Multiple Interferon Stimulated Genes Synergize with the Zinc Finger Antiviral Protein to Mediate Anti-Alphavirus Activity

The zinc finger antiviral protein (ZAP) is a host factor that mediates inhibition of viruses in the Filoviridae, Retroviridae and Togaviridae families. We previously demonstrated that ZAP blocks replication of Sindbis virus (SINV), the prototype Alphavirus in the Togaviridae family at an early step prior to translation of the incoming genome and that synergy between ZAP and one or more interferon stimulated genes (ISGs) resulted in maximal inhibitory activity. The present study aimed to identify those ISGs that synergize with ZAP to mediate Alphavirus inhibition. Using a library of lentiviruses individually expressing more than 350 ISGs, we screened for inhibitory activity in interferon defective cells with or without ZAP overexpression. Confirmatory tests of the 23 ISGs demonstrating the largest infection reduction in combination with ZAP revealed that 16 were synergistic. Confirmatory tests of all potentially synergistic ISGs revealed 15 additional ISGs with a statistically significant synergistic effect in combination with ZAP. These 31 ISGs are candidates for further mechanistic studies. The number and diversity of the identified ZAP-synergistic ISGs lead us to speculate that ZAP may play an important role in priming the cell for optimal ISG function

Inducible viral receptor, A possible concept to induce viral protection in primitive immune animals

A pseudolysogen (PL) is derived from the lysogenic Vibrio harveyi (VH) which is infected with the VHS1 (Vibrio harveyi Siphoviridae-like 1) bacteriophage. The lysogenic Vibrio harveyi undergoes an unequivalent division of the extra-chromosomal VHS1 phage genome and its VH host chromosome and produces a true lysogen (TL) and pseudolysogen (PL). The PL is tolerant to super-infection of VHS1, as is of the true lysogen (TL), but the PL does not contain the VHS1 phage genome while the TL does. However, the PL can become susceptible to VHS1 phage infection if the physiological state of the PL is changed. It is postulated that this is due to a phage receptor molecule which can be inducible to an on-and-off regulation influence by an alternating condition of the bacterial host cell. This characteristic of the PL leads to speculate that this phenomenon can also occur in high organisms with low immunity such as shrimp. This article proposes a hypothesis that the viral receptor molecule on the target cell can play a crucial role in which the invertebrate aquaculture animals can become tolerant to viral infection. A possible mechanism may be that the target cell disrupts the viral receptor molecule to prevent super infection. This concept can explain a mechanism for the prevention of viral infection in invertebrate animals which do not have acquired immunity in response to pathogens. It can guide us to develop a mechanism of immunity to viral infection in low-evolved-immune animals. Also, it can be an additional mechanism that exists in high immune organism, as in human for the prevention of viral infectio

The Price of Corporate Social Responsibility: The Case of Black Economic Empowerment Transactions in South Africa

Since the demise of apartheid in South Africa, corporations have been encouraged to participate in the governmental goal of increasing corporate ownership by the black majority population. One vehicle that has arisen to help facilitate an increase in corporate ownership has been black economic empowerment (BEE) transactions. BEE transactions are essentially private placements of equity. Firms that have taken this socially activist position of selling portions of their equity, usually at a substantial discount, to black empowerment groups have received positive media attention in the name of 'good corporate citizenship.' This study investigates the market performance of these BEE transactions, specifically addressing three questions. The first question is whether BEE transactions create or destroy wealth. To address this question we use an event study methodology to calculate the cumulative abnormal returns (CARs) associated with public announcements of BEE transactions. The second question is whether specific types of BEE transactions did better or worse than others. We address this question by analyzing the cross-sectional variation in the CARs associated with public announcements of BEE transactions. The third question is whether firms that engage in BEE transactions experience negative post-announcement price performance. This last question is motivated by popular press accounts of the exploitation of black empowerment groups by white-owned South African corporations. To address this question, we test whether BEE transactions have benefited white corporate South Africa at the expense of the participating black empowerment groups

Corporate social responsibility: an empirical investigation of U.S. organizations

