Vitamin D deficiency affects the immunity against Mycobacterium tuberculosis infection in mice.

The aim of the study is to investigate the immunological changes after stimulation with bacillus Calmette-Guerin (BCG) in mice with vitamin D deficiency. After weaning, mice were divided into the vitamin D-deficient group (-D group), the normal group (N group), and the vitamin D-supplemented group (+D group). Twelve-week-old mice were intraperitoneally injected with 0.5 mg/ml BCG (≥1.0 × 10(6) CFU/mg) and maintained for 6 weeks. Spleen lymphocytes were isolated, and the percentages of CD4(+) and CD8(+) lymphocytes were determined by flow cytometry. IFN-γ levels, IL-10 levels, and the TB-PPD-specific antibody titer were determined by ELISA. The inter-group difference was analyzed using one-way ANOVA, and multiple comparisons were analyzed using the LSD test. The percentage of CD4(+) cells was 27.1 ± 0.6 in the -D group, 23.62 ± 0.42 in the N group, and 19.46 ± 0.32 in the +D group (P < 0.05). The percentage of CD8(+) lymphocytes was 12.15 ± 0.61 in the -D group, 8.7 ± 0.64 in the N group, and 7.12 ± 0.48 in the +D group (P < 0.05). The CD4(+)/CD8(+) ratio was 2.23 ± 0.15 in the -D group, 2.71 ± 0.21 in the N group, and 2.73 ± 0.31 in the +D group (P < 0.05). The plasma IFN-γ levels were 416.42 ± 16.42 pg/ml in the -D group, 325.41 ± 11.16 pg/ml in the N group, and 276.26 ± 25.32 pg/ml in the +D group (P < 0.005). The plasma IL-10 levels were 16.45 ± 1.58 pg/ml in the -D group, 24.31 ± 2.16 pg/ml in the N group, and 26.28 ± 0.42 pg/ml in the +D group (P < 0.005). The serum TB-PPD-specific antibody level was significantly higher in the -D group than in the N and +D groups. Vitamin D deficiency affects the immunity against Mycobacterium tuberculosis infection in mice.