Cytotoxicity of WT1-reactive T cells against Wilms tumor: An implication for antigen-specific adoptive immunotherapy.

Introduction: T cells that recognize WT1 peptides have been shown to efficiently eliminate WT1-expressing tumor cells. This study was designed to investigate the feasibility of isolating WT1-reactive T cells from peripheral blood mononuclear cells (PBMCs) from healthy donors and patients with Wilms tumor, and to assess the cytotoxicity mediated by these cells against Wilms tumor cells (WiTu cells). Methods: WT1-reactive T cells were enriched and isolated by stimulating PBMCs with a WT1 peptide pool and interferon-γ capture-based immunomagnetic separation (IMS). Using the lactate dehydrogenase release assay, the in vitro cytotoxicity of the isolated cells and standard chemotherapy was evaluated on WiTu cells. Results: Higher proportions of WT1-reactive T cells were isolated from patients with Wilms tumor compared to those isolated from HDs. WT1-reactive T cells produced > 50% specific lysis when co-cultured with WT1+ WiTu cells at the highest effector-to-target (E:T) ratio in this study (i.e., 5:1), compared to <23% when co-cultured with WT1- WiTu cells at the same ratio. WT1-reactive T cells showed anti-tumoral activity in a dose-dependent manner and mediated significantly greater cytotoxicity than the non-WT1-reactive fraction of PBMCs on WT1+ WiTu cells. The cytotoxicity of standard chemotherapy was significantly lower than that of WT1-reactive T cells when co-cultured with WT1+ WiTu cells at E:T ratios of 2:1 and 5:1. Conclusion: WT1-reactive T cells can be effectively enriched from the PBMCs of patients with Wilms tumor. Ex vivo generated WT1-reactive T cells might be considered an adoptive immunotherapeutic option for WT1+ Wilms tumors.

Chemo-immune cell therapy by intratumoral injection of adoptive NK cells with capecitabine in gastric cancer xenograft model.

Introduction: Gastric cancer is one of the most commonly known malignancies and is the fifth cancer-related death globally. Whereas natural killer (NK) cells play a critical role in tumor elimination; therefore, adoptive NK cell therapy has become a promising approach in cancer cytotherapy. Hence, this study investigated the chemo-immune cell therapy in MKN-45 derived xenograft gastric cancer model. Methods: Three groups of animals have received the following treatments separately: activated NK cells, capecitabine, the combination of capecitabine and activated NK cells, and one was considered as the control group. Morphometric properties of tumor samples were evaluated at the end of the study. NK cells infiltration was evaluated by immunohistochemistry (IHC) of hCD56. Mitotic count and treatment response was assessed by hematoxylin and eosin (H&E) staining. The proliferation ratio to apoptosis was determined by IHC assessment of Ki67 and caspase 3. Results: The results indicated that the NK cell therapy could effectively decrease the mitotic count in pathology assessment, but the tumor was not completely eradicated. In combination with metronomic chemotherapy (MC) of capecitabine, NK cell therapy demonstrated a significant difference in tumor morphometric properties compared to the control group. The proliferation ratio to apoptosis was also in line with pathology data. Conclusion: Although NK cell therapy could effectively decrease the mitotic count in vivo, the obtained findings indicated lesser potency than MC despite ex vivo activation. In order to enhance NK cell therapy effectiveness, suppressive features of the tumor microenvironment and inhibitory immune checkpoints blockade should be considered.

Synergistic cytotoxicity effect of the combination of chitosan nanoencapsulated imatinib mesylate and quercetin in BCR-ABL positive K562 cells.

