scholarly journals HIV modulates the expression of ligands important in triggering natural killer cell cytotoxic responses on infected primary T-cell blasts

Blood ◽  
2007 ◽  
Vol 110 (4) ◽  
pp. 1207-1214 ◽  
Author(s):  
Jeffrey Ward ◽  
Matthew Bonaparte ◽  
Jennifer Sacks ◽  
Jacqueline Guterman ◽  
Manuela Fogli ◽  
...  

AbstractThe ability of natural killer (NK) cells to kill virus-infected cells depends on the presence of ligands for activation receptors on the target cells. We found the presence of few, if any, NKp30 and NK46 ligands on T cell blasts infected with HIV, although NKp44 ligands were found on infected cells. HIV does induce the NKG2D ligands ULBP-1, -2, and -3. These ligands are involved in triggering NK cells to kill autologous HIV-infected cells, because interfering with the interaction between NKG2D, but not NKp46, on NK cells and its ligands on HIV-infected cells drastically reduced the lysis of infected cells. Interfering with the binding of the NK-cell coreceptors NTB-A and 2B4 to their ligands also decreased destruction by NK cells. The coreceptor ligands, NTB-A and CD48, were also found to be down-regulated during the course of HIV infection. Thus, ligands for NK-cell receptors are modulated during the course of HIV infection, which may greatly alter NK cells' ability to kill the infected cells.

Blood ◽  
2012 ◽  
Vol 119 (16) ◽  
pp. 3734-3743 ◽  
Author(s):  
Lishomwa C. Ndhlovu ◽  
Sandra Lopez-Vergès ◽  
Jason D. Barbour ◽  
R. Brad Jones ◽  
Aashish R. Jha ◽  
...  

Abstract Natural killer (NK) cells are innate lymphocytes that play an important role against viral infections and cancer. This effect is achieved through a complex mosaic of inhibitory and activating receptors expressed by NK cells that ultimately determine the magnitude of the NK-cell response. The T-cell immunoglobulin– and mucin domain–containing (Tim)–3 receptor was initially identified as a T-helper 1–specific type I membrane protein involved in regulating T-cell responses. Human NK cells transcribe the highest amounts of Tim-3 among lymphocytes. Tim-3 protein is expressed on essentially all mature CD56dimCD16+ NK cells and is expressed heterogeneously in the immature CD56brightCD16– NK-cell subset in blood from healthy adults and in cord blood. Tim-3 expression was induced on CD56brightCD16− NK cells after stimulation with IL-15 or IL-12 and IL-18 in vitro, suggesting that Tim-3 is a maturation marker on NK cells. Whereas Tim-3 has been used to identify dysfunctional T cells, NK cells expressing high amounts of Tim-3 are fully responsive with respect to cytokine production and cytotoxicity. However, when Tim-3 was cross-linked with antibodies it suppressed NK cell–mediated cytotoxicity. These findings suggest that NK-cell responses may be negatively regulated when NK cells encounter target cells expressing cognate ligands of Tim-3.


1993 ◽  
Vol 178 (3) ◽  
pp. 961-969 ◽  
Author(s):  
M S Malnati ◽  
P Lusso ◽  
E Ciccone ◽  
A Moretta ◽  
L Moretta ◽  
...  

Natural killer (NK) cells provide a first line of defense against viral infections. The mechanisms by which NK cells recognize and eliminate infected cells are still largely unknown. To test whether target cell elements contribute to NK cell recognition of virus-infected cells, human NK cells were cloned from two unrelated donors and assayed for their ability to kill normal autologous or allogeneic cells before and after infection by human herpesvirus 6 (HHV-6), a T-lymphotropic herpesvirus. Of 132 NK clones isolated from donor 1, all displayed strong cytolytic activity against the NK-sensitive cell line K562, none killed uninfected autologous T cells, and 65 (49%) killed autologous T cells infected with HHV-6. A panel of representative NK clones from donors 1 and 2 was tested on targets obtained from four donors. A wide heterogeneity was observed in the specificity of lysis of infected target cells among the NK clones. Some clones killed none, some killed only one, and others killed more than one of the different HHV-6-infected target cells. Killing of infected targets was not due to complete absence of class I molecules because class I surface levels were only partially affected by HHV-6 infection. Thus, target cell recognition is not controlled by the effector NK cell alone, but also by polymorphic elements on the target cell that restrict NK cell recognition. Furthermore, NK clones from different donors display a variable range of specificities in their recognition of infected target cells.


