Personalized RNA neoantigen vaccines stimulate T cells in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is lethal in 88% of patients1, yet harbours mutation-derived T cell neoantigens that are suitable for vaccines 2,3. Here in a phase I trial of adjuvant autogene cevumeran, an individualized neoantigen vaccine based on uridine mRNA-lipoplex nanoparticles, we synthesized mRNA neoantigen vaccines in real time from surgically resected PDAC tumours. After surgery, we sequentially administered atezolizumab (an anti-PD-L1 immunotherapy), autogene cevumeran (a maximum of 20 neoantigens per patient) and a modified version of a four-drug chemotherapy regimen (mFOLFIRINOX, comprising folinic acid, fluorouracil, irinotecan and oxaliplatin). The end points included vaccine-induced neoantigen-specific T cells by high-threshold assays, 18-month recurrence-free survival and oncologic feasibility. We treated 16 patients with atezolizumab and autogene cevumeran, then 15 patients with mFOLFIRINOX. Autogene cevumeran was administered within 3 days of benchmarked times, was tolerable and induced de novo high-magnitude neoantigen-specific T cells in 8 out of 16 patients, with half targeting more than one vaccine neoantigen. Using a new mathematical strategy to track T cell clones (CloneTrack) and functional assays, we found that vaccine-expanded T cells comprised up to 10% of all blood T cells, re-expanded with a vaccine booster and included long-lived polyfunctional neoantigen-specific effector CD8+ T cells. At 18-month median follow-up, patients with vaccine-expanded T cells (responders) had a longer median recurrence-free survival (not reached) compared with patients without vaccine-expanded T cells (non-responders; 13.4 months, P = 0.003). Differences in the immune fitness of the patients did not confound this correlation, as responders and non-responders mounted equivalent immunity to a concurrent unrelated mRNA vaccine against SARS-CoV-2. Thus, adjuvant atezolizumab, autogene cevumeran and mFOLFIRINOX induces substantial T cell activity that may correlate with delayed PDAC recurrence.

Altered Basal Lipid Metabolism Underlies the Functional Impairment of Naive CD8+ T Cells in Elderly Humans.

Aging is associated with functional deficits in the naive T cell compartment, which compromise the generation of de novo immune responses against previously unencountered Ags. The mechanisms that underlie this phenomenon have nonetheless remained unclear. We found that naive CD8+ T cells in elderly humans were prone to apoptosis and proliferated suboptimally in response to stimulation via the TCR. These abnormalities were associated with dysregulated lipid metabolism under homeostatic conditions and enhanced levels of basal activation. Importantly, reversal of the bioenergetic anomalies with lipid-altering drugs, such as rosiglitazone, almost completely restored the Ag responsiveness of naive CD8+ T cells. Interventions that favor lipid catabolism may therefore find utility as adjunctive therapies in the elderly to promote vaccine-induced immunity against targetable cancers and emerging pathogens, such as seasonal influenza viruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Exosome-Based Vaccines: History, Current State, and Clinical Trials.

Extracellular vesicles (EVs) are released by most cell types as part of an intracellular communication system in crucial processes such as inflammation, cell proliferation, and immune response. However, EVs have also been implicated in the pathogenesis of several diseases, such as cancer and numerous infectious diseases. An important feature of EVs is their ability to deliver a wide range of molecules to nearby targets or over long distances, which allows the mediation of different biological functions. This delivery mechanism can be utilized for the development of therapeutic strategies, such as vaccination. Here, we have highlighted several studies from a historical perspective, with respect to current investigations on EV-based vaccines. For example, vaccines based on exosomes derived from dendritic cells proved to be simpler in terms of management and cost-effectiveness than dendritic cell vaccines. Recent evidence suggests that EVs derived from cancer cells can be leveraged for therapeutics to induce strong anti-tumor immune responses. Moreover, EV-based vaccines have shown exciting and promising results against different types of infectious diseases. We have also summarized the results obtained from completed clinical trials conducted on the usage of exosome-based vaccines in the treatment of cancer, and more recently, coronavirus disease.

From COVID-19 to Cancer mRNA Vaccines: Moving From Bench to Clinic in the Vaccine Landscape.