Organizations that believe they should give something back to the society have embraced the concept of corporate social responsibility (CSR). Although the theoretical underpinnings of CSR have been frequently debated, empirical studies often involve only limited aspects, implying that theory may not be congruent with actual practices and may impede understanding and further development of CSR. The authors investigate actual CSR practices related to five different stakeholder groups, develop an instrument to measure those CSR practices, and apply it to a survey of 401 U.S. organizations. Four different clusters of organizations emerge, depending on the CSR practice focus. The distinctive features of each cluster relate to organizational demographics, perceived influence of stakeholders, managers perceptions of the influence of CSR on performance, and organizational performance

Financial and corporate social performance in the UK listed firms: the relevance of non-linearity and lag effects

Using environmental, social and governance scores compiled by Reuters Datastream for each company’s corporate social performance (CSP), we examine the relationship between CSP and corporate financial performance (CFP) of 314 UK listed companies over the period 2002–2015. We further evaluate the relationship between prior and subsequent CFP and prior and subsequent CSP. Based on the system-GMM estimation method, we provide direct evidence that suggests that while CFP and CSP can be linked linearly; however, when we examine the impact of CSP on CFP, the association is more non-linear (cubic) than linear. Our results suggest that firms periodically adjust their level of commitment to society, in order to meet their target CSP. The primary contributions of this paper are testing (1) the non-monotonous relationship between CSP and CFP, (2) the lagged relationship between the two and the optimality of CSP levels, and (3) the presence of a virtuous circle. Our results further suggest that CSP contributes to CFP better during post-crisis years. Our findings are robust to year-on-year changes in CFP and CSP, financial versus non-financial firms, and the intensity of corporate social responsibility (CSR) engagement across industries

Environmental Perception, Organizational Design and Organizational Performance: A Comparative Study

Peter A. Stanwick is an Assistant Professor of Management at Auburn University. Larry P. Pleshko is an Assistant Professor of Marketing in the Andreas School of Business at Barry University

HIV-1 replication is controlled at the level of T cell activation and proviral integration.

During progression of the Acquired Immune Deficiency Syndrome (AIDS), the human immunodeficiency virus type 1 (HIV-1) is harbored in CD4+ T cells, which act as the primary reservoir for the virus. In vitro, HIV-1 requires activated T cells for a productive infection; however, in vivo, the number of circulating T cells in the activated state that are potential targets for HIV-1 infection is low. We have investigated the ability of HIV-1 to infect resting T cells, and the consequences of such an infection. T cell activation was not required for HIV-1 infection; however, viral DNA was unable to integrate in resting T cells and was maintained extrachromosomally. Subsequent T cell activation allowed integration of extrachromosomal forms and led to a productive viral life cycle. Extrachromosomal forms of viral DNA were found to persist for several weeks after infection of resting T cells and, following T cell activation, these forms maintained their ability to integrate and act as a template for infectious virus. Several lines of evidence, including temporal analysis of HIV-1 replication and analysis of an HIV-1 integrase deletion mutant, indicated that extra-chromosomal HIV-1 DNA genomes were transcriptionally active. These results are compatible with a model whereby HIV-1 can persist in a non-productive extra-chromosomal state in resting T cells until subsequent antigen-induced or mitogen-induced T cell activation, virus integration and release. Thus agents that induce T cell activation may control the rate of HIV-1 replication and spread during AIDS progression

Quiescent T lymphocytes as an inducible virus reservoir in HIV-1 infection

To better understand the basis for human immunodeficiency virus type 1 (HIV-1) persistence and latency, the form in which viral DNA exists in the peripheral T lymphocyte reservoir of infected individuals was investigated. In asymptomatic individuals, HIV-1 was harbored predominantly as full-length, unintegrated complementary DNA. These extrachromosomal DNA forms retained the ability to integrate upon T cell activation in vitro. In patients with acquired immunodeficiency syndrome (AIDS), there was an increase in integrated relative to extrachromosomal DNA forms. By analysis of DNA from patient lymphocyte subpopulations depleted of human lymphocyte antigen-Dr receptor-positive cells, quiescent T cells were identified as the source of extrachromosomal HIV-1 DNA. Thus quiescent T lymphocytes may be a major and inducible HIV-1 reservoir in infected individuals