SARS-CoV-2 RBD protein enhances the oncolytic activity of the vesicular stomatitis virus

Despite recent advances in the research on oncolytic viruses (OVs), a better understanding of how to enhance their replication is key to improving their therapeutic index. Understanding viral replication is important to improve treatment outcomes based on enhanced viral spreading within the tumor milieu. The VSV-Δ51 oncolytic virus has been widely used as an anticancer agent with a high selectivity profile. In this study, we examined the role of the SARS-CoV-2 spike protein receptor-binding domain (RBD) in enhancing VSV-Δ51 viral production and oncolytic activity. To test this hypothesis, we first generated a novel VSV-Δ51 mutant that encoded the SARS-COV-2 RBD and compared viral spreading and viral yield between VSV-Δ51-RBD and VSV-Δ51 in vitro. Using the viral plaque assay, we demonstrated that the presence of the SARS-CoV-2 RBD in the VSV-Δ51 genome is associated with a significantly larger viral plaque surface area and significantly higher virus titers. Subsequently, using an ATP release-based assay, we demonstrated that the SARS-CoV-2 RBD could enhance VSV-Δ51 oncolytic activity in vitro. This observation was further supported using the B16F10 tumor model. These findings highlighted a novel use of the SARS-CoV-2 RBD as an anticancer agent.Instituto de BiotecnologíaFil: Alkayyal, Almohanad A. University of Tabuk. Faculty of Applied Medical Sciences. Department of Medical Laboratory Technology; Arabia SauditaFil: Alkayyal, Almohanad A. King Abdullah International Medical Research Center. Immunology Research Program; Arabia SauditaFil: Ajina, Reham. King Abdullah International Medical Research Center. Immunology Research Program; Arabia SauditaFil: Ajina, Reham. King Saud bin Abdulaziz University for Health Sciences. College of Applied Medical Sciences. Department of Clinical Laboratory Sciences; Arabia SauditaFil: Cacciabue, Marco Polo Domingo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Cacciabue, Marco Polo Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cacciabue, Marco Polo Domingo. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Alkayyal, Aaesha A. Taibah University. College of Medicine; Arabia SauditaFil: Saeedi, Nizar H. University of Tabuk. Faculty of Applied Medical Sciences. Department of Medical Laboratory Technology; Arabia SauditaFil: Hussain Alshehry, Taofik. Ministry of National Guard Health Affairs. King Saud University for Health Sciences. King Abdullah International Medical Research Centre; Arabia SauditaFil: Kaboha, Feras. Ministry of National Guard Health Affairs. King Saud University for Health Sciences. King Abdullah International Medical Research Centre; Arabia SauditaFil: Alotaibi, Mohammed A. University of Tabuk. Faculty of Applied Medical Sciences. Department of Medical Laboratory Technology; Arabia SauditaFil: Alotaibi, Mohammed A. Ministry of National Guard Health Affairs. King Saud University for Health Sciences. King Abdullah International Medical Research Centre; Arabia SauditaFil: Zaidan, Nada. King Abdulaziz City for Science and Technology. Joint Centers of Excellence Program. 8King Abdulaziz City for Science and Technology-Brigham and Women's Hospital (KACST-BWH) Centre of Excellence for Biomedicine; Arabia SauditaFil: Shah, Khalid. Harvard Medical School. Brigham and Women’s Hospital. Center for Stem Cell and Translational Immunotherapy (CSTI); Estados UnidosFil: Shah, Khalid. Harvard Medical School. Brigham and Women’s Hospital. Department of Neurosurgery; Estados UnidosFil: Shah, Khalid. Harvard University. Harvard Stem Cell Institute; Estados UnidosFil: Alroqi, Fayhan. King Abdullah International Medical Research Center. Immunology Research Program; Arabia SauditaFil: Alroqi, Fayhan. Ministry of the National Guard. Department of Immunology; Arabia SauditaFil: Alroqi, Fayhan. King Saud bin Abdulaziz University for Health Sciences. Faculty of Medicine; Arabia SauditaFil: Bakur Mahmoud, Ahmad. Taibah University. College of Applied Medical Sciences; Arabia SauditaFil: Bakur Mahmoud, Ahmad. Taibah University. Strategic Research and Innovation Laboratories; Arabia SauditaFil: Bakur Mahmoud, Ahmad. King Abdullah International Medical Research Center. Immunology Research Program; Arabia Saudit