Blood ◽  
2002 ◽  
Vol 100 (6) ◽  
pp. 1935-1947 ◽  
Author(s):  
Sherif S. Farag ◽  
Todd A. Fehniger ◽  
Loredana Ruggeri ◽  
Andrea Velardi ◽  
Michael A. Caligiuri

AbstractNatural killer (NK) cells have held great promise for the immunotherapy of cancer for more than 3 decades. However, to date only modest clinical success has been achieved manipulating the NK cell compartment in patients with malignant disease. Progress in the field of NK cell receptors has revolutionized our concept of how NK cells selectively recognize and lyse tumor and virally infected cells while sparing normal cells. Major families of cell surface receptors that inhibit and activate NK cells to lyse target cells have been characterized, including killer cell immunoglobulinlike receptors (KIRs), C-type lectins, and natural cytotoxicity receptors (NCRs). Further, identification of NK receptor ligands and their expression on normal and transformed cells completes the information needed to begin development of rational clinical approaches to manipulating receptor/ligand interactions for clinical benefit. Indeed, clinical data suggest that mismatch of NK receptors and ligands during allogeneic bone marrow transplantation may be used to prevent leukemia relapse. Here, we review how NK cell receptors control natural cytotoxicity and novel approaches to manipulating NK receptor-ligand interactions for the potential benefit of patients with cancer.


Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2417 ◽  
Author(s):  
Tram N. Dao ◽  
Sagar Utturkar ◽  
Nadia Atallah Lanman ◽  
Sandro Matosevic

Among natural killer (NK) cell receptors, the T-cell immunoglobulin and mucin-containing domain (TIM-3) has been associated with both inhibitory and activating functions, depending on context and activation pathway. Ex vivo and in vitro, expression of TIM-3 is inducible and depends on activation stimulus. Here, we report that TIM-3 expression can be downregulated on NK cells under specific conditions. When NK cells are exposed to cancer targets, they synergize with stimulation conditions to induce a substantial decrease in TIM-3 expression on their surface. We found that such downregulation occurs following prior NK activation. Downregulated TIM-3 expression correlated to lower cytotoxicity and lower interferon gamma (IFN-γ) expression, fueling the notion that TIM-3 might function as a benchmark for human NK cell dysfunction.


1995 ◽  
Vol 181 (3) ◽  
pp. 1133-1144 ◽  
Author(s):  
J E Gumperz ◽  
V Litwin ◽  
J H Phillips ◽  
L L Lanier ◽  
P Parham

Although inhibition of natural killer (NK) cell-mediated lysis by the class I HLA molecules of target cells is an established phenomenon, knowledge of the features of class I molecules which induce this effect remains rudimentary. Using class I alleles HLA-B*1502 and B*1513 which differ only at residues 77-83 which define the Bw4 and Bw6 serological epitopes, we tested the hypothesis that the presence of the Bw4 epitope on class I molecules determines recognition by NKB1+ NK cells. HLA-B*1513 possesses the Bw4 epitope, whereas B*1502 has the Bw6 epitope. Lysis by NKB1+ NK cell clones of transfected target cells expressing B*1513 as the only HLA-A, -B, or -C molecule was inhibited, whereas killing of transfectants expressing B*1502 was not. Addition of an an anti-NKB1 monoclonal antibody reconstituted lysis of the targets expressing B*1513, but did not affect killing of targets bearing B*1502. The inhibitory effect of B*1513 could be similarly prevented by the addition of an anti-class I monoclonal antibody. These results show that the presence of the Bw4 epitope influences recognition of HLA-B molecules by NK cells that express NKB1, and suggest that the NKB1 molecule may act as a receptor for Bw4+ HLA-B alleles. Sequences outside of the Bw4 region must also affect recognition by NKB1+ NK cells, because lysis of transfectants expressing HLA-A*2403 or A*2501, which possess the Bw4 epitope but are in other ways substantially different from HLA-B molecules, was not increased by addition of the anti-NKB1 antibody. Asparagine 86, the single site of N-linked glycosylation on class I molecules, is in close proximity to the Bw4/Bw6 region. The glycosylation site of the Bw4-positive molecule B*5801 was mutated, and the mutant molecules tested for inhibition of NKB1+ NK cells. Inhibition that could be reversed by addition of the anti-NKB1 monoclonal antibody was observed, showing the presence of the carbohydrate moiety is not essential for class I recognition by NKB1+ NK cell clones.


