Use of Electronic Health Records at Federally Qualified Health Centers: a Potent Tool to Increase Viral Hepatitis Screening and Address the Climbing Incidence of Liver Cancer.

Viral hepatitis B and C are among the leading causes of acute and chronic liver disease in the USA. The nature of chronic liver disease is often asymptomatic. This is problematic because the majority of individuals living with chronic hepatitis B and chronic hepatitis C do not know that they are infected and can communicate the disease to others. Furthermore, early disease recognition and treatment have been shown to improve long-term outcomes and decrease healthcare cost. These diseases affect vulnerable populations disproportionately. Asian Americans and Pacific Islanders are more likely than the general US population to have CHB, and the baby boomer generation is more likely than any other age group to have CHC. Federally Qualified Health Centers play a vital role in providing comprehensive primary care to medically underserved populations. Utilization of electronic health records reminders in Federally Qualified Health Centers results in increased screening, reduced provider screening bias and improved opportunity for management of patients living with chronic viral hepatitis. Electronic health records technology is a potent tool kit to aggressively screen, treat, and prevent viral hepatitis, ultimately, leading to decreased incidence of liver cancer.

Immune Escape After Adoptive T-cell Therapy for Malignant Gliomas.

PURPOSE: Immunotherapy has been demonstrably effective against multiple cancers, yet tumor escape is common. It remains unclear how brain tumors escape immunotherapy and how to overcome this immune escape. EXPERIMENTAL DESIGN: We studied KR158B-luc glioma-bearing mice during treatment with adoptive cellular therapy (ACT) with polyclonal tumor-specific T cells. We tested the immunogenicity of primary and escaped tumors using T-cell restimulation assays. We used flow cytometry and RNA profiling of whole tumors to further define escape mechanisms. To treat immune-escaped tumors, we generated escape variant-specific T cells through the use of escape variant total tumor RNA and administered these cells as ACT. In addition, programmed cell death protein-1 (PD-1) checkpoint blockade was studied in combination with ACT. RESULTS: Escape mechanisms included a shift in immunogenic tumor antigens, downregulation of MHC class I, and upregulation of checkpoint molecules. Polyclonal T cells specific for escape variants displayed greater recognition of escaped tumors than primary tumors. When administered as ACT, these T cells prolonged median survival of escape variant-bearing mice by 60%. The rational combination of ACT with PD-1 blockade prolonged median survival of escape variant glioma-bearing mice by 110% and was dependent upon natural killer cells and T cells. CONCLUSIONS: These findings suggest that the immune landscape of brain tumors are markedly different postimmunotherapy yet can still be targeted with immunotherapy.

Integration of a CD19 CAR into the TCR Alpha Chain Locus Streamlines Production of Allogeneic Gene-Edited CAR T Cells.

Adoptive cellular therapy using chimeric antigen receptor (CAR) T cell therapies have produced significant objective responses in patients with CD19+ hematological malignancies, including durable complete responses. Although the majority of clinical trials to date have used autologous patient cells as the starting material to generate CAR T cells, this strategy poses significant manufacturing challenges and, for some patients, may not be feasible because of their advanced disease state or difficulty with manufacturing suitable numbers of CAR T cells. Alternatively, T cells from a healthy donor can be used to produce an allogeneic CAR T therapy, provided the cells are rendered incapable of eliciting graft versus host disease (GvHD). One approach to the production of these cells is gene editing to eliminate expression of the endogenous T cell receptor (TCR). Here we report a streamlined strategy for generating allogeneic CAR T cells by targeting the insertion of a CAR transgene directly into the native TCR locus using an engineered homing endonuclease and an AAV donor template. We demonstrate that anti-CD19 CAR T cells produced in this manner do not express the endogenous TCR, exhibit potent effector functions in vitro, and mediate clearance of CD19+ tumors in an in vivo mouse model.

Systemic activation of antigen-presenting cells via RNA-loaded nanoparticles.

