101
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Abstract
PURPOSE OF REVIEW Over the last decade our understanding of the role of natural killer cells in HIV infection has changed dramatically due to strong epidemiological, phenotypic, and functional data providing evidence for their involvement in antiviral control. Here we review the current literature on natural killer cells in the control of HIV infection, with a specific focus on their role in HIV controllers, individuals that spontaneously control HIV replication in the absence of antiretroviral therapy. RECENT FINDINGS Differences between progressors and controllers are highlighted in the context of genetic influences, natural killer cell phenotypes, function and dysregulation. Also, recent findings on the role of natural killer cell-mediated antibody-dependent cellular cytotoxicity in HIV control are summarized. SUMMARY This evolving understanding of the complex biology of natural killer cells and their multifaceted role in HIV infection offer exciting new approaches for future vaccine strategies. Furthermore, the specific natural killer cell phenotype and function observed in controllers may guide new vaccine modalities that specifically harness the antiviral power of natural killer cells as adjuvants, or as direct effectors.
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102
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Abstract
Natural killer (NK) cells are bone marrow–derived granular lymphocytes that have a key role in immune defense against viral and bacterial infections and malignancies. NK cells are traditionally defined as cells of the innate immune response because they lack RAG recombinase–dependent clonal antigen receptors. However, evidence suggests that specific subsets of mouse NK cells can nevertheless develop long-lived and highly specific memory to a variety of antigens. Here we review published evidence of NK cell–mediated, RAG-independent adaptive immunity. We also compare and contrast candidate mechanisms for mammalian NK cell memory and antigen recognition with other examples of RAG-independent pathways that generate antigen receptor diversity in non-mammalian species and discuss NK cell memory in the context of lymphocyte evolution.
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Affiliation(s)
- Silke Paust
- Harvard Medical School, Department of Pathology, Boston, Massachusetts, USA
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103
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Almerigogna F, Fassio F, Giudizi MG, Biagiotti R, Manuelli C, Chiappini E, Galli L, Romagnani S, De Martino M. Natural killer cell deficiencies in a consecutive series of children with herpetic encephalitis. Int J Immunopathol Pharmacol 2011; 24:231-8. [PMID: 21496407 DOI: 10.1177/039463201102400128] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Natural killer (NK) cells play a fundamental role in innate and early phases of adaptive immunity against viral infections, both in humans and in animal models. To date, NK cell deficiencies in patients with severe herpetic infections have been reported in single cases, and their role as predisposing factor is still controversial. Five children affected by herpetic encephalitis were consecutively admitted to the Anna Meyer Children's Hospital in Florence (Italy) between 2003 and 2005. We therefore investigated the presence of NK cell deficiencies in a consecutive series of children with herpetic encephalitis. Five healthy children were included in the study as controls. Differential WBC counts, main Ig and IgE class serum analysis, cytofluorimetric analysis of circulating T, B and NK cells were performed on our study population. Sequencing of a selected region of CD16A gene transcript was carried out in two patients. All patients resulted to be affected by deficiencies related to NK cells in respect to controls. One patient was also affected by lymphopenia, while no other significant deficits of immunity were detected in the study population. To date, this is the first survey that demonstrates isolated NK cell deficiencies in a cohort of consecutive patients affected by severe herpes simplex infections. These findings suggest a role for NK cell deficiencies as a predisposing factor for increased susceptibility and severe course of disease in these patients.
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Affiliation(s)
- F Almerigogna
- Department of Internal Medicine, University of Florence, Italy
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104
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Sun JC, Lopez-Verges S, Kim CC, DeRisi JL, Lanier LL. NK cells and immune "memory". THE JOURNAL OF IMMUNOLOGY 2011; 186:1891-7. [PMID: 21289313 DOI: 10.4049/jimmunol.1003035] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Immunological memory is a hallmark of the adaptive immune system. However, the ability to remember and respond more robustly against a second encounter with the same pathogen has been described in organisms lacking T and B cells. Recently, NK cells have been shown to mediate Ag-specific recall responses in several different model systems. Although NK cells do not rearrange the genes encoding their activating receptors, NK cells experience a selective education process during development, undergo a clonal-like expansion during virus infection, generate long-lived progeny (i.e., memory cells), and mediate more efficacious secondary responses against previously encountered pathogens--all characteristics previously ascribed only to T and B cells in mammals. This review describes past findings leading up to these new discoveries, summarizes the evidence for and characteristics of NK cell memory, and discusses the attempts and future challenges to identify these long-lived memory NK cell populations in humans.
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Affiliation(s)
- Joseph C Sun
- Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
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105
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Natural killer cells in human cancer: from biological functions to clinical applications. J Biomed Biotechnol 2011; 2011:676198. [PMID: 21541191 PMCID: PMC3085499 DOI: 10.1155/2011/676198] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 02/25/2011] [Indexed: 12/19/2022] Open
Abstract
Natural killer (NK) cells are central components of the innate immunity. In murine models, it has been shown that NK cells can control both local tumor growth and metastasis due to their ability to exert direct cellular cytotoxicity without prior sensitization and to secrete immunostimulatory cytokines like IFN-γ. The latter participates in cancer elimination by inhibiting cellular proliferation and angiogenesis, promoting apoptosis, and stimulating the adaptive immune system, and it is instrumental for enhancing Ag processing and presentation. Nevertheless, NK cells display impaired functionality and capability to infiltrate tumors in cancer patients. Also, NK cells are feasible targets of stimulation to participate in immunotherapeutic approaches like antibody-based strategies and adoptive cell transfer. Thus, multiple attempts currently aim to manipulate NK for utilization in the immunotherapy of cancer.