Recently, mRNA vaccines have become a significant type of therapeutic and have created new fields in the biopharmaceutical industry. mRNA vaccines are promising next-generation vaccines that have introduced a new age in vaccinology. The recent approval of two COVID-19 mRNA vaccines (mRNA-1273 and BNT162b2) has accelerated mRNA vaccine technology and boosted the pharmaceutical and biotechnology industry. These mRNA vaccines will help to tackle COVID-19 pandemic through immunization, offering considerable hope for future mRNA vaccines. Human trials with data both from mRNA cancer vaccines and mRNA infectious disease vaccines have provided encouraging results, inspiring the pharmaceutical and biotechnology industries to focus on this area of research. In this article, we discuss current mRNA vaccines broadly in two parts. In the first part, mRNA vaccines in general and COVID-19 mRNA vaccines are discussed. We presented the mRNA vaccine structure in general, the different delivery systems, the immune response, and the recent clinical trials for mRNA vaccines (both for cancer mRNA vaccines and different infectious diseases mRNA vaccines). In the second part, different COVID-19 mRNA vaccines are explained. Finally, we illustrated a snapshot of the different leading mRNA vaccine developers, challenges, and future prospects of mRNA vaccines.

Adenoviral vaccines promote protective tissue-resident memory T cell populations against cancer.

BACKGROUND: Adenoviral vectors emerged as important platforms for cancer immunotherapy. Vaccination with adenoviral vectors is promising in this respect, however, their specific mechanisms of action are not fully understood. Here, we assessed the development and maintenance of vaccine-induced tumor-specific CD8+ T cells elicited upon immunization with adenoviral vectors. METHODS: Adenoviral vaccine vectors encoding the full-length E7 protein from human papilloma virus (HPV) or the immunodominant epitope from E7 were generated, and mice were immunized intravenously with different quantities (107, 108 or 109 infectious units). The magnitude, kinetics and tumor protection capacity of the induced vaccine-specific T cell responses were evaluated. RESULTS: The adenoviral vaccines elicited inflationary E7-specific memory CD8+ T cell responses in a dose-dependent manner. The magnitude of these vaccine-specific CD8+ T cells in the circulation related to the development of E7-specific CD8+ tissue-resident memory T (TRM) cells, which were maintained for months in multiple tissues after vaccination. The vaccine-specific CD8+ T cell responses conferred long-term protection against HPV-induced carcinomas in the skin and liver, and this protection required the induction and accumulation of CD8+ TRM cells. Moreover, the formation of CD8+ TRM cells could be enhanced by temporal targeting CD80/CD86 costimulatory interactions via CTLA-4 blockade early after immunization. CONCLUSIONS: Together, these data show that adenoviral vector-induced CD8+ T cell inflation promotes protective TRM cell populations, and this can be enhanced by targeting CTLA-4.

Editorial: mRNA Vaccines and Immunotherapy in Oncology: A New Era for Personalized Medicine.

Synthetic mRNA and the expression of therapeutic proteins have accelerated vaccine development to prevent infection and heralds a new era in targeted immunotherapy in oncology. Therapeutic mRNA vaccines rely on available tumor tissue for gene sequencing analysis to compare the patient's normal cellular DNA sequences and those of the tumor. Carrier-based mRNA vaccines for cancer immunotherapy are now in development that use delivery systems based on peptides, lipids, polymers, and cationic nano-emulsions. There have also been recent developments in dendritic cell-based mRNA vaccines. For patients with available tumor tissue samples, it is possible to develop mRNA vaccines that result in the expression of tumor antigens by antigen-presenting cells (APCs), resulting in innate and adaptive immune responses. Ongoing developments in mRNA immunotherapy include modifications in the route of administration and combined delivery of multiple mRNA vaccines with checkpoint inhibitors. This Editorial aims to present a brief overview of how mRNA immunotherapy may change the therapeutic landscape of personalized medicine for patients with solid malignant tumors.

The Rapid Development and Early Success of Covid 19 Vaccines Have Raised Hopes for Accelerating the Cancer Treatment Mechanism.

