Influenza virus infection is a significant cause of global mortality. However, the development of influenza vaccines that induce robust immune responses at the site of respiratory mucosal exposure has proven challenging. Here, we assessed immune responses and protective efficacy of a rhesus adenovirus serotype 52 (RhAd52) vectored influenza vaccine encoding the hemagglutinin (HA) glycoprotein from A/California/07/2009 administrated by systemic or mucosal routes of immunization. We observed robust and durable systemic and mucosal immunity, including IgA and tissue resident memory T cells in the respiratory mucosa, in mice that received the vaccine intranasally or intratracheally. In contrast, only systemic immune responses were observed in mice that received the vaccine intramuscularly. Moreover, a single intranasal or intratracheal dose of RhAd52-HA provided near complete protection against a lethal challenge with a mouse-adapted influenza virus strain, whereas intramuscular immunization with RhAd52-HA and mRNA-HA provided less robust protection. Our data demonstrate the importance of mucosal immunity for enhancing vaccine protection against influenza.
© 2025 The Authors.

The clinical use of interleukin-2 (IL-2) for cancer immunotherapy is limited by severe toxicity. Emerging IL-2 therapies with reduced IL-2 receptor alpha (IL-2Rα) binding aim to mitigate toxicity and regulatory T cell (Treg) expansion but have had limited clinical success. Here, we show that IL-2Rα engagement is critical for the anti-tumor activity of systemic IL-2 therapy. A "non-α" IL-2 mutein induces systemic expansion of CD8+ T cells and natural killer (NK) cells over Tregs but exhibits limited anti-tumor efficacy. We develop a programmed cell death protein 1 (PD-1)-targeted, receptor-masked IL-2 immunocytokine, PD1-IL2Ra-IL2, which attenuates systemic IL-2 activity while maintaining the capacity to engage IL-2Rα on PD-1+ T cells. Mice treated with PD1-IL2Ra-IL2 show no systemic toxicities observed with unmasked IL-2 treatment yet achieve robust tumor growth control. Furthermore, PD1-IL2Ra-IL2 can be effectively combined with other T cell-mediated immunotherapies to enhance anti-tumor responses. These findings highlight the therapeutic potential of PD1-IL2Ra-IL2 as a targeted, receptor-masked, and "α-maintained" IL-2 therapy for cancer.
Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.

Bacillus Calmette-Guérin (BCG) remains the only approved tuberculosis (TB) vaccine despite limited efficacy. Preclinical studies of next-generation TB vaccines typically use a murine aerosol model with a supraphysiologic challenge dose. Here, we show that the protective efficacy of a live attenuated Mycobacterium tuberculosis (Mtb) vaccine ΔLprG markedly exceeds that of BCG in a low-dose murine aerosol challenge model. BCG reduced bacterial loads but did not prevent establishment or dissemination of infection in this model. In contrast, ΔLprG prevented detectable infection in 61% of mice and resulted in anatomic containment of 100% breakthrough infections to a single lung. Protection was partially abrogated in a repeated low-dose challenge model, which showed serum IL-17A, IL-6, CXCL2, CCL2, IFN-γ, and CXCL1 as correlates of protection. These data demonstrate that ΔLprG provides increased protection compared to BCG, including reduced detectable infection and anatomic containment, in a low-dose murine challenge model.
© 2023 The Authors.

In vitro studies suggest that mapping the spatiotemporal complexity of nuclear factor κB (NF-κB) signaling is essential to understanding its function. The lack of tools to directly monitor NF-κB proteins in vivo has hindered such efforts. Here, we introduce reporter mice with the endogenous RelA (p65) or c-Rel labeled with distinct fluorescent proteins and a double knockin with both subunits labeled. Overcoming hurdles in simultaneous live-cell imaging of RelA and c-Rel, we show that quantitative features of signaling reflect the identity of activating ligands, differ between primary and immortalized cells, and shift toward c-Rel in microglia from aged brains. RelA:c-Rel heterodimer is unexpectedly depleted in the nuclei of stimulated cells. Trajectories of subunit co-expression in immune lineages reveal a reduction at key cell maturation stages. These results demonstrate the power of these reporters in gaining deeper insights into NF-κB biology, with the spectral complementarity of the labeled NF-κB proteins enabling diverse applications.
Published by Elsevier Inc.

Oncolytic virotherapies have shown excellent promise in a variety of cancers by promoting antitumor immunity. However, the effects of oncolytic virus-mediated type I interferon (IFN-I) production on antitumor immunity remain unclear. Recent reports have highlighted immunosuppressive functions of IFN-I in the context of checkpoint inhibitor and cell-based therapies. In this study, we demonstrate that oncolytic virus-induced IFN-I promotes the expression of PD-L1 in tumor cells and leukocytes in a IFN receptor (IFNAR)-dependent manner. Inhibition of IFN-I signaling using a monoclonal IFNAR antibody decreased IFN-I-induced PD-L1 expression and promoted tumor-specific T cell effector responses when combined with oncolytic virotherapy. Furthermore, IFNAR blockade improved therapeutic response to oncolytic virotherapy in a manner comparable with PD-L1 blockade. Our study highlights a critical immunosuppressive role of IFN-I on antitumor immunity and uses a combination strategy that improves the response to oncolytic virotherapy.
© 2022 The Author(s).