Objectives: Intolerable side effects and resistance to chemotherapeutic drugs have encouraged scientists to develop new methods of drug combinations with fewer complications. This study aimed to investigate the synergistic effects of quercetin and imatinib encapsulated in chitosan nanoparticles on cytotoxicity, apoptosis, and cell growth of the K562 cell line. Materials and Methods: Imatinib and quercetin were encapsulated in chitosan nanoparticles and their physical properties were determined using standard methods and SEM microscope images. BCR-ABL positive K562 cells were cultured in a cell culture medium, cytotoxicity of drugs was determined by MTT assay and the effects of nano drugs on apoptosis in cells were investigated by Annexin V-FITC staining. The expression level of genes associated with apoptosis in cells was measured by real-time PCR. Results: The IC50 for the combination of the nano drugs at 24 and 48 hr was 9.324 and 10.86 µg/ml, respectively. The data indicated that the encapsulated form of drugs induced apoptosis more effectively than the free form (P<0.05). Moreover, the synergistic effect of nano drugs in statistical analysis was proved (P=0.001). The combination of nano drugs resulted in the caspase 3, 8, and TP53 genes upregulation (P=0.001). Conclusion: The results of the present study showed that the encapsulated form of imatinib and quercetin nano drugs with chitosan has more cytotoxicity than the free form of the drugs. In addition, the combination of imatinib and quercetin as a nano-drug complex has a synergistic effect on the induction of apoptosis in imatinib-resistant K562 cells.

Efficacy of adoptively transferred allogeneic CIK cells on colorectal cancer: Augmentative antitumoral effects of GvHD.

OBJECTIVE: A preclinical study was designed to evaluate the effects of adoptively transferred cytokine-induced killer (CIK) cells on colorectal adenocarcinoma. METHODS: Forty NOG mice bearing HT-29 xenograft tumors were developed and equally divided into 2 groups of treatment and control. The mice in the treatment group received cumulatively 40-60 × 106 CIK cells in four divided doses. RESULTS: Median tumor doubling times for HT-29 xenograft tumors in the treatment and control groups were found to be 8.98 and 4.32 days; respectively. The treatment resulted in tumor growth delay (TGD) of 52.5 %. CIK cell-induced log cell kill (LCK) was found to be 0.67, which implies reduction of 78.6 % of neoplastic colorectal cells. Median length of survival in the treated mice was significantly longer than controls (57 (41-63) vs 41 (31-57) days, P < 0.001). Mice in the treatment group experienced graft-versus-host disease (GvHD) from median of day 13th after the cell therapy. LCK and TGD significantly increased after emergence of GvHD. After necropsy, tumors of the treatment group contained high levels of human-originated CD3+, CD4+ and CD8+ cells and showed significantly lower mitotic counts (P < 0.001) and residual tumor scores (P = 0.005) than the controls (entirely negative for the mentioned CD markers). Ninety percent of the treated mice were found to be responding. CONCLUSIONS: Adoptive transfer of allogeneic CIK cells may be an efficient antitumoral therapy for colorectal cancer. Allogeneic CIK cell-mediated GvHD may contribute to amplification of graft-versus-tumor effects of the cellular therapy.

Effects of polybrene and retronectin as transduction enhancers on the development and phenotypic characteristics of VHH-based CD19-redirected CAR T cells: a comparative investigation.

Chimeric antigen receptor T cells (CAR T cells) have improved the prognosis of patients with certain hematologic malignancies. However, broader clinical application of this type of therapy is dependent on production protocols. We characterized VHH-based CD19-redirected CAR T cells generated using the transduction enhancers (TEs) polybrene or retronectin. The proliferation rate of activated T cells transduced using polybrene concentrations > 6 mg/mL decreased compared with untreated group. There was a direct relationship between polybrene concentration and transduction efficacy. Moreover, we demonstrated the proliferation of retronectin-transduced T cells increased in a dose-dependent manner (4-20 µg/mL). Whereas, different retronectin concentrations did not mediate a significant increase in T cell transduction rate. Moreover, lentiviral transduction rate was also dependent on the concentration of lentiviruses. At optimized TE concentrations, multiplicity of infection (MOI) of > 10 decreased living T cell transduction rate. Additionally, we demonstrated that CAR T cell phenotype is highly affected by TE type. Naïve T cell differentiation to central memory T cell was observed in the beginning of the expansion process and effector memory T cells became the predominant subset in the second week of expansion. Importantly, retronectin increased the proliferation of CAR T cells alongside medicating higher transduction rates, resulting in more naïve and central memory T cells. We demonstrated that a higher percentage of CAR T cells were generated using retronectin (with a less differentiated phenotype) making retronectin a more effective TE than polybrene for long-term CAR T cell processing in preclinical or clinical studies.

Evaluation of direct intramural injection to the bladder wall as a method for developing orthotopic tumor models.

