Enhanced Human T Lymphocyte Antigen Priming by Cytokine-Matured Dendritic Cells Overexpressing Bcl-2 and IL-12

BCL2 Inhibition Reveals a Dendritic Cell-Specific Immune Checkpoint That Controls Tumor Immunosurveillance

We developed a phenotypic screening platform for the functional exploration of dendritic cells (DC). Here, we report a genome-wide CRISPR screen that revealed BCL2 as an endogenous inhibitor of DC function. Knockout of BCL2 enhanced DC antigen presentation and activation as well as the capacity of DCs to control tumors and to synergize with PD-1 blockade. The pharmacologic BCL2 inhibitors venetoclax and navitoclax phenocopied these effects and caused a cDC1-dependent regression of orthotopic lung cancers and fibrosarcomas. Thus, solid tumors failed to respond to BCL2 inhibition in mice constitutively devoid of cDC1, and this was reversed by the infusion of DCs. Moreover, cDC1 depletion reduced the therapeutic efficacy of BCL2 inhibitors alone or in combination with PD-1 blockade and treatment with venetoclax caused cDC1 activation, both in mice and in patients. In conclusion, genetic and pharmacologic BCL2 inhibition unveils a DC-specific immune checkpoint that restrains tumor immunosurveillance.

SIGNIFICANCE

BCL2 inhibition improves the capacity of DCs to stimulate anticancer immunity and restrain cancer growth in an immunocompetent context but not in mice lacking cDC1 or mature T cells. This study indicates that BCL2 blockade can be used to sensitize solid cancers to PD-1/PD-L1-targeting immunotherapy. This article is featured in Selected Articles from This Issue, p. 2293.

Targeting the dendritic cell-T cell axis to develop effective immunotherapies for glioblastoma

Glioblastoma is an aggressive primary brain tumor that has seen few advances in treatments for over 20 years. In response to this desperate clinical need, multiple immunotherapy strategies are under development, including CAR-T cells, immune checkpoint inhibitors, oncolytic viruses and dendritic cell vaccines, although these approaches are yet to yield significant clinical benefit. Potential reasons for the lack of success so far include the immunosuppressive tumor microenvironment, the blood-brain barrier, and systemic changes to the immune system driven by both the tumor and its treatment. Furthermore, while T cells are essential effector cells for tumor control, dendritic cells play an equally important role in T cell activation, and emerging evidence suggests the dendritic cell compartment may be deeply compromised in glioblastoma patients. In this review, we describe the immunotherapy approaches currently under development for glioblastoma and the challenges faced, with a particular emphasis on the critical role of the dendritic cell-T cell axis. We suggest a number of strategies that could be used to boost dendritic cell number and function and propose that the use of these in combination with T cell-targeting strategies could lead to successful tumor control.

Dendritic Cell Vaccines: A Shift from Conventional Approach to New Generations

In the emerging era of cancer immunotherapy, immune checkpoint blockades (ICBs) and adoptive cell transfer therapies (ACTs) have gained significant attention. However, their therapeutic efficacies are limited due to the presence of cold type tumors, immunosuppressive tumor microenvironment, and immune-related side effects. On the other hand, dendritic cell (DC)-based vaccines have been suggested as a new cancer immunotherapy regimen that can address the limitations encountered by ICBs and ACTs. Despite the success of the first generation of DC-based vaccines, represented by the first FDA-approved DC-based therapeutic cancer vaccine Provenge, several challenges remain unsolved. Therefore, new DC vaccine strategies have been actively investigated. This review addresses the limitations of the currently most adopted classical DC vaccine and evaluates new generations of DC vaccines in detail, including biomaterial-based, immunogenic cell death-inducing, mRNA-pulsed, DC small extracellular vesicle (sEV)-based, and tumor sEV-based DC vaccines. These innovative DC vaccines are envisioned to provide a significant breakthrough in cancer immunotherapy landscape and are expected to be supported by further preclinical and clinical studies.