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106
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Abraham RS. Relevance of laboratory testing for the diagnosis of primary immunodeficiencies: a review of case-based examples of selected immunodeficiencies. Clin Mol Allergy 2011; 9:6. [PMID: 21477322 PMCID: PMC3080807 DOI: 10.1186/1476-7961-9-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 04/09/2011] [Indexed: 12/18/2022] Open
Abstract
The field of primary immunodeficiencies (PIDs) is one of several in the area of clinical immunology that has not been static, but rather has shown exponential growth due to enhanced physician, scientist and patient education and awareness, leading to identification of new diseases, new molecular diagnoses of existing clinical phenotypes, broadening of the spectrum of clinical and phenotypic presentations associated with a single or related gene defects, increased bioinformatics resources, and utilization of advanced diagnostic technology and methodology for disease diagnosis and management resulting in improved outcomes and survival. There are currently over 200 PIDs with at least 170 associated genetic defects identified, with several of these being reported in recent years. The enormous clinical and immunological heterogeneity in the PIDs makes diagnosis challenging, but there is no doubt that early and accurate diagnosis facilitates prompt intervention leading to decreased morbidity and mortality. Diagnosis of PIDs often requires correlation of data obtained from clinical and radiological findings with laboratory immunological analyses and genetic testing. The field of laboratory diagnostic immunology is also rapidly burgeoning, both in terms of novel technologies and applications, and knowledge of human immunology. Over the years, the classification of PIDs has been primarily based on the immunological defect(s) ("immunophenotype") with the relatively recent addition of genotype, though there are clinical classifications as well. There can be substantial overlap in terms of the broad immunophenotype and clinical features between PIDs, and therefore, it is relevant to refine, at a cellular and molecular level, unique immunological defects that allow for a specific and accurate diagnosis. The diagnostic testing armamentarium for PID includes flow cytometry - phenotyping and functional, cellular and molecular assays, protein analysis, and mutation identification by gene sequencing. The complexity and diversity of the laboratory diagnosis of PIDs necessitates many of the above-mentioned tests being performed in highly specialized reference laboratories. Despite these restrictions, there remains an urgent need for improved standardization and optimization of phenotypic and functional flow cytometry and protein-specific assays. A key component in the interpretation of immunological assays is the comparison of patient data to that obtained in a statistically-robust manner from age and gender-matched healthy donors. This review highlights a few of the laboratory assays available for the diagnostic work-up of broad categories of PIDs, based on immunophenotyping, followed by examples of disease-specific testing.
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Affiliation(s)
- Roshini S Abraham
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
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107
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Abstract
MHC class I (MHC I) is essential to NK- and T-cell effector and surveillance functions. However, it is unknown whether MHC I polymorphism influences adaptive immunity through NK cells. Previously, we found that MHC I D(k), a cognate ligand for the Ly49G2 inhibitory receptor, was essential to NK control of murine (M)CMV infection. Here we assessed the significance of NK inhibitory receptor recognition of MCMV on CD8 T cells in genetically defined MHC I D(k) disparate mice. We observed that D(k)-licensed Ly49G2⁺ NK cells stabilized and then enhanced conventional dendritic cells (cDCs) recovery after infection. Furthermore, licensed NK support of cDC recovery was essential to enhance the tempo, magnitude, and effector activity of virus-specific CD8 T cells. Minimal cDC and CD8 T-cell number differences after low-dose MCMV in D(k) disparate animals further implied that licensed NK recognition of MCMV imparted qualitative cDC changes to enhance CD8 T-cell priming.
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108
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Johansson SE, Brauner H, Hinkula J, Wahren B, Berg L, Johansson MH. Accumulation and activation of natural killer cells in local intraperitoneal HIV-1/MuLV infection results in early control of virus infected cells. Cell Immunol 2011; 272:71-8. [DOI: 10.1016/j.cellimm.2011.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 08/19/2011] [Accepted: 09/09/2011] [Indexed: 11/16/2022]
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109
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Björkström NK, Lindgren T, Stoltz M, Fauriat C, Braun M, Evander M, Michaëlsson J, Malmberg KJ, Klingström J, Ahlm C, Ljunggren HG. Rapid expansion and long-term persistence of elevated NK cell numbers in humans infected with hantavirus. ACTA ACUST UNITED AC 2010; 208:13-21. [PMID: 21173105 PMCID: PMC3023129 DOI: 10.1084/jem.20100762] [Citation(s) in RCA: 372] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Acute hantavirus infection in humans triggers a rapid expansion and long-term persistence of NK cells. Natural killer (NK) cells are known to mount a rapid response to several virus infections. In experimental models of acute viral infection, this response has been characterized by prompt NK cell activation and expansion followed by rapid contraction. In contrast to experimental model systems, much less is known about NK cell responses to acute viral infections in humans. We demonstrate that NK cells can rapidly expand and persist at highly elevated levels for >60 d after human hantavirus infection. A large part of the expanding NK cells expressed the activating receptor NKG2C and were functional in terms of expressing a licensing inhibitory killer cell immunoglobulin-like receptor (KIR) and ability to respond to target cell stimulation. These results demonstrate that NK cells can expand and remain elevated in numbers for a prolonged period of time in humans after a virus infection. In time, this response extends far beyond what is considered normal for an innate immune response.
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Affiliation(s)
- Niklas K Björkström
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden
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110
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Sun JC, Beilke JN, Lanier LL. Immune memory redefined: characterizing the longevity of natural killer cells. Immunol Rev 2010; 236:83-94. [PMID: 20636810 DOI: 10.1111/j.1600-065x.2010.00900.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Natural killer (NK) cells respond rapidly to transformed, stressed, or virally infected cells and provide a first-line immune defense against pathogen invasion and cancer. Thought to involve short-lived effector cells that are armed for battle, NK cells were not previously known to contribute in recall responses to pathogen re-encounter. Here, we highlight recent discoveries demonstrating that NK cells are not limited to driving primary immune responses to foreign antigen but can mount secondary responses contributing to immune memory. We also further characterize the phenotype and function of long-lived memory NK cells generated during viral infection.