BACKGROUND: Bladder cancer poses a great burden on society and its high rate of recurrence and treatment failure necessitates use of appropriate animal models to study its pathogenesis and test novel treatments. Orthotopic models are superior to other types since they provide a normal microenvironment. Four methods are described for developing bladder cancer models inside the animal's bladder. Direct intramural injection is one of these methods and is widely used. However, its efficacy in model development has not yet been studied. We aimed to evaluate the efficacy and success rate of the direct intramural injection method of developing an orthotopic model for the study of bladder cancer. METHOD: Tumor cell lines were prepared in four microtubes. Aliquots of 200 × 103 cells were injected through a 27 gauge needle into the ventral wall of the bladders of 4 male and 4 female BALB/c mice following a midline 1 cm laparotomy incision. In addition, 1 million cells from each microtube were injected into the flanks of control mice. To prevent infection and alleviate pain, 5 mg/kg enrofloxacin and 2.5 mg/kg flunixin meglumine, respectively, were injected subcutaneously. RESULTS: Tumors formed in all mice, resulting in 100% take rate and zero post-operation mortality. Surgery time was ≤15 min per mouse. In two mice, tumors were found in the peritoneal space as well. CONCLUSION: Direct intramural injection is a rapid, reliable, and reproducible method for developing orthotopic models of bladder cancer. It can be done on both male and female mice and only requires readily available surgical tools. However, needle track can result in cell spillage and peritoneal tumors.

Combination of T-DM1 and platinum-based chemotherapy in patient-derived xenograft models of muscle-invasive bladder cancer.

Objectives: To assess the efficacy and safety of T-DM1, as an anti-HER2 antibody-drug conjugate (ADC), alone and in combination with two platinum-based chemotherapy regimens in patient-derived xenografts (PDXs) of muscle-invasive bladder cancer (MIBC) established in immunodeficient mice. Materials and Methods: After treatment initiation, tumor size was measured twice a week. Percent of tumor growth inhibition (TGI) and tumor response rates were calculated as efficacy endpoints. To evaluate treatment toxicity, relative body weight (RBW) was calculated for each group. For comparison of TGIs between treatment groups, the Kruskal-Wallis test was used. Also, the significance of the overall response (OR) rate between placebo groups with treatment groups was analyzed using Fisher's exact test. Immunohistochemistry and fluorescence in situ hybridization techniques were used to evaluate the level of HER2 expression. Results: Our data showed that T-DM1 alone induced a moderate antitumor activity. While chemotherapy regimens induced a slight TGI when administered alone, interestingly, they showed strong antitumor activity when administered combined with T-DM1. The OR rates were higher when T-DM1 was combined with chemotherapy regimens than T-DM1 alone. When compared with the placebo group, the OR rates of combination groups were statistically significant. Our data also showed that the administered dose of each drug was well tolerated in mice. Conclusion: The combination of T-DM1 and platinum-based chemotherapy may represent a new treatment option for bladder tumors with even low HER2 expression, and could also provide substantial novel insight into tackling the challenges of MIBC management.

Anti-inflammatory effect of mesenchymal stem cells on hepatocellular carcinoma in the xenograft mice model.

BACKGROUND: Hepatocellular carcinoma (HCC) is the fifth most diagnosed cancer and the second leading cause of cancer-related deaths worldwide. Sorafenib is the standard treatment used in the advanced stages of HCC. Cell therapy with mesenchymal stem cells (MSCs)-based cell therapy has proven effective in immune regulation and tumour growth inhibition. OBJECTIVES: In this study, we investigated the anti-inflammatory effect of MSCs on HCC xenografts. METHODS: Human HepG2 cell lines were subcutaneously implanted into the flank of 12 nude mice, divided into three groups: the control group, the IV group (intravenous MSCs injection) and the local group (local MSCs injection). Mice were sacrificed 6 weeks after tumour implantation, and tumours were resected entirety. Quantitative real-time polymerase chain reaction (qRT-PCR) measured the gene expression of inflammatory markers, including tumour necrosis factor-α (TNF-α), interleukin (IL)-1α and IL-10. Aspartate transaminase (AST), alanine transaminase (ALT) and urea levels were measured using spectrophotometry to ensure the safety of MSC therapy. RESULTS: Gene expressions for all three inflammatory markers were reduced in both MSCs groups compared to the control group. AST, ALT and urea levels remained in normal ranges. CONCLUSIONS: MSC therapy can reduce inflammation in HCC xenograft mouse models.

