Development of natural killer (NK) cells is thought to depend on interactions between NK progenitors and the bone marrow (BM) microenvironment; however, little is known about the molecular signals involved. Here we show that lymphotoxin (LT) provides an important signal for the development of both NK cells and NK/T cells. LTalpha-/- mice show marked reduction in splenic and BM NK and NK/T cell ...

Natural killer (NK) cells are composed of subsets characterized by the expression of inhibitory or activating receptors, or both, specific for different major histocompatibility complex (MHC) class I determinants. We have previously shown that inhibitory receptor blockade of syngeneic NK cells was an effective means of ex vivo purging of leukemia-contaminated bone marrow and that the transplant...

We report that human peripheral NK cells expressing high CD56 levels (CD56(+high)) are terminally differentiated cells indistinguishable from mature NK cells recently activated in the presence of IL-12, and not a functionally distinct NK-cell subset or progenitors to mature CD56(+low) NK cells. CD56(+high) NK cells coexpress all differentiation Ags constitutive or inducible in mature (CD56(+)) ...

Acquisition of a functional NK cell repertoire, known as education or licensing, is a complex process mediated through inhibitory receptors that recognize self. We found that NK cells containing self-killer Ig-like receptors for cognate HLA ligand in vivo were less susceptible to apoptosis. In vitro IL-15 withdrawal showed that uneducated NK cells upregulated Bim and Fas. Conversely, educated N...

Background Natural killer (NK) cells are immune that can detect and eliminate tumor bridge innate to adaptive responses. Tumor specific activation of NK is thus an area active investigation in oncology, but date has relied on complex biologic modalities (e.g., antibodies, fusion proteins, or cell therapies), each which inherent disadvantages this application. Thus, alternative approaches warran...

Background/objective: Studies of the decidual leukocyte populations in women suffering from spontaneous early pregnancy loss may provide insight into immunpathological aspects and even cast light on the etiology of recurrent spontaneous abortion.Methods: In order to clarify the immunological role of endometrial leukocytes in repetitive abortion of unknown etiology, a comparative analysis of phe...

Natural killer (NK) cells are innate immune effector that efficient in identifying and killing cancer through the release of cytokines cytotoxic enzymes. NK lymphocytes with crucial roles resistance against various cancers, dysfunction often outcomes advanced progression. However, functional regulation NSCLC (PC9 gefitinib resistant PC9-MET cells) remains largely unknown. In this study, flow cy...

BACKGROUND Natural killer (NK) cells in the upper respiratory airways are not well characterized. In the current study, we sought to characterize and functionally assess murine nasal NK cells. METHODS Using immunohistochemistry and flow cytometry, we compared the nasal NK cells of Ncr1GFP/+ knock-in mice, whose NK cells produced green fluorescent protein, with their splenic and pulmonary coun...

Recently, it has become apparent that surface proteins commonly transfer between immune cells in contact. Inhibitory receptors and ligands exchange between cells during NK cell surveillance and we report here that NK cells also acquire activating ligands from target cells. Specifically, the stress-inducible activating ligand for NKG2D, MHC class I-related chain A (MICA), transferred to NK cells...

Melanomas are aggressive skin tumors characterized by high metastatic potential. Immunotherapy is a valuable alternative for metastatic melanoma patients resistant to chemotherapy. Natural Killer (NK) cells are efficient anti-tumor cytotoxic effectors. We previously showed that blood NK cells from stage IV metastatic melanoma patients display decreased NK receptors and that chemotherapy modifie...