Natural killer (NK) cells function as early effector cells in the innate immune defense against viral infections and also participate in the regulation of normal and malignant hematopoiesis. NK cell activities have been associated with early clearance of viremia in experimental simian immunodeficiency virus and clinical human immunodeficiency virus type 1 (HIV-1) infections. We have previously shown that NK cells function as major cytotoxic effector cells in vaccine-induced immune protection against Friend virus (FV)-induced leukemia, and NK cell depletion totally abrogates the above protective immunity.
View Article and Find Full Text PDFHyperthermia (HT), in combination with other conventional therapeutic modalities, has become a promising approach in cancer therapy. In addition to heat-induced apoptosis, an augmented immunological effect is considered to be a benefit of hyperthermic treatment over chemo- or radiotherapy. Here, we investigated the effect of regional HT targeting the liver on immune cells, especially T cells and antigen-presenting cells, which are important in recognizing and eliminating tumor cells and pathogens such as viruses.
View Article and Find Full Text PDFThe envelope glycoprotein (Env) of human immunodeficiency viruses (HIVs) and simian immunodeficiency viruses (SIVs) is heavily glycosylated, and this feature has been speculated to be a reason for the insufficient immune control of these viruses by their hosts. In a macaque AIDS model, we demonstrated that quintuple deglycosylation in Env altered a pathogenic virus, SIVmac239, into a novel attenuated mutant virus (delta5G). In delta5G-infected animals, strong protective immunity against SIVmac239 was elicited.
View Article and Find Full Text PDFRecently, encouraging AIDS vaccine trials in macaques have implicated cytotoxic T lymphocytes (CTLs) in the control of the simian human immunodeficiency virus SHIV89.6P that induces acute CD4(+) T cell depletion. However, none of these vaccine regimens have been successful in the containment of replication of the pathogenic simian immunodeficiency viruses (SIVs) that induce chronic disease progression.
View Article and Find Full Text PDF