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.

Identification of immunodominant epitopes on nucleocapsid and spike proteins of the SARS-CoV-2 in Iranian COVID-19 patients.

Given the emergence of SARS-CoV-2 virus as a life-threatening pandemic, identification of immunodominant epitopes of the viral structural proteins, particularly the nucleocapsid (NP) protein and receptor-binding domain (RBD) of spike protein, is important to determine targets for immunotherapy and diagnosis. In this study, epitope screening was performed using a panel of overlapping peptides spanning the entire sequences of the RBD and NP proteins of SARS-CoV-2 in the sera from 66 COVID-19 patients and 23 healthy subjects by enzyme-linked immunosorbent assay (ELISA). Our results showed that while reactivity of patients' sera with reduced recombinant RBD protein was significantly lower than the native form of RBD (P < 0.001), no significant differences were observed for reactivity of patients' sera with reduced and non-reduced NP protein. Pepscan analysis revealed weak to moderate reactivity towards different RBD peptide pools, which was more focused on peptides encompassing amino acids (aa) 181-223 of RBD. NP peptides, however, displayed strong reactivity with a single peptide covering aa 151-170. These findings were confirmed by peptide depletion experiments using both ELISA and western blotting. Altogether, our data suggest involvement of mostly conformational disulfide bond-dependent immunodominant epitopes in RBD-specific antibody response, while the IgG response to NP is dominated by linear epitopes. Identification of dominant immunogenic epitopes in NP and RBD of SARS-CoV-2 could provide important information for the development of passive and active immunotherapy as well as diagnostic tools for the control of COVID-19 infection.

In vivo study of the angiogenesis potential of bone marrow-derived mesenchymal stem cell aggregates in their niche like environment.

BACKGROUND: Sufficient blood vessel formation in bioengineered tissues is essential in order to keep the viability of the organs. Impaired development of blood vasculatures results in failure of the implanted tissue. The cellular source which is seeded in the scaffold is one of the crucial factors involved in tissue engineering methods. MATERIALS AND METHODS: Considering the notable competence of Bone Marrow derived Mesenchymal Stem Cell aggregates for tissue engineering purposes, in this study BM-aggregates and expanded BM-MSCs were applied without any inductive agent or co-cultured cells, in order to investigate their own angiogenesis potency in vivo. BM-aggregates and BM-MSC were seeded in Poly-L Lactic acid (PLLA) scaffold and implanted in the peritoneal cavity of mice. RESULT: Immunohistochemistry results indicated that there was a significant difference (p < 0.050) in CD31+ cells between PLLA scaffolds contained cultured BM-MSC; PLLA scaffolds contained BM-aggregates and empty PLLA. According to morphological evidence, obvious connections with recipient vasculature and acceptable integration with surroundings were established in MSC and aggregate-seeded scaffolds. CONCLUSION: Our findings revealed cultured BM-MSC and BM-aggregates, capacity in order to develop numerous connections between PLLA scaffold and recipient's vasculature which is crucial to the survival of tissues, and considerable tendency to develop constructs containing CD31+ endothelial cells which can contribute in vessel's tube formation.

Optimizing interleukin-2 concentration, seeding density and bead-to-cell ratio of T-cell expansion for adoptive immunotherapy.

BACKGROUND: The successful ex vivo expansion of T-cells in great numbers is the cornerstone of adoptive cell therapy. We aimed to achieve the most optimal T-cell expansion condition by comparing the expansion of T-cells at various seeding densities, IL-2 concentrations, and bead-to-cell ratios. we first expanded the peripheral blood mononuclear cells (PBMCs) of a healthy donor at a range of 20 to 500 IU/mL IL-2 concentrations, 125 × 103 to 1.5 × 106 cell/mL, and 1:10 to 10:1 B:C (Bead-to-cell) ratios and compared the results. We then expanded the PBMC of three healthy donors using the optimized conditions and examined the growth kinetics. On day 28, CD3, CD4, and CD8 expression of the cell populations were analyzed by flow cytometry. RESULTS: T-cells of the first donor showed greater expansion results in IL-2 concentrations higher than 50 IU/mL compared to 20 IU/mL (P = 0.02). A seeding density of 250 × 103 cell/mL was superior to higher or lower densities in expanding T-cells (P = 0.025). Also, we witnessed a direct correlation between the B:C ratio and T-cell expansion, in which, in 5:1 and 10:1 B:C ratios T-cell significantly expanded more than lower B:C ratios. The results of PBMC expansions of three healthy donors were similar in growth kinetics. In the optimized condition, 96-98% of the lymphocyte population expressed CD3. While the majority of these cells expressed CD8, the mean expression of CD4 in the donors was 19.3, 16.5, and 20.4%. CONCLUSIONS: Our methodology demonstrates an optimized culture condition for the production of large quantities of polyclonal T-cells, which could be useful for future clinical and research studies.