Spontaneous xenogeneic GvHD in Wilms' tumor Patient-Derived xenograft models and potential solutions.

Severely immunocompromised NOD.Cg-Prkdcscid Il2rgtm1Sug (NOG) mice are among the ideal animal recipients for generation of human cancer models. Transplantation of human solid tumors having abundant tumor-infiltrating lymphocytes (TILs) can induce xenogeneic graft-versus-host disease (xGvHD) following engraftment and expansion of the TILs inside the animal body. Wilms' tumor (WT) has not been recognized as a lymphocyte-predominant tumor. However, 3 consecutive generations of NOG mice bearing WT patient-derived xenografts (PDX) xenotransplanted from a single donor showed different degrees of inflammatory symptoms after transplantation before any therapeutic intervention. In the initial generation, dermatitis, auto-amputation of digits, weight loss, lymphadenopathy, hepatitis, and interstitial pneumonitis were observed. Despite antibiotic treatment, no response was noticed, and thus the animals were prematurely euthanized (day 47 posttransplantation). Laboratory and histopathologic evaluations revealed lymphoid infiltrates positively immunostained with anti-human CD3 and CD8 antibodies in the xenografts and primary tumor, whereas no microbial infection or lymphoproliferative disorder was found. Mice of the next generation that lived longer (91 days) developed sclerotic skin changes and more severe pneumonitis. Cutaneous symptoms were milder in the last generation. The xenografts of the last 2 generations also contained TILs, and lacked lymphoproliferative transformation. The systemic immunoinflammatory syndrome in the absence of microbial infection and posttransplant lymphoproliferative disorder was suggestive of xGvHD. While there are few reports of xGvHD in severely immunodeficient mice xenotransplanted from lymphodominant tumor xenografts, this report for the first time documented serial xGvHD in consecutive passages of WT PDX-bearing models and discussed potential solutions to prevent such an undesired complication.

Patient-derived xenograft (PDX) models, applications and challenges in cancer research.

The establishing of the first cancer models created a new perspective on the identification and evaluation of new anti-cancer therapies in preclinical studies. Patient-derived xenograft models are created by tumor tissue engraftment. These models accurately represent the biology and heterogeneity of different cancers and recapitulate tumor microenvironment. These features have made it a reliable model along with the development of humanized models. Therefore, they are used in many studies, such as the development of anti-cancer drugs, co-clinical trials, personalized medicine, immunotherapy, and PDX biobanks. This review summarizes patient-derived xenograft models development procedures, drug development applications in various cancers, challenges and limitations.

Adoptive NK-cell transfer as a potential treatment paradigm for Wilms tumor: A preclinical study.

BACKGROUND: Natural killer (NK) cell therapy has been shown to be effective in the treatment of some cancers. However, the effects of this adoptive immunotherapy have not been investigated for Wilms tumor (WT). In this study, the effects of adoptive NK-cell transfer on a patient-derived xenograft (PDX) model of anaplastic WT were evaluated, and the impacts of cell source and ex vivo activation strategy on the therapeutic efficacy of NK-cell product were appraised. METHODS: NK cells were isolated from human peripheral blood mononuclear cells (NKPB ) and human cord blood (NKCB ), and were expanded and activated using a cytokine cocktail. Another group of NK cells (NKET ) was produced through activation with the exosomes extracted from previously challenged NKPB cells with WT. PDX-bearing mice were treated with clinically relevant doses of NKPB , NKCB , NKET , standard chemotherapy, and placebo (phosphate-buffered saline). RESULTS: PDX models treated with NKCB showed a better survival rate, though the difference among the study groups was not significant. Compared with the placebo control group, NKCB significantly improved the histopathologic response, NKPB significantly inhibited the proliferation of neoplastic cells, and NKET led to a significant decrease in the metastasis score (all p-values <.05). Standard chemotherapy provided the greatest tumor growth inhibition and the lowest mitotic count, though it did not show any significant advantage over NK-cell therapies in any of the outcome parameters in two-by-two comparisons. CONCLUSIONS: This study spotlights the efficacy of adoptive NK-cell transfer as a potential treatment candidate for high-risk WT.

Magnetic Resonance Imaging of Tumor-Infiltrating Lymphocytes by Anti-CD3-Conjugated Iron Oxide Nanoparticles.