Enhancement of live vaccines by co-delivery of immune modulating proteins

Vaccines are very effective in providing protection against many infectious diseases. However, it has proven difficult to develop highly efficacious vaccines against some pathogens and so there is a continuing need to improve vaccine technologies. The first successful and widely used vaccines were based on attenuated pathogens (e.g., laboratory passaged Pasteurella multocida to vaccinate against fowl cholera) or closely related non-pathogenic organisms (e.g., cowpox to vaccinate against smallpox). Subsequently, live vaccines, either attenuated pathogens or non-pathogenic microorganisms modified to deliver heterologous antigens, have been successfully used to induce protective immune responses against many pathogens. Unlike conventional killed and subunit vaccines, live vaccines can deliver antigens to mucosal surfaces in a similar manner and context as the natural infection and hence can often produce a more appropriate and protective immune response. Despite these advantages, there is still a need to improve the immunogenicity of some live vaccines. The efficacy of injectable killed and subunit vaccines is usually enhanced using adjuvants such mineral salts, oils, and saponin, but such adjuvants cannot be used with live vaccines. Instead, live vaccines can be engineered to produce immunomodulatory molecules that can stimulate the immune system to induce more robust and long-lasting adaptive immune responses. This review focuses on research that has been undertaken to engineer live vaccines to produce immunomodulatory molecules that act as adjuvants to increase immunogenicity. Adjuvant strategies with varying mechanisms of action (inflammatory, antibody-mediated, cell-mediated) and delivery modes (oral, intramuscular, intranasal) have been investigated, with varying degrees of success. The goal of such research is to define adjuvant strategies that can be adapted to enhance live vaccine efficacy by triggering strong innate and adaptive immune responses and produce vaccines against a wider range of pathogens.

The generation and application of antigen-specific T cell therapies for cancer and viral-associated disease

Immunotherapy with antigen-specific T cells is a promising, targeted therapeutic option for patients with cancer as well as for immunocompromised patients with virus infections. In this review, we characterize and compare current manufacturing protocols for the generation of T cells specific to viral and non-viral tumor-associated antigens. Specifically, we discuss: (1) the different methodologies to expand virus-specific T cell and non-viral tumor-associated antigen-specific T cell products, (2) an overview of the immunological principles involved when developing such manufacturing protocols, and (3) proposed standardized methodologies for the generation of polyclonal, polyfunctional antigen-specific T cells irrespective of donor source. Ex vivo expanded cells have been safely administered to treat numerous patients with virus-associated malignancies, hematologic malignancies, and solid tumors. Hence, we have performed a comprehensive review of the clinical trial results evaluating the safety, feasibility, and efficacy of these products in the clinic. In summary, this review seeks to provide new insights regarding antigen-specific T cell technology to benefit a rapidly expanding T cell therapy field.

Exploration on the Application Path of College English MOOCS Teaching under the Background of Internet of Things

While the development of information and communication technology has brought great changes to social industrial structure and economic development, it has also reshaped people's cognition and thinking modes to a great extent and has paid attention to the field of education under the guidance of technology. The reform of education is taking place. According to the background of the Internet of things, the teaching quality evaluation index is reconstructed with the help of principal component analysis, support vector machine, and fuzzy algorithms, and the application performance and practical results of the improved teaching path are analyzed. The results show that the evaluation accuracy of the improved hybrid algorithm for teaching quality reaches more than 90%, and its evaluation time is far less than that of the SVM algorithm (10.23 s), and it has a good application effect on the evaluation of teaching quality. The increase of students' satisfaction with the improved teaching quality has reached 5.8%, and their professional skills have improved by 6–25 points. After expert evaluation, it is found that the maximum satisfaction frequency of teaching content and teaching effect can reach 96.7% and 91.3%, respectively. Reconstructing the index system of the English path under the background of the Internet of things can better grasp students' learning needs and integrate multiple methods to provide new research ideas for follow-up English teaching.