The regional distribution of different types of influenza receptors in cultured human alveolar epithelial cells and correlation with in vitro infection

BACKGROUND: Sialic acid (Sia) linked glycoproteins are the classical influenza receptors for influenza virus haemagglutinin to bind. The distribution of Sia on cell surfaces is one of the determinants of host tropism, and understanding its expression on human cells and tissues is important for understanding influenza pathogenesis. Previous research has shown the differences in apical versus basolateral infection and release of different influenza virus from polarized epithelial cells1 and correlated this with sialic acid distribution in the human respiratory tract. Moreover, mass spectrometric analysis was recently employed to elucidate the glycans present in the tissue in a higher resolution in human lung.2 The objective of this study was to examine in detail the distribution of these Sia-linked glycans at the cellular level by the use of confocal microscopy …link_to_OA_fulltex

Replication and innate host response of influenza A virus in lung microvascular endothelial cells: new insights into systemic infection and pathogenesis

INTRODUCTION: Though influenza A virus replication kinetics and host responses have been previously studied in umbilical vein endothelial cell or transformed endothelial cell lines, the tropism of influenza A virus including H5N1 and pandemic H1N1pdm for primary human lung microvascular endothelial cell has not been well defined.1 In this study we employed primary human lung microvascular endothelial cells, which are more physiologically relevant for understanding pathogenesis of influenza in the lung as to obtain a better understanding of the links of endothelial cell infection to systematic virus dissemination and multiple organ involvement in severe human influenza …link_to_OA_fulltex

Tropism and innate host response of the 2009 pandemic H1N1 influenza virus compared with related swine influenza viruses and reassortants in ex vivo and in vitro cultures of the human respiratory tract and conjunctiva

BACKGROUND: Pandemic influenza H1N1 (H1N1pdm) virus of swine-origin causes mild disease, but occasionally is associated with acute respiratory distress syndrome and death.1,2 It is important to understand the pathogenesis of this new disease. Previously we showed a comparable virus tropism and host innate immune responses between H1N1pdm and seasonal H1N1 influenza virus in the human respiratory tract,3 however H1N1pdm virus differed from seasonal H1N1 influenza virus in its ability to replicate in human conjunctiva, suggesting subtle differences in receptor-binding profile and highlighting the potential role of the conjunctiva as an additional route of infection. We now compare the tropism and host responses elicited by pandemic H1N1 with that of related swine influenza viruses and a pandemic-swine reassortant virus in ex vivo and in vitro cultures of the human respiratory tract and conjunctiva. We have used recombinant virus to investigate the role of the hemagglutinin (HA) and neuraminidase (NA) of H1N1pdm virus in its conjunctival tropism. These findings are relevant for understanding transmission and therapy …link_to_OA_fulltex