Application of a newly-developed cynomolgus macaque BiTE-mediated cytotoxic T-lymphocyte activity assay to various immunomodulatory agents in vitro.

The immunotoxic potential of drug candidates is assessed through the examination of results from a variety of in vitro and in vivo immunophenotyping and functional study endpoints in pre-clinical studies. CD8+ cytotoxic T-lymphocyte (CTL) activity impairment by immunosuppressive agents is recognized to be a potentiating factor for decreased antiviral defense and increased cancer risk. A bi-specific T-cell engager (BiTE®)-mediated CTL activity assay that applies to ex vivo experimentation in non-human primates in the context of toxicology studies was successfully developed and applied in cynomolgus monkey regulatory studies. While an ex vivo analysis conducted in the context of repeat-dose toxicology studies focuses on the long-term impact on CTL function, an in vitro assay with the same experimental design captures acute effects in the presence of the test article. Here, the in vitro assay was applied to a list of drugs with known clinical immunomodulatory impact to understand the applicability of the assay. The results showed this assay was sensitive to a wide range of immunosuppressants directly targeting cell-intrinsic signaling pathways in activated CTL. However, agents executing immuno-modulation through inhibiting cytokines/cytokine receptors, co-stimulatory molecules, and cell adhesion and migration pathways did not impair the CTL activity in this short-term in vitro culture. In addition, anti-PD-1/PD-L1 immune checkpoint blockers enhanced the CTL activity. Taken together, the results here demonstrate that in concordance with their mechanism of action, the in vitro BiTE®-mediated CTL assay is applicable and sensitive to immunomodulatory agents acting via a variety of mechanisms.

Immunomodulatory and cellular anti-oxidant activities of caffeic, ferulic, and p-coumaric phenolic acids: a structure-activity relationship study.

Many studies have been performed to assess the potential utility of natural products as immunomodulatory agents to enhance host responses and to reduce damage to the human body. To determine whether phenolic compounds (caffeic, ferulic, and p-coumaric acids) have immunomodulatory effects and clarify which types of immune effector cells are stimulated in vitro, we evaluated their effect on splenocyte proliferation and lysosomal enzyme activity. We also investigated the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL). In addition, induction of the cellular antioxidant activity in splenocytes, macrophages, and red blood cells was determined by measuring the fluorescence of the DCF product. The study first results indicated that caffeic, ferulic, and p-coumaric acids significantly promote LPS-stimulated splenocyte proliferation, suggesting a potential activation of B cells, and enhanced humoral immune response in hosts treated by the tested natural products. Phenolic acids significantly enhanced the killing activity of isolated NK and CTL cells but had negligible effects on mitogen-induced proliferation of splenic T cells. We showed that caffeic acid enhances lysosomal enzyme activity in murine peritoneal macrophages, suggesting a potential role in activating such cells. Immunomodulatory activity was concomitant with the cellular antioxidant effect in macrophages and splenocytes of caffeic and ferulic acids. We conclude from this study that caffeic, ferulic, and p-coumaric acids exhibited an immunomodulatory effect which could be ascribed, in part, to their cytoprotective effect via their antioxidant capacity. Furthermore, these results suggest that these natural products could be potentially used to modulate immune cell functions in physiological and pathological conditions.

Flavones induce immunomodulatory and anti-inflammatory effects by activating cellular anti-oxidant activity: a structure-activity relationship study.

Flavonoids impart a variety of biological activities, including anti-oxidant, anti-inflammatory, and anti-genotoxic effects. This study investigated the effects of flavone luteolin and apigenin on immune cell functions, including proliferation, natural killer (NK) cell activity, and cytotoxic T lymphocyte (CTL) activity of isolated murine splenocytes. We report for the first time that flavones enhance lymphocyte proliferation at 10 µM. Luteolin and apigenin significantly promote lipopolysaccharide (LPS)-stimulated splenocyte proliferation and enhance humoral immune responses. Luteolin induces a weak cell proliferation of lectin-stimulated splenic T cells, when compared to apigenin. In addition, both flavones significantly enhance NK cell and CTL activities. Furthermore, our study demonstrated that both flavones could inhibit lysosomal enzyme activity, suggesting a potential anti-inflammatory effect. The anti-inflammatory activity was concomitant with the cellular anti-oxidant effect detected in macrophages, red blood cells, and splenocytes. We conclude from this study that flavones exhibited an immunomodulatory effect which could be ascribed, in part, to its cytoprotective capacity via its anti-oxidant activity.