While RNA-pulsed dendritic cell (DC) vaccines have shown promise, the advancement of cellular therapeutics is fraught with developmental challenges. To circumvent the challenges of cellular immunotherapeutics, we developed clinically translatable nanoliposomes that can be combined with tumor-derived RNA to generate personalized tumor RNA-nanoparticles (NPs) with considerable scale-up capacity. RNA-NPs bypass MHC restriction, are amenable to central distribution, and can provide near immediate immune induction. We screened commercially available nanoliposomal preparations and identified the cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as an efficient mRNA courier to antigen-presenting cells (APCs). When administered intravenously, RNA-NPs mediate systemic activation of APCs in reticuloendothelial organs such as the spleen, liver, and bone marrow. RNA-NPs increase percent expression of MHC class I/II, B7 co-stimulatory molecules, and maturation markers on APCs (all vital for T-cell activation). RNA-NPs also increase activation markers on tumor APCs and elicit potent expansion of antigen-specific T-cells superior to peptide vaccines formulated in complete Freund's adjuvant. We demonstrate that both model antigen-encoding and physiologically-relevant tumor-derived RNA-NPs expand potent antitumor T-cell immunity. RNA-NPs were shown to induce antitumor efficacy in a vaccine model and functioned as a suitable alternative to DCs in a stringent cellular immunotherapy model for a radiation/temozolomide resistant invasive murine high-grade glioma. Although cancer vaccines have suffered from weak immunogenicity, we have advanced a RNA-NP formulation that systemically activates host APCs precipitating activated T-cell frequencies necessary to engender antitumor efficacy. RNA-NPs can thus be harnessed as a more feasible and effective immunotherapy to re-program host-immunity.

Know your neighbors: Different tumor microenvironments have implications in immunotherapeutic targeting strategies across MB subgroups.

Medulloblastoma (MB) is the most common pediatric brain tumor with few reports of successful immunologic targeting. We have recently demonstrated the immune tumor microenvironment as well as response to immune checkpoint blockade differ across subtypes of murine MB.

Differential Immune Microenvironments and Response to Immune Checkpoint Blockade among Molecular Subtypes of Murine Medulloblastoma.

PURPOSE: Despite significant strides in the identification and characterization of potential therapeutic targets for medulloblastoma, the role of the immune system and its interplay with the tumor microenvironment within these tumors are poorly understood. To address this, we adapted two syngeneic animal models of human Sonic Hedgehog (SHH)-driven and group 3 medulloblastoma for preclinical evaluation in immunocompetent C57BL/6 mice. EXPERIMENTAL DESIGN AND RESULTS: Multicolor flow cytometric analyses were used to phenotype and characterize immune infiltrating cells within established cerebellar tumors. We observed significantly higher percentages of dendritic cells, infiltrating lymphocytes, myeloid-derived suppressor cells, and tumor-associated macrophages in murine SHH model tumors compared with group 3 tumors. However, murine group 3 tumors had higher percentages of CD8(+) PD-1(+) T cells within the CD3 population. PD-1 blockade conferred superior antitumor efficacy in animals bearing intracranial group 3 tumors compared with SHH group tumors, indicating that immunologic differences within the tumor microenvironment can be leveraged as potential targets to mediate antitumor efficacy. Further analysis of anti-PD-1 monoclonal antibody localization revealed binding to PD-1(+) peripheral T cells, but not tumor infiltrating lymphocytes within the brain tumor microenvironment. Peripheral PD-1 blockade additionally resulted in a marked increase in CD3(+) T cells within the tumor microenvironment. CONCLUSIONS: This is the first immunologic characterization of preclinical models of molecular subtypes of medulloblastoma and demonstration that response to immune checkpoint blockade differs across subtype classification. Our findings also suggest that effective anti-PD-1 blockade does not require that systemically administered antibodies penetrate the brain tumor microenvironment.

