Announcements

1. “Episomal Vectors for Stable Production of Recombinant Proteins and Engineered Antibodies”
by Ian Fallahee and Daniel Hawiger
Antibodies 2024, 13(1), 18; https://doi.org/10.3390/antib13010018
Available online: https://www.mdpi.com/2073-4468/13/1/18

Cover Story: There is tremendous interest in the production of recombinant proteins, particularly bispecific antibodies and antibody–drug conjugates for research and therapeutic use. Here, we demonstrate a highly versatile plasmid system that allows the rapid generation of stable Expi293 cell pools by episomal retention of transfected DNA. By linking protein expression to puromycin resistance through an attenuated internal ribosome entry site, we achieve stable cell pools producing proteins of interest. In addition, split intein–split puromycin-mediated selection of two separate protein expression cassettes allows the stable production of bispecific antibody-like molecules or antibodies with distinct C-terminal heavy chain modifications, such as an antigen on one chain and a sortase tag on the other chain.

2. “Beyond bNAbs: Uses, Risks, and Opportunities for Therapeutic Application of Non-Neutralising Antibodies in Viral Infection”
by Kahlio Mader and Lynn B. Dustin
Antibodies 2024, 13(2), 28; https://doi.org/10.3390/antib13020028
Available online: https://www.mdpi.com/2073-4468/13/2/28

Cover Story: The vast majority of antibodies generated against a virus will be non-neutralising. However, this does not denote an absence of protective capacity. Yet, within the field, there is typically a large focus on antibodies capable of directly blocking infection (neutralising antibodies, NAbs) of either specific viral strains or multiple viral strains (broadly-neutralising antibodies, bNAbs). More recently, a focus on non-neutralising antibodies (nNAbs), or neutralisation-independent effects of NAbs, has emerged. These can have additive effects on protection or, in some cases, be a major correlate of protection. As their name suggests, nNAbs do not directly neutralise infection but instead, through their Fc domains, may mediate interaction with other immune effectors to induce clearance of viral particles or virally infected cells.

3. “Humanization of Pan-HLA-DR mAb 44H10 Hinges on Critical Residues in the Antibody Framework”
by Audrey Kassardjian, Danton Ivanochko, Brian Barber, Arif Jetha and Jean-Philippe Julien
Antibodies 2024, 13(3), 57; https://doi.org/10.3390/antib13030057
Available online: https://www.mdpi.com/2073-4468/13/3/57

Cover Story: Reducing the immunogenicity of animal-derived monoclonal antibodies (mAbs) for use in humans is critical to maximize therapeutic effectiveness and preclude potential adverse events. While traditional humanization methods have primarily focused on grafting antibody Complementarity-Determining Regions (CDRs) on homologous human antibody scaffolds, framework regions can also play essential roles in antigen binding. Here, we describe the humanization of the pan-HLA-DR mAb 44H10, a murine antibody displaying significant involvement of the framework region in antigen binding.

4. “Preventative Cancer Vaccine-Elicited Human Anti-MUC1 Antibodies Have Multiple Effector Functions”
by Michelle L. McKeague, Jason Lohmueller, Matthew T. Dracz, Najla Saadallah, Eric D. Ricci, Donella M. Beckwith, Ramya Ayyalasomayajula, Maré Cudic and Olivera J. Finn
Antibodies 2024, 13(4), 85; https://doi.org/10.3390/antib13040085
Available online: https://www.mdpi.com/2073-4468/13/4/85

Cover Story: Background/Objectives: Mucin-1 (MUC1) is a transmembrane glycoprotein that is overexpressed and hypoglycosylated in premalignant and malignant epithelial cells compared to normal cells, creating a target antigen for humoral and cellular immunity. Healthy individuals with a history of advanced colonic adenomas and at high risk for colon cancer were enrolled in a clinical trial to evaluate the feasibility of using a MUC1 peptide vaccine to prevent colon cancer. Anti-MUC1 antibodies elicited by this vaccine were cloned using peripheral blood B cells and sera collected two weeks after a one-year booster. Twelve of these fully human monoclonal antibodies (mAb) were tested for binding to MUC1+ target cells, and three with the highest binding were further evaluated for various effector functions important for tumor rejection.