A universal influenza candidate vaccine that targets multiple conserved influenza virus epitopes from hemagglutinin (HA), neuraminidase (NA) and matrix (M2e) proteins was combined with the potent Army liposomal adjuvant (ALFQ) to promote induction of broad immunity to seasonal and pandemic influenza strains. The unconjugated and CRM-conjugated composite peptides formulated with ALFQ were highly immunogenic and induced both humoral and cellular immune responses in mice. Broadly reactive serum antibodies were induced across various IgG isotypes. Mice immunized with the unconjugated composite peptide developed antibody responses earlier than mice immunized with conjugated peptides, and the IgG antibodies were broadly reactive and neutralizing across Groups 1 and 2 influenza viruses. Multi-epitope unconjugated influenza composite peptides formulated with ALFQ provide a novel strategy for the development of a universal influenza vaccine. These synthetic peptide vaccines avoid the pitfalls of egg-produced influenza vaccines and production can be scaled up rapidly and economically.

An unconjugated composite peptide vaccine targeting multiple conserved influenza epitopes from hemagglutinin, neuraminidase, and matrix protein and formulated with a safe and highly potent adjuvant, Army Liposome formulation (ALFQ), generated broad and durable immune responses in outbred mice. The antibodies recognized specific epitopes in influenza peptides and several human, avian, and swine influenza viruses. Comparable antibody responses to influenza viruses were observed with intramuscular and intradermal routes of vaccine administration. The peptide vaccine induced cross-reactive antibodies that recognized influenza virus subtypes A/H1N1, A/H3N2, A/H5N1, B/Victoria, and B/Yamagata. In addition, immune sera neutralized seasonal and pandemic influenza strains (Group 1 and Group 2). This composite multi-epitope peptide vaccine, formulated with ALFQ and administered via intramuscular and intradermal routes, provides a high-performance supra-seasonal vaccine that would be cost-effective and easily scalable, thus moving us closer to a viable strategy for a universal influenza vaccine and pandemic preparedness.

Background Patients with impaired immunity often have rapid progression of tuberculosis (TB) which can lead to highly lethal Mycobacterium tuberculosis (MTB) sepsis. Opsonic monoclonal antibodies (MABs) directed against MTB that enhance phagocytic killing activity and clearance of MTB from blood may be useful to enhance TB immunity. Methods BALB/c mice were immunized with ethanol-killed MTB (EK-MTB) and MABs were produced and screened by ELISA for binding to killed and live Mycobacterium smegmatis (SMEG) and MTB. MAB opsonophagocytic killing activity (OPKA) was examined using SMEG with HL60 and U-937 cells and MTB with U-937 cells. Clearance of MTB from blood was evaluated in Institute of Cancer Research (ICR) mice given opsonic anti-MTB MABs or saline (control) 24 h prior to intravenous infusion with 10⁸ CFUs gamma-irradiated MTB (HN878). MTB levels in murine blood collected 0.25, 4 and 24 h post-challenge were assessed by qPCR. MAB binding to peptidoglycan (PGN) was examined by ELISA using PGN cell wall mixture and ultra-pure PGN. Results Two MABs (GG9 and JG7) bound to killed and live SMEG and MTB (susceptible and resistant), and promoted OPKA with live MTB. MAB JG7 significantly enhanced OPKA of MTB. Both MABs significantly enhanced clearance of killed MTB from murine blood at 4 and 24 h as measured by qPCR. These opsonic MABs bound to PGN, a major cell wall constituent. Conclusions Anti-MTB MABs that promote bactericidal phagocytic activity of MTB and enhance clearance of killed MTB from the blood, may offer an immunotherapeutic approach for treatment of MTB bacteremia or sepsis, and augment treatment of multi-drug resistant (MDR) or extensively drug resistant (XDR) TB.

Background: The emergence of novel reassortant influenza A virus strains and zoonotic transmission to the human population is a critical factor in the development of a global pandemic, as exemplified by the 2009 swine flu pandemic and the ongoing threat of an H5N1 avian flu pandemic. Small, unconjugated synthetic peptide vaccines comprising multiple, highly conserved epitopes may provide an important strategy towards a cost‐effective, easily scalable, supra‐seasonal universal influenza vaccine that can target across human, swine, and avian strains, advancing pandemic preparedness. Objective: The aim of this study was to evaluate the immunogenicity of a synthetic, single, unconjugated, multi‐epitope composite peptide vaccine targeting human, swine, and avian zoonotic viruses. Methods: Outbred mice were immunized with different doses of the single peptide vaccine LHNVD‐110, and immunogenicity was evaluated using ELISA, Hemagglutinin Inhibition Assay, Microneutralization Assay, and Enzyme‐linked Lectin Assay. Results: Strong IgG1 (Th2) and IgG2a (Th1) responses were generated against HA, NA, and Matrix epitopes, and multiple strains of influenza A/H1N1pdm09, A/H3N2, A/H5N1 (HPAI), and B/Victoria viruses. Cross‐reactive, neutralizing antibodies also showed inhibition of multiple viral HA and NA subtypes, demonstrating the breadth of humoral responses. Conclusion: This single, unconjugated, multi‐epitope, composite peptide vaccine generated a robust and balanced immune response inhibiting multiple HA and NA subtypes across human, swine, and avian viruses. This approach provides a cost‐effective, easily scalable, seasonal, and pandemic vaccine option with the potential of a universal influenza vaccine and efficient pandemic readiness.

The ability to measure the opsonic activity of antibody may be critical in choosing among potential therapeutic candidates. It has been shown in numerous studies that the ability of antibody to mediate clearance of bacterial organisms in animal models and in humans is related to its in vitro opsonic activity and not solely to its antigen binding activity. We have developed a rapid and robot adaptable opsonophagocytosis assay for Staphylococci based on bioluminescence produced by bacteria transfected with the luciferase operon. Opsonophagocytosis is measured by the loss of bioluminescence as bacteria are opsonized by phagocytes and killed. Pagibaximab is a humanized monoclonal anti-lipoteichoic acid (LTA) antibody opsonic for S. epidermidis and S. aureus, which we used to develop this rapid bioluminescence assay.