[Effects of herbal cake separated moxibustion on Tim-4 and ubiquitination of PD-1 in rabbits with immunosuppression].

OBJECTIVE: To observe the effects of herbal cake separated moxibustion on macrophage effector molecule T-cell immunoglobulin and mucin-domain containing-4 (Tim-4) and ubiquitination of programmed cell death protein 1 (PD-1) in rabbits with immunosuppression, and to explore the possible mechanism on herbal cake separated moxibustion in improving immunosuppression. METHODS: Thirty-two big-ear white rabbits were randomly divided into a normal group, a model group, a moxa stick moxibustion group and a herbal cake separated moxibustion group, 8 rabbits in each group. Except the normal group, the immunosuppression model was established by intraperitoneal injection of cyclophosphamide of60 mg/kg in the other 3 groups. "Shenque" (CV 8), "Shenshu" (BL 23), "Zusanli" (ST 36), etc. were selected in both the moxa stick moxibustion group and the herbal cake separated moxibustion group. Moxa stick moxibustion was applied in the moxa stick moxibustion group, one cone at each acupoint; herbal cake separated moxibustion was applied in the herbal cake separated moxibustion group, 5 cones at each acupoint. The intervention was given once every other day for 10 times in both groups. Leukocyte content in peripheral blood was detected by blood cell analyzer; the positive expression of PD-1 in CD+4 T lymphocytes, CD+8T lymphocytes and CD+68 macrophages in peripheral blood was measured by flow cytometry, the serum levels of interleukin 2 (IL-2), CD8, CD68 and Tim-4 were detected by ELISA, and the expression of Tim-4 and F-box only protein 38 (FBXO38) in the liver and spleen tissues was measured by immunohistochemistry. RESULTS: Compared with the normal group, in the model group, white blood cell count (WBC) and percentage of neutrophils (NEU%) were decreased while percentage of lymphocyte (LYM%) was increased (P<0.01) in peripheral blood; the positive expression rates of PD-1 in CD+4 T lymphocytes, CD+8T lymphocytes and CD+68 macrophages in peripheral blood were increased (P<0.01); the serum levels of IL-2, CD68 and Tim-4 were increased (P<0.01), the serum level of CD8 was decreased (P<0.01); the average optical density (AOD) of Tim-4 in the liver tissue and FBXO38 in the liver and spleen tissues was increased (P<0.01). Compared with the model group, in the moxa stick moxibustion group and the herbal cake separated moxibustion group, WBC and NEU% were increased (P<0.01); the positive expression rates of PD-1 in CD+4 T lymphocytes, CD+8T lymphocytes and CD+68 macrophages in peripheral blood were decreased (P<0.01); the serum levels of IL-2, CD68 and Tim-4 were decreased (P<0.01), the serum levels of CD8 were increased (P<0.01); the AOD of Tim-4 and FBXO38 in the liver tissue and FBXO38 in the spleen tissue was decreased (P<0.01, P<0.05). Compared with the moxa stick moxibustion group, in the herbal cake separated moxibustion group, the positive expression rate of PD-1 in CD+68 macrophages in peripheral blood was increased (P<0.05); serum level of Tim-4 was increased (P<0.01); AOD of Tim-4 in the liver tissue was decreased (P<0.05). CONCLUSION: Herbal cake separated moxibustion can improve immunosuppression by regulating the expression of macrophage effector molecule Tim-4 and the FBXO38 mediated ubiquitination of PD-1, Tim-4 may be one of the specific indexes of immunomodulation involving with herbal cake separated moxibustion.