China
Africa
Explore chapters and articles related to this topic
Pathogenesis of Tuberculosis
Published in Lloyd N. Friedman, Martin Dedicoat, Peter D. O. Davies, Clinical Tuberculosis, 2020
Divya B. Reddy, Jerrold J. Ellner
NK cells are traditionally consider as innate cells but recent studies suggest that NK cells can distinguish Ags, and that memory NK cells expand and protect against viral pathogens and have an important role in mycobacterial infections.69 In fact, a subpopulation of memory-like NK cells (CD3-NKp46+CD27+KLRG1+) expand in BCG-vaccinated mice and LTBI+ individuals to provide protection against MTB infection.70
Innate lymphoid cells
Published in Phillip D. Smith, Richard S. Blumberg, Thomas T. MacDonald, Principles of Mucosal Immunology, 2020
In the intestine, the presence of the commensal microbiota induces a vigorous type 3 immune response, at the steady state and in the absence of pathogens. The highest density of ILC3s and TH17 cells is found in the ileal lamina propria, where these cells play a critical role in the containment of the microbiota through the production of IL-17, IL-22, and lymphotoxins. Upon infection with pathogens, such as enteropathogenic Escherichia coli and related Proteobacteria species, ILC3s are critical effectors as they produce the bulk of IL-22 early in infection, which in turn induces the expression of protective AMPs by epithelial cells. However, during infection with Salmonella enterica, which is an invasive organism and elicits a strong inflammatory response, a subset of ILC3s expressing the NK marker NKp46, coexpresses IFN-γ and causes tissue damage.
Monocyte and lymphocyte membrane markers: Ontogeny and clinical significance
Published in Gabriel Virella, Medical Immunology, 2019
Scott Sugden, Damien Montamat-Sicotte, Karen K. Yam, Joseph Murphy, Bader Yassine Diab, Virginia Litwin
Natural cytotoxicity receptors (NKp46, NKp3, NKp44) are selectively expressed on NK cells at varying surface densities. They associate with different ITAMs such as CD3ζ, FcεRIγ, or DAP12and play a major role in activating lysis of tumor and virally infected targets.
Double-edged role of natural killer cells during RSV infection
Published in International Reviews of Immunology, 2020
Rauf Bhat, Mohamed A. Farrag, Fahad N. Almajhdi
NK cells play a vital role in host defense against viral infections, though viruses can also infect NK cells. Incubation of the NK cells with viral particles influences the NK cell function and phenotype. Viruses can also affect the cytokine production of immune cells, causing the polarization and migration of the NK cells to virus replication sites and specific regions of the lymphoid tissues [2, 6]. DNAM-1 and NKG2D, as well as natural cytotoxicity receptors (NCRs), are the main NK cell-activating receptors involved in the recognition and clearance of the virus-infected cells [7]. The ligands for DNAM-1 are poliovirus receptor (PVR, also known as CD155) and Nectin-2 (CD112). These ligands play an important role in cell-cell adhesion and polarization of the NK cells upon interaction with the virus-infected cells [7, 8]. NKG2D is a type II transmembrane and a C-type lectin-like receptor. NKG2D ligands are ULBPs and MICA/B, which are up-regulated in tumors and infected cells [8, 9]. NCRs, including NKp30, NKp44, and NKp46, are major receptors uniquely expressed in the NK cells. NKp46 initiates the NK cell activation in response to viral ligands encoded by different viruses [10–13]. NK cells also shape adaptive antiviral responses by modulating the adaptive T and the antigen-presenting B cell responses. NK cells cooperate with the B cells to inhibit virus replication via antibody-dependent cellular cytotoxicity (ADCC) [2–4].
A novel combination of chemotherapy and immunotherapy controls tumor growth in mice with a human immune system
Published in OncoImmunology, 2019
Aude Burlion, Rodrigo N. Ramos, Pukar KC, Kélhia Sendeyo, Aurélien Corneau, Christine Ménétrier-Caux, Eliane Piaggio, Daniel Olive, Christophe Caux, Gilles Marodon
In addition to human CD3+ T cells, our CyTOF analysis showed that the tumors of HuMice could also contain rare populations of immune cells known to play important roles during the anti-tumor immune response, such as monocytes or pDCs. The pDC subset that we describe here for the first time in the tumor of HuMice might have played a role in the amplification of ICOS+ Treg, as described in breast cancer patients.21 We also revealed the presence of NK cells with low expression of NKp46 in the tumor, suggesting impaired function, in agreement with clinical observations.45 Nevertheless, innate human subsets were rare and not always present in HuMice, casting doubts on their effective role during the anti-tumor immune response in regular HuMice. It will be important in the future to monitor the human myeloid compartment in HuMice models optimized for innate human cells development, since those cells can positively46 and/or negatively affect the local anti-tumor immune response.47
Circulating NKp46+ Natural Killer cells have a potential regulatory property and predict distinct survival in Non-Small Cell Lung Cancer
Published in OncoImmunology, 2019
Emilie Picard, Yann Godet, Caroline Laheurte, Magalie Dosset, Jeanne Galaine, Laurent Beziaud, Romain Loyon, Laura Boullerot, Elodie Lauret Marie Joseph, Laurie Spehner, Marion Jacquin, Guillaume Eberst, Béatrice Gaugler, Françoise Le pimpec-Barthes, Elizabeth Fabre, Virginie Westeel, Anne Caignard, Christophe Borg, Olivier Adotévi
Although NKp46 is the main activating receptor involved in NK cell functions,43,44 the downregulation of this receptor observed in our study has also been reported in many other cancers.17–19,24,45,46 This suggests an involvement of tumor-related factors in the phenotypic alteration of NK cells. Indeed, some immune suppressive cytokines or soluble factors such as TGF-β or IDO secreted by tumor cells or stromal cells have been shown to decrease the expression of NCRs or NKG2D on NK cells.47,48 Moreover, tumor cells are able to release a soluble form of MIC ligands which keeps away NK cells and downregulates NKG2D expression.49,50 Thus possible NKp46 ligands or immunosuppressive factors released from tumor cells and could also promote a downregulation of NKp46 on NK cells. On this view, we investigated the correlation between the rate of NKp46+ NK cells and the concentration of several cytokines in the serum of patients. We found a positive correlation between the concentration of TGF-β and the level of NKp46+ NK cells while IL-10 is inversely correlated.