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Affiliation(s)
- Joseph C Sun
- Department of Microbiology and Immunology and the Cancer Research Institute, University of California, San Francisco, CA 94143, USA
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111
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Monaco-Shawver L, Schwartz L, Tuluc F, Guo CJ, Lai JP, Gunnam SM, Kilpatrick LE, Banerjee PP, Douglas SD, Orange JS. Substance P inhibits natural killer cell cytotoxicity through the neurokinin-1 receptor. J Leukoc Biol 2010; 89:113-25. [PMID: 20940324 DOI: 10.1189/jlb.0410200] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
SP is a potent neuroimmunomodulator that functions through ligating members of the neurokinin receptor family, one of which, NK1R, is widely expressed in immune cells. As in humans, circulating SP levels are increased in pathologic states associated with impairment of NK cell functions, such as depression and HIV infection, we hypothesized that SP has a direct, inhibitory effect upon NK cells. We have studied a clonal human NK cell line (YTS) as well as ex vivo human NK cells and have determined that truncated and full-length NK1R isoforms are expressed in and SP bound by ex vivo NK cells and the YTS NK cell line. Incubation of YTS cells with 10⁻⁶ M SP and ex vivo NK cells with 10⁻⁵ M SP inhibited cytotoxic ability by ∼20% and reduced degranulation. This inhibitory effect upon cytotoxicity was partially prevented by the NK1R antagonist CP96,345. The treatment of YTS or ex vivo NK cells with SP neither down-modulated NCR expression nor affected triggering receptor-induced NF-κB activation. Preincubation of YTS cells with SP, however, did abbreviate the typically prolonged intracellular calcium increase induced by target cell engagement and reduced triggering receptor-induced pERK. Thus, SP has the potential to regulate NK cell functions and acts downstream from neurokinin receptors to modulate NK cell activation signaling. This mechanism may contribute to impairment of NK cell function in certain disease states associated with increased circulating SP. Antagonism of this system may present an opportunity to augment NK cell function therapeutically in selected human diseases.
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Affiliation(s)
- Linda Monaco-Shawver
- The Children's Hospital of Philadelphia Research Institute, University of Pennsylvania, Pediatrics, Philadelphia, PA 19104, USA
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112
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Abstract
Mucosal surfaces are exploited as a portal of entry into hosts by a wide variety of microorganisms. Over the past decade, an advanced understanding of the immune system of the gastrointestinal and the respiratory mucosae has been gained. However, despite the fact that many viruses are transmitted sexually through the genital tract, the immune system of the male and female genital mucosae has received much less attention. Here, I describe and highlight differences in the innate and adaptive immune systems of the genital and intestinal mucosae, and discuss some of the challenges we face in the development of successful vaccines against sexually transmitted viral pathogens.
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113
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CD56 negative NK cells: origin, function, and role in chronic viral disease. Trends Immunol 2010; 31:401-6. [PMID: 20829113 DOI: 10.1016/j.it.2010.08.003] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Revised: 08/05/2010] [Accepted: 08/12/2010] [Indexed: 12/11/2022]
Abstract
Natural killer (NK) cells serve as a first line of defense against acute viral infections. Immunogenetic association data suggest that NK cells also influence the course of chronic viral infections, such as infections with HIV-1 and hepatitis C virus (HCV). Chronic stages of these infections have a negative impact on NK cell function and promote the appearance of phenotypically and functionally abnormal NK cells. In this paper, we summarize available data on CD56(neg) NK cells, an aberrant NK cell subset found in small numbers in healthy individuals and at elevated levels in individuals chronically infected with HIV-1 and HCV. We discuss current knowledge of CD56(neg) NK cells, with a particular emphasis on their accumulation during chronic infection and the possible consequences of this for the host.
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114
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Höglund P, Brodin P. Current perspectives of natural killer cell education by MHC class I molecules. Nat Rev Immunol 2010; 10:724-34. [PMID: 20818413 DOI: 10.1038/nri2835] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
From the early days of natural killer (NK) cell research, it was clear that MHC genes controlled the specificity of mouse NK cell-dependent responses, such as the ability to reject transplanted allogeneic bone marrow and to kill tumour cells. Although several mechanisms that are involved in this 'education' process have been clarified, most of the mechanisms have still to be identified. Here, we review the current understanding of the processes that are involved in NK cell education, including how the host MHC class I molecules regulate responsiveness and receptor repertoire formation in NK cells and the signalling pathways that are involved.
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Affiliation(s)
- Petter Höglund
- Department of Microbiology, Tumour and Cell Biology, Karolinska Institutet, SE-171 77, Stockholm, Sweden
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115
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Bostik P, Takahashi Y, Mayne AE, Ansari AA. Innate immune natural killer cells and their role in HIV and SIV infection. HIV THERAPY 2010; 4:483-504. [PMID: 20730028 PMCID: PMC2922771 DOI: 10.2217/hiv.10.28] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The findings that early events during HIV-1 and SIV infection of Asian rhesus macaques dictate the levels of viremia and rate of disease progression prior to the establishment of mature and effective adaptive immune responses strongly suggest an important role for innate immune mechanisms. In addition, the fact that the major target of HIV and SIV during this period of acute infection is the gastrointestinal tissue suggests that whatever role the innate immune system plays must either directly and/or indirectly focus on the GI tract. The object of this article is to provide a general overview of the innate immune system with a focus on natural killer (NK) cells and their role in the pathogenesis of lentivirus infection. The studies summarized include our current understanding of the phenotypic heterogeneity, the putative functions ascribed to the subsets, the maturation/differentiation of NK cells, the mechanisms by which their function is mediated and regulated, the studies of these NK-cell subsets, with a focus on killer cell immunoglobulin-like receptors (KIRs) in nonhuman primates and humans, and finally, how HIV and SIV infection affects these NK cells in vivo. Clearly much has yet to be learnt on how the innate immune system influences the interaction between lentiviruses and the host within the GI tract, knowledge of which is reasoned to be critical for the formulation of effective vaccines against HIV-1.
