“
“Axin, a negative regulator of the Wnt signaling pathway, plays a critical role in various cellular events including cell proliferation and cell death. Axin-regulated cell death affects multiple processes, including viral replication. For example, axin expression suppresses herpes simplex virus (HSV)-induced necrotic cell death and enhances viral replication. Based on these observations, this study investigated the involvement of autophagy in LY294002 regulation of HSV replication and found axin expression inhibits autophagy-mediated suppression of viral replication in L929 cells. HSV infection induced autophagy

in a time- and viral dose-dependent manner in control L929 cells (L-EV), whereas virus-induced autophagy was delayed in axin-expressing L929 cells (L-axin). Subsequent analysis showed that induction of autophagy by rapamycin reduced HSV replication, and that inhibiting autophagy by 3-methyladenine (3MA) and beclin-1 knockdown facilitated

viral replication in L-EV cells. In addition, preventing autophagy with 3MA suppressed virus-induced cytotoxicity see more in L-EV cells. In contrast, HSV replication in L-axin cells was resistant to changes in autophagy. These results suggest that axin expression may render L929 cells resistant to HSV-infection induced autophagy, leading to enhanced viral replication. “
“NK cells are rapid IFN-γ responders to Plasmodium falciparum-infected erythrocytes (PfRBC) in vitro and are involved in controlling early parasitaemia in murine models, yet little is known about their contribution to immune responses following malaria infection in humans. Here, we studied the dynamics of and requirements for in vitro NK responses to PfRBC in malaria-naïve volunteers undergoing a single experimental malaria infection under highly

controlled circumstances, and in naturally exposed individuals. NK-specific IFN-γ responses to PfRBC following exposure resembled an immunological recall pattern and were tightly correlated with T-cell responses. However, although very PBMC depleted of CD56+ cells retained 20–55% of their total IFN-γ response to PfRBC, depletion of CD3+ cells completely abrogated the ability of remaining PBMC, including NK cells, to produce IFN-γ. Although NK responses to PfRBC were partially dependent on endogenous IL-2 signaling and could be augmented by exogenous IL-2 in whole PBMC populations, this factor alone was insufficient to rescue NK responses in the absence of T cells. Thus, NK cells make a significant contribution to total IFN-γ production in response to PfRBC as a consequence of their dependency on (memory) T-cell help, with likely positive implications for malaria vaccine development. NK cells are lymphocytes belonging to the innate immune system whose hallmark is their potent activity against altered self-cells, such as tumor cells and virus-infected cells 1, but are also capable of responding against extracellular protozoan pathogens 2, 3, including Plasmodia.