Storm at the Time of Corona: A Glimpse at the Current Understanding and Therapeutic Opportunities of the SARS-CoV-2 Cytokine Storm.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may lead to severe disease in some cases, leading to acute respiratory distress syndrome, multi-organ failure, and death. This severe phenotype seems to be associated with a cytokine storm and immune dysregulation. Increased pro-inflammatory cytokines and CD14+CD16+ inflammatory monocytes, lymphopenia, and decreased levels of regulatory T cells are some of the immunological features that are seen in patients with SARS-CoV-2. As the outcome of SARS-CoV-2 is influenced by both viral virulence and dysregulated inflammatory response, a combination therapy approach using antiviral drugs plus anti-inflammatory treatments, such as corticosteroids, monoclonal antibodies against the IL-6 and IL-1ß pathways, and JAK inhibitors are under clinical trials.

Newborn Screening for Presymptomatic Diagnosis of Complement and Phagocyte Deficiencies.

The clinical outcomes of primary immunodeficiencies (PIDs) are greatly improved by accurate diagnosis early in life. However, it is not common to consider PIDs before the manifestation of severe clinical symptoms. Including PIDs in the nation-wide newborn screening programs will potentially improve survival and provide better disease management and preventive care in PID patients. This calls for the detection of disease biomarkers in blood and the use of dried blood spot samples, which is a part of routine newborn screening programs worldwide. Here, we developed a newborn screening method based on multiplex protein profiling for parallel diagnosis of 22 innate immunodeficiencies affecting the complement system and respiratory burst function in phagocytosis. The proposed method uses a small fraction of eluted blood from dried blood spots and is applicable for population-scale performance. The diagnosis method is validated through a retrospective screening of immunodeficient patient samples. This diagnostic approach can pave the way for an earlier, more comprehensive and accurate diagnosis of complement and phagocytic disorders, which ultimately lead to a healthy and active life for the PID patients.

Antigen-independent killer cells prepared for adoptive immunotherapy: One source, divergent protocols, diverse nomenclature.

Adoptive cell therapy (ACT) using tumor antigen-independent killer cells has been widely used in clinical trials of cancer treatment. Circumventing the need for identification of a particular tumor-associated antigen on tumor cells, the approach has opened possibilities for the extension of ACT immunotherapy to patients with a wide variety of cancer types. Namely, Natural Killer (NK), Lymphokine-activated Killer (LAK) cells and Cytokine-induced killer (CIK) cells are the most commonly used cell types in antigen-independent adoptive immunotherapy of cancer. They all originate from peripheral blood mononuclear cells and share several common features in their killing mechanisms. However, despite broad application in clinical settings, the boundaries between these cell types are not very clearly defined. The current study aims to review different aspects of these cell populations in terms of phenotypical characteristic and preparation media, to clarify how the boundaries are set.

Impact of various culture conditions on ex vivo expansion of polyclonal T cells for adoptive immunotherapy.

Currently, adoptive immunotherapy is considered as one of the leading treatments in cancer. Successful adoptive immunotherapy depends on producing large numbers of desired T cells ex vivo for infusion. This requires an effective protocol for maximum functional T-cell expansion while keeping the time and costs to a minimum. Current T-cell expansion protocols are diverse in their methodology, and a universal protocol of expansion is wanting. Also, new findings regarding T-cell biology, signaling, and activation have reshaped the strategies of T-cell propagation over the years, introducing new ways to expand T cells. Here, we reviewed different conditions for blood-derived polyclonal T-cell expansion so as to elucidate the influential factors of T-cell expansion and their efficacy.

Generation of CD19-Targeted Chimeric Antigen Receptor T Cells.