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Affiliation(s)
- Pavel Bostik
- Faculty of Military Health Sciences, University of Defense & Department of Infectious Diseases, Charles University School of Medicine, Hradec-Kralove, Czech Republic
| | - Yoshiaki Takahashi
- Room 2309 WMB, Department of Pathology, Emory University School of Medicine, 101 Woodruff Circle, Atlanta, GA 30322, USA
| | - Ann E Mayne
- Room 2309 WMB, Department of Pathology, Emory University School of Medicine, 101 Woodruff Circle, Atlanta, GA 30322, USA
| | - Aftab A Ansari
- Room 2309 WMB, Department of Pathology, Emory University School of Medicine, 101 Woodruff Circle, Atlanta, GA 30322, USA
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116
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Champsaur M, Beilke JN, Ogasawara K, Koszinowski UH, Jonjic S, Lanier LL. Intact NKG2D-independent function of NK cells chronically stimulated with the NKG2D ligand Rae-1. THE JOURNAL OF IMMUNOLOGY 2010; 185:157-65. [PMID: 20530257 DOI: 10.4049/jimmunol.1000397] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human tumors frequently express membrane-bound or soluble NK group 2, member D (NKG2D) ligands. This results in chronic engagement of NKG2D on the surfaces of NK and CD8(+) T cells and rapid internalization of the receptor. Although it is well appreciated that this phenomenon impairs NKG2D-dependent function, careful analysis of NKG2D-independent functions in cells chronically stimulated through NKG2D is lacking. Using a mouse model of chronic NKG2D ligand expression, we show that constant exposure to NKG2D ligands does not functionally impair NK cells and CD8(+) T cells in the context of viral infection.
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Affiliation(s)
- Marine Champsaur
- Department of Microbiology and Immunology, Biomedical Sciences Graduate Program, University of California at San Francisco, San Francisco, CA 94143, USA
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117
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Membrane nanotubes facilitate long-distance interactions between natural killer cells and target cells. Proc Natl Acad Sci U S A 2010; 107:5545-50. [PMID: 20212116 DOI: 10.1073/pnas.0910074107] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Membrane nanotubes are membranous tethers that physically link cell bodies over long distances. Here, we present evidence that nanotubes allow human natural killer (NK) cells to interact functionally with target cells over long distances. Nanotubes were formed when NK cells contacted target cells and moved apart. The frequency of nanotube formation was dependent on the number of receptor/ligand interactions and increased on NK cell activation. Most importantly, NK cell nanotubes contained a submicron scale junction where proteins accumulated, including DAP10, the signaling adaptor that associates with the activating receptor NKG2D, and MHC class I chain-related protein A (MICA), a cognate ligand for NKG2D, as occurs at close intercellular synapses between NK cells and target cells. Quantitative live-cell fluorescence imaging suggested that MICA accumulated at small nanotube synapses in sufficient numbers to trigger cell activation. In addition, tyrosine-phosphorylated proteins and Vav-1 accumulated at such junctions. Functionally, nanotubes could aid the lysis of distant target cells either directly or by moving target cells along the nanotube path into close contact for lysis via a conventional immune synapse. Target cells moving along the nanotube path were commonly polarized such that their uropods faced the direction of movement. This is the opposite polarization than for normal cell migration, implying that nanotubes can specifically drive target cell movement. Finally, target cells that remained connected to an NK cell by a nanotube were frequently lysed, whereas removing the nanotube using a micromanipulator reduced lysis of these target cells.
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118
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Abstract
The lungs are a major site of entry of pathogens into the body and thus require rapid and effective innate responses to prevent pathogens establishing infection and to limit their spread. Additionally, the immune response in the lung must be tightly regulated such that pathogens are cleared, but immunopathology and chronic inflammation are prevented. In this review, I consider the role of natural killer (NK) cells in pulmonary infection and inflammation, specifically their contributions to influenza, tuberculosis, asthma and chronic obstructive pulmonary disease (COPD), which are major causes of morbidity and mortality world-wide. Despite evidence of the importance of NK cells in these diseases, there are still major gaps in our understanding of how their function is regulated in this unique tissue environment. Understanding how different beneficial and detrimental effector functions of NK cells are triggered will be crucial if NK cells are to be exploited therapeutically in respiratory disease.
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Affiliation(s)
- Fiona J Culley
- Respiratory Medicine, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London W21PG, UK.
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119
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Ma Y, Yang H, Qi J, Liu D, Xiong P, Xu Y, Feng W, Zheng G, Li P, Fang M, Tan Z, Zheng F, Gong F. CD2AP is indispensable to multistep cytotoxic process by NK cells. Mol Immunol 2009; 47:1074-82. [PMID: 19945749 DOI: 10.1016/j.molimm.2009.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 10/29/2009] [Accepted: 11/03/2009] [Indexed: 12/13/2022]
Abstract
CD2-associated protein (CD2AP) is a cytoplasmic protein which localizes to membrane ruffles, lipid rafts and the leading edges of cells. It is implicated in podocyte homeostasis, signal transduction, dynamic actin remodeling and also membrane trafficking during endocytosis and cytokinesis. CD2AP was reported to orchestrate receptor patterning and cytoskeletal polarity in T cell contacts and it could also modulate TCR signaling. However, whether it plays a role in NK cell killing remains unknown. In this study, we discovered that interfering with CD2AP expression strongly reduced cytotoxicity of human NK92 cell line and this effect was independent of FasL sensitivity of target cells. Conjugate formation and degranulation were impeded in NK92 cells after CD2AP knockdown. Upon encountering target cells, CD2AP in NK92 is enriched near contact site and colocalizes with FasL-bearing granules. In contrast, FasL-bearing granules were found rarely polarized toward cell contact site after CD2AP knockdown. Furthermore, by immunoprecipitation from NK92 cell lysates and transient expression studies in 293T and Hela cells, we demonstrated that CD2AP associates with FasL. Thus, CD2AP, through facilitating conjugate formation and directed transport of lytic granules, plays an important role in NK cells killing.
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Affiliation(s)
- Yuting Ma
- Department of Immunology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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120
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Geurs TL, Zhao YM, Hill EB, French AR. Ly49H engagement compensates for the absence of type I interferon signaling in stimulating NK cell proliferation during murine cytomegalovirus infection. THE JOURNAL OF IMMUNOLOGY 2009; 183:5830-6. [PMID: 19828630 DOI: 10.4049/jimmunol.0901520] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
NK cells vigorously proliferate during viral infections, resulting in an expanded pool of innate lymphocytes that are able to participate in early host defense. The relative contributions of cytokines and activation receptors in stimulating NK cell proliferation during viral infections are not well characterized. In this study, we demonstrated that signaling through the NK cell activation receptor Ly49H was able to compensate for the absence of cytokine stimulation in the preferential phase of viral-induced proliferation during murine cytomegalovirus infection. In the absence of type I IFN stimulation, NK cell proliferation was strongly biased toward cells expressing the Ly49H receptor, even at early time points when minimal preferential Ly49H-mediated proliferation was observed in wild-type mice. In the absence of effective Ly49H signaling or following infection with virus that did not express the ligand for Ly49H, no difference was observed in the proliferation of subsets of NK cells that either express or lack expression of Ly49H, although the overall proliferation of NK cells in IFNalphabetaR(-/-) mice was substantially reduced. These results highlight the contribution of NK cell activation receptors in stimulating proliferation and subsequent expansion of NK cells that are able to recognize virally infected cells.
