Objective: To investigate the influence of cyclosporine A (CsA) on the mRNA and protein expression of major histocompatibility (MHC) I and II.
Methods: 14 New Zealand white rabbits were randomly divided into three groups to be injected intramuscularly 5 mg/kg once a day for 30 days (low dose CsA group, n = 5), 20 mg/kg (high dose CsA group, n = 5), or normal saline (control group, n = 4). Peripheral blood sample was collected every 5 days, monouclear cells were isolated, total RNA was extracted, and 30 days later the rabbits were killed and their livers, spleens, kidneys, and thyroid glands were taken out, total RNA was extracted, RT-PCR and Western blotting were used to examine the mRNA and protein expression of MHCI and MHCII.
Results: The peripheral blood monouclear cell MHCI and MHCII mRNA expression levels on day 10 of the low dose CsA group were 1.78 +/- 0.15 and 7.30 +/- 0.51, both significantly higher than those before the injection of CsA (0.23 +/- 0.04 and 2.77 +/- 0.25, both P < 0.01); the MHCI and MHCII protein expression levels were 11.32 +/- 1.45 and 22.31 +/- 1.91, both significantly higher than those before the injection (2.31 +/- 0.14 and 12.52 +/- 1.23, both P < 0.01). In high dose CsA group, the MHCI and MHCII mRNA expression levels on day 10 were 4.72 +/- 0.28 and 14.20 +/- 2.58, both significantly higher than those before the injection (0.24 +/- 0.06 and 2.56 +/- 0.33, both P < 0.01); the protein expression levels were 13.81 +/- 1.38 and 24.22 +/- 2.88, both significantly higher than those before the injection (2.42 +/- 0.06 and 12.51 +/- 1.31, both P < 0.01). Since the day 15, the levels of MHCI and MHCII mRNA and protein expression levels began decrease gradually until the levels before the injection. By the end of the experiment there was no significant difference in the MHCI and MHCII mRNA and protein expression levels of the liver, spleen, kidney, and thymus among the 3 groups.
Conclusion: Cyclosporine can increase the host MHCI and MHCII expression for a period of time.