HPV16 E5 peptide vaccine in treatment of cervical cancer in vitro and in vivo.

Human papillomavirus (HPV)-induced cervical cancer is the second most common cancer among women worldwide. Despite the encouraging development of the preventive vaccine for HPV, a vaccine for both prevention and therapy or pre-cancerous lesions remains in high priority. Thus far, most of the HPV therapeutic vaccines are focused on HPV E6 and E7 oncogene. However these vaccines could not completely eradicate the lesions. Recently, HPV E5, which is considered as an oncogene, is getting more and more attention. In this study, we predicted the epitopes of HPV16 E5 by bioinformatics as candidate peptide, then, evaluated the efficacy and chose an effective one to do the further test. To evaluate the effect of vaccine, rTC-1 (TC-1 cells infected by rAAV-HPV16E5) served as cell tumor model and rTC-1 loading mice as an ectopic tumor model. We prepared vaccine by muscle injection. The vaccine effects were determined by evaluating the function of tumor-specific T cells by cell proliferation assay and ELISPOT, calculating the tumor volume in mice and estimating the survival time of mice. Our in vitro and in vivo studies revealed that injection of E5 peptide+CpG resulted in strong cell-mediated immunity (CMI) and protected mice from tumor growth, meanwhile, prolonged the survival time after tumor cell loading. This study provides new insights into HPV16 E5 as a possible target on the therapeutic strategies about cervical cancer.

[Preparation of HPV18 E7 peptide plus CpG vaccine and its immunologic effects in vitro].

OBJECTIVE: To screen and prepare the vaccine of human papillomavirus (HPV) 18 E7 peptide target at human leukocyte antigen (HLA)-A2 plus CpG through SYFPEITHI. METHODS: (1) The SYFPEITHI database was employed for predicting and screening of HPV18 E7 HLA-A2 restricted T cell epitopes.(2) The peripheral blood and tumor tissue sample of HLA-A2 positive and HPV18 positive/negative patients were collected and randomly divided into 7 groups, i.e. E7PA + CpG, E7PB + CpG, E7PC + CpG, E7PD + CpG, CpG, IR-T + CpG and control groups respectively. T cell proliferation was detected by thiazolyl blue tetrazolium bromide (MTT) assay at different timepoints. Lactate dehydrogenase delivery method (LDH) was used to test the cytolytic t lymphocyte (CTL) activity of peripheral blood mononuclear cell (PBMC) in different ratios of effect and target (E:T). And the level of activity T cells was evaluated by interferon gamma (IFN-γ)-related enzyme-linked immuno-spot assay (ELISPOT). RESULTS: (1) Four peptides named E7PA, E7PB, E7PC and E7PD were obtained separately with high levels of affinity and specificity. (2) During continuous observations after vaccination, the E7PA + CpG group had the most pronounced proliferation rate. When E:T = 100:1, the E7PA + CpG group had more powerful CTL effect than the control group with statistic significance (P < 0.00). E:T was concentration-dependent. Except for IR-T + CpG, all other groups had great difference than control group with statistic significance (P < 0.05) but no significant difference between the groups. The levels of IFN-γ spot-forming T cells were higher in the E7PA + CpG group than the control group with statistic significance (P < 0.01). In terms of specificity, E7PA + CpG in the HPV18 positive group could induce the proliferation of IFN-γ-secreting T cells. And there was statistical difference with the control group (P < 0.05). CONCLUSION: Screening the HPV18 E7 peptide target at HLA-A2 plus CpG as the candidate targets by SYFPEITHI may active specific immunological cellular responses to HPV18 positive disease.

[Effect of HPV16 peptide vaccine in combination with paclitaxel-cisplatin chemotherapy on cervical cancer in vitro and in vivo].