The Covid-19 pandemic has brought about rapid change in medical science. The production of new generation vaccines for this disease has surprised even their most optimistic supporters. Not only have these vaccines proven to be effective, but the importance of this disease and pandemic situation also significantly shortened the long-standing process of validating such products. Vaccination is a type of immunotherapy. Researchers have long been looking at vaccines as a possible treatment for cancer (Geynisman et al., 2014). In the same way that vaccines work against infectious diseases, attempts are being made to develop vaccines to identify specific proteins on cancer cells. This helps the immune system recognize and attack cancer cells. Cancer vaccines may help: I) Prevent the growth of cancer cells (Bialkowski et al., 2016), II) Prevent recurrence of cancer (Stanton and Disis, 2015), III) Destroy cancer cells left over from other treatments. The following types of cancer vaccines are being studied: Antigen Vaccines. These vaccines are made from specific proteins or antigens of cancerous cells. Their purpose is to stimulate the immune system to attack cancer cells (Tagliamonte et al., 2014). Whole-Cell Vaccines. A whole-cell vaccine uses the entire cancer cell, not just a specific molecule (antigen), to generate the vaccine. (Keenan and Jaffee, 2012).Dendritic Cell Vaccines. Dendritic cells help the immune system identify abnormal cells, such as cancerous cells. Dendritic cells are grown with cancer cells in the laboratory to produce the vaccine. The vaccine then stimulates the immune system to attack cancer. (Wang et al., 2014; Mastelic-Gavillet et al., 2019). DNA Vaccines. These vaccines are made from DNA fragments of cancer cells. They can be injected into the body to facilitate immune system cells can better respond and kill cancer cells (Gatti-Mays et al., 2017).Other Types of Cancer Vaccines. such as Anti idiotype vaccines. This vaccine stimulates the body to generate antibodies against cancerous cells. An example of an anti-idiotype antibody is Racotumomab or Vaxira (Cancer, 2016). However, conditions and considerations after Corona does not seem to be the same as before. The current pandemic situation has also led to major changes in the pharmaceutical and Vaccine production process and international protocols. Some of the most critical issues that can accelerate the introduction of cancer vaccines are: 1. Typical drug and vaccine development timeline. A typical vaccine needs 5 to 10 years and sometimes longer to design secure funding, and get approval (Figure 1). Less than 10 percent of new drugs, which are entered in the different phases of clinical trials, are advanced to approval by the Food and Drug Administration (FDA)(Cancer, 2020a). However, now the situation is not normal. Dozens of Covid 19 vaccines are starting clinical trials. Some of them use RNA and DNA technology, which delivers the body with missions to produce its antibodies against the virus. There are already at least 254 therapies and 95 vaccines related to Covid-19 being explored. However, it seems that the experiences gained in this pandemic, and advances in technology, may be effective in shortening the production path of other vaccines and drugs and the process of its approval at the national and international levels in the future. In Figure 2, the time course of production of conventional vaccines in comparison with Covid 19 vaccines (Cancer, 2020b) is shown.2. The introduction of messenger RNA (mRNA) technology into the field of prevention and treatment. Over the past decades, this technology has been considered an excellent alternative to conventional vaccination methods. Proper potency and low side effects, the possibility of fast production and relatively low production cost are its advantages. However, until recently, the instability of this molecule has been a major problem in its application. This research was started many years ago by two companies that played a significant role in developing the first Covid vaccines, so BioNTech and Moderna were able to quickly transfer their experience in the field of Covid vaccine development (Pardi et al., 2018; Moderna, 2020). Figure 3 shows how mRNA vaccines work. Bout Pfizer – BioNTech and Moderna mRNA vaccines were more than 90 % effective in preclinical stages. Millions of doses of these two vaccines are currently being injected into eligible individuals worldwide. 3. Considering the use of artificial intelligence in assessing the effectiveness of vaccines. There are always doubts about the effectiveness of the new drug in treating the disease. Once the vaccine is widely available, we will know more about its effectiveness versus it works under carefully controlled scientific testing conditions. Vaccines will continue to be monitored after use. The data collected helps professionals understand how they work in different groups of people (depending on factors such as age, ethnicity, and people with different health conditions) and also the length of protection provided by the vaccine. Artificial intelligence (AI) is an emerging field, which reaches everywhere and not only as a beneficial industrial tool but also as a practical tool in medical science and plays a crucial role in developing the computation vision, risk assessment, diagnostic, prognostic, etc. models in the field of medicine (Amisha et al., 2019). According to the wide range of AI applications in the analysis of different types of data, it can be used in vaccine production, safety assessments, clinical and preclinical studies and Covid 19 vaccines adverse reactions (CDC, 2019). Indeed, most cancer vaccines are therapeutic, rather than prophylactic, and seek to stimulate cell-mediated responses, such as those from CTLs, capable of clearing or reducing tumor burden. There are currently FDA-approved products for helping cancer treatment such as BREYANZI, TECARTUS and YESCARTA for lymphoma, IMLYGIC for melanoma, KYMRIAH for acute lymphoblastic leukemia, and PROVENGE for prostate cancer. Over the past decade, most of BioNTech's activities have been in the field of cancer vaccine design and production for melanoma (two clinical trials), breast cancer (one clinical trial), and the rest concerning viral and veterinary vaccines (two clinical trials). Also Maderno company has been working on Individualized cancer vaccines (one clinical trials), and vaccines for viral infections such as Zika and Influenza and veterinary vaccines (several clinical trials) (Pardi et al., 2018). Therefore, it can be said, mRNA technology that has been the subject of much research into the treatment of cancer has been shifted and rapidly used to produce and use the Covid 19 vaccine. The current pandemic situation has necessitated the acceleration of Covid 19 vaccines and drugs and national and international protocols for their approval. If the currently produced vaccines can continue to be as successful as the preclinical and early phase studies, these changes and evolution have raised hopes for accelerating the use of these technologies and mechanisms in the field of cancer and other diseases vaccines, including HIV and influenza.

