IL-21 enhances NK cell functions and survival in healthy and HIV-infected patients with minimal stimulation of viral replication
Abstract
IL-21 plays an important role in regulating immune response and controlling chronic viral infections. Recently, we reported its decreased serum concentrations and their immunological consequences in HIV-infected persons. In this study, we have investigated how exogenous IL-21 enhances NK cell responses in these persons. We show that the cytokine receptors are expressed equally on all NK cell subsets defined by expression of CD16 and CD56; the cytokine activates STAT-3, MAPK, and Akt to enhance NK cell functions; the STAT-3 activation plays a key role in constitutive and IL-21-mediated enhancement of NK cell functions; the cytokine increases expression of antiapoptotic proteins Bcl-2 and Bcl-X(L) and enhances viability of NK cells but has no effect on their proliferation; the cytokine enhances HIV-specific ADCC, secretory, and cytotoxic functions, as well as viability of NK cells from HIV-infected persons; it exerts its biological effects on NK cells with minimal stimulation of HIV-1 replication; and the cytokine-activated NK cells inhibit viral replication in cocultured, HIV-infected, autologous CD4(+) T cells in a perforin- and LFA-1-dependent manner. These data suggest that IL-21 may serve as a valuable therapeutic tool for e...Continue Reading
References
Interleukin-21 activates human natural killer cells and modulates their surface receptor expression.
Citations
Related Concepts
Related Feeds
Adrenocortical Carcinoma
Adrenocortical carcinoma (ACC) is a rare malignancy of the adrenal cortex, associated with a generally dismal prognosis owing to its aggressive behavior. Here are the latest discoveries pertaining to this disease.
Antibody-Dependent Cell Cytotoxicity
Antibody-dependent cellular toxicity refers to the lysis of a target cell by a non-sensitized effector cell of the immune system as a result of antibodies binding to the target cell membrane and engaging the Fc receptors on the immune effector cells. Find the latest research on antibody-dependent cellular toxicity here.
Cell Adhesion Molecules in the Brain
Cell adhesion molecules found on cell surface help cells bind with other cells or the extracellular matrix to maintain structure and function. Here is the latest research on their role in the brain.
Cancer Biology: Molecular Imaging
Molecular imaging enables noninvasive imaging of key molecules that are crucial to tumor biology. Discover the latest research in molecular imaging in cancer biology in this feed.
BCL-2 Family Proteins
BLC-2 family proteins are a group that share the same homologous BH domain. They play many different roles including pro-survival signals, mitochondria-mediated apoptosis and removal or damaged cells. They are often regulated by phosphorylation, affecting their catalytic activity. Here is the latest research on BCL-2 family proteins.