Search

BACKGROUND. Therapeutic vaccinations against cancer have mainly targeted differentiation antigens, cancer-testis antigens, and overexpressed antigens and have thus far resulted in little clinical benefit. Studies conducted by multiple groups have demonstrated that T cells recognizing neoantigens are present in most cancers and offer a specific and highly immunogenic target for personalized vaccination. METHODS. We recently developed a process using tumor-infiltrating lymphocytes to identify the specific immunogenic mutations expressed in patients' tumors. Here, validated, defined neoantigens, predicted neoepitopes, and mutations of driver genes were concatenated into a single mRNA construct to vaccinate patients with metastatic gastrointestinal cancer. RESULTS. The vaccine was safe and elicited mutation-specific T cell responses against predicted neoepitopes not detected before vaccination. Furthermore, we were able to isolate and verify T cell receptors targeting [KRAS.sup.G12D] mutation. We observed no objective clinical responses in the 4 patients treated in this trial. CONCLUSION. This vaccine was safe, and potential future combination of such vaccines with checkpoint inhibitors or adoptive T cell therapy should be evaluated for possible clinical benefit in patients with common epithelial cancers. TRIAL REGISTRATION. Phase I/II protocol (NCT03480152) was approved by the IRB committee of the NIH and the FDA. FUNDING. Center for Clinical Research, NCI, NIH., Introduction Protective vaccination against infectious diseases has proven to be one of the most effective health measures in medicine; however, therapeutic vaccination against established diseases such as persistent infections and [...]

The optimal use of many biotherapeutics is restricted by Anti-drug antibodies (ADAs) and hypersensitivity responses which can affect potency and ability to administer a treatment. Here we demonstrate that Re-surfacing can be utilized as a generalizable approach to engineer proteins with extensive surface residue modifications in order to avoid binding by pre-existing ADAs. This technique was applied to E. coli Asparaginase (ASN) to produce functional mutants with up to 58 substitutions resulting in direct modification of 35% of surface residues. Re-surfaced ASNs exhibited significantly reduced binding to murine, rabbit and human polyclonal ADAs, with a negative correlation observed between binding and mutational distance from the native protein. Reductions in ADA binding correlated with diminished hypersensitivity responses in an in vivo mouse model. By using computational design approaches to traverse extended distances in mutational space while maintaining function, protein Re-surfacing may provide a means to generate novel or second line therapies for life-saving drugs with limited therapeutic alternatives. [ABSTRACT FROM AUTHOR]

Sphingosine-1-phosphate (S1P) has been shown to modulate intracellular Ca2+ through both G protein-coupled receptors and intracellular second messenger pathways. The precise mechanism by which S1P activates store-operated calcium entry (SOCE) in vascular smooth muscle cells (VSMCs) has not been fully characterized. Because sphingolipids and Ca2+ modulate proliferation and constriction in VSMCs, characterizing the connection between S1P and SOCE may provide novel therapeutic targets for vascular diseases. We found that S1P triggered STIM1 puncta formation and SOCE in VSMCs. S1P-activated SOCE was inhibited by 2-aminoethoxydiphenyl borate (2-APB), diethylstilbestrol (DES), and gadolinium (Gd3+). SOCE was observed in VSMCs lacking either S1P2 or S1P3 receptors, suggesting that S1P acts via multiple signaling pathways. Indeed, both extracellular and intracellular S1P application increased the total internal reflection fluorescence signal in VSMCs cells transfected with STIM1-yellow fluorescent protein in a 2-APB-sensitive manner. These data, and the fact that 2-APB, DES, and Gd3+ all inhibited S1P-induced cerebral artery constriction, suggest that SOCE modulates S1P-induced vasoconstriction in vivo. Finally, S1P-induced SOCE was larger in proliferative than in contractile VSMCs, correlating with increases in STIM1, Orai1, S1P1, and S1P3 receptor mRNA. These data demonstrate that S1P can act through both receptors and a novel intracellular pathway to activate SOCE. Because S1P-induced SOCE contributes to vessel constriction and is increased in proliferative VSMCs, it is likely that S1P/SOCE signaling in proliferative VSMCs may play a role in vascular dysfunction such as atherosclerosis and diabetes. [ABSTRACT FROM AUTHOR]

mRNA vaccines induce potent immune responses in preclinical models and clinical studies. Adjuvants are used to stimulate specific components of the immune system to increase immunogenicity of vaccines. We utilized a constitutively active mutation (V155M) of the stimulator of interferon (IFN) genes (STING), which had been described in a patient with STING-associated vasculopathy with onset in infancy (SAVI), to act as a genetic adjuvant for use with our lipid nanoparticle (LNP)-encapsulated mRNA vaccines. mRNA-encoded constitutively active STING V155M was most effective at maximizing CD8 + T cell responses at an antigen/adjuvant mass ratio of 5:1. STING V155M appears to enhance development of antigen-specific T cells by activating type I IFN responses via the nuclear factor κB (NF-κB) and IFN-stimulated response element (ISRE) pathways. mRNA-encoded STING V155M increased the efficacy of mRNA vaccines encoding the E6 and E7 oncoproteins of human papillomavirus (HPV), leading to reduced HPV + TC-1 tumor growth and prolonged survival in vaccinated mice. This proof-of-concept study demonstrated the utility of an mRNA-encoded genetic adjuvant., Competing Interests: Declaration of interests E.H., S.-W.T., K.M., J.I., and K.H. are inventors on patent applications directed to “Messenger ribonucleic acids for enhancing immune responses and methods of use thereof” (US20180311343A1). All authors are current or previous employees of Moderna, Inc. and have received salary and stock options as compensation for their employment., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)