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Baharom F, Rankin G, Blomberg A, Smed-Sörensen A. Human Lung Mononuclear Phagocytes in Health and Disease. Front Immunol 2017; 8:499. [PMID: 28507549 PMCID: PMC5410584 DOI: 10.3389/fimmu.2017.00499] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/11/2017] [Indexed: 12/17/2022] Open
Abstract
The lungs are vulnerable to attack by respiratory insults such as toxins, allergens, and pathogens, given their continuous exposure to the air we breathe. Our immune system has evolved to provide protection against an array of potential threats without causing collateral damage to the lung tissue. In order to swiftly detect invading pathogens, monocytes, macrophages, and dendritic cells (DCs)-together termed mononuclear phagocytes (MNPs)-line the respiratory tract with the key task of surveying the lung microenvironment in order to discriminate between harmless and harmful antigens and initiate immune responses when necessary. Each cell type excels at specific tasks: monocytes produce large amounts of cytokines, macrophages are highly phagocytic, whereas DCs excel at activating naïve T cells. Extensive studies in murine models have established a division of labor between the different populations of MNPs at steady state and during infection or inflammation. However, a translation of important findings in mice is only beginning to be explored in humans, given the challenge of working with rare cells in inaccessible human tissues. Important progress has been made in recent years on the phenotype and function of human lung MNPs. In addition to a substantial population of alveolar macrophages, three subsets of DCs have been identified in the human airways at steady state. More recently, monocyte-derived cells have also been described in healthy human lungs. Depending on the source of samples, such as lung tissue resections or bronchoalveolar lavage, the specific subsets of MNPs recovered may differ. This review provides an update on existing studies investigating human respiratory MNP populations during health and disease. Often, inflammatory MNPs are found to accumulate in the lungs of patients with pulmonary conditions. In respiratory infections or inflammatory diseases, this may contribute to disease severity, but in cancer patients this may improve clinical outcomes. By expanding on this knowledge, specific lung MNPs may be targeted or modulated in order to attain favorable responses that can improve preventive or treatment strategies against respiratory infections, lung cancer, or lung inflammatory diseases.
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Affiliation(s)
- Faezzah Baharom
- Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Gregory Rankin
- Department of Public Health and Clinical Medicine, Division of Medicine, Umeå University, Umeå, Sweden
| | - Anders Blomberg
- Department of Public Health and Clinical Medicine, Division of Medicine, Umeå University, Umeå, Sweden
| | - Anna Smed-Sörensen
- Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
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Blank F, von Garnier C, Obregon C, Rothen-Rutishauser B, Gehr P, Nicod L. Role of dendritic cells in the lung: in vitro models, animal models and human studies. Expert Rev Respir Med 2010; 2:215-33. [PMID: 20477250 DOI: 10.1586/17476348.2.2.215] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Dendritic cells (DCs) are the most potent antigen-presenting cells in the human lung and are now recognized as crucial initiators of immune responses in general. They are arranged as sentinels in a dense surveillance network inside and below the epithelium of the airways and alveoli, where they are ideally situated to sample inhaled antigen. DCs are known to play a pivotal role in maintaining the balance between tolerance and active immune response in the respiratory system. It is no surprise that the lungs became a main focus of DC-related investigations as this organ provides a large interface for interactions of inhaled antigens with the human body. During recent years there has been a constantly growing body of lung DC-related publications that draw their data from in vitro models, animal models and human studies. This review focuses on the biology and functions of different DC populations in the lung and highlights the advantages and drawbacks of different models with which to study the role of lung DCs. Furthermore, we present a number of up-to-date visualization techniques to characterize DC-related cell interactions in vitro and/or in vivo.
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Affiliation(s)
- Fabian Blank
- Institute of Anatomy, Division of Histology, University of Berne, Baltzerstrasse 2, CH-3000 Berne 9, Switzerland.
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Zaba LC, Smith GP, Sanchez M, Prystowsky SD. Dendritic cells in the pathogenesis of sarcoidosis. Am J Respir Cell Mol Biol 2009; 42:32-9. [PMID: 19372243 DOI: 10.1165/rcmb.2009-0033tr] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Sarcoidosis is a noncaseating granulomatous disease, likely of autoimmune etiology, that causes inflammation and tissue damage in multiple organs, most commonly the lung, but also skin, and lymph nodes. Reduced dendritic cell (DC) function in sarcoidosis peripheral blood compared with peripheral blood from control subjects suggests that blunted end organ cellular immunity may contribute to sarcoidosis pathogenesis. Successful treatment of sarcoidosis with tumor necrosis factor (TNF) inhibitors, which modulate DC maturation and migration, has also been reported. Together, these observations suggest that DCs may be important mediators of sarcoidosis immunology. This review focuses on the phenotype and function of DCs in the lung, skin, blood, and lymph node of patients with sarcoidosis. We conclude that DCs in end organs are phenotypically and functionally immature (anergic), while DCs in the lymph node are mature and polarize pathogenic Th1 T cells. The success of TNF inhibitors is thus likely secondary to inhibition of DC-mediated Th1 polarization in the lymph node.
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Affiliation(s)
- Lisa C Zaba
- Laboratory for Investigative Dermatology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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MÖLLER GM, OVERBBEK SE, VAN HELDEN-MEEUWSEN CG, VAN HAARST JMW, PRENS EP, MULDER PG, POSTMA DS, HOOGSTEDEN HC. Increased numbers of dendritic cells in the bronchial mucosa of atopic asthmatic patients: downregulation by inhaled corticosteroids. Clin Exp Allergy 2006. [DOI: 10.1111/j.1365-2222.1996.tb00571.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bleier JI, Pillarisetty VG, Shah