Immunotherapy in liver transplantation for hepatocellular carcinoma:Pros and cons

Liver transplantation(LT)has emerged as a curative strategy for hepatocellular carcinoma(HCC),but contributes to a higher predisposition to HCC recurrence in the immunosuppression context,especially for tumors beyond the Milan criteria.Although immunotherapy has dramatically improved survival for immunocompetent patients and has become the standard of care for a variety of tumors,including HCC,it is mainly used outside the scope of organ transplantation owing to potentially fatal allograft rejection.Nevertheless,accumulative evidence has expanded the therapeutic paradigms of immunotherapy for HCC,from downstaging or bridging management in the pretransplant setting to the salvage or adjuvant strategy in the posttransplant setting.Generally,immunotherapy mainly includes immune checkpoint inhibitors(ICIs),adoptive cell transfer(ACT)and vaccine therapy.ICIs,followed by ACT,have been most investigated in LT,with some promising results.Because of the complex tumor microenvironment and immunoreactivity when immunosuppressants are combined with immunotherapy,it is difficult to reach formulations for immunosuppressant adjustment and the optimal selection of immunotherapy as well as patients.In addition,the absence of effective biomarkers for identifying rejection and tumor response is still an unresolved barrier to successful clinical immunotherapy applications for LT.In this review,we comprehensively summarize the available evidence of immunotherapy used in LT that is specific to HCC.Moreover,we discuss clinically concerning issues regarding the concurrent goals of graft protection and antitumor response.

Technical advances in NK cell-based cellular immunotherapy

Natural killer(NK)cells represent a promising future for tumor immunotherapy because of their unique biological functions and characteristics.This review focuses on technical advances in NK cell-based cellular immunotherapy and summarizes the developments of recent years in cell sources,genetic modification,manufacturing systems,clinical programs,and outcomes.Future prospects and challenges in NK cell immunotherapy are also discussed,including off-the-shelf NK cell exploitation,automatic and closed manufacturing systems,cryopreservation,and therapies involving regulatory checkpoints.

Biological drug and drug delivery-mediated immunotherapy

The initiation and development of major infammatory diseases,i.e.,cancer,vascular infammation,and some autoimmune diseases are closely linked to the immune system.Biologics-based immunotherapy is exerting a critical role against these diseases,whereas the usage of the immunomodulators is always limited by various factors such as susceptibility to digestion by enzymes in vivo,poor penetration across biological barriers,and rapid clearance by the reticuloendothelial system.Drug delivery strategies are potent to promote their delivery.Herein,we reviewed the potential targets for immunotherapy against the major infammatory diseases,discussed the biologics and drug delivery systems involved in the immunotherapy,particularly highlighted the approved therapy tactics,and finally offer perspectives in this feld.

Tracking in vivo migration and distribution of antigen-specific cytotoxic T lymphocytes by 5,6-carboxyfluorescein diacetate succinimidyl ester staining during cancer immunotherapy

Background Killing of targeted tumors during adoptive cell transfer therapy is associated with cytotoxic T lymphocyte （CTL） numbers,immunophenotype,tumor-specificity,and in vivo residence time,migration,and distribution.Therefore,tracing in vivo persistence,migration,and distribution of CTLs is important for cancer immunotherapy.Methods Optimal staining concentration for CTL proliferation was determined by cell counting kit-8 （CCK-8） assay and killing efficiencies of CTLs or carboxyfluorescein diacetate succinimidyl ester （CFSE）-labeled melanoma antigen-specific cytotoxic T lymphocytes （CFSE-CTLs） for malignant melanoma cells in vitro were compared.Additionally,CFSE-CTLs were intravenously transfused to mice receiving B16 melanoma,and their residence time,migration,and distribution in vivo were observed by measuring fluorescence intensities of CFSE-CTLs per gram of tissue （％FI/g） in various tissues and analyzing tumor/non-tumor （T/NT） values.Anti-tumor effects of transferred CTLs and correlation between ％FI/g and D-value of tumor size were analyzed.Results Five-micromolar CFSE was optimal for labeling CTLs with minimal cytotoxicity.No significant difference occurred between CTLs and CFSE-CTLs for tumor cell killing （P=0.849） or interleukin-2 （P=0.318） and interferon-y （P=0.201）levels.Distribution of CTLs in vivo varied with time.A negative correlation between ％FI/g in tumors and D-value of tumor sizes by Spearman correlation analysis was observed.CTLs were recruited to and killed tumors from 6 hours to 3 days after cell infusion.CTLs were observed up to three weeks later in the tumor,liver,kidneys,and spleen; this was related to the abundant blood supply or the nature of immune organs.Conclusions CCK-8 assay is a novel method to select optimal CFSE staining concentrations.Fluorescence intensity of transferred CTLs reflects their killing efficiency of tumors.CFSE fluorescent markers can trace in vivo CTL persistence,migration,and distribution because of its stability,long half-life,and low toxicity.

The dark side of immunotherapy:pancreatic cancer

Since the journal Science deemed cancer immunotherapy as the“breakthrough of the year”in 2014,there has been an explosion of clinical trials involving immunotherapeutic approaches that,in the last decade-thanks also to the renaissance of the immunosurveillance theory(renamed the three Es theory)-have been continuously and successfully developed.In the latest update of the development of the immuno-oncology drug pipeline,published last November by Nature Review Drug Discovery,it was clearly reported that the immunoactive drugs under study almost doubled in just two years.Of the different classes of passive and active immunotherapies,“cell therapy”is the fastest growing.The aim of this review is to discuss the preclinical and clinical studies that have focused on different immuno-oncology approaches applied to pancreatic cancer,which we assign to the“dark side”of immunotherapy,in the sense that it represents one of the solid tumors showing less response to this type of therapeutic strategy.

Breast Cancer Immunotherapy

Breast cancer is a leading cause of cancer-related deaths in women worldwide.Although tumorectomy, radiotherapy,chemotherapy and hormone replacement therapy have been used for the treatment of breast cancer,there is no effective therapy for patients with invasive and metastatic breast cancer.Immunotherapy may be proved effective in treating patients with advanced breast cancer.Breast cancer immunotherapy includes antibody based immunotherapy,cancer vaccine immunotherapy,adoptive T cell transfer immunotherapy and T cell receptor gene transfer immunotherapy.Antibody based immunotherapy such as the monoclonal antibody against HER-2/neu (trastuzumab) is successfully used in the treatment of breast cancer patients with over-expressed HER-2/neu,however,HER-2/neu is over-expressed only in 25-30% of breast cancer patients.Cancer vaccine immunotherapy is a promising method to treat cancer patients.Cancer vaccines can be used to induce specific anti-tumor immunity in breast cancer patients,but cannot induce objective tumor regression.Adoptive T cell transfer immunotherapy is an effective method in the treatment of melanoma patients.Recent advances in anti-tumor T cell generation ex vivo and limited clinical trial data have made the feasibility of adoptive T cell transfer immunotherapy in the treatment of breast cancer patients.T cell receptor gene transfer can redirect the specificity of T cells.Chimeric receptor,scFv(anti-HER-2/neu)/zeta receptor,was successfully used to redirect cytotoxic T lymphocyte hybridoma cells to obtain anti-HER-2/neu positive tumor cells,suggesting the feasibility of treatment of breast cancer patients with T cell receptor gene transfer immunotherapy.Clinical trials will approve that immunotherapy is an effective method to cure breast cancer disease in the near future.Cellular & Molecular Immunology.2004;1(4):247-255.