Blood ◽  
2006 ◽  
Vol 108 (7) ◽  
pp. 2316-2323 ◽  
Author(s):  
Stefania Marcenaro ◽  
Federico Gallo ◽  
Stefania Martini ◽  
Alessandra Santoro ◽  
Gillian M. Griffiths ◽  
...  

Abstract Natural killer (NK) cells from patients with familial hemophagocytic lymphohistiocytosis because of PRF1 (FHL2, n = 5) or MUNC13-4 (FHL3, n = 8) mutations were cultured in IL-2 prior to their use in various functional assays. Here, we report on the surface CD107a expression as a novel rapid tool for identification of patients with Munc13-4 defect. On target interaction and degranulation, FHL3 NK cells displayed low levels of surface CD107a staining, in contrast to healthy control subjects or perforin-deficient NK cells. B-EBV cell lines and dendritic cell targets reveal the FHL3 NK-cell defect, whereas highly susceptible tumor targets were partially lysed by FHL3 NK cells expressing only trace amounts of Munc13-4 protein. Perforin-deficient NK cells were completely devoid of any ability to lyse target cells. Cytokine production induced by mAb-crosslinking of triggering receptors was comparable in patients and healthy control subjects. However, when cytokine production was induced by coculture with 721.221 B-EBV cells, FHL NK cells resulted in high producers, whereas control cells were almost ineffective. This could reflect survival versus elimination of B-EBV cells (ie, the source of NK-cell stimulation) in patients versus healthy control subjects, thus mimicking the pathophysiologic scenario of FHL.


Blood ◽  
1985 ◽  
Vol 65 (1) ◽  
pp. 65-70 ◽  
Author(s):  
HW Ziegler-Heitbrock ◽  
H Rumpold ◽  
D Kraft ◽  
C Wagenpfeil ◽  
R Munker ◽  
...  

Many patients with B-type chronic lymphocytic leukemia (CLL) exhibit a profound defect in their natural killer (NK) cell activity, the basis of which is still obscure. Hence, we analyzed the NK cells from peripheral blood samples from 11 patients with CLL for phenotype and function, after removal of the leukemic cells with a monoclonal antibody (BA-1) plus complement. Phenotypic analysis of these nonleukemic cells with monoclonal antibodies (MoAbs) against NK cells revealed that the CLL patients had higher percentages of HNK-1-positive cells (23.5% compared to controls with 14.7%). In contrast, VEP13- positive cells were absent or low in seven patients (0.8% compared to controls with 11.2%) and normal in four patients (10.5%). When testing NK cell activities against K562 or MOLT 4 target cells, patients with no or minimal numbers of VEP13-positive cells were found to be deficient, while patients with normal percentages of VEP13-positive cells had NK cell activity comparable to controls. Isolation by fluorescence-activated cell sorter of HNK-1-positive cells from patients lacking VEP13-positive cells and NK cell activity indicated that the majority of the HNK-1-positive cells in these patients had the large granular lymphocyte morphology that is characteristic of NK cells. Thus, the deficiency of NK cell activity in CLL patients appears to result from the absence of cells carrying the VEP13 marker.


