To observe the effectof herbal cake separatedmoxibustion on themethylation of ignaling lymphocytic activation molecule（SLAM）and poliovirus related receptor 2 gene（PVRL2）and the costimulatory molecule［tumor necrosis factor superfamily member 9（4-1BB）］in immunosuppressed rats.

Fifty SD ratswere random ly divided into blank group，immunosuppressivemodel group，herbal cake separated moxibustion group，fake cakemoxibustion group and Chinese herbalmedicine gavage group，with 10 rats in each group. The modelwasmade by intraperitoneal injection of cyclophosphamide，and the other groups except the blank group set up themodelwith the dose of 30 mg/kg for 3 days.“Shenque（RN8）”“Guanyuan（RN4）”“Zhongwan（RN12）”and“ Zusanli（ST36）（double）”were selected for intervention in the herbal cake separated moxibustion group and the fake cakemoxibustion group for 10 consecutive days. The Chinese herbalmedicine gavage group was given Liuwei Dihuang Decoction（六味地黄汤）suspension for 10 days. The number of white blood cells（WBC）in each group was detected by blood routine，and the contents of CD28，4-1BB，tumor necrosis factor ligand superfamily member 9（4-1BBL）and interleukin-17（IL-17）in serum were detected by ELISA. The average fluorescence intensity of4-1BB and 4-1BBL in spleen tissue was detected by immunofluorescence. BSP method was used to detect SLAM and PVRL2.

The blood routine results showed that compared with those of the blank group，the white blood cells in the model group were significantly reduced. ELISA results showed that compared with those of the blank group，the levels of CD28，4-1BB and IL-17 in the immunosuppressive model group were significantly increased. Compared with those of the immunosuppressivemodel group，the levels of CD28，4-1BB and IL-17 in the herbal cake separatedmoxibustion group were significantly decreased. The results of immunofluorescence showed that the average fluorescence intensity of 4-1BB and 4-1BBL in the mmunosuppressivemodel group was significantly higher than that in the blank group. Compared with those of the model group，the fluorescence intensities of 4-1BB and 4-1BBL in the herbal cake separated moxibustion group were significantly decreased. The methylation results showed that compared with those of the blank group，the methylation rates of SLAM and PVRL2 promoter regions in the mmunosuppressivemodel group were decreased. Compared with those of themodel group，themethylation rate of SLAM in the herbal cake separated moxibustion group increased，but the methylation rate of PVRL2 decreased.

Herbal cake separated moxibustion may improve the immunosuppressive state by regulating the methylation level of costimulatorymolecule 4-1BB and its ligand as well as SLAM，thereby significantly improving the immune function.