The clinical picture of severe acute respiratory syndrome (SARS) is characterized by pulmonary inflammation and respiratory failure, resembling that of acute respiratory distress syndrome. However, the events that lead to the recruitment of leukocytes are poorly understood. To study the cellular response in the acute phase of SARS coronavirus (SARS-CoV)-host cell interaction, we investigated the induction of chemokines, adhesion molecules, and DC-SIGN (dendritic cell-specific ICAM-3-grabbing nonintegrin) by SARS-CoV. Immunohistochemistry revealed neutrophil, macrophage, and CD8 T-cell infiltration in the lung autopsy of a SARS patient who died during the acute phase of illness. Additionally, pneumocytes and macrophages in the patient's lung expressed P-selectin and DC-SIGN. In in vitro study, we showed that the A549 and THP-1 cell lines were susceptible to SARS-CoV. monocytes, and activated T cells in a chemotaxis assay. We also demonstrated that DC-SIGN was inducible in THP-1 as well as A549 cells after SARS-CoV infection. Our in vitro experiments modeling infection in humans together with the study of a lung biopsy of a patient who died during the early phase of infection demonstrated that SARS-CoV, through a dynamic interaction with lung epithelial cells and monocytic cells, creates an environment conducive for immune cell migration and accumulation that eventually leads to lung injury.Severe acute respiratory syndrome (SARS) in adults causes new pulmonary infiltration, lymphopenia, thrombocytopenia, and high levels of proinflammatory cytokines and chemokines (30) and C-reactive protein (28) in the sera. The clinical picture is characterized by a cascade of immunological events leading to pulmonary inflammation and respiratory failure (9, 17), resembling adult acute respiratory distress syndrome (ARDS) (8). High levels of chemokines and cytokines, triggered by the host immune response to SARS coronavirus (SARS-CoV), are believed to contribute to the progressive pulmonary infiltration of macrophages (16), polymorphonuclear leukocytes (2), and T cells (11) and to eventual diffuse alveolar damage and fibrosis (12). However, it remains to be determined how the cellular response in the early stage of virus-host cell interaction results in the sequence of events that leads to the severe clinical outcome.In situ hybridization and immunohistochemistry revealed that both SARS-CoV nucleic acids and antigens are present within type II pneumocytes (26). Alveolar macrophages are also reported to harbor SARS-CoV (23). Hence, it is important to investigate how the interaction between SARS-CoV and pneumocytes and macrophages influences the subsequent events in the lung.DC-SIGN (dendritic cell-specific ICAM-3-grabbing nonintegrin) is a type II C-type lectin that is naturally expressed in human dendritic cells. It has been reported that DC-SIGN binds SARS-CoV and mediates its entry into myeloid dendritic cells by binding to the spike protein (31). However, the inducibility of DC-SIGN in cells encountering the virus and its si...

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Green and environmental practices are considered critical to enhancing firm innovation and performance. Previous research has not fully explained how and why buyers collaborate with suppliers in green practices. This study aimed to verify the driving effects of stakeholders and the underlying mechanism in buyer–supplier collaboration. Questionnaires were used to collect empirical data from selected purchasing managers in listed Taiwanese electronics firms. Structural equation modeling was used to analyze the collected data and proposed model. Customer pressure and top management commitment are found to have a positive influence on buyer–supplier collaboration. Competitor pressure and regulatory pressure indirectly affect buyer–supplier collaboration through the mediating effects of customer pressure and top management commitment. However, green investment pressure does not significantly influence top management commitment and buyer–supplier collaboration. The results suggest that customers can leverage the pressure exerted by competing suppliers by bargaining with their current suppliers to improve collaboration with second‐tier suppliers.

Bamboo mosaic virus (BaMV) is a positive-sense RNA virus belonging to the genus Potexvirus. Open reading frame 1 (ORF1) encodes the viral replication protein that consists of a capping enzyme domain, a helicase-like domain (HLD), and an RNA-dependent RNA polymerase domain from the N to C terminus. ORF5 encodes the viral coat protein (CP) required for genome encapsidation and the virus movement in plants. In this study, application of a yeast-two hybrid assay detected an interaction between the viral HLD and CP. However, the interaction did not affect the NTPase activity of the HLD. To identify the critical amino acids of CP interacting with the HLD, a random mutational library of CP was created using error-prone PCR, and the mutations adversely affecting the interaction were screened by a bacterial two-hybrid system. As a result, the mutations A209G and N210S in CP were found to weaken the interaction. To determine the significance of the interaction, the mutations were introduced into a BaMV infectious clone, and the mutational effects on viral replication, movement, and genome encapsidation were investigated. There was no effect on accumulations of BaMV CP and genomic RNAs within protoplasts; however, the virus cell-to-cell movement in plants was restricted. Sequence alignment revealed that A209 of BaMV CP is conserved in many potexviruses. Mutation of the corresponding residue in Foxtail mosaic virus CP also reduced the viral HLD-CP interaction and restricted the virus movement, suggesting that interaction between CP and a widely conserved HLD in the potexviral replication protein is crucial for viral trafficking through plasmodesmata.To spread throughout hosts, plant viruses have evolved a number of pathways to allow their progeny to pass across plasmodesmata into neighboring cells and travel along the vascular system (8, 26). The virus-encoded movement proteins play a pivotal role through diverse mechanisms in these cellto-cell and vascular transports. Ancillary proteins, for example, the viral coat proteins (CPs) in some cases, and host factors may also participate in these processes. Numerous studies have been conducted to elucidate the movement mechanisms. Many of the results have been summarized in a number of recent reviews (23,28,30). They provided in-depth discussions on issues such as the identification and characterization of the involved viral and host proteins and the transport models for some exemplified viruses, such as Tobacco mosaic virus (TMV) and Potato virus X (PVX). Despite these efforts, many details of the processes remain elusive.Members of the genus Potexvirus have a positive-strand RNA genome that contains five open reading frames (ORFs), a 5Ј methyl cap, and a 3Ј poly(A) tail. ORF1 encodes the viral replication protein, consisting of a capping enzyme domain, a helicase-like domain (HLD), and an RNA-dependent RNA polymerase domain (RdRp) from the N terminus to the C terminus (16,17). The HLD has RNA 5Ј-triphosphatase and nucleoside triphosphatase (NTPase) activities (18). With the co...