Influenza remains a persistent global health challenge, largely due to the virus' continuous antigenic drift and occasional shift, which impede the development of a universal vaccine. To address this, the identification of broadly neutralizing antibodies and their epitopes is crucial. Nanobodies, with their unique characteristics and binding capacity, offer a promising avenue to identify such epitopes. Here, we isolate and purify a hemagglutinin (HA)-specific nanobody that recognizes an H7 subtype of influenza A virus. The nanobody, named E10, exhibits broad-spectrum binding, cross-group neutralization and in vivo protection across various influenza A subtypes. Through phage display and in vitro characterization, we demonstrate that E10 specifically targets an epitope on HA head which is part of the conserved lateral patch and is highly immunodominant upon H7 infection. Importantly, immunization with a peptide including the E10 epitope elicits cross-reactive antibodies and mediates partial protection from lethal viral challenge. Our data highlights the potential of E10 and its associated epitope as a candidate for future influenza prevention strategies.
© 2024. The Author(s).

Pyroptosis, driven by the N-terminal domain of gasdermin proteins (GSDM), promotes antitumor immunity by attracting lymphocytes to the tumor microenvironment (TME). However, current pyroptosis-inducing therapies like drug injections and phototherapy are limited to localized treatments, making them unsuitable for widespread or microscopic metastatic lesions. This study engineered oncolytic M1 viruses (rM1-mGSDME_FL and rM1-mGSDME_NT) to selectively deliver GSDME to tumor cells. These modified viruses enhanced tumor cell death in breast cancer models, suppressed tumor growth, extended survival in mice, and boosted immune cell infiltration, demonstrating significant anticancer potential through pyroptosis induction.
© 2024 The Author(s).

Influenza remains a persistent global health challenge, largely due to the virus’ continuous antigenic drift and shift, which impede the development of a universal vaccine. To address this, the identification of broadly neutralizing antibodies and their epitopes is crucial. Nanobodies, with their unique characteristics and binding capacity, offer a promising avenue to identify such epitopes. Here, we isolated and purified a hemagglutinin (HA)-specific nanobody that recognizes an H7 subtype of influenza A virus. Notably, the nanobody, named E10, exhibited broad-spectrum binding, cross-group neutralization and in vivo protection across various influenza A subtypes. Through phage display and in vitro characterization, we demonstrated that E10 specifically targets an epitope on HA head. This epitope is part of the conserved lateral patch of HA head and proved to be highly immunodominant upon H7 infection. Importantly, immunization with a peptide including the E10 epitope elicited cross-reactive antibodies and mediated partial protection from lethal viral challenge. Our data highlight the potential of E10 and its associated epitope as a candidate for future influenza prevention strategies.

PACAP (pituitary adenylate cyclase activating polypeptide) is a widespread neuropeptide with cytoprotective and anti-inflammatory effects. It plays a role in innate and adaptive immunity, but data are limited about gut-associated lymphoid tissue. We aimed to reveal differences in Peyer's patches between wild-type (WT) and PACAP-deficient (KO) mice. Peyer's patch morphology from young (3-months-old) and aging (12-15-months-old) mice was examined, along with flow cytometry to assess immune cell populations, expression of checkpoint molecules (PD-1, PD-L1, TIM-3, Gal-9) and functional markers (CD69, granzyme B, perforin) in CD3+, CD4+, and CD8+ T cells. We found slight differences between aging, but not in young, WT, and KO mice. In WT mice, aging reduced CD8+ T cell numbers frequency and altered checkpoint molecule expression (higher TIM-3, granzyme B; lower Gal-9, CD69). CD4+ T cell frequency was higher with similar checkpoint alterations, indicating a regulatory shift. In PACAP KO mice, aging did not change cell population frequencies but led to higher TIM-3, granzyme B and lower PD-1, PD-L1, Gal-9, and CD69 expression in CD4+ and CD8+ T cells, with reduced overall T cell activity. Thus, PACAP deficiency impacts immune dysfunction by altering checkpoint molecules and T cell functionality, particularly in CD8+ T cells, suggesting complex immune responses by PACAP, highlighting its role in intestinal homeostasis and potential implications for inflammatory bowel diseases.

Targeting exhausted immune systems would be a promising therapeutic strategy to achieve a functional cure for HBV infection in patients with chronic hepatitis B (CHB). However, animal models recapitulating the immunokinetics of CHB are very limited. We aimed to develop an immunocompetent mouse model of CHB for intrahepatic immune profiling.
CHB mice were created by intrahepatic delivery of the Sleeping Beauty transposon vector tandemly expressing the hepatitis B virus (HBV) genome and fumarylacetoacetate hydrolase (FAH) cDNA into C57BL/6J congenic FAH knockout mice via hydrodynamic tail vein injection. We profiled the viral and intrahepatic immune kinetics in CHB mice with or without treatment with recombinant IFNα or the hepatotropic Toll-like receptor 7 agonist SA-5 using single-cell RNA-seq.
CHB mice exhibited sustained HBV viremia and persistent hepatitis. They showed intrahepatic expansion of exhausted CD8+ T (Tex) cells, the frequency of which was positively associated with viral load. Recruited macrophages increased in number but impaired inflammatory responses in the liver. The cytotoxicity of mature natural killer (NK) cells also increased in CHB mice. IFNα and SA-5 treatment both resulted in viral suppression with mild hepatic flares in CHB mice. Although both treatments activated NK cells, SA-5 had the capacity to revitalize the impaired function of Tex cells and liver-recruited macrophages.
Our novel CHB mouse model recapitulated the intrahepatic exhausted antiviral immunity in patients with CHB, which might be able to be reinvigorated by a hepatotropic TLR7 agonist.
Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.