Repurposing the oncolytic virus VSV∆51M as a COVID-19 vaccine

The coronavirus disease 2019 (COVID-19) pandemic imposes an urgent and continued need for the development of safe and cost-effective vaccines to induce preventive responses for limiting major outbreaks around the world. To combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we repurposed the VSV∆51M oncolytic virus platform to express the spike receptor-binding domain (RBD) antigen. In this study, we report the development and characterization of the VSV∆51M-RBD vaccine. Our findings demonstrate successful expression of the RBD gene by the VSV∆51M-RBD virus, inducing anti-RBD responses without attenuating the virus. Moreover, the VSV∆51M-RBD vaccine exhibited safety, immunogenicity, and the potential to serve as a safe and effective alternative or complementary platform to current COVID-19 vaccines

Licensed and unlicensed NK cells: Differential roles in cancer and viral control

NK cells are known for their well characterized ability to control viral infections and eliminate tumor cells. Through their repertoire of activating and inhibitory receptors, NK cells are able to survey different potential target cells for various surface markers, such as MHC-I—which signals to the NK cell that the target is healthy—as well as stress ligands or viral proteins, which alert the NK cell to the aberrant state of the target and initiate a response. According to the licensing hypothesis, interactions between self-specific MHC-I receptors—Ly49 in mice and KIR in humans—and self-MHC-I molecules during NK cell development is crucial for NK cell functionality. However, there also exists a large proportion of NK cells in mice and humans which lack self-specific MHC-I receptors and are consequentially ‘unlicensed’. While the licensed NK cell subset plays a major role in the control of MHC-I-deficient tumors, this review will go on to highlight the important role of the unlicensed NK cell subset in the control of MHC-I-expressing tumors, as well as in viral control. Unlike the licensed NK cells, unlicensed NK cells seem to benefit from the lack of self-specific inhibitory receptors, which could otherwise be exploited by some aberrant cells for immunoevasion by upregulating the expression of ligands or mimic ligands for these receptors

Influenza Virus Evades NK Cell Responses by Enhancing Ly49:MHC-I Interactions

Natural killer (NK) cells are a type of innate immune cell that can identify and eliminate viral infected cells and cancer cells. NK cells express an array of inhibitory and activating receptors such as natural cytotoxicity receptors, the mouse Ly49 or human KIR family, and NKR-P1 family. The integration of signals that NK cells receive through these receptors controls their activation and ability to kill target cells. Both Ly49 and KIR recognize MHC-I molecules on healthy cells Ly49:MHC-I engagement is essential for functional NK cell development. In the absence of these interactions NK cell is consider as ‘uneducated’ or ‘unlicensed’. Ly49 receptor interactions with MHC-I are critical in an effective NK cell response against cancer. However, the role of unlicensed NK cells in NK-mediated control of viruses is poorly understood. \ud Using NKCKD mice, we sought to determine how the loss of Ly49:MHC-I education, and the concomitant loss of inhibition via MHC-I, affected survival against influenza infection. In this study, we show that Ly49-deficient mice exhibit lower viral load and greater protection than WT mice when infected with influenza. However, this protection was lost when Ly49I was transgenically restored to these mice. Similarly, MHC-I-deficient mice, that also lack educated NK cells, were resistant to influenza infection, and lost this protection when NK cells were depleted before challenge. Based on the markedly reduced inflammation in the Ly49-deficient mice compared to the WT, we conclude that the Ly49-deficient NK cells are swifter and more effective in clearing influenza, resulting in less viral burden and consequentially less need for a dangerously aggressive inflammatory response. Furthermore, influenza infection enhanced MHC-I expression on lung epithelial cells, which could be responsible for inhibition of NK cells. Consequently, blockade of inhibitory Ly49C/I receptors protected WT mice from lethal influenza infection. Additionally, Perforin-deficient NKCKD succumbed to the infection demonstrating that NK cell directly eliminate influenza-infected cells. Collectively, these results confirm that influenza is capable of inhibiting NK cells through MHC-I engagement of KIR/Ly49, and suggests that blocking this interaction may provide a viable therapeutic avenue for severe influenza cases.\ud these results challenge our understanding of basic NK cell function and suggest that, rather than subdividing NK cells into ‘licensed’ and ‘unlicensed’ based on their expression of self-specific Ly49 receptors, a more accurate depiction of these NK subsets would be ‘cancer-specialized’ and ‘pathogen-specialized’. While further work is required to fully test this paradigm of cancer- and pathogen-specialized NK cells, I hope that my findings will stimulate a new appreciation for the role of NK cells in virus control, and lead to a better understanding of this critical immune cell

Redefining the battle against colorectal cancer: a comprehensive review of emerging immunotherapies and their clinical efficacy