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Affiliation(s)
- Theresa L Geurs
- Division of Pediatric Rheumatology, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
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121
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Mehr SS, Kemp AS. Prolonged varicella viraemia and streptococcal toxic shock syndrome following varicella vaccination of a health care worker. Med J Aust 2009; 191:413-4. [DOI: 10.5694/j.1326-5377.2009.tb02864.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 07/21/2009] [Indexed: 11/17/2022]
Affiliation(s)
- Sam S Mehr
- Children's Hospital at Westmead, Sydney, NSW
| | - Andrew S Kemp
- Children's Hospital at Westmead, Sydney, NSW
- Discipline of Paediatrics and Child Health, University of Sydney Clinical School, Sydney, NSW
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122
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Renner ED, Hartl D, Rylaarsdam S, Young ML, Monaco-Shawver L, Kleiner G, Markert ML, Stiehm ER, Belohradsky BH, Upton MP, Torgerson TR, Orange JS, Ochs HD. Comèl-Netherton syndrome defined as primary immunodeficiency. J Allergy Clin Immunol 2009; 124:536-43. [PMID: 19683336 PMCID: PMC3685174 DOI: 10.1016/j.jaci.2009.06.009] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 05/12/2009] [Accepted: 06/02/2009] [Indexed: 11/25/2022]
Abstract
BACKGROUND Mutations in serine protease inhibitor Kazal-type 5 (SPINK5), encoding the serine protease inhibitor lympho-epithelial Kazal-type 5 related inhibitor (LEKTI), cause Comèl-Netherton syndrome, an autosomal-recessive disease characterized by congenital ichthyosis, bamboo hair, and atopic diathesis. Despite increased frequency of infections, the immunocompetence of patients with Comèl-Netherton syndrome has not been extensively investigated. OBJECTIVE To define Comèl-Netherton syndrome as a primary immunodeficiency disorder and to explore the benefit of intravenous immunoglobulin replacement therapy. METHODS We enrolled 9 patients with Comèl-Netherton syndrome, sequenced SPINK5, and analyzed LEKTI expression by immunohistochemistry. Immune function was assessed by measuring cognate immunity, serum cytokine levels, and natural killer cell cytotoxicity. RESULTS All patients presented with recurrent skin infections caused predominantly by Staphylococcus aureus. All but 1 reported recurrent respiratory tract infections; 78% had sepsis and/or pneumonia; 67% had recurrent gastrointestinal disease and failure to thrive. Mutations in SPINK5-including 6 novel mutations-were identified in 8 patients. LEKTI expression was decreased or absent in all patients. Immunologic evaluation revealed reduced memory B cells and defective responses to vaccination with Pneumovax and bacteriophage phiX174, characterized by impaired antibody amplification and class-switching. Immune dysregulation was suggested by a skewed T(h)1 phenotype and elevated proinflammatory cytokine levels, whereas serum concentrations of the chemokine (C-C motif) ligand 5 and natural killer cell cytotoxicity were decreased. Treatment with intravenous immunoglobulin resulted in remarkable clinical improvement and temporarily increased natural killer cell cytotoxicity. CONCLUSION These data provide new insights into the immunopathology of Comèl-Netherton syndrome and demonstrate that this multisystem disorder, characterized by lack of LEKTI expression in epithelial cells, is complicated by cognate and innate immunodeficiency that responds favorably to intravenous immunoglobulin therapy.
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Affiliation(s)
- Ellen D Renner
- Dr v Haunersches Kinderspital, Ludwig-Maximilians-Universität, Munich, Germany
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123
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Davis DM. Mechanisms and functions for the duration of intercellular contacts made by lymphocytes. Nat Rev Immunol 2009; 9:543-55. [PMID: 19609264 DOI: 10.1038/nri2602] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Communication across intercellular contacts is central to establishing appropriate innate and adaptive immune responses. Recent imaging of lymphocyte interactions suggests that a complex orchestration of cell-cell contact times is a key correlate to establishing appropriate immune responses. Here I review the molecular and cellular processes that influence the duration of intercellular contacts, including integrin activation and dynamic changes in membrane morphology. I discuss how these processes can be regulated, for example, by the balance of activating and inhibitory receptor signals, and how they can establish the appropriate outcome for individual cell-cell interactions.
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Affiliation(s)
- Daniel M Davis
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College London, South Kensington, London, SW7 2AZ, UK.
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125
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Calderón-Garcidueñas L, Macías-Parra M, Hoffmann HJ, Valencia-Salazar G, Henríquez-Roldán C, Osnaya N, Monte OCD, Barragán-Mejía G, Villarreal-Calderon R, Romero L, Granada-Macías M, Torres-Jardón R, Medina-Cortina H, Maronpot RR. Immunotoxicity and Environment: Immunodysregulation and Systemic Inflammation in Children. Toxicol Pathol 2009; 37:161-9. [DOI: 10.1177/0192623308329340] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Environmental pollutants, chemicals, and drugs have an impact on children’s immune system development. Mexico City (MC) children exposed to significant concentrations of air pollutants exhibit chronic respiratory inflammation, systemic inflammation, neuroinflammation, and cognitive deficits. We tested the hypothesis that exposure to severe air pollution plays a role in the immune responses of asymptomatic, apparently healthy children. Blood measurements for markers of immune function, inflammatory mediators, and molecules interacting with the lipopolysaccharide recognition complex were obtained from two cohorts of matched children (aged 9.7 ± 1.2 years) from southwest Mexico City (SWMC) (n = 66) and from a control city (n = 93) with criteria pollutant levels below current standards. MC children exhibited significant decreases in the numbers of natural killer cells ( p = .003) and increased numbers of mCD14+ monocytes ( p < .001) and CD8+ cells ( p = .02). Lower concentrations of interferon γ ( p = .009) and granulocyte–macrophage colony-stimulating factor ( p < .001), an endotoxin tolerance-like state, systemic inflammation, and an anti-inflammatory response were also present in the highly exposed children. C-reactive protein and the prostaglandin E metabolite levels were positively correlated with twenty-four- and forty-eight-hour cumulative concentrations of PM2.5. Exposure to urban air pollution is associated with immunodysregulation and systemic inflammation in children and is a major health threat.
