN-γ SFC detected by ELISpot were [410(380 ~500) ] SFC/1 × 106 PBMC in PBC group and [ 340(280 ~ 390)] SFC/1 × 106 PBMC in control group, respectively (Z = 4. 312, P <0. 05). The levels of serum IFN-γ in PBC group and control group were (67.21 ± 11.27) ng/L and (31.45 ± 8. 17) ng/L, respectively ( t = 27.25, P < 0. 01 ). The level of IFN-γ in PBC group was higher than that of control group. The number of IL-4 SFC were [73(60 ~ 100) ]SFC/1 × 106 PBMC in PBC group vs [245(230 -280) ] SFC/1 × 106 PBMC in control group, Z=5. 112,P <0. 01. The levels of serum IL-4 in PBC group and control group were (12.65 ±4. 17) μ/L and (28.31 ±6.31) μg/L, respectively (t =25.34,P < 0. 01 ). The level of IL-4 in PBC group was lower than that of control group. Conclusions The quantity of TCRVα2.4+ Vβ11+ NKT in PBC group is lower than that in control group. After in vitro activation, the capacity of expansion and producing IL-4 of NKT is decreased in PBC group, while the capacity of producing IFN-γ of NKT is increased in PBC group. The reduction of NKT cells and the immune dysfunction may be one of the important factors in the pathogenesis of PBC.