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Abstract
PURPOSE OF REVIEW We summarize what is known about neutrophils in HIV infection, focusing on their potential roles in HIV protection, acquisition, and pathogenesis. RECENT FINDINGS Recent studies have demonstrated that neutrophil-associated proteins and cytokines in genital tissue pre-infection associate with HIV acquisition. However, recent in vivo assessment of highly exposed seronegative individuals and in vitro studies of anti-HIV functions of neutrophils add to older literature evidence that neutrophils may be important in a protective response to HIV infection. Neutrophils are important for containment of pathogens but can also contribute to tissue damage due to their release of reactive oxygen species, proteases, and other potentially harmful effector molecules. Overall, there is a clear evidence for both helpful and harmful roles of neutrophils in HIV acquisition and pathogenesis. Further study, particularly of tissue neutrophils, is needed to elucidate the kinetics, phenotype, and functionality of neutrophils in HIV infection to better understand this dichotomy.
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2
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Yaseen MM, Abuharfeil NM, Yaseen MM, Shabsoug BM. The role of polymorphonuclear neutrophils during HIV-1 infection. Arch Virol 2017; 163:1-21. [PMID: 28980078 DOI: 10.1007/s00705-017-3569-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/14/2017] [Indexed: 12/23/2022]
Abstract
It is well-recognized that human immunodeficiency virus type-1 (HIV-1) mainly targets CD4+ T cells and macrophages. Nonetheless, during the past three decades, a huge number of studies have reported that HIV-1 can directly or indirectly target other cellular components of the immune system including CD8+ T cells, B cells, dendritic cells, natural killer cells, and polymorphonuclear neutrophils (PMNs), among others. PMNs are the most abundant leukocytes in the human circulation, and are known to play principal roles in the elimination of invading pathogens, regulating different immune responses, healing of injured tissues, and maintaining mucosal homeostasis. Until recently, little was known about the impact of HIV-1 infection on PMNs as well as the impact of PMNs on HIV-1 disease progression. This is because early studies focused on neutropenia and recurrent microbial infections, particularly, during advanced disease. However, recent studies have extended the investigation area to cover new aspects of the interactions between HIV-1 and PMNs. This review aims to summarize these advances and address the impact of HIV-1 infection on PMNs as well as the impact of PMNs on HIV-1 disease progression to better understand the pathophysiology of HIV-1 infection.
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Affiliation(s)
- Mahmoud Mohammad Yaseen
- Medical Laboratory Sciences, College of Applied Medical Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan.
| | - Nizar Mohammad Abuharfeil
- Applied Biological Sciences, College of Science and Arts, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Mohammad Mahmoud Yaseen
- Public Health, College of Medicine, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Barakat Mohammad Shabsoug
- Chemical Sciences, College of Science and Arts, Jordan University of Science and Technology, Irbid, 22110, Jordan
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3
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Miralda I, Uriarte SM, McLeish KR. Multiple Phenotypic Changes Define Neutrophil Priming. Front Cell Infect Microbiol 2017; 7:217. [PMID: 28611952 PMCID: PMC5447094 DOI: 10.3389/fcimb.2017.00217] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 05/11/2017] [Indexed: 12/15/2022] Open
Abstract
Exposure to pro-inflammatory cytokines, chemokines, mitochondrial contents, and bacterial and viral products induces neutrophils to transition from a basal state into a primed one, which is currently defined as an enhanced response to activating stimuli. Although, typically associated with enhanced generation of reactive oxygen species (ROS) by the NADPH oxidase, primed neutrophils show enhanced responsiveness of exocytosis, NET formation, and chemotaxis. Phenotypic changes associated with priming also include activation of a subset of functions, including adhesion, transcription, metabolism, and rate of apoptosis. This review summarizes the breadth of phenotypic changes associated with priming and reviews current knowledge of the molecular mechanisms behind those changes. We conclude that the current definition of priming is too restrictive. Priming represents a combination of enhanced responsiveness and activated functions that regulate both adaptive and innate immune responses.