BACKGROUND: Current advancements in the field of chimeric antigen receptor (CAR) therapy, particularly U.S. FDA approval of Kymriah and Yescarta, heralds a new era of cancer treatment. This rapid progress in technology has urged more countries and institutions to keep pace with the fast-growing and developing technology of producing CAR T cell-based therapies in the race to develop new cancer-targeting drugs. Hence, for stepping in line with global advances and to pave the way for subsequent preclinical and clinical studies, we have established a development protocol for a cancer-targeting CAR T cell; we have chosen CD19 CAR T cell as a well-defined model to set-up T cell expansion, activation, and viral transduction as the prerequisites for diverse CAR T cell therapies. METHODS: T cells from peripheral blood mononuclear cells (PBMCs) were activated and expanded. CD19 CAR lentiviral particles were produced in the Lenti-X™ 293T Cell Line using PolyFect Transfection Reagent. RESULTS: Activation protocol resulted in (65 ± 4%; P = 0.046) increase in the rate of activated T cells 24 hours after the initiation of the procedure. The expansion methodology resulted in a high purity of the T cell population (96 ± 3%) in the pool of PBMCs within 14 days of the procedure. Finally, 35 ± 6% of T cells were transduced with CD19 lentivirus with MOI of 3. CONCLUSION: Collectively, the results of this study prove that we have successfully overcome the first hurdle on the road to reach CAR T cell technology which is the prerequisite for developing preclinical and clinical phases of CAR therapy in settings with basic resources.

Addressing cancer immunotherapy research in Iran: adoptive cell therapy on the horizon.

Recent advances in immunotherapeutic modalities have profoundly changed the prospect of cancer treatment. These modalities mainly focus on modulating the immune response toward tumor cells by using monoclonal antibodies, cancer vaccines, adoptive cell transfer or combination of these methods. In the last few years, Iranian scientists have conducted several projects in these arenas. Here, we provide an overview of these studies and analyze the quality and trend of publications in each sub-specialty of the field. In addition, the contribution of different universities and scientific institutes is assessed. This study may benefit scientific community and policymakers to plan future cancer immunotherapies in Iran and other countries.

Antigenic targets of CAR T Cell Therapy. A retrospective view on clinical trials.

Chimeric antigen receptor (CAR) T cell therapy is anticipated to be increasingly implemented in the context of cancer treatment after two current FDA approval of anti-CD19 CAR-T cells (Kymriah™ & Yescarta™). The success of CD19 is mainly attributable to the proper selection of the antigen, CD19, as the target of the disease, highlighting the importance of target selection for other CAR therapies. Therefore, here we performed a global analysis of targets that are the prime focus for various CAR T cell therapies in human clinical trials.

Improved Efficacy of a Dendritic Cell-Based Vaccine against a Murine Model of Colon Cancer: The Helper Protein Effect.

PURPOSE: Targeted immunotherapy using dendritic cells (DCs) has been employed in numerous investigations aiming at combating neoplasms. We previously showed that copulsing of an antigen with a helper protein could considerably enhance antigen presenting capacity of ex vivo-generated DCs. In this study, we attempted to administer an effective treatment in a murine model of colon cancer with DCs pulsed with the mixture of a tumor-specific gp70-derived peptide (AH1) and a helper protein, ovalbumin (OVA). MATERIALS AND METHODS: First, the presence of gp70 in CT26 tumor cells and tumor tissues was verified using immunofluorescence and Western blot analyses. Next, DCs were purified from normal mice, loaded ex vivowith AH1 and OVA (DC-Pep-OVA), and injected into tumor-bearing mice. Tumor volume, in vitro antigen (Ag)-specific proliferation of splenic cells, and survival rate were measured to determine the efficacy of DC-Pep-OVA. As the control groups, tumor-bearing mice were vaccinated with DC-Pep, unpulsed DC, and DCs loaded with a mixture of OVA and an irrelevant peptide (P15), or were not vaccinated at all. RESULTS: DC-Pep-OVA showed superior efficacy over other groups, as indicated by smaller tumor volume, higher Ag-specific proliferation rate of splenic cells, and prolonged survival. CONCLUSION: Overall, in the present study we showed for the first time that DCs copulsed with AH1 (tumor Ag) and OVA (helper molecule) could be considered as potentially robust weapons for use in future antitumor immunotherapies.

Potentiation strategies of dendritic cell-based antitumor vaccines: combinational therapy takes the front seat.

Despite recent attempts to take advantage of dendritic cell (DC)-based vaccines for cancer immunotherapy, the results of clinical studies have been disappointing. This is mainly as a result of the diverse immune escape mechanisms used by the tumor together with the insufficient ability of DCs to mount an effective immune response against these mechanisms. In this regard, several approaches have been devised to improve the efficacy of DC-based vaccines. However, the application of each individual approach per se might not be sufficient to overwhelm the diverse immune escape mechanisms. In this review, we focus on current strategies for the ex vivo potentiation of DC-based vaccines, with an emphasis on combinational therapy methods as a promising alternative for tumor immunotherapy.