Natural killer (NK) cells belong to the innate immune system and are key effectors in the immune response against cancer and infection. Recent studies have contributed to the knowledge of events controlling NK cell fate. The use of knockout mice has enabled the discovery of key transcription factors (TFs) essential for NK cell development and function. Yet, unwrapping the downstream targets of ...

Natural killer (NK) cells express killer inhibitory receptors that mediate negative regulation of NK cell cytotoxicity upon binding to MHC class I molecules on target cells. Unrelated inhibitory receptors on B cells have recently been shown to function through recruitment of phosphotyrosine phosphatase 1C (PTP-1C). Here, we show that a human killer inhibitory receptor specific for HLA-C also re...

MBT-2 in C3H/HeN mice was used as a model to examine cytotoxic activity. The cytotoxic activities examined were those of natural killer cells (NK), lymphokine activated killer cells (LAK), and tumorcidal macrophage (M psi). NK activity increased in early tumor bearers, but LAK and M psi activities increased in middle tumor bearers. NK activity was inhibited in late tumor bearers, but LAK and M ...

Myelodysplastic syndromes (MDS) are clonal stem cell disorders characterized by ineffective hematopoiesis that lead to leukemia. Disorders of the immune system serve important functions in the pathophysiology and progression of this disease. Different levels or mechanisms of natural killer (NK) cells in patients with MDS have been measured in previous studies, making it challenging to understan...

Background. Natural killer (NK) and natural killer T (NKT) cells contribute to the innate host defense but their role in bacterial sepsis remains controversial. Methods. C57BL/6 mice were infected intratracheally with 5 × 10(5) cfu of Streptococcus pneumoniae. Animals were divided into sham group (Sham); pretreated with isotype control antibody (CON) group; pretreated with anti-asialo GM1 antib...

Although transfer of membrane proteins has been shown to occur during immune cell interactions, the functional significance of this process is not well understood. Here we describe the intercellular transfer of NKG2D and MHC class I chain-related molecule (MIC) B proteins at the cytotoxic natural killer cell immune synapse (cNK-IS). MICB expressed on the 721.221 cell line induced clustering of ...

The efficacy of various combinations of stem cell factor (SCF), FLT3 ligand, interleukin (IL)-2, IL-7 and IL-15 to induce and expand cord blood-derived cytokine-induced killer (CIK) cells was investigated. There were three treatment groups: group A: SCF combined with IL-2, IL-7 and IL-15; group B: SCF, FLT3 ligand combined with IL-2, IL-7 and IL-15, and group C: IL-2, IL-7 and IL-15, the contro...

During cancer immunoediting, loss of major histocompatibility complex class I (MHC-I) in neoplasm contributes to the evasion of tumours from host immune system. Recent studies have demonstrated that most natural killer (NK) cells that are found in advanced cancers are defective, releasing the malignant MHC-I-deficient tumours from NK-cell-dependent immune control. Here, we show that a natural k...

The association of Natural Killer (NK) cell deficiencies with disease susceptibility has established a central role for NK cells in host defence. In this context, genetic approaches have been pivotal in elucidating and characterizing the molecular mechanisms underlying NK cell function. To this end, homozygosity mapping and linkage analysis in humans have identified mutations that impact NK cel...

BACKGROUND A change in number and/or activity of natural killer cells has repeatedly been reported in depressive illness. Much less attention has yet been given to the subgroup of natural killer cells that are positive for the T-cell marker CD3 (NK-T cells). These cells possibly have important immunoregulatory properties. METHODS We compared number and percentage of NK-T cells (defined as CD3...