OBJECTIVE: to the explore the effect of Human papillomavirus (HPV) 16 peptide vaccine in combination with paclitaxel-cisplatin (TP) chemotherapy on cervical cancer in vitro and in vivo. METHODS: (1) the major histocompatibility complex (MHC) class I restricted T cell epitopes were studied by bioinformatics for transporter associated with antigen processing (TAP). Their effects were compared and E7Pa had the most dramatic effect. (2) In vivo, the C57BL/6 mice were divided equally into 6 groups randomly after loading with TC-1 cells (HPV 16 positive tumor cells from C57BL/6 mouse), named as E7Pa + CpG + TP, E7Pa + CpG, CpG + TP, TP and CpG group as experiment groups and control (blank injection with physiological saline). The tumor volumes were measured regularly by tumor growth curve to compare the therapeutic effects in different groups; the related cell factors in murine peripheral blood were evaluated by enzyme-linked immunosorbent assay (ELISA); the TUNEL test kit was used to explore cellular apoptosis in tumor tissue; the survival curve was drawn from the TC-1 cell loading to natural death; safety was tested by pathological test and leucocyte count. RESULTS: at day 60 of tumor growth, the tumor volume of immunotherapy plus TP chemotherapy group was (0.013 ± 0.010) cm(3) versus the control (1.900 ± 0.075) cm(3) with a great significant deviation (P < 0.01). Meanwhile, the volumes were E7Pa + CpG group (0.340 ± 0.038) cm(3), TP + CpG group (0.650 ± 0.029) cm(3), TP group (1.100 ± 0.052) cm(3) and that of CpG group was (0.890 ± 0.047) cm(3) separately. And these groups had significant difference with the controls (P < 0.05). The average survival time of different groups were E7Pa + CpG + TP group (108.50 ± 8.97) d, E7Pa + CpG group (100.02 ± 2.27) d, CpG + TP group (79.63 ± 4.05) d, TP group (73.24 ± 3.11) d, CpG group (68.63 ± 1.38) d and controls (52.37 ± 2.47) d. And the difference between the E7Pa + CpG + TP and E7Pa + CpG groups had great significance with the controls (P < 0.01). Furthermore, the immune system was effectively stimulated for suppressing tumor growth in the immunotherapy group while cell apoptosis was significantly induced in the chemotherapy group. The combination of immunotherapy and chemotherapy was significantly efficacious than either of them alone. And it could thoroughly stimulate the immune effects and enhance the anti-tumor function of chemotherapeutical drugs. In safety test, there was no significant difference among all groups. CONCLUSION: the HPV16 peptide vaccine in combination with TP chemotherapy can treat the HPV16 E7 positive tumor effectively in experiment.

[Preparation of human papillomavirus 16 E7 peptide vaccine and its effectiveness in vitro and in vivo.].

OBJECTIVE: To prepare the human papillomavirus (HPV) 16 peptide vaccine and explore the effect in vitro and in vivo. METHODS: (1) Prediction of the major histocompatibility complex (MHC) class I restricted T cell epitopes by bioinformatics target at transporter associated with antigen processing (TAP) and named by E7Pa, E7Pb, E7Pc separately. (2) In vivo, the C57BL/6 mice were divided into five groups with same amounts randomly after loading with TC-1 cells (HPV 16 positive tumor cells from C57BL/6 mouse), named as E7Pa + CpG, E7Pb + CpG, E7Pc + CpG (as experiment groups, and added 50 microg/ml E7Pa, E7Pb, E7Pc, respectively), CpG (as positive control group and added Con A with 12 mg/L final concentration) and blank control group (without any treatment). The T cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) assay at different time points; the lactate dehydrogenase (LDH) delivery method was used to test the cytolytic T lymphocyte (CTL) activity of mouse splenic lymphocyte in different ratio of effector cells and target cells (E:T); the related cytokines in tumor tissue and mouse peripheral blood were evaluated by real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The tumor volumes were measured to contrast the therapeutic effect in different groups. RESULTS: (1) Three peptide named E7Pa, E7Pb, E7Pc were successfully preparated which had high affinity and specificity. (2) After vaccination of 24, 48, 72, 96 hours, MTT results shown that the proliferation rate in E7Pa + CpG group were (131 +/- 32)%, (302 +/- 15)%, (552 +/- 28)%, (731 +/- 24)% individually, which were much higher than those in blank control [(72 +/- 15)%, (120 +/- 57)%, (176 +/- 41)%, (288 +/- 29)%; P < 0.01], and the other groups i.e. E7Pb + CpG, E7Pc + CpG and CpG groups all proliferated much higher than those in blank control group with statistic signification (P < 0.05), but there was no significant difference between groups (P > 0.05); the LDH delivery assay showed that when the ratio of E:T was 100:1, the activity of CTL in the E7Pa + CpG group was most powerful than the other groups with statistic signification (P < 0.01).Meanwhile, the ratio of E:T was concentration-dependent. Compared E7Pb + CpG, E7Pc + CpG or CpG groups with blank control group, there were significantly difference (P < 0.05), while there was no significant difference between groups (P > 0.05). The mRNA levels of interferon gamma (IFN-gamma), interleukin-2 (IL-2) in tumor tissue and peripheral blood in E7Pa + CpG group were significantly higher than those in blank control group (P < 0.01), which was the similar results when compared E7Pb + CpG, E7Pc + CpG or CpG groups with control group (P < 0.05), and without significant difference between groups (P > 0.05). The tumor volumes were suppressed obviously in all the experiment groups, especially at the 60th days, the volumes in E7Pa + CpG group were much smaller than that in blank control group with statistic signification (P < 0.01), which was the similar results that E7Pb + CpG, E7Pc + CpG or CpG groups had difference than blank control group with statistic signification (P < 0.05), and without significant difference between groups (P > 0.05). CONCLUSION: The HPV16 E7 peptide target at TAP combination with CpG as a vaccine could treat effectively the HPV16 E7 positive tumor in experiment.