Biology subjects

Hefesha, H.

Publications and source records attributed to Hefesha, H..

3 recordsLinked to original sources

bioRxiv2026

Comprehensive Profiling of Monkeypox Virus Antigens Identifies Potent Targets for Next-Generation mRNA Vaccine Development

The 2022 Monkeypox virus (MPXV) outbreak renewed interest in vaccines for orthopoxviruses. Initial development efforts focused on well-established antigen targets, especially A35, B6, and M1. However, orthopoxvirus surfaces are complex, displaying many antigens across two infectious forms, mature virions (MV) and extracellular virions (EV) and targets relevant to protection remain to be comprehensively defined. We leveraged advances in orthopoxvirus protein biology and mRNA vaccine technology to compare immunity to all feasible targets. Mice were immunized with mRNAs encoding each antigen, or antigen complex, and neutralizing antibody responses were measured prior to heterologous challenge with vaccinia virus. Among MV antigens, A28 induced potent complement-mediated neutralizing antibodies, and the A17:G10 complex induced neutralizing antibodies and protected from challenge. For EV antigens, A36 induced neutralizing antibodies and protected from challenge. Our results affirm the consensus strategy focusing on key antigens while highlighting additional targets that could enhance updated MPXV mRNA vaccines. SIGNIFICANCEMonkeypox virus, a member of the Orthopoxvirus genus along with variola virus, has been associated with two recent outbreaks of mpox disease leading to a renewed focus on orthopoxvirus vaccine development. We report an agnostic screen of all monkeypox virus surface antigens where we combined recent advances in structural biology and mRNA technology to evaluate these potential new vaccine targets. We confirmed that historically prioritized antigens M1, A35 and B6 were protective but also discovered new antigens of interest including A28, the A17:G10 complex and A36 that can be the targets of protective immune responses. These findings are critical to inform next-generation vaccine designs should novel orthopoxviruses emerge as human pathogens.

microbiology↗

bioRxiv2026

Lung-targeted cytokine-coding RNA-lipoplexes induce T and NK cell-mediated anti-tumor immune response

Lung is a major site of metastases for many primary cancers associated with poor outcomes. A central challenge in cancer immunotherapy is overcoming tumor immune evasion, which limits effective antitumor responses. Here, we investigated whether combinatorial mRNA-encoded cytokine therapy can overcome tumor immune evasion by coordinately engaging innate and adaptive immunity, using murine models of pulmonary metastases. We employed intravenously administered cationic nucleoside-modified mRNA-lipoplexes (RNA-LPX) for targeted delivery of mRNA-encoded cytokines to the lung. The cytokine mix containing interferon-, half-life extended interleukin (IL)-7, and a half-life extended IL-2 variant with reduced CD25-binding modulated the tumor immune microenvironment resulting in a potent and broad anti-tumor response and prolonged survival with good tolerability at the conditions tested. Using cell depletion experiments, we demonstrated that both T and natural killer (NK) cells are crucial mediators of the observed anti-tumor efficacy of the cytokine RNA mix, which induced activation and effector function of NK and T cells, coupled with reduced regulatory T cells (Treg) numbers and Treg activation in the lung. Importantly, antitumor efficacy was maintained in models of impaired antigen presentation, including loss of an immunodominant tumor antigen and MHC class I deficiency, where NK cells served as the primary effectors. The cytokine RNA mix induced immune cell activation in the primary human lung tumor culture, suggesting potential for translational application. Collectively, these findings demonstrate that combinatorial cytokine therapy can drive both antigen-dependent and antigen-independent tumor control for the treatment of lung metastases.

immunology↗

bioRxiv2022

Exposure to BA.4/BA.5 Spike glycoprotein drives pan-Omicron neutralization in vaccine-experienced humans and mice

The SARS-CoV-2 Omicron variant and its sublineages show pronounced viral escape from neutralizing antibodies elicited by vaccination or prior SARS-CoV-2 variant infection owing to over 30 amino acid alterations within the spike (S) glycoprotein. We and others have recently reported that breakthrough infection of vaccinated individuals with Omicron sublineages BA.1 and BA.2 are associated with distinct patterns of cross-neutralizing activity against SARS-CoV-2 variants of concern (VOCs). BA.2 breakthrough infection mediated overall stronger cross-neutralization of BA.2 and its descendants (BA.2.12.1, BA.4, and BA.5) compared to BA.1 breakthrough infection. Here we characterized the effect of Omicron BA.4/BA.5 S glycoprotein exposure on the magnitude and breadth of the neutralizing antibody response upon breakthrough infection in vaccinated individuals and in mice upon booster vaccination. We show that immune sera from triple mRNA-vaccinated individuals with subsequent Omicron BA.4/BA.5 breakthrough infection display broad and robust neutralizing activity against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/BA.5. Administration of a prototypic BA.4/BA.5-adapted mRNA booster vaccine to mice following SARS-CoV-2 wild-type strain-based primary immunization is associated with similarly broad neutralizing activity. Immunization of naive mice with a bivalent mRNA vaccine (wild-type + Omicron BA.4/BA.5) induces strong and broad neutralizing activity against Omicron VOCs and previous variants. These findings suggest that when administered as boosters, mono- and bivalent Omicron BA.4/BA.5-adapted vaccines may enhance neutralization breadth, and in a bivalent format may also have the potential to confer protection to individuals with no pre-existing immunity against SARS-CoV-2.

immunology↗