Objective To establish a stable and efficient method of culturing imDCs in vitro,and to explore the effect of GW5074, which blocks ERK1/2 signal pathway in the process of imnature dentritic cells (imDCs) on inducing differentiation of the na(i)ve allogeneic CD4+ T cells into Treg cells in vitro. Methods The imDCs and mature DCs (mDCs) were isolated and cultured from the peripheral blood mononuclear cells (PBMC) derived from a healthy adult male volunteer, and they were identified by cell morphology, cell surface marker and cell functions respectively. Na(i)ve CD4+ T cells were isolated from newborn umbilical vein blood and were divided into 5 groups to be cultured: (1) Blank control group: Na(i)ve CD4+ T cells were cultured alone;(2) Positive control group: The irrDCs were Middle-concentration GW5074 group;(5) High-concentration GW5074 group. In the last three groups, imDCs and na(i)ve CD4+ T cells were co-cultured, the same as the positive control group, but these groups were added by GW5074 dilution at the concentrations of 8, 24, and 40μmol/Lrespectively. After co-culture for 5 days, the transformation ratio from naive CD4+T cells to Treg T cells was detected by flow cytometry. Results On the surface of imDCs, there was stronger pression of CD1a, but weaker expression of CD80 and CD83. On the contrary, on the surface of mDCs, there was weaker expression of CD1a, but stronger expression of CD80 and CD83. The stimulation index in imDCs group and mDCs group was 1.12±0.03 and 2.85±0. 07 respectively. The transformation ratio of Treg T cells in blank control group, positive control group, low-concentration GW5074 group, middle-concentration GW5074 group and high-concentration GW5074 group was (5. 81±1.36)%, (35.73±2.07)%, (22.53±2.11)%, (11.55±1.73)%, and (4.97±1.83)%respectively. One-way ANOVA analysis revealed that there was no significant difference between high-concentration GW5074 group and blank control group, P＞0. 05, but significant difference between the remaining groups, P＜0.01. Conclusion High purity of imDCs can be obtained from PBMC by induction with rhGM-CSF and rhIL-4. ERK1/2 signal pathway plays a role in inducing the immune tolerance. GW5074 can inhibit differentiation of na(i)ve CD4+ T cells into Treg T cells.

Enzalumide has not been approved for therapy in metastatic hormone sensitive prostate cancer (mHSPC) patients in China. This study retrospectively analyzed the response to treatment of Enzalutamide as first-line neoadjuvant hormonal therapy for mHSPC. A 69-year-old man with prostate cancer characterized with clinical staging T 3bN 1M 1b, tPSA 240.69ng/ml and Gleason score 8, was administrated with Enzalumide as neoadjuvant hormonal therapy for 6 months. Re-examination for prostate MRI indicated the prostate, tumor lesion and the enlarged lymph nodes in the pelvic cavity were significantly smaller than before. Therefore, a robot-assisted laparoscopic radical prostatectomy was performed. Postoperative pathology showed resection margins were negative and no metastasis was observed in lymph nodes of pelvic cavity. After the operation, adjuvant hormonal therapy was performed. Blood tPSA was 0.016ng/ml at 6 weeks, and no tumor recurrence or enlarged lymph nodes were found in pelvic MRI at 6 months. Therefore, in this case, Enzalutamide as first-line neoadjuvant hormonal therapy can reduce the clinical staging of mHSPC, which may allow surgical resection of the tumor.