Natural killer (NK) cells produce many chemokines and inflammatory cytokines in response to, and exhibit cytotoxic activity against, pathogen-infected cells. They contribute to the prevention of various infectious diseases, especially during the early phases of infection, before CD8+ cytotoxic T lymphocyte (CTL) induction. Natural killer (NK) cells, including NKT cells, are components of the innate immune system and contribute significantly to the clearance of pathogen-infected or malignant cells. Recently, it has been demonstrated that quite diverse pattern-recognition receptors expressed on dendritic cells (DCs) and macrophages (M) recognize pathogen-specific components and subsequently initiate NK cell activation through two distinct signals: soluble factors and cell-to-cell contact. Crosstalk between NK cells and DCs plays a pivotal role in bridging innate and acquired immunity. Most pathogens and some lactic acid bacteria can modulate the immune balance towards a Th1-predominance. Therefore, bacteria themselves or their components are used to improve the disrupted immune balance or to induce Th1 responses critical for the prevention of infectious diseases, cancers and allergies. The cellular and molecular mechanisms of regulating the innate and acquired immune responses by bacterial stimuli and NKT cell ligands via reciprocal interactions among DCs, NK and NKT cells has been reviewed. Sustaining healthy conditions in mice and humans require precise control of immune responses towards exogenous antigens because disruption of immune homeostasis causes various immune-associated diseases, such as allergy, autoimmune disease and cancer.
|Title of host publication||Natural Killer Cells|
|Number of pages||12|
|Publication status||Published - 2010|
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)