The role of autophagy in viral infections

Highlights 1. This review focuses on the interaction between autophagy and viruses, explaining how autophagy serves multiple roles in viral infection, with either proviral or antiviral functions. 2. Based on different steps of autophagy and the regulation of immune responses by autophagy, this review oversees the role of autophagy in viral replication, maturation, egress and cell–cell spreading. 3. This review provides an important foundation for the development of broad-spectrum antiviral treatment strategies and drugs based on the regulation of autophagy

Evaluation of the Mucosal Immunity Effect of Bovine Viral Diarrhea Virus Subunit Vaccine E2Fc and E2Ft

Classified as a class B infectious disease by the World Organization for Animal Health (OIE), bovine viral diarrhea/mucosal disease is an acute, highly contagious disease caused by the bovine viral diarrhea virus (BVDV). Sporadic endemics of BVDV often lead to huge economic losses to the dairy and beef industries. To shed light on the prevention and control of BVDV, we developed two novel subunit vaccines by expressing bovine viral diarrhea virus E2 fusion recombinant proteins (E2Fc and E2Ft) through suspended HEK293 cells. We also evaluated the immune effects of the vaccines. The results showed that both subunit vaccines induced an intense mucosal immune response in calves. Mechanistically, E2Fc bonded to the Fc γ receptor (FcγRI) on antigen-presenting cells (APCs) and promoted IgA secretion, leading to a stronger T-cell immune response (Th1 type). The neutralizing antibody titer stimulated by the mucosal-immunized E2Fc subunit vaccine reached 1:64, which was higher than that of the E2Ft subunit vaccine and that of the intramuscular inactivated vaccine. The two novel subunit vaccines for mucosal immunity developed in this study, E2Fc and E2Ft, can be further used as new strategies to control BVDV by enhancing cellular and humoral immunity

The generation of hemagglutinin monoclonal antibodies against H9N2 influenza virus

Abstract H9N2 avian influenza viruses (AIVs) are widely distributed, causing continuous outbreaks in poultry and sporadic infections in humans. Vaccination is the primary method used to prevent and control H9N2 AIV infection. However, the ongoing evolution and mutation of AIVs often result in limited protection effects from vaccines. Therapeutic monoclonal antibodies (mAbs) targeting influenza viruses offer a promising alternative. In this study, we immunized mice with inactivated H9N2-W1 virus, and we screened and acquired five mAbs, namely 4D12, F4, 5C8, 2G8 and A11. We showed that all five mAbs specifically targeted the HA protein of various H9N2 AIV strains. In vitro neutralization tests demonstrated that all five mAbs exhibited neutralization activity against H9N2 AIVs, with mAb F4 displaying the most potent neutralization effect. The F4 mAb exhibited dose-dependent preventive and therapeutic effects against lethal H9N2-115 infection, and the administration of F4 at a dose of 3 μg/g provided complete protection in vivo. Our study presents an alternative approach for preventing and controlling H9N2 AIV infection. Furthermore, the identified F4 mAb holds promise as a solution to potential pandemics in humans caused by H9N2 AIVs