Deoxypodophyllotoxin Induces a Th1 Response and Enhances the Antitumor Efficacy of a Dendritic Cell-based Vaccine.

BACKGROUND: Dendritic cell (DC)-based vaccines are currently being evaluated as a novel strategy for tumor vaccination and immunotherapy. However, inducing long-term regression in established tumor-implanted mice is difficult. Here, we show that deoxypohophyllotoxin (DPT) induces maturation and activation of bone marrow-derived DCs via Toll-like receptor (TLR) 4 activation of MAPK and NF-κB. METHODS: The phenotypic and functional maturation of DPT-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. DPT-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity and for tumor regression against melanoma. RESULTS: DPT promoted the activation of CD8(+) T cells and the Th1 immune response by inducing IL-12 production in DCs. In a B16F10 melanoma-implanted mouse model, we demonstrated that DPT-treated DCs (DPT-DCs) enhance immune priming and regression of an established tumor in vivo. Furthermore, migration of DPT-DCs to the draining lymph nodes was induced via CCR7 upregulation. Mice that received DPT-DCs displayed enhanced antitumor therapeutic efficacy, which was associated with increased IFN-γ production and induction of cytotoxic T lymphocyte activity. CONCLUSION: These findings strongly suggest that the adjuvant effect of DPT in DC vaccination is associated with the polarization of T effector cells toward a Th1 phenotype and provides a potential therapeutic antitumor immunity.

Deoxypodophyllotoxin Induces a Th1 Response and Enhances the Antitumor Efficacy of a Dendritic Cell-based Vaccine

BACKGROUND: Dendritic cell (DC)-based vaccines are currently being evaluated as a novel strategy for tumor vaccination and immunotherapy. However, inducing long-term regression in established tumor-implanted mice is difficult. Here, we show that deoxypohophyllotoxin (DPT) induces maturation and activation of bone marrow-derived DCs via Toll-like receptor (TLR) 4 activation of MAPK and NF-kappaB. METHODS: The phenotypic and functional maturation of DPT-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. DPT-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity and for tumor regression against melanoma. RESULTS: DPT promoted the activation of CD8+ T cells and the Th1 immune response by inducing IL-12 production in DCs. In a B16F10 melanoma-implanted mouse model, we demonstrated that DPT-treated DCs (DPT-DCs) enhance immune priming and regression of an established tumor in vivo. Furthermore, migration of DPT-DCs to the draining lymph nodes was induced via CCR7 upregulation. Mice that received DPT-DCs displayed enhanced antitumor therapeutic efficacy, which was associated with increased IFN-gamma production and induction of cytotoxic T lymphocyte activity. CONCLUSION: These findings strongly suggest that the adjuvant effect of DPT in DC vaccination is associated with the polarization of T effector cells toward a Th1 phenotype and provides a potential therapeutic antitumor immunity.

In vivo CTL Activity Induced by Prime-boost Vaccination using Recombinant Vaccinia Virus and DNA Vaccine Expressing Epitope Specific for CD8+ T Cells

DNA vaccine approaches have been applied to generate the protective immunity against various pathogens. However, the strength of immune responses induced by DNA vaccine is weak compared with conventional vaccines. The primeboost vaccination using DNA vaccine and other viral vector has been suggested as one way to circumvent this limitation. In the present study, we used in vivo CTL activity assay to determine CD8+ T cell-mediated immunity induced by prime-boost vaccination with a DNA vaccine (gB498-505 DNA) and recombinant vaccinia virus (VVgB498-505) expressing gB498-505 epitope peptide (SSIEFARL) of herpes simplex virus type 1 (HSV-1) glycoprotein B (gB). The most potent in vivo CTL activity was induced in mice received VVgB498-505 when both gB498-505 and VVgB498-505 were used at priming step and boosted with the alternative vaccine vector expressing whole antigen protein (gBw). Priming with vaccine vector expressing gBw followed by the use of VVgB498-505 at boosting step also induced strong in vivo CTL activity. We also examined in vivo CTL activity after immunization of mice with epitope-expressing vaccine vector at both priming and boosting step. Curiously, in vivo CTL activity mediated by CD8+ T cells was strongly elicited at memory stage when animals were primed with VVgB498-505 and subsequently boosted with gB498-505 DNA. Because the use of VVgB498-505 at priming followed by boosting with gB498-505 DNA induced most optimal immunity, these results suggest that the order of vaccine type should be carefully considered when used vaccine type expressing only epitope for prime-boost vaccination.