Clinical and immunological effects of mRNA vaccines in malignant diseases.

In vitro-transcribed messenger RNA-based therapeutics represent a relatively novel and highly efficient class of drugs. Several recently published studies emphasize the potential efficacy of mRNA vaccines in treating different types of malignant and infectious diseases where conventional vaccine strategies and platforms fail to elicit protective immune responses. mRNA vaccines have lately raised high interest as potent vaccines against SARS-CoV2. Direct application of mRNA or its electroporation into dendritic cells was shown to induce polyclonal CD4+ and CD8+ mediated antigen-specific T cell responses as well as the production of protective antibodies with the ability to eliminate transformed or infected cells. More importantly, the vaccine composition may include two or more mRNAs coding for different proteins or long peptides. This enables the induction of polyclonal immune responses against a broad variety of epitopes within the encoded antigens that are presented on various MHC complexes, thus avoiding the restriction to a certain HLA molecule or possible immune escape due to antigen-loss. The development and design of mRNA therapies was recently boosted by several critical innovations including the development of technologies for the production and delivery of high quality and stable mRNA. Several technical obstacles such as stability, delivery and immunogenicity were addressed in the past and gradually solved in the recent years.This review will summarize the most recent technological developments and application of mRNA vaccines in clinical trials and discusses the results, challenges and future directions with a special focus on the induced innate and adaptive immune responses.

Emerging Immunotherapies against Novel Molecular Targets in Breast Cancer.

Immunotherapy is a highly emerging form of breast cancer therapy that enables clinicians to target cancers with specific receptor expression profiles. Two popular immunotherapeutic approaches involve chimeric antigen receptor-T cells (CAR-T) and bispecific antibodies (BsAb). Briefly mentioned in this review as well is the mRNA vaccine technology recently popularized by the COVID-19 vaccine. These forms of immunotherapy can highly select for the tumor target of interest to generate specific tumor lysis. Along with improvements in CAR-T, bispecific antibody engineering, and therapeutic administration, much research has been done on novel molecular targets that can especially be useful for triple-negative breast cancer (TNBC) immunotherapy. Combining emerging immunotherapeutics with tumor marker discovery sets the stage for highly targeted immunotherapy to be the future of cancer treatments. This review highlights the principles of CAR-T and BsAb therapy, improvements in CAR and BsAb engineering, and recently identified human breast cancer markers in the context of in vitro or in vivo CAR-T or BsAb treatment.

mRNA vaccine for cancer immunotherapy.