Immune checkpoint blockade, considered a revolutionary approach in cancer treatment, is only effective in patients with high tumor-infiltrating lymphocytes (TILs). This work aimed to investigate the feasibility of targeted contrast agent (CA) based on dextran-coated superparamagnetic iron oxide nanoparticles (SPIONs-DEX) for TILs detection by magnetic resonance imaging (MRI) studies. To do so, we synthesized an MRI CA by conjugating SPIONs-DEX to an anti-CD3 monoclonal antibody via cyanogen bromide as a cross-linker. In vitro assessments demonstrated the higher labeling efficiency of the developed CA to CD3+ lymphocytes compared to SPIONs-DEX. In vivo MRI of a xenograft model of CD3+ lymphocytes revealed the significant signal loss after the intravenous injection of the bioconjugate by ∼34 % and 21 % in T2 *-weighted and T2 -weighted images, respectively. The histopathological evaluation of xenograft tumors confirmed the labeling of lymphocytes by the targeted CA. This approach could open up a new horizon in the non-invasive assessment of TILs to identify patients eligible for immunotherapy.

Flow Cytometric Measurement of Reactive Oxygen Species to Assess the Effects of Preconditioning Total Body Irradiation on NOG Mice.

BACKGROUND: Preclinical development of new drugs for cancer immunotherapy requires preconditioning total body irradiation (TBI) of mice to be humanized via hematopoietic stem cell transplantation. To assess the effect of preconditioning TBI, we detected the reactive oxygen species (ROS), Annexin V, propidium iodide (PI) level in bone marrow samples by flow cytometer. METHODS: We divided all NOG mice between irradiated (n = 20) and control groups (n = 10) for two time points. Irradiated mice were exposed to 3.5 Gy of radiation. After sacrificing BM samples were collected, the flow cytometric percentage of ROS, Annexin V, and PI markers were investigated on days 2 and 14 after exposure. RESULTS: At the first time point, the level of ROS was higher in the irradiated group than in the control group, and this difference was statistically significant (P < 0.05). Also, at the second time point, the mean differences of all markers in the irradiated group were significantly compared to the control group (P < 0.05). CONCLUSION: Thus, in NOG mice, the measurement of ROS level is helpful to the assessment of preconditioning TBI.

The effects of Sorafenib and Natural killer cell co-injection in combinational treatment of hepatocellular carcinoma; an in vivo approach.

BACKGROUND: Natural killer cells (NKC) and Sorafenib (Sor) are two important agents for the treatment of hepatocellular carcinoma (HCC). Over the past decade, the interaction of Sor and NKC against HCC has been widely challenging. This study aimed to assess the efficacy of NKC & Sor for the treatment of HCC in vivo. METHODS: Subcutaneous xenograft models of HCC were established in nude mice. For safety assessment of treatment, the kidney and liver functions were analyzed. Paraffin embedded tumor sections were histopathologically studied and immunohistochemistry (IHC) tests were done to evaluate the angiogenesis (CD34) and proliferation (Ki67) indexes. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to identify the tumor cells undergoing apoptosis. The serum levels of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were measured by enzyme-linked immunosorbent assay (ELISA) and expression levels of major inflammatory cytokines and cytoplasmic granules in xenograft HCC were quantified using real-time PCR. RESULTS: NKC & Sor significantly inhibited necrosis and apoptosis in tumor cells and increased angiogenesis and proliferation of HCC compared to the monotherapy of NKC or Sor alone. The serum levels of TNF-α, IFN-γ as well as the expression levels of TNF-α, IFN-γ, interleukins (ILs)-1, 6, 10, granzyme-B and perforin in the xenograft HCC tissues of the treated mice with NKC & Sor were significantly lower than those of treated with NKC or Sor alone. CONCLUSION: Therapy with the specific dosage of NKC & Sor could not inhibit the HCC xenograft growth rate through a synergistic effect in a mouse model of HCC.

The first report of clonidine in vivo/in vitro effects on infertile women with polycystic ovary syndrome (in vivo/in vitro study).

