Blockade of the C5a-C5aR axis alleviates lung damage in hDPP4-transgenic mice infected with MERS-CoV.

The pathogenesis of highly pathogenic Middle East respiratory syndrome coronavirus (MERS-CoV) remains poorly understood. In a previous study, we established an hDPP4-transgenic (hDPP4-Tg) mouse model in which MERS-CoV infection causes severe acute respiratory failure and high mortality accompanied by an elevated secretion of cytokines and chemokines. Since excessive complement activation is an important factor that contributes to acute lung injury after viral infection, in this study, we investigated the role of complement in MERS-CoV-induced lung damage.

C5a receptor1 inhibition alleviates influenza virus-induced acute lung injury.

Influenza A virus is an important human pathogen that causes 3 to 5 million severe cases of influenza worldwide each year. An aberrant innate immune response, particularly hypercytokinemia, is thought to play an important role in the disease, although the pathogenesis of severe influenza virus infection remains unclear and no specific and efficacious immunotherapy is available. This study reports dysregulated complement activation in mice after infection with A/Puerto Rico/8/34 (PR8).

Treatment of Paraquat-Induced Lung Injury With an Anti-C5a Antibody: Potential Clinical Application.

Objectives: Complement activation product C5a plays a critical role in systemic inflammatory response syndrome induced by viruses, bacteria, and toxic agents including paraquat poisoning. This study is to explore the efficiency of anti-C5a-based intervention on systemic inflammatory responses induced by paraquat poisoning.

Design: Study of cynomolgus macaque model and plasma from paraquat-poisoning patients.

Highly conserved M2e and hemagglutinin epitope-based recombinant proteins induce protection against influenza virus infection.

Highly pathogenic influenza viruses continue to cause serious threat to public health due to their pandemic potential, calling for an urgent need to develop effective, safe, convenient, and universal vaccines against influenza virus infection. In this study, we constructed two recombinant protein vaccines, 2H5M2e-2H7M2e-H5FP-H7FP (hereinafter M2e-FP-1) and 2H5M2e-H5FP-2H7M2e-H7FP (hereinafter M2e-FP-2), by respectively linking highly conserved sequences of two molecules of ectodomain of M2 (M2e) and one molecule of fusion peptide (FP) epitope of hemagglutinin (HA) of H5N1 and H7N9 influenza viruses in different orders. The Escherichia coli-expressed M2e-FP-1 and M2e-FP-2 proteins induced similarly high-titer M2e-FP-specific antibodies in the immunized mice.