mRNA vaccines have become a promising platform for cancer immunotherapy. During vaccination, naked or vehicle loaded mRNA vaccines efficiently express tumor antigens in antigen-presenting cells (APCs), facilitate APC activation and innate/adaptive immune stimulation. mRNA cancer vaccine precedes other conventional vaccine platforms due to high potency, safe administration, rapid development potentials, and cost-effective manufacturing. However, mRNA vaccine applications have been limited by instability, innate immunogenicity, and inefficient in vivo delivery. Appropriate mRNA structure modifications (i.e., codon optimizations, nucleotide modifications, self-amplifying mRNAs, etc.) and formulation methods (i.e., lipid nanoparticles (LNPs), polymers, peptides, etc.) have been investigated to overcome these issues. Tuning the administration routes and co-delivery of multiple mRNA vaccines with other immunotherapeutic agents (e.g., checkpoint inhibitors) have further boosted the host anti-tumor immunity and increased the likelihood of tumor cell eradication. With the recent U.S. Food and Drug Administration (FDA) approvals of LNP-loaded mRNA vaccines for the prevention of COVID-19 and the promising therapeutic outcomes of mRNA cancer vaccines achieved in several clinical trials against multiple aggressive solid tumors, we envision the rapid advancing of mRNA vaccines for cancer immunotherapy in the near future. This review provides a detailed overview of the recent progress and existing challenges of mRNA cancer vaccines and future considerations of applying mRNA vaccine for cancer immunotherapies.

New viral vectors for infectious diseases and cancer.

Since the discovery in 1796 by Edward Jenner of vaccinia virus as a way to prevent and finally eradicate smallpox, the concept of using a virus to fight another virus has evolved into the current approaches of viral vectored genetic vaccines. In recent years, key improvements to the vaccinia virus leading to a safer version (Modified Vaccinia Ankara, MVA) and the discovery that some viruses can be used as carriers of heterologous genes encoding for pathological antigens of other infectious agents (the concept of 'viral vectors') has spurred a new wave of clinical research potentially providing for a solution for the long sought after vaccines against major diseases such as HIV, TB, RSV and Malaria, or emerging infectious diseases including those caused by filoviruses and coronaviruses. The unique ability of some of these viral vectors to stimulate the cellular arm of the immune response and, most importantly, T lymphocytes with cell killing activity, has also reawakened the interest toward developing therapeutic vaccines against chronic infectious diseases and cancer. To this end, existing vectors such as those based on Adenoviruses have been improved in immunogenicity and efficacy. Along the same line, new vectors that exploit viruses such as Vesicular Stomatitis Virus (VSV), Measles Virus (MV), Lymphocytic choriomeningitis virus (LCMV), cytomegalovirus (CMV), and Herpes Simplex Virus (HSV), have emerged. Furthermore, technological progress toward modifying their genome to render some of these vectors incompetent for replication has increased confidence toward their use in infant and elderly populations. Lastly, their production process being the same for every product has made viral vectored vaccines the technology of choice for rapid development of vaccines against emerging diseases and for 'personalised' cancer vaccines where there is an absolute need to reduce time to the patient from months to weeks or days. Here we review the recent developments in viral vector technologies, focusing on novel vectors based on primate derived Adenoviruses and Poxviruses, Rhabdoviruses, Paramixoviruses, Arenaviruses and Herpesviruses. We describe the rationale for, immunologic mechanisms involved in, and design of viral vectored gene vaccines under development and discuss the potential utility of these novel genetic vaccine approaches in eliciting protection against infectious diseases and cancer.

Mitigating Coronavirus Induced Dysfunctional Immunity for At-Risk Populations in COVID-19: Trained Immunity, BCG and "New Old Friends".

The novel, highly contagious coronavirus SARS-CoV-2 spreads rapidly throughout the world, leading to a deadly pandemic of a predominantly respiratory illness called COVID-19. Safe and effective anti-SARS-CoV-2 vaccines are urgently needed. However, emerging immunological observations show hallmarks of significant immunopathological characteristics and dysfunctional immune responses in patients with COVID-19. Combined with existing knowledge about immune responses to other closely related and highly pathogenic coronaviruses, this could forebode significant challenges for vaccine development, including the risk of vaccine failure. Animal data from earlier coronavirus vaccine efforts indicate that elderly people, most at risk from severe COVID-19 disease, could be especially at risk from immunopathologic responses to novel coronavirus vaccines. Bacterial "new old friends" such as Bacille Calmette-Guérin (BCG) or Mycobacterium obuense have the ability to elevate basal systemic levels of type 1 cytokines and immune cells, correlating with increased protection against diverse and unrelated infectious agents, called "trained immunity." Here we describe dysfunctional immune responses induced by coronaviruses, representing potentially difficult to overcome obstacles to safe, effective vaccine development for COVID-19, and outline how trained immunity could help protect high risk populations through immunomodulation with BCG and other "new old friends."