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Affiliation(s)
- Lilian Calderón-Garcidueñas
- Instituto Nacional de Pediatría, Mexico City, Mexico
- Department of Biomedical and Pharmaceutical Sciences, College of Health Professions and Biomedical Sciences, The University of Montana, Missoula, Montana, USA
| | | | - Hans J. Hoffmann
- Department of Respiratory Diseases, Aarhus University Hospital, Aarhus, Denmark
| | | | | | - Norma Osnaya
- Instituto Nacional de Pediatría, Mexico City, Mexico
| | | | | | - Rodolfo Villarreal-Calderon
- Department of Biomedical and Pharmaceutical Sciences, College of Health Professions and Biomedical Sciences, The University of Montana, Missoula, Montana, USA
| | - Lina Romero
- Instituto Nacional de Pediatría, Mexico City, Mexico
| | - Margarita Granada-Macías
- Postgrado en Ciencias Biológicas, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ricardo Torres-Jardón
- Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | - Robert R. Maronpot
- Experimental Pathology Laboratories, Inc., Research Triangle Park, North Carolina, USA
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126
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Abstract
The mammalian immune response to infection is mediated by 2 broad arms, the innate and adaptive immune systems. Innate immune cells are a first-line defense against pathogens and are thought to respond consistently to infection, regardless of previous exposure, i.e., they do not exhibit memory of prior activation. By contrast, adaptive immune cells display immunologic memory that has 2 basic characteristics, antigen specificity and an amplified response upon subsequent exposure. Whereas adaptive immune cells have rearranged receptor genes to recognize the universe of antigens, natural killer (NK) cells are innate immune lymphocytes with a limited repertoire of germ-line encoded receptors for target recognition. NK cells also produce cytokines such as IFN-gamma (IFN-gamma) to protect the host during the innate response to infection. Herein, we show that cytokine-activated NK cells transferred into naïve hosts can be specifically detected 7-22 days later when they are phenotypically similar to naïve cells and are not constitutively producing IFN-gamma. However, they produce significantly more IFN-gamma when restimulated. This memory-like property is intrinsic to the NK cell. By contrast, memory-like NK cells do not express granzyme B protein and kill targets similarly to naïve NK cells. Thus, these experiments identify an ability of innate immune cells to retain an intrinsic memory of prior activation, a function until now attributed only to antigen-specific adaptive immune cells.
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127
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Abstract
Natural killer (NK) cells were discovered more than 30 years ago. NK cells are large granular lymphocytes that belong to the innate immune system because unlike T or B lymphocytes of the adaptive or antigen-specific immune system, NK cells do not rearrange T-cell receptor or immunoglobulin genes from their germline configuration. During the past 2 decades there has been a substantial gain in our understanding of what and how NK-cells "see," lending important insights into their functions and purpose in normal immune surveillance. The most recent discoveries in NK-cell receptor biology have fueled translational research that has led to remarkable results in treating human malignancy.
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128
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Abstract
The natural killer (NK)-cell immunological synapse is the dynamic interface formed between an NK cell and its target cell. Formation of the NK-cell immunological synapse involves several distinct stages, from the initiation of contact with a target cell to the directed delivery of lytic-granule contents for target-cell lysis. Progression through the individual stages is regulated, and this tight regulation underlies the precision with which NK cells select and kill susceptible target cells (including virally infected cells and cancerous cells) that they encounter during their routine surveillance of the body.
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Affiliation(s)
- Jordan S Orange
- University of Pennsylvania School of Medicine, Joseph Stokes Jr Research Institute of The Children's Hospital of Philadelphia, 3615 Civic Center Boulevard, ARC 1016H, Philadelphia, Pennsylvania 19104, USA.
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129
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Grzywacz B, Miller JS, Verneris MR. Use of natural killer cells as immunotherapy for leukaemia. Best Pract Res Clin Haematol 2008; 21:467-83. [PMID: 18790450 PMCID: PMC2615405 DOI: 10.1016/j.beha.2008.07.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Natural killer (NK) cells potentially play a significant role in eradicating residual disease following allogeneic haematopoietic cell transplantation, and have been explored as tools for adoptive immunotherapy for chemotherapy-refractory patients. NK cell cytotoxicity is modulated by multiple activating and inhibitory receptors that maintain a balance between self-tolerance and providing surveillance against pathogens and malignant transformation. The functional characteristics of NK cells are dictated by the strength of inhibitory receptor signalling. Major histocompatibility complex (MHC)-specific inhibitory receptor acquisition occurs sequentially during NK cell development, and is determined by the nature of immunological reconstitution after allogeneic haematopoietic cell transplantation. Polymorphisms of inhibitory receptors [killer immunoglobulin-like receptors (KIRs)] and their ligands (MHC) contribute to interindividual variability. As a result, the functional NK cell repertoire of individual donors has variable potential for graft-vs-leukaemia reactions. Models predicting NK cell alloreactivity, including KIR ligand mismatch and missing KIR ligand strategies, are discussed as algorithms for optimal NK cell donor selection. Future modifications to improve NK cell adoptive immunotherapy by means of increasing target recognition and reducing inhibitory signalling are being explored.