Expression of recombinant human MUC1-MBP fusion protein in E coli DH5?,and its purification and detection of immune responses in mice / 中国免疫学杂志

Objective:To study MUC1 based cancer vaccine.Methods:MUC1 gene was inserted into pMAL-p2 vector and constructed recombinant pMAL-MUC1. MUC1-MBP fusion protein expression was induced by IPTG in E coli DH5? transformed by the recombinant pMAL-MUC1 .The fusion protein was analyzed by Western blot and purified by amylose affinity chromatography. The antiserum,T cell proliferation and CTL activity of spleen from C57 mice immunized by MUC1-MBP were determined respectively by ELISA,adding 3H-TdR and MTT.Results:Had successfully constructed pMAL-MUC1 expression vector,and purified MUC1-MBP and MBP. C57 mice immunized by MUC-MBP generated MUC1 specific antibody and CTL.The titer of polyclonal antibody to MUC1 was about 1∶5 760?3 221. CTL cytotoxicity to the MCF7 and lewis lung cancer cells respectively were at 47.7%?4.3% and 67.5%?6.5%.Conclusion:Human recombinant MUC1-MBP fusion protein activated T and B cell response in mice.The results suggested that the recombinant Muc1 may be used to develop protein vaccine against carcinoma.

The Anti-Tumor Effect of Recombinant Human MUC1-MBP Fusion Protein / 中国肿瘤生物治疗杂志

Objective: To study the anti-tumor effect of recombinant human MUC1-MBP. Methods: The C57BL/6 mice were in oculated with MUC1-MBP by subcutaneous. MUC1 specific CTL activity of spleen were determined by MTT; The effects on prevention and treatment of tumor were observed by establishing lewis lung cancer-carrying mice. Results: The cytotoxicity of CTL from immunized mice to the MCF7 and Lewis lung cancer cells respectively was (47.7?4.3) % and (67.5 ?6.5) %; 5?10 5 lewis lung cancer cells following immunization were injected iv into C57BL/6 mice, after three weeks, the number of lung and tail tumor colonies was 51 and 5 for PBS and MUC1-MBP groups respectively and the suvival time was significantly delayed in immunized mice. The average volume of tumors in mice with MUC1-MBP was 386 mm 3 wherea control group was 4 000 mm 3 at tumor treating experiment. Conclusions: Recombinant human MUC1-MBP have significantly effects on prevention, treatment and inhibiting metastases of tumor. Our results suggested that the recombinant MUC1-MBP might be used to develop protein vaccine against human carcinoma.

The study of antitumor effect of tumor-draining lymph node cells from lung cancer patients induced by different stimulus in vitro / 中国免疫学杂志

Objective:To find a feasible method to stimulate tumor-draining lymph node(TDLN) cells in clinic.Methods:CTL activity of TDLN cells induced by different stimulus (IL-2 group, IL-2+autologous tumor antigen group, IL-2+GM-CSF+IL-4+autologous tumor antigen group) was measured by the method of maximal LDH enzyme release. The mechanisms were explored by observation in morphology and detection of the CD83 positive rate of TDLN cells.Results:The level of growth of TDLN cells induced by (IL-2+GM-CSF+IL-4+autologous tumor antigen) was significantly higher than TDLN cells induced by IL-2 and (IL-2+autologous tumor antigen)(P

CTL activity detection of immune response to hepatitis Cviral nucleic acid vaccine / 中国免疫学杂志

Objective:To discuss mice cellular immune response to the hepatitis C viral nucleic acid vaccine.Methods:Hepatitis C viral nucleic acid vaccine pSVL HCV/C+E 1 was inoculated BALB/C mice by subcutaneous injection.To detect the CTL activity of immune mice,Made the standard 4 hours lysis test by labeling the target cells with (Na) 2 51 CrO 4,which was prepared from the syngentic BALB/C mouse myeloma derived cell strain SP2/0 transfected by the eukaryotic expression recombinant plasmid pEGFP N 1 HCV/C+E 1.Results:The kill ratio of CTL is up to 40.7%.Conclusion:The result suggested hepatitis C viral nucleic acid vaccine could induce strong cellular immune response