Changes in Cytokine Levels and NK Cell Activation Associated with Influenza

Several studies have highlighted the important role played by murine natural killer (NK) cells in the control of influenza infection. However, human NK cell responses in acute influenza infection, including infection with the 2009 pandemic H1N1 influenza virus, are poorly documented. Here, we examined changes in NK cell phenotype and function and plasma cytokine levels associated with influenza infection and vaccination. We show that absolute numbers of peripheral blood NK cells, and particularly those of CD56bright NK cells, decreased upon acute influenza infection while this NK cell subset expanded following intramuscular influenza vaccination. NK cells exposed to influenza antigens were activated, with higher proportions of NK cells expressing CD69 in study subjects infected with seasonal influenza strains. Vaccination led to increased levels of CD25+ NK cells, and notably CD56bright CD25+ NK cells, whereas decreased amounts of this subset were present in the peripheral blood of influenza infected individuals, and predominantly in study subjects infected with the 2009 pandemic H1N1 influenza virus. Finally, acute influenza infection was associated with low plasma concentrations of inflammatory cytokines, including IFN-γ, MIP-1β, IL-2 and IL-15, and high levels of the anti-inflammatory cytokines IL-10 and IL-1ra. Altogether, these data suggest a role for the CD56bright NK cell subset in the response to influenza, potentially involving their recruitment to infected tissues and a local production and/or uptake of inflammatory cytokines

CD56negCD16+NK cells are activated mature NK cells with impaired effector function during HIV-1 infection

BACKGROUND: A subset of CD3(neg)CD56(neg)CD16(+) Natural Killer (NK) cells is highly expanded during chronic HIV-1 infection. The role of this subset in HIV-1 pathogenesis remains unclear. The lack of NK cell lineage-specific markers has complicated the study of minor NK cell subpopulations. RESULTS: Using CD7 as an additional NK cell marker, we found that CD3(neg)CD56(neg)CD16(+) cells are a heterogeneous population comprised of CD7(+) NK cells and CD7(neg) non-classical myeloid cells. CD7(+)CD56(neg)CD16(+) NK cells are significantly expanded in HIV-1 infection. CD7(+)CD56(neg)CD16(+) NK cells are mature and express KIRs, the C-type lectin-like receptors NKG2A and NKG2C, and natural cytotoxicity receptors similar to CD7(+)CD56(+)CD16(+) NK cells. CD7(+)CD56(neg) NK cells in healthy donors produced minimal IFNγ following K562 target cell or IL-12 plus IL-18 stimulation; however, they degranulated in response to K562 stimulation similar to CD7(+)CD56(+) NK cells. HIV-1 infection resulted in reduced IFNγ secretion following K562 or cytokine stimulation by both NK cell subsets compared to healthy donors. Decreased granzyme B and perforin expression and increased expression of CD107a in the absence of stimulation, particularly in HIV-1-infected subjects, suggest that CD7(+)CD56(neg)CD16(+) NK cells may have recently engaged target cells. Furthermore, CD7(+)CD56(neg)CD16(+) NK cells have significantly increased expression of CD95, a marker of NK cell activation. CONCLUSIONS: Taken together, CD7(+)CD56(neg)CD16(+) NK cells are activated, mature NK cells that may have recently engaged target cells

Different Drivers: Exploring employee involvement in corporate philanthropy

Corporate Philanthropy (CP) is multi-dimensional, differs between sectors and involves both individual and organizational decision-making to achieve business and social goals. However, the CP literature characteristically focuses on strategic decisions made by business leaders and ignores the role of employees, especially those in lower status and lower paid positions. To redress this imbalance, we conducted a qualitative study of employees’ involvement in CP processes in ten workplaces in the South East of England to identify whether and how they are involved in CP decision-making and to capture their perspective on the nature of CP and the benefits generated by such activities. We specifically chose to study workplaces where employees are involved in the actual execution of the CP strategy, prioritising companies with a visible presence on the high street. The results illustrate the benefits of involving employees in CP decision-making, which we argue derives in part from the ‘liminal-like states’ that typify CP activities organised by shop floor staff, involving the temporary overturning of hierarchies, humanising of workplaces and opportunities for lower-level staff to prioritise their personal philanthropic preferences and signal their charitable identity to colleagues and customers. Whilst the data also suggests that CP decision-making remains predominantly top-down and driven by profit-oriented goals, we conclude that employees should be involved in choosing charitable causes as well as in designing and implementing workplace fundraising, in order to maximise the advantages of CP for the company and for wider society

Biomechanical factors in atherosclerosis: mechanisms and clinical implications

Blood vessels are exposed to multiple mechanical forces that are exerted on the vessel wall (radial, circumferential and Longitudinal forces) or on the endothelial surface (shear stress). The stresses and strains experienced by arteries influence the initiation of atherosclerotic Lesions, which develop at regions of arteries that are exposed to complex blood flow. In addition, plaque progression and eventually plaque rupture is influenced by a complex interaction between biological and mechanical factors mechanical forces regulate the cellular and molecular composition of plaques and, conversely, the composition of plaques determines their ability to withstand mechanical load. A deeper understanding of these interactions is essential for designing new therapeutic strategies to prevent lesion development and promote plaque stabilization. Moreover, integrating clinical imaging techniques with finite element modelling techniques allows for detailed examination of local morphological and biomechanical characteristics of atherosclerotic lesions that may be of help in prediction of future events. In this ESC Position Paper on biomechanical factors in atherosclerosis, we summarize the current 'state of the art' on the interface between mechanical forces and atherosclerotic plaque biology and identify potential clinical applications and key questions for future research

Nonlinear influences of stressors on general adjustment: the case of Japanese expatriates and their spouses

Integrating research on parental demands, learning, and expatriate adjustment, we examine potential nonlinear influences of two stressors – parental demands and perceived culture novelty – on general adjustment of expatriates and their spouses. Using a sample of 170 matched pairs of Japanese expatriates and spouses assigned to the US, we found a quadratic effect of parental demands and a cubic effect of cultural novelty on spouse general adjustment but not on expatriate general adjustment. Implications and directions for future research are discussed. Journal of International Business Studies (2007) 38, 928–943. doi:10.1057/palgrave.jibs.8400298