The sympathetic nervous system (SNS) is hyperactive in women with polycystic ovary syndrome (PCOS). This study was designed in two sections: in vivo/in vitro with clonidine as the alpha-2 adrenoceptor (ADR-α2) agonist for modulating this hyperactivity. Eighty women with PCO participated in this randomised clinical trial (in vivo). A clonidine (0.1 mg) tablet was given twice a day for two months. Polycystic ovary morphology (PCOM) and pregnancy rate were the main outcome measurements. In the candidates for in vitro fertilisation (IVF), clonidine was added to the culture medium during IVF for two study groups (PCO-clonidine/PCO-without) and two control groups (egg donors-clonidine/egg donors-without). Our results showed that the pregnancy rate significantly was higher in the study group (p = .002). The mRNA expression of ADR-α1 and ADR-ß2 in PCO was higher than control group (p value <.001). But ADR-α1 expression in PCO-clonidine group decreased (p value = .042), the same as ADR-α2 expression. The intensity of this effect showed a pattern for ADR-α1

Bio-conjugation of anti-human CD3 monoclonal antibodies to magnetic nanoparticles by using cyanogen bromide: A potential for cell sorting and noninvasive diagnosis.

The conjugation of monoclonal antibodies with superparamagnetic iron oxide nanoparticles (SPIONs) has appeared as a potential multifunctional clinical tool, which can effectively diagnose cancers and monitor their treatment, specifically. Despite the presence of different methods for conjugating antibodies to iron oxide nanoparticles, novel cost-effective and simpler conjugation techniques should be performed in this regard. In current study, an anti-CD3 monoclonal antibody was conjugated to the Fe3O4 coated by carboxymethyl dextran (CMD) using cyanogen bromide (CNBr). Moreover, EDC/NHS techniques were applied as a positive control. The experimental results showed that the Conjugation was performed and the presence of the antibody conjugated to the MNPs in human xenograft tumors was confirmed using Prussian blue (PB) staining, following magnetic resonance imaging (MRI), 30 min after injection. This conjugation method was shown to be able to separate CD3+ T lymphocytes efficiently from whole blood with high purity. Accordingly, this type of bio-conjugation method can be utilized in the future for cell sorting, and can be applied for adopted cell therapies such as CAR-T cell (Chimeric antigen receptor T cell) therapy, as well as targeted MRI imaging.

Adaptive NK Cell Therapy Modulated by Anti-PD-1 Antibody in Gastric Cancer Model.

Recently, adaptive NK cell therapy has become a promising treatment but has limited efficacy as a monotherapy. The identification of immune checkpoint inhibitor (ICI) molecules has opened a new horizon of immunotherapy. Herein, we aimed to demonstrate the cytotoxic effects of a polytherapy consisting of ex vivo expanded IL-2-activated NK cells combined with human anti-PD-1 antibody as an important checkpoint molecule in a xenograft gastric cancer mouse model. EBV-LCL cell is used as a feeder to promote NK cell proliferation with a purity of 93.4%. Mice (NOG, female, 6-8 weeks old) with xenograft gastric tumors were treated with PBS, ex vivo IL-2-activated NK cells, IL-2-activated NK cell along with human anti-PD-1 (Nivolumab), and IL-2-activated pretreated NK cells with anti-PD-1 antibody. The cytotoxicity of ex vivo expanded NK cells against MKN-45 cells was assessed by a lactate dehydrogenase (LDH) assay. Tumor volume was evaluated for morphometric properties, and tumor-infiltrating NK cells were assessed by immunohistochemistry (IHC) and quantified by flow cytometry. Pathologic responses were considered by H and E staining. Ex vivo LDH evaluation showed the cytotoxic potential of treated NK cells against gastric cancer cell line. We indicated that the adoptive transfer of ex vivo IL-2-activated NK cells combined with anti-PD-1 resulted in tumor growth inhibition in a xenograft gastric cancer model. Mitotic count was significantly decreased (*p < 0.05), and the tumor was associated with improved infiltration of NK cells in the NK-anti-PD-1 pretreated group (*p < 0.05). In conclusion, the combination approach of activated NK cells and anti-PD-1 therapy results in tumor growth inhibition, accompanied by tumor immune cell infiltration in the gastric tumor model.

An outlook on antigen-specific adoptive immunotherapy for viral infections with a focus on COVID-19.