2022 ◽  
Author(s):  
Sara G Dosil ◽  
Sheila Lopez-Cobo ◽  
Ana Rodriguez-Galan ◽  
Irene Fernandez-Delgado ◽  
Marta Ramirez-Huesca ◽  
...  

Natural killer (NK) cells recognise and kill target cells undergoing different types of stress. NK cells are also capable of modulating immune responses. In particular, they regulate T cell functions. Small RNA next-generation sequencing of resting and activated NK cells and their secreted EVs led to the identification of a specific repertoire of NK-EV-associated microRNAs and their post-transcriptional modifications signature. Several microRNAs of NK-EVs, namely miR-10b-5p, miR-92a-3p and miR-155-5p, specifically target molecules involved in Th1 responses. NK-EVs promote the downregulation of GATA-3 mRNA in CD4+ T cells and subsequent T-bet de-repression that leads to Th1 polarization and IFN-γ and IL-2 production. NK-EVs also have an effect on monocyte and moDCs function, driving their activation and increased presentation and co-stimulatory functions. Nanoparticle-delivered NK-EV microRNAs partially recapitulate NK-EV effects in vivo. Our results provide new insights on the immunomodulatory roles of NK-EVs that may help to improve their use as immunotherapeutic tools.


Blood ◽  
2005 ◽  
Vol 106 (10) ◽  
pp. 3567-3574 ◽  
Author(s):  
Chung-Wu Lin ◽  
Ting-Yun Liu ◽  
Shee-Uan Chen ◽  
Kun-Teng Wang ◽  
L. Jeffrey Medeiros ◽  
...  

AbstractMost lymphoblastic lymphomas (LBLs) are regarded as neoplasms of immature T cells because they express cytoplasmic CD3 and frequently carry T-cell receptor (TCR) gene rearrangements. Immature natural killer (NK) and T cells, however, have a common bipotent T/NK-cell precursor in the thymus, and NK cells also express cytoplasmic CD3. Thus, some LBLs could arise from immature NK cells. Mature NK cells express 2 CD94 transcripts: 1A, induced by interleukin 15 (IL-15), and 1B constitutively. Because immature NK cells require IL-15 for development, CD94 1A transcripts could be a marker of NK-LBL. To test this hypothesis, we used laser capture microdissection to isolate IL-15 receptor α+ lymphoid cells from the thymus and showed that these cells contained CD94 1A transcripts. We then assessed for CD94 transcripts in 21 cases of LBL that were cytoplasmic CD3+, nuclear terminal deoxynucleotidyl transferase positive (TdT+), and CD56-, consistent with either the T-cell or NK-cell lineage. We found that 7 LBLs expressed CD94 1A transcripts without TCR gene rearrangements, suggesting NK-cell lineage. Patients with NK-LBL were younger than patients with T-LBL (15 years versus 33 years; P = .11) and had a better 2-year survival (100% versus 27%; P < .01). These results improve the current classification of LBL and contribute to our understanding of NK-cell differentiation.


2011 ◽  
Vol 286 (27) ◽  
pp. 24142-24149 ◽  
Author(s):  
Stefanie Margraf-Schönfeld ◽  
Carolin Böhm ◽  
Carsten Watzl

2B4 (CD244) is an important activating receptor for the regulation of natural killer (NK) cell responses. Here we show that 2B4 is heavily and differentially glycosylated in primary human NK cells and NK cell lines. The differential glycosylation could be attributed to sialic acid residues on N- and O-linked carbohydrates. Using a recombinant fusion protein of the extracellular domain of 2B4, we demonstrate that N-linked glycosylation of 2B4 is essential for the binding to its ligand CD48. In contrast, sialylation of 2B4 has a negative impact on ligand binding, as the interaction between 2B4 and CD48 is increased after the removal of sialic acids. This was confirmed in a functional assay system, where the desialylation of NK cells or the inhibition of O-linked glycosylation resulted in increased 2B4-mediated lysis of CD48-expressing tumor target cells. These data demonstrate that glycosylation has an important impact on 2B4-mediated NK cell function and suggest that regulated changes in glycosylation during NK cell development and activation might be involved in the regulation of NK cell responses.


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