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Affiliation(s)
- Bartosz Grzywacz
- Department of Paediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, MN, USA
| | - Jeffrey S. Miller
- Department of Medicine, Division of Blood and Marrow Transplantation, University of Minnesota, MN, USA
| | - Michael R. Verneris
- Department of Paediatrics, Division of Blood and Marrow Transplantation, University of Minnesota, MN, USA
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130
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131
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Extrinsic and intrinsic regulation of early natural killer cell development. Immunol Res 2008; 40:193-207. [PMID: 18266115 DOI: 10.1007/s12026-007-8006-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Natural killer (NK) cells are lymphocytes that play a critical role in both adaptive and innate immune responses. These cells develop from multipotent progenitors in the embryonic thymus and neonatal or adult bone marrow and recent evidence suggests that a subset of these cells may develop in the thymus. Thymus- and bone marrow-derived NK cells have unique phenotypes and functional abilities supporting the hypothesis that the microenvironment dictates the outcome of NK cell development. A detailed understanding of the mechanisms controlling this developmental program will be required to determine how alterations in NK cell development lead to disease and to determine how to harness this developmental program for therapeutic purposes. In this review, we discuss some of the known extrinsic stromal-cell derived factors and cell intrinsic transcription factors that function in guiding NK cell development.
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132
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Natural killer cell-directed therapies: moving from unexpected results to successful strategies. Nat Immunol 2008; 9:486-94. [PMID: 18425105 DOI: 10.1038/ni1580] [Citation(s) in RCA: 220] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Natural killer (NK) cells influence innate and adaptive immune host defenses. Existing data indicate that manipulating the balance between inhibitory and activating NK receptor signals, the sensitivity of target cells to NK cell-mediated apoptosis, and NK cell cross-talk with dendritic cells might hold therapeutic promise. Efforts to modulate NK cell trafficking into inflamed tissues and/or lymph nodes, and to counteract NK cell suppressors, might also prove fruitful in the clinic. However, deeper investigation into the benefits of combination therapy, greater understanding of the functional distinctions between NK cell subsets, and design of new tools to monitor NK cell activity are needed to strengthen our ability to harness the power of NK cells for therapeutic aims.
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133
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Abstract
Natural killer (NK) cells are effector lymphocytes of the innate immune system that control several types of tumors and microbial infections by limiting their spread and subsequent tissue damage. Recent research highlights the fact that NK cells are also regulatory cells engaged in reciprocal interactions with dendritic cells, macrophages, T cells and endothelial cells. NK cells can thus limit or exacerbate immune responses. Although NK cells might appear to be redundant in several conditions of immune challenge in humans, NK cell manipulation seems to hold promise in efforts to improve hematopoietic and solid organ transplantation, promote antitumor immunotherapy and control inflammatory and autoimmune disorders.
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134
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A role for interleukin-12/23 in the maturation of human natural killer and CD56+ T cells in vivo. Blood 2008; 111:5008-16. [PMID: 18319400 DOI: 10.1182/blood-2007-11-122259] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Natural killer (NK) cells have been originally defined by their "naturally occurring" effector function. However, only a fraction of human NK cells is reactive toward a panel of prototypical tumor cell targets in vitro, both for the production of interferon-gamma (IFN-gamma) and for their cytotoxic response. In patients with IL12RB1 mutations that lead to a complete IL-12Rbeta1 deficiency, the size of this naturally reactive NK cell subset is diminished, in particular for the IFN-gamma production. Similar data were obtained from a patient with a complete deficit in IL-12p40. In addition, the size of the subset of effector memory T cells expressing CD56 was severely decreased in IL-12Rbeta1- and IL-12p40-deficient patients. Human NK cells thus require in vivo priming with IL-12/23 to acquire their full spectrum of functional reactivity, while T cells are dependent upon IL-12/23 signals for the differentiation and/or the maintenance of CD56(+) effector memory T cells. The susceptibility of IL-12/23 axis-deficient patients to Mycobacterium and Salmonella infections in combination with the absence of mycobacteriosis or salmonellosis in the rare cases of human NK cell deficiencies point to a role for CD56(+) T cells in the control of these infections in humans.
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135
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ATF3 regulates MCMV infection in mice by modulating IFN-gamma expression in natural killer cells. Proc Natl Acad Sci U S A 2008; 105:2544-9. [PMID: 18268321 DOI: 10.1073/pnas.0712182105] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Activating transcription factor 3 (ATF3) is a negative regulator of proinflammatory cytokine expression in macrophages, and ATF3-deficient mice are more susceptible to endotoxic shock. Here, we demonstrate that ATF3 interacts with a cis-regulatory element of the IFN-gamma gene in natural killer (NK) cells, and that ATF3null NK cells show increased transcription and secretion of IFN-gamma. NK cell-derived IFN-gamma has previously been demonstrated to be protective against murine cytomegalovirus (MCMV) infection, and we show here that ATF3null mice exhibit decreased hepatic viral load and reduced liver histopathology upon challenge with MCMV. Reconstitution of NK-deficient mice with ATF3null NK cells more effectively controlled MCMV infection than mice reconstituted with WT cells, indicating that ATF3 acts within NK cells to regulate antiviral responses.
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137
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Estefanía E, Gómez-Lozano N, Portero F, de Pablo R, Solís R, Sepúlveda S, Vaquero M, González MA, Suárez E, Roustán G, Vilches C. Influence of KIR gene diversity on the course of HSV-1 infection: resistance to the disease is associated with the absence of KIR2DL2 and KIR2DS2. ACTA ACUST UNITED AC 2007; 70:34-41. [PMID: 17559579 DOI: 10.1111/j.1399-0039.2007.00844.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herpes simplex virus type 1 (HSV-1) causes lifelong latent infections in most humans. Periodical virus reactivations from latency in the neurons of sensitive ganglia lead to transport to mucocutaneous regions and productive replication, which results in recurrent inflammatory herpetic lesions or in asymptomatic virus shedding. The medical consequences of such lesions and the frequency of recurrences vary greatly in different subjects. Furthermore, many infected individuals never suffer manifestations of the disease, even when exposed to stimuli that trigger clinical recurrences in other humans. The origin of the variability in the clinical course of HSV-1 infection remains unexplained. Herpesviruses and other pathogens sabotage the expression of major histocompatibility complex class I molecules by infected cells, thus subverting T-cell-mediated immunity. Subversion of antigen presentation is counteracted by natural killer cells, which survey the human leukocyte antigen (HLA) expression by specific receptors. These include the killer cell immunoglobulin-like receptors (KIRs), which are encoded by a complex of extremely diverse and rapidly evolving genes. Here, we analyze the contribution of KIR gene diversity to the variable clinical course of HSV-1 infection by comparing the distribution of these genes in humans with clinical manifestations of the disease with that in asymptomatically infected donors. This study provides preliminary evidence that the receptors KIR2DL2 and KIR2DS2 predispose to symptomatic HSV-1 infection and favor the frequently recurring forms of the disease. Possible contribution of the 'HLA-C1' ligand to HSV-1 disease was not statistically supported. Because of an absolute genetic linkage between KIR2DL2 and KIR2DS2, we could not determine which receptor was primarily responsible for the observed association, but our results suggest that presence in the genome of KIR2DL2 and KIR2DS2 hinders an effective cellular response to HSV-1.
