Research on the effects of CD137 signaling on the function of CD3^-CD56^+NK cells

Objective： To investigate the effects of CD137 signaling on the regulation of CD3-CD56＋NK cells function. Methods： CD3 CD56＋NK cells were treated with CD137 mAb or mouse IgG 1 isotype control to study the effects of CD 137 signaling on the function of CD3-CD56＋NK cells. Cytotoxicity was measured by LDH activity in the supernatants of cell cultures; NKG2D and LFA-I expression on CD3-CD56＋NK cells were analyzed by flow cytometry. Results： CD137 was expressed on activated CD3-CD56＋NK cells. The CD137 mAb enhanced the ability of CDB-CD56＋NK cells to kill lung cancer cells（A549）; Further studies revealed that the expression of NKG2D and LFA-1 was significantly increased in activated cells, and blockade of NKG2D and LFA-1 dramatically attenuated CD3CD56＋NK cytolysis of A549 cancer cells. Conclusion： CD 137 signaling increases the ability of CD3-CD56＋NK cells to kill cancer cells via up- regulating the expression of NKG2D and LFA-1.

Depletion but Activation of CD56dimCD16+ NK Cells in Acute Infection with Severe Fever with Thrombocytopenia Syndrome Virus

Severe fever with thrombocytopenia syndrome(SFTS)is an emerging infectious disease with high mortality(12%–30%).The mechanism by which the SFTS bunyavirus(SFTSV)causes severe illness remains unclear.To evaluate the phenotypic and functional characteristics of the NK cell subsets in SFTS patients,twenty-nine SFTS patients were sequentially sampled from admission until recovery.Phenotypic and functional characteristics of NK cell subsets in circulating blood were analysed via flow cytometry.Then,correlations between NK cell subset frequencies and the SFTS index(SFTSI)were evaluated in all SFTS patients(15 mild,14 severe)upon admission.The frequencies of CD56dimCD16+NK cells were greatly decreased in early SFTSV infection and were negatively correlated with disease severity.Additionally,higher Ki-67 and granzyme B expression and relatively lower NKG2 A expression in CD56dimCD16+NK cells were observed in acute infection.Moreover,the effector function of CD56dimNK cells was increased in the acute phase compared with the recovery phase in nine severe SFTS patients.Additionally,interleukin(IL)-15,interferon(IFN)-a,IL-18 and IFN-c secretion was markedly increased during early infection.Collectively,despite depletion of CD56dimCD16+NK cells,activation and functional enhancement of CD56dimCD16+NK cells were still observed,suggesting their involvement in defence against early SFTSV infection.

The Hematopoietic and Immunomodulatory Effect of rhIL-12 for Liver Cancer

Purpose: To explore the effect of rhIL-12 on the number of the blood cells and CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells in liver cancer patients following radiation therapy. Methods: We selected forty liver cancer patients who carried out by cyber knife (the patients were given 5 Gy every time for 5 times continuously) to observe the size of the tumor. After thirty hours, rhIL-12 was injected into the liver cancer patients via subcutaneous at the concentration of 50 ng/kg, 100 ng/kg, 200 ng/kg and 300 ng/kg in different patients, respectively. And there were ten patients in the four groups, respectively. The twenty patients who were selected from the hospital without rhIL-12 treatment were used as controls. All the blood cells were collected from different groups on day 0, hour 12, day 7, day 14, day 21 and day 28 after rhIL-12 treatment, respectively. The full number of blood cells in every group was analyzed by ELISA. The number of CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells were detected by Flow Cytometry. After one month with rhIL-12 treatment, ECOG and WHO were used to evaluate the prognosis of liver cancer. Results: In present study, we found that the number of blood cells was significantly decreased on day 0 - day 3, while recovered from day 7 - day 14 and down-regulated on day 21 after rhIL-12 treatment. The number of CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells was elevated with any concentration of rhIL-12. Furthermore, results showed that number of white blood cells was obviously higher than in patients without rhIL-12 treatment (P < 0.05). However, there was no significant difference of erythrocyte and platelet, between groups treated with rhIL-12 and control groups. In addition, the immune cells including CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells were reduced on day 0 - day 3, recovered from day 7, and then decreased from day 21 in rhIL-12 treatment groups related to control groups (P < 0.05). Furthermore, studies showed that five patients developed symptoms of fever, bilirubin increased and liver dysfunction with the dose of 300 ng/kg. So we found that the safe and well-tolerated human dose of 200 ng/kg is within this efficacious range based on exposure parameters through the research. Higher ECOG and WHO scores were observed in rhIL-12 treatment groups compared to control groups (P = 0.025, P = 0.044, respectively). Conclusion: Our results suggested that rhIL-12 could recover the liver cancer induced aberrant blood cell number and CD4/8+ T, CD45+ leukocytes, and CD56+ NK cells , which may be an effective method to alleviate the progress of liver cancer and played an important role in treating liver cancer.