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

Abstract

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 0.5mg/ml BCG (≥1.0×10(6)CFU/mg) and maintained for 6weeks. 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±16.42pg/ml in the -D group, 325.41±11.16pg/ml in the N group, and 276.26±25.32pg/ml in the +D group (P<0.005). The plasma IL-10 levels were 16.45±1.58pg/ml in the -D group, 24.31±2.16pg/ml in the N group, and 26.28±0.42pg/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.