Colorectal cancer (CRC) is the third most common cancer globally and presents a significant challenge owing to its high mortality rate and the limitations of traditional treatment options such as surgery, radiotherapy, and chemotherapy. While these treatments are foundational, they are often poorly effective owing to tumor resistance. Immunotherapy is a groundbreaking alternative that has recently emerged and offers new hope for success by exploiting the body’s own immune system. This article aims to provide an extensive review of clinical trials evaluating the efficacy of various immunotherapies, including CRC vaccines, chimeric antigen receptor T-cell therapies, and immune checkpoint inhibitors. We also discuss combining CRC vaccines with monoclonal antibodies, delve into preclinical studies of novel cancer vaccines, and assess the impact of these treatment methods on patient outcomes. This review seeks to provide a deeper understanding of the current state of CRC treatment by evaluating innovative treatments and their potential to redefine the prognosis of patients with CRC

Phage display derived monoclonal antibodies: from bench to bedside

Monoclonal antibodies (mAbs) have become one of the most important classes of biopharmaceutical products, and they continue to dominate the universe of biopharmaceutical markets in terms of approval and sales. They are the most profitable single product class, where they represent six of the top ten selling drugs. At the beginning of the 1990s, an in vitro antibody selection technology known as antibody phage display was developed by John McCafferty and Sir. Gregory Winter that enabled the discovery of human antibodies for diverse applications, particularly antibody-based drugs. They created combinatorial antibody libraries on filamentous phage to be utilized for generating antigen specific antibodies in a matter of weeks. Since then, more than 70 phage–derived antibodies entered clinical studies and 14 of them have been approved. These antibodies are indicated for cancer, and non-cancer medical conditions, such as inflammatory, optical, infectious, or immunological diseases. This review will illustrate the utility of phage display as a powerful platform for therapeutic antibodies discovery and describe in detail all the approved mAbs derived from phage display

Ly49 receptors: Innate and adaptive immune paradigms

The Ly49 receptors are type II C-type lectin-like membrane glycoproteins encoded by a family of highly polymorphic and polygenic genes within the mouse natural killer gene complex (NKC). This gene family is designated Klra, and includes genes that encode both inhibitory and activating Ly49 receptors in mice. Ly49 receptors recognize class I major histocompatibility complex (MHC-I) and MHC-I-like proteins on normal as well as altered cells. Their functional homologs in humans are the killer cell immunoglobulin-like receptors (KIRs), which recognize HLA class I molecules as ligands. Classically, Ly49 receptors are described as being expressed on both the developing and mature natural killer (NK) cells. The inhibitory Ly49 receptors are involved in NK cell education, a process in which NK cells acquire function and tolerance towards cells that express ‘self-MHC-I’. On the other hand, the activating Ly49 receptors recognize altered cells expressing activating ligands. New evidence shows a broader Ly49 expression pattern on both innate and adaptive immune cells. Ly49 receptors have been described on multiple NK cell subsets, such as uterine NK (uNK) and memory NK cells, as well as NKT cells, dendritic cells (DC), plasmacytoid dendritic cells (pDC), macrophages, neutrophils and cells of the adaptive immune system, such as activated T cells and regulatory CD8+ T cells. In this review we discuss the expression pattern and proposed functions of Ly49 receptors on various immune cells and their contribution to immunity

Influenza Virus Targets Class I MHC-Educated NK Cells for Immunoevasion.

The immune response to influenza virus infection comprises both innate and adaptive defenses. NK cells play an early role in the destruction of tumors and virally-infected cells. NK cells express a variety of inhibitory receptors, including those of the Ly49 family, which are functional homologs of human killer-cell immunoglobulin-like receptors (KIR). Like human KIR, Ly49 receptors inhibit NK cell-mediated lysis by binding to major histocompatibility complex class I (MHC-I) molecules that are expressed on normal cells. During NK cell maturation, the interaction of NK cell inhibitory Ly49 receptors with their MHC-I ligands results in two types of NK cells: licensed ("functional"), or unlicensed ("hypofunctional"). Despite being completely dysfunctional with regard to rejecting MHC-I-deficient cells, unlicensed NK cells represent up to half of the mature NK cell pool in rodents and humans, suggesting an alternative role for these cells in host defense. Here, we demonstrate that after influenza infection, MHC-I expression on lung epithelial cells is upregulated, and mice bearing unlicensed NK cells (Ly49-deficient NKCKD and MHC-I-deficient B2m-/- mice) survive the infection better than WT mice. Importantly, transgenic expression of an inhibitory self-MHC-I-specific Ly49 receptor in NKCKD mice restores WT influenza susceptibility, confirming a direct role for Ly49. Conversely, F(ab')2-mediated blockade of self-MHC-I-specific Ly49 inhibitory receptors protects WT mice from influenza virus infection. Mechanistically, perforin-deficient NKCKD mice succumb to influenza infection rapidly, indicating that direct cytotoxicity is necessary for unlicensed NK cell-mediated protection. Our findings demonstrate that Ly49:MHC-I interactions play a critical role in influenza virus pathogenesis. We suggest a similar role may be conserved in human KIR, and their blockade may be protective in humans