Although not a standard-of-care yet, adoptive immunotherapeutic approaches have gradually earned a place within the list of antiviral therapies for some of fatal and hard-to-treat viral diseases. To maintain robust antiviral immunity and to effectively target the viral particles and virally-infected cells, immune cells capable of recognizing the viral antigens are required. While conventional vaccination can induce these cells in vivo; another option is to prime and generate antigen-specific immune cells ex vivo. This approach has been successfully trialed for virulent opportunistic viral infections after bone marrow transplantation. Amid the crisis of SARS-CoV2 pandemic, which has been followed by the success of certain early-authorized vaccines; some institutions and companies have explored the effects of viral-specific adoptive cell transfers (ACTs) in trials, as alternative treatments. Aimed at outlining a perspective on antigen-specific adoptive immunotherapy for viral infections, this review article specifically provides an appraisal of ACT-based studies/trials on SARS-CoV2 infection.

Down-regulation of immune checkpoints by doxorubicin and carboplatin-containing neoadjuvant regimens in a murine breast cancer model.

OBJECTIVES: Immune checkpoint expression on tumor-infiltrating lymphocytes (TILs) has a correlation with the outcome of neoadjuvant chemotherapy (NAC) in breast cancer. However, the reciprocal effect of these regimens on the quality and quantity of immune checkpoints has hitherto not been addressed. We aimed to evaluate the impact of three NAC regimens on TILs and immune checkpoints in a murine triple-negative breast cancer model. MATERIALS AND METHODS: Syngeneic model of locally-advanced breast cancer was established in immunocompetent mice using a 4T1 cell line. Tumor-bearing animals were treated with human-equivalent dosages of doxorubicin, paclitaxel, paclitaxel and carboplatin combination, and placebo. Infiltration of CD3+, CD8+, and FoxP3+ cells into the tumor was assessed by immunohistochemistry. Expression of immune checkpoints, including PD-1, CTLA-4, and TIM-3, was evaluated by real-time PCR. RESULTS: Doxorubicin led to a significant (P<0.01) increase in the percentage of the stromal infiltrating CD3+ and CD8+ lymphocytes. Doxorubicin also suppressed significantly (P<0.05) the relative expression of PD-1 compared with the placebo. PD-1 expression was significantly (P<0.05) lower in the group treated with paclitaxel and carboplatin combination as compared with the placebo. The relative expression of TIM-3 was significantly (P<0.05) suppressed in doxorubicin-treated mice in comparison with other interventions. CONCLUSION: Our findings hypothesize that NAC with doxorubicin may potentiate antitumor immunity not merely by recruitment of TILs, but via down-regulation of PD-1 and TIM-3 checkpoints. Carboplatin-containing NAC may suppress PD-1 as well.

Data-Driven Discovery of Molecular Targets for Antibody-Drug Conjugates in Cancer Treatment.

Antibody-drug conjugate therapy has attracted considerable attention in recent years. Since the selection of appropriate targets is a critical aspect of antibody-drug conjugate research and development, a big data research for discovery of candidate targets per tumor type is outstanding and of high interest. Thus, the purpose of this study was to identify and prioritize candidate antibody-drug conjugate targets with translational potential across common types of cancer by mining the Human Protein Atlas, as a unique big data resource. To perform a multifaceted screening process, XML and TSV files including immunohistochemistry expression data for 45 normal tissues and 20 tumor types were downloaded from the Human Protein Atlas website. For genes without high protein expression across critical normal tissues, a quasi H-score (range, 0-300) was computed per tumor type. All genes with a quasi H - score ≥ 150 were extracted. Of these, genes with cell surface localization were selected and included in a multilevel validation process. Among 19670 genes that encode proteins, 5520 membrane protein-coding genes were included in this study. During a multistep data mining procedure, 332 potential targets were identified based on the level of the protein expression across critical normal tissues and 20 tumor types. After validation, 23 cell surface proteins were identified and prioritized as candidate antibody-drug conjugate targets of which two have interestingly been approved by the FDA for use in solid tumors, one has been approved for lymphoma, and four have currently been entered in clinical trials. In conclusion, we identified and prioritized several candidate targets with translational potential, which may yield new clinically effective and safe antibody-drug conjugates. This large-scale antibody-based proteomic study allows us to go beyond the RNA-seq studies, facilitates bench-to-clinic research of targeted anticancer therapeutics, and offers valuable insights into the development of new antibody-drug conjugates.