Novel role of hematopoietic stem cells in immunologic rejection of malignant gliomas.

Adoptive cellular therapy (ACT) after lymphodepletive conditioning can induce dramatic clinical responses, but this approach has been largely limited to melanoma due to a lack of reliable methods for expanding tumor-specific lymphocytes from the majority of other solid cancers. We have employed tumor RNA-pulsed dendritic cells (DCs) to reliably expand CD4+ and CD8+ tumor-reactive T lymphocytes for curative ACT in a highly-invasive, chemotherapy- and radiation-resistant malignant glioma model. Curative treatment of established intracranial tumors involved a synergistic interaction between myeloablative (MA) conditioning, adoptively transferred tumor-specific T cells, and tumor RNA-pulsed DC vaccines. Hematopoietic stem cells (HSCs), administered for salvage from MA conditioning, rapidly migrated to areas of intracranial tumor growth and facilitated the recruitment of tumor-specific lymphocytes through HSC-elaborated chemokines and enhanced immunologic rejection of intracranial tumors during ACT. Furthermore, HSC transplant under non-myeloablative (NMA) conditions also enhanced immunologic tumor rejection, indicating a novel role for the use of HSCs in the immunologic treatment of malignant gliomas and possibly other solid tumors.

Chasing cancer with chimeric antigen receptor therapy.

Many attempts to use genetically modified T cells to halt tumor progression have been met with disappointment and significant challenges in the successful application within human patients. Porter et al., however, describe the use of genetically modified lymphocytes bearing a chimeric antigen receptor that bypasses many of the common limitations of adoptive lymphocyte therapy. Through incorporation of a costimulatory domain within the chimeric antigen receptor, the investigators engineered lymphocytes with significantly higher tumor rejection activity and demonstrated significant expansion and prolonged survival after in vivo transfer to a single patient who showed a complete regression of refractory chronic lymphoid leukemia. This recent success in using genetically modified T cells to kill chronic lymphoid leukemia tumor cells is an encouraging advancement in the development of specific and targeted immune-based therapies against cancer.

Inactivation of genes encoding plastoglobuli-like proteins in Synechocystis sp. PCC 6803 leads to a light-sensitive phenotype.

Plastoglobulins (PGL) are the predominant proteins of lipid globules in the plastids of flowering plants. Genes encoding proteins similar to plant PGL are also present in algae and cyanobacteria but in no other organisms, suggesting an important role for these proteins in oxygenic photosynthesis. To gain an understanding of the core and fundamental function of PGL, the two genes that encode PGL-like polypeptides in the cyanobacterium Synechocystis sp. PCC 6803 (pgl1 and pgl2) were inactivated individually and in combination. The resulting mutants were able to grow under photoautotrophic conditions, dividing at rates that were comparable to that of the wild-type (WT) under low-light (LL) conditions (10 microeinsteins x m(-2) x s(-1)) but lower than that of the WT under moderately high-irradiance (HL) conditions (150 microeinsteins x m(-2) x s(-1)). Under HL, each Deltapgl mutant had less chlorophyll, a lower photosystem I (PSI)/PSII ratio, more carotenoid per unit of chlorophyll, and very much more myxoxanthophyll (a carotenoid symptomatic of high light stress) per unit of chlorophyll than the WT. Large, heterogeneous inclusion bodies were observed in cells of mutants inactivated in pgl2 or both pgl2 and pgl1 under both LL and HL conditions. The mutant inactivated in both pgl genes was especially sensitive to the light environment, with alterations in pigmentation, heterogeneous inclusion bodies, and a lower PSI/PSII ratio than the WT even for cultures grown under LL conditions. The WT cultures grown under HL contained 2- to 3-fold more PGL1 and PGL2 per cell than cultures grown under LL conditions. These and other observations led us to conclude that the PGL-like polypeptides of Synechocystis play similar but not identical roles in some process relevant to the repair of photooxidative damage.