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Affiliation(s)
- E Estefanía
- Department of Immunology, Hospital Universitario Puerta de Hierro, Universidad Autónoma de Madrid, San Martin de Porres 4, 28035 Madrid, Spain
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138
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Bryceson YT, Rudd E, Zheng C, Edner J, Ma D, Wood SM, Bechensteen AG, Boelens JJ, Celkan T, Farah RA, Hultenby K, Winiarski J, Roche PA, Nordenskjöld M, Henter JI, Long EO, Ljunggren HG. Defective cytotoxic lymphocyte degranulation in syntaxin-11 deficient familial hemophagocytic lymphohistiocytosis 4 (FHL4) patients. Blood 2007; 110:1906-15. [PMID: 17525286 PMCID: PMC1976360 DOI: 10.1182/blood-2007-02-074468] [Citation(s) in RCA: 219] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Accepted: 05/11/2007] [Indexed: 12/27/2022] Open
Abstract
Familial hemophagocytic lymphohistiocytosis (FHL) is typically an early onset, fatal disease characterized by a sepsislike illness with cytopenia, hepatosplenomegaly, and deficient lymphocyte cytotoxicity. Disease-causing mutations have been identified in genes encoding perforin (PRF1/FHL2), Munc13-4 (UNC13D/FHL3), and syntaxin-11 (STX11/FHL4). In contrast to mutations leading to loss of perforin and Munc13-4 function, it is unclear how syntaxin-11 loss-of-function mutations contribute to disease. We show here that freshly isolated, resting natural killer (NK) cells and CD8(+) T cells express syntaxin-11. In infants, NK cells are the predominant perforin-containing cell type. NK cells from FHL4 patients fail to degranulate when encountering susceptible target cells. Unexpectedly, IL-2 stimulation partially restores degranulation and cytotoxicity by NK cells, which could explain the less severe disease progression observed in FHL4 patients, compared with FHL2 and FHL3 patients. Since the effector T-cell compartment is still immature in infants, our data suggest that the observed defect in NK-cell degranulation may contribute to the pathophysiology of FHL, that evaluation of NK-cell degranulation in suspected FHL patients may facilitate diagnosis, and that these new insights may offer novel therapeutic possibilities.
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Affiliation(s)
- Yenan T Bryceson
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
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139
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Lee SH, Miyagi T, Biron CA. Keeping NK cells in highly regulated antiviral warfare. Trends Immunol 2007; 28:252-9. [PMID: 17466596 DOI: 10.1016/j.it.2007.04.001] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 03/19/2007] [Accepted: 04/16/2007] [Indexed: 02/08/2023]
Abstract
Natural killer (NK) cells use multiple mechanisms to defend against viral infections, and different stimuli can activate these antiviral effects. When engaged, receptors for innate cytokines produced during infections and for ligands on target cells can both induce NK cell cytotoxicity and the production of cytokines. These stimuli use different classes of intracellular signaling pathways to elicit the overlapping responses. What is the advantage of using different roads to the same ends? One answer might be in the nature of the alternative regulatory pathways that are in place to control the respective stimuli. A model of flexibility in accessing NK cell function, in the context of negative regulation of particular intracellular signaling pathways, is proposed here.
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Affiliation(s)
- Seung-Hwan Lee
- Department of Molecular Microbiology and Immunology, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA
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140
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Carneiro-Sampaio M, Coutinho A. Immunity to microbes: lessons from primary immunodeficiencies. Infect Immun 2007; 75:1545-55. [PMID: 17283094 PMCID: PMC1865715 DOI: 10.1128/iai.00787-06] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Magda Carneiro-Sampaio
- Children's Hospital, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Enéas Carvalho Aguiar 647, 05403-900 São Paulo, Brazil.
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141
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Fleisher TA. Evaluation of suspected immunodeficiency. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 601:291-300. [PMID: 17713017 DOI: 10.1007/978-0-387-72005-0_31] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The clinical utility and capacity to evaluate immunologic function has evolved significantly over the past few decades. This chapter summarizes screening methods and more sophisticated approaches to assess the immune system when there is a suspicion of an immune deficiency.
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Affiliation(s)
- Thomas A Fleisher
- Department of Laboratory Medicine, NIH Clinical Center, National Institutes of Health, DHHS, Bethesda, MD, USA.
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142
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Orange JS. The lytic NK cell immunological synapse and sequential steps in its formation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 601:225-33. [PMID: 17713009 DOI: 10.1007/978-0-387-72005-0_23] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Natural killer (NK) cells are lymphocytes of the innate immune system that are critical in host defense. They are best known for their ability to mediate cytotoxicity, which involves a coordinated series of events resulting in the directed secretion of lytic granules onto a target cell. This process requires the formation of an immunological synapse in NK cells. The NK cell immunological synapse involves the reorganization of the actin cytoskeleton and clustering of certain cell surface receptors in the NK cell at the interface with the target cell. The lytic NK cell immunological synapse, specialized for mediating cytotoxicity, is further distinguished by the polarization of lytic granules, which are then secreted through this region onto the target cell. These events unfold in a definitive sequence and lead to critical checkpoints that provide regulatory control at specific stages in the formation of the NK cell lytic synapse.
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Affiliation(s)
- Jordan S Orange
- University of Pennsylvania School of Medicine, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
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