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Affiliation(s)
- Irina Miralda
- Department of Microbiology, University of Louisville School of MedicineLouisville, KY, United States
| | - Silvia M Uriarte
- Department of Microbiology, University of Louisville School of MedicineLouisville, KY, United States.,Department of Medicine, University of Louisville School of MedicineLouisville, KY, United States
| | - Kenneth R McLeish
- Department of Medicine, University of Louisville School of MedicineLouisville, KY, United States.,Robley Rex VA Medical CenterLouisville, KY, United States
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4
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Younas M, Psomas C, Reynes J, Corbeau P. Immune activation in the course of HIV-1 infection: Causes, phenotypes and persistence under therapy. HIV Med 2015; 17:89-105. [PMID: 26452565 DOI: 10.1111/hiv.12310] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2015] [Indexed: 12/31/2022]
Abstract
Systemic immune activation is a striking consequence of HIV-1 infection. Even in virologically suppressed patients, some hyperactivity of the immune system and even of the endothelium and of the coagulation pathway may persist. Apart from immune deficiency, this chronic activation may contribute to various morbidities including atherothrombosis, neurocognitive disorders, liver steatosis and osteoporosis, which are currently main challenges. It is therefore of major importance to better understand the causes and the phenotypes of immune activation in the course of HIV-1 infection. In this review we will discuss the various causes of immune activation in HIV-1 infected organisms: the presence of the virus together with other microbes, eventually coming from the gut, CD4+ T cell lymphopenia, senescence and dysregulation of the immune system, and/or genetic factors. We will also describe the activation of the immune system: CD4+ and CD8+ T cells, B cells, NKT and NK cells, dendritic cells, monocytes and macrophages, and neutrophils of the inflammation cascade, as well as of the endothelium and the coagulation system. Finally, we will see that antiretroviral therapy reduces the hyperactivity of the immune and coagulation systems and the endothelial dysfunction, but often does not abolish it. A better knowledge of this phenomenon might help us to identify biomarkers predictive of non AIDS-linked comorbidities, and to define new strategies aiming at preventing their emergence.
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Affiliation(s)
- M Younas
- Institute of Human Genetics, CNRS UPR1142, Montpellier Cedex 5, France
| | - C Psomas
- Infectious Diseases Department, University Hospital, Montpellier Cedex 5, France.,UMI 233, IRD-Montpellier University, Montpellier Cedex 5, France
| | - J Reynes
- Infectious Diseases Department, University Hospital, Montpellier Cedex 5, France.,UMI 233, IRD-Montpellier University, Montpellier Cedex 5, France.,Montpellier University, Montpellier, France
| | - P Corbeau
- Institute of Human Genetics, CNRS UPR1142, Montpellier Cedex 5, France.,Montpellier University, Montpellier, France.,Immunology Department, University Hospital, Nîmes Cedex, France
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5
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Manna PP, Hira SK, Das AA, Bandyopadhyay S, Gupta KK. IL-15 activated human peripheral blood dendritic cell kill allogeneic and xenogeneic endothelial cells via apoptosis. Cytokine 2012; 61:118-26. [PMID: 23058476 DOI: 10.1016/j.cyto.2012.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 07/15/2012] [Accepted: 09/07/2012] [Indexed: 11/26/2022]
Abstract
IL-15 is a pleotropic cytokine, which plays an important role in natural killer (NK) cell activity, T cell proliferation, and T cell cytotoxic activity. Dendritic cells (DCs) are the major antigen presenting cells in the immune system and presumed to play an important role in immune recognition of allo and xenotransplantation. We showed that IL-15 activated human peripheral blood DC is cytotoxic to human and porcine aortic endothelial cells. Unlike DCs, CD14+ monocytes show no cytotoxicity against the endothelial cells. This cytotoxic potential of IL-15 activated DC against endothelial cells is dose dependent and increases significantly upon treatment of endothelial cells with inflammatory cytokines like TNF-α or IFN-γ. The cytotoxic potential of IL-15 activated DC is associated with apoptosis of endothelial cells, as indicated by the increased Annexin V staining, caspase activation and loss of mitochondrial membrane potential. Further it was observed that DC mediated cytotoxicity against endothelial cell is mediated via granzyme B possibly secreted by the activated DCs.
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Affiliation(s)
- Partha Pratim Manna
- Immunobiology Laboratory, Banaras Hindu University, Varanasi 221 005, India.
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6
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Abdul-Careem MF, Mian MF, Yue G, Gillgrass A, Chenoweth MJ, Barra NG, Chew MV, Chan T, Al-Garawi AA, Jordana M, Ashkar AA. Critical role of natural killer cells in lung immunopathology during influenza infection in mice. J Infect Dis 2012; 206:167-77. [PMID: 22561366 DOI: 10.1093/infdis/jis340] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Influenza viral infection results in excessive pulmonary inflammation that has been linked to the damage caused by immune responses and viral replication. The multifunctional cytokine interleukin (IL-15), influences the proliferation and maintenance of immune cells such as CD8(+) T cells and natural killer (NK) cells. Here we show that IL-15(-/-) mice are protected from lethal influenza infection. Irrespective of the mouse strains, the protection observed was linked to the lack of NK cells. Increased survival in the IL-15(-/-) or NK1.1(+) cell-depleted wild-type mice was associated with significantly lower lung lesions as well as decreased mononuclear cells and neutrophils in the airway lumen. Levels of interleukin 10 were significantly higher and levels of proinflammatory cytokines, including interleukin 6 and interleukin 12, were significantly lower in the bronchoalveolar lavage fluid from IL-15(-/-) and NK1.1(+) cell-depleted wild-type mice than in that from control mice. Our data suggest that NK cells significantly augment pulmonary inflammation, contributing to the pathogenesis of influenza infection.
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Affiliation(s)
- Mohamed F Abdul-Careem
- McMaster Immunology Research Centre and Institute for Infectious Diseases Research, Department of Pathology and Molecular Medicine, McMaster University Health Sciences Center, Hamilton, Ontario, Canada
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7
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Abstract
Cytokines are involved early in the pathogenesis of HIV infection and disease progression as a component of immunologic dysregulation and immunodeficiency and as determinants controlling virus replication. Several steps, before and after retroviral integration into host DNA in T cells and macrophages, are affected by cytokines whereas CCR5 and CXCR4 binding chemokines can interfere with viral entry. A growing number of potential players--including the gamma-common interleukin (IL)-7, IL-15, and IL-21 together with IL-17, IL-18, IL-19, IL-20, IL-23, and IL-27--are discussed in terms of their perturbation in HIV infection and of their effects on virus replication. Thus, an increasing intersection of HIV infection and the cytokine network represents a crucial determinant of virus replication and immunologic dysregulation and will likely play a key role in the development of effective strategies of HIV prevention and immunologic reconstitution.
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Affiliation(s)
- Massimo Alfano
- P2/P3 Laboratories, DIBIT, Via Olgettina n. 58, 20132, Milano, Italy
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8
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Interleukin-15 increases Paracoccidioides brasiliensis killing by human neutrophils. Cytokine 2008; 41:48-53. [DOI: 10.1016/j.cyto.2007.10.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 09/19/2007] [Accepted: 10/25/2007] [Indexed: 11/17/2022]
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9
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Gill N, Ashkar AA. Adaptive immune responses fail to provide protection against genital HSV-2 infection in the absence of IL-15. Eur J Immunol 2007; 37:2529-38. [PMID: 17668897 DOI: 10.1002/eji.200636997] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
IL-15 plays a crucial role in innate defense against viral infections. The role of IL-15 in the generation and function of adaptive immunity, following mucosal immunization, against genital HSV-2 has not been studied. Here, we report that immunized IL-15(-/-) mice were able to generate antibody and T cell-mediated immune responses against HSV-2, comparable to those seen in immunized B6 mice. However, immunized IL-15(-/-) mice were not protected against subsequent HSV-2 challenge, compared to B6 immunized mice, even with a ten times lower challenge dose. We then examined if the adaptive immune responses generated in the absence of IL-15 could provide protection against HSV-2 in an IL-15-positive environment. Adoptive transfer of lymphocytes from immunized IL-15(-/-) to naive mice were able to provide protection against HSV-2 challenge similar to protection with immunized cells from control mice. This suggests that the adaptive immune responses raised in the absence of IL-15 are functional in vivo. Reconstitution of the innate components, particularly IL-15, NK cells and NK cell-derived IFN-gamma, in immunized IL-15(-/-) mice restored their protective adaptive immunity against subsequent genital HSV-2 challenge. Our results clearly suggest that innate antiviral activity of IL-15 is necessary for protective adaptive immunity against genital HSV-2 infection.
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Affiliation(s)
- Navkiran Gill
- Centre for Gene Therapeutics, Department of Pathology and Molecular Medicine, McMaster University Health Sciences Centre, Hamilton, Ontario, Canada
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10
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Heit B, Jones G, Knight D, Antony JM, Gill MJ, Brown C, Power C, Kubes P. HIV and other lentiviral infections cause defects in neutrophil chemotaxis, recruitment, and cell structure: immunorestorative effects of granulocyte-macrophage colony-stimulating factor. THE JOURNAL OF IMMUNOLOGY 2006; 177:6405-14. [PMID: 17056572 DOI: 10.4049/jimmunol.177.9.6405] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Patients with HIV infection exhibit deficits in bacterial and fungal clearance, and possibly depressed innate immunity. In this study, we observed that neutrophils from HIV-infected patients have a profound defect in chemotaxis in response to endogenous (IL-8) and bacterial (fMLP) chemoattractants, which was directly correlated with peripheral CD4(+) lymphocyte levels but not plasma viral load. A similar chemotactic defect was observed in the feline immunodeficiency virus (FIV) model of HIV infection. Intravital microscopy of FIV-infected animals revealed marked impairment in the in vivo recruitment of leukocytes; specifically integrin-dependent neutrophil adhesion and emigration induced by bacterial products. Treatment of FIV-infected animals with GM-CSF re-established both neutrophil recruitment (rolling, adhesion, and emigration) and in vitro chemotaxis to the levels seen in uninfected animals. This restoration of neutrophil responses was not due to GM-CSF-mediated priming. Rather, HIV and FIV infections resulted in defective neutrophil development, with an ensuing reduction in neutrophil granularity and chemotactic receptor expression. GM-CSF therapy restored neutrophil granularity, implying restoration of normal neutrophil development. Together, our findings underscore the fundamental defects in innate immunity caused by lentivirus infections, while also indicating that GM-CSF may be a potential immunorestorative therapy for HIV-infected patients.
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Affiliation(s)
- Bryan Heit
- Immunology Research Group, Department of Physiology and Biophysics, University of Calgary, 3330 Hospital Drive Northwest, Calgary, Alberta, Canada T2N 4N1
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11
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Stoklasek TA, Schluns KS, Lefrançois L. Combined IL-15/IL-15Ralpha immunotherapy maximizes IL-15 activity in vivo. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2006; 177:6072-80. [PMID: 17056533 PMCID: PMC2847275 DOI: 10.4049/jimmunol.177.9.6072] [Citation(s) in RCA: 289] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-15 has substantial potential as an immunotherapeutic agent for augmenting immune responses. However, the activity of IL-15 is mediated by a unique mechanism in which the cytokine is transpresented by cell-bound high-affinity IL-15Ralpha to target cells expressing the IL-15Rbeta and the common gamma-chain. Thus, the efficacy of administered IL-15 alone may be limited by the availability of free IL-15Ralpha. We now show that administration of soluble IL-15/IL-15Ralpha complexes greatly enhanced IL-15 half-life and bioavailability in vivo. Treatment of mice with this complex, but not with IL-15 alone, resulted in robust proliferation of memory CD8 T cells, NK cells, and NK T cells. The activity of the complex required IL-15Rbeta, but not IL-15Ralpha, expression by the responding cells and was IL-7-independent. Interestingly, IL-15/IL-15Ralpha immunotherapy also caused naive CD8 T cell activation and development into effector cells and long-term memory T cells. Lastly, complexed IL-15, as compared with IL-15 alone, dramatically reduced tumor burden in a model of B16 melanoma. These findings hold significant importance for the use of IL-15 as a potential adjuvant/therapeutic and inducer of homeostatic proliferation, without the necessity for prior immunodepletion.
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Affiliation(s)
- Thomas A. Stoklasek
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
| | | | - Leo Lefrançois
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030
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12
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Alfano M, Poli G. Role of cytokines and chemokines in the regulation of innate immunity and HIV infection. Mol Immunol 2005; 42:161-82. [PMID: 15488606 DOI: 10.1016/j.molimm.2004.06.016] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The earliest defense against microbial infection is represented by the responses of the innate (or natural) immune system, that also profoundly regulates the adaptive (or acquired) T- and B-cell immune responses. Activation of the innate immune system is primed by microbial invasion in response to conserved structures present in large groups of microorganisms (LPS, peptidoglycan, double-stranded RNA), and is finely tuned by different cell types (including dendritic cells, macrophages, natural killer cells, natural killer T cells, and gammadelta T cells). In addition, several soluble factors (complement components, defensins, mannose-binding lectins, interferons, cytokines and chemokines) can play a major role in the regulation of both the innate and adaptive immunity. In this review, we will briefly overview the regulation of some cellular subsets of the innate immune system particularly involved in human immunodeficiency virus (HIV) infection and then focus our attention on those cytokines and chemokines whose levels of expression are more profoundly affected by HIV infection and that, conversely, can modulate virus infection and replication.
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Affiliation(s)
- Massimo Alfano
- AIDS Immunopathogenesis Unit, San Raffaele Scientific Institute, P2-P3 Laboratories, DIBIT, Via Olgettina no. 58, 20132 Milano, Italy
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13
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Mastroianni CM, d'Ettorre G, Forcina G, Vullo V. Teaching tired T cells to fight HIV: time to test IL-15 for immunotherapy? Trends Immunol 2004; 25:121-5. [PMID: 15036038 DOI: 10.1016/j.it.2004.01.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Claudio M Mastroianni
- Department of Infectious and Tropical Diseases, La Sapienza University, Viale del Policlinico 155, 00161 Rome, Italy.
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14
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Kubes P, Heit B, van Marle G, Johnston JB, Knight D, Khan A, Power C. In vivo impairment of neutrophil recruitment during lentivirus infection. THE JOURNAL OF IMMUNOLOGY 2004; 171:4801-8. [PMID: 14568958 DOI: 10.4049/jimmunol.171.9.4801] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Evidence indicates that the lentivirus, HIV, infection affects neutrophil response to bacteria and bacterial products in vitro. We used a novel model of rapid onset immunosuppression following infection with a similar lentivirus, feline immunodeficiency virus (FIV), in cats to examine neutrophil function within the microvasculature in vivo and to determine the steps that are impaired in the neutrophil recruitment cascade. In uninfected cats and cats infected neonatally with FIV, the mesentery was exteriorized, but remained autoperfused during intravital microscopy for 4 h. When the tissue was superfused with 10 micro g/ml of LPS for 4 h, intravital microscopy displayed a profound increase in neutrophil rolling at both 8 and 12 wk of age in uninfected cats. At 12 wk of age, FIV-infected animals showed a profound decrease in the number of rolling neutrophils. In vitro studies revealed that neutrophils from infected and uninfected animals rolled equally well on surrogate selectin substrata. In addition, in vivo neutrophil adhesion and emigration out of the vasculature were severely reduced, and in vitro neutrophil chemotaxis from FIV-infected animals was significantly impaired in response to fMLP or IL-8. However, FIV infection of neutrophils could not be detected. In summary, in vivo lentivirus infection with immunosuppression leads to a severe impairment in neutrophil rolling, adhesion, and emigration in response to bacterial stimulants potentially involving both endothelial and neutrophil dysfunction. These in vivo studies also indicate that neutrophil dysfunction should be taken into account when treating infections and tissue injury.
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Affiliation(s)
- Paul Kubes
- Department of Physiology and Biophysics, University of Calgary, Alberta, Canada.
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15
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d'Ettorre G, Forcina G, Lichtner M, Mengoni F, D'Agostino C, Massetti AP, Mastroianni CM, Vullo V. Interleukin-15 in HIV infection: immunological and virological interactions in antiretroviral-naive and -treated patients. AIDS 2002; 16:181-8. [PMID: 11807301 DOI: 10.1097/00002030-200201250-00006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the immunological and virological interactions between interleukin (IL)-15 and HIV in antiretroviral-naive and highly active antiretroviral therapy (HAART)-treated patients. DESIGN Three groups of HIV-infected patients were studied: 20 untreated patients with advanced disease; eight patients with viral suppression and immunological response to HAART; and 10 patients with virological and immunological treatment failure. Eleven healthy blood donors were included as controls. METHODS The following parameters were evaluated: the production of IL-15 by peripheral blood mononuclear cells (PBMC) stimulated with lipopolysaccharide,Candida albicans and Mycobacterium avium complex; the ability of IL-15 to induce the secretion of IL-8 and monocyte chemotactic protein-1 (MCP-1) from HIV-positive monocytes; and the virological effect of IL-15 and IL-2 on HIV replication in mononuclear cells. RESULTS IL-15 production by PBMC was significantly decreased in antiretroviral-naive patients and in those with treatment failure. On the contrary, in patients with response to HAART IL-15 production was comparable to that of healthy donors. IL-15 was able to stimulate HIV-positive monocytes to produce chemokines, such as IL-8 and MCP-1, that specifically attract neutrophils and monocytes to the site of inflammation thus possibly improving immune response to pathogens during HIV infection. Finally, IL-15 had no major effect on HIV replication in vitro, while only simultaneous administration with IL-2 may induce high levels of HIV production. CONCLUSIONS This in vitro study provides new insights in the area of IL-15-HIV interactions and suggests that IL-15 may represent a potential candidate for cytokine treatment in combination with HAART during HIV infection.
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Affiliation(s)
- Gabriella d'Ettorre
- Department of Infectious and Tropical Diseases, La Sapienza University of Rome, Italy
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16
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Rutella S, Pierelli L, Bonanno G, Mariotti A, Sica S, Sorà F, Chiusolo P, Scambia G, Rumi C, Leone G. Immune reconstitution after autologous peripheral blood progenitor cell transplantation: effect of interleukin-15 on T-cell survival and effector functions. Exp Hematol 2001; 29:1503-16. [PMID: 11750110 DOI: 10.1016/s0301-472x(01)00747-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the occurrence of T-cell spontaneous apoptosis (A(spont)) and its modulation in vitro by the interleukin-2 receptor (IL-2R) gamma-chain (gammac)-signaling cytokine IL-15 in patients transplanted with autologous peripheral blood progenitor cells (PBPC) for hematologic malignancies. MATERIALS AND METHODS Patients were examined on days 30-60, 60-90, and 90-120 after PBPC infusion. Dissipation of mitochondrial transmembrane potential, a hallmark of T-cell apoptosis, has been detected using the fluorescent probe 3,3'-dihexyloxacarbocyanine iodide, after short-term T-cell culture in the absence or presence of exogenous cytokines. Expression of Bcl-2 family members has been studied by flow cytometry and reverse transcriptase polymerase chain reaction. T-cell proliferative responses to recall antigens have been estimated in autologous mixed leukocyte cultures. RESULTS A(spont) was seen in 45% +/- 6% of CD4(+) and 55% +/- 6% of CD8(+) T cells cultured in the absence of cytokines. Of interest, IL-15 and, to a lesser extent, its structural cousin IL-2 counteracted T-cell A(spont) by inhibiting the processing of caspase-3 and up-regulating Bcl-2 mRNA and protein levels. Cell division tracking confirmed that IL-15 did not rescue T cells from A(spont) by promoting proliferation but rather acted as a genuine survival factor. Addition of a gammac-blocking antibody to cytokine-conditioned cultures abrogated both apoptosis inhibition and Bcl-2 induction by IL-15, suggesting involvement of the IL-2Rgammac signal transduction pathway. Whereas cytokine-unprimed posttransplant T cells mounted inadequate responses to recall antigens, T cells conditioned with IL-15 expanded vigorously, indicating restoration of antigen-specific proliferation. CONCLUSIONS T cells recovering after autologous PBPC transplantation are highly susceptible to spontaneous apoptosis in vitro. This phenomenon can be counteracted by the gammac-signaling cytokine IL-15. These findings suggest that IL-15 might be a promising immunomodulating agent to improve postgrafting T-cell function.
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Affiliation(s)
- S Rutella
- Department of Hematology, Catholic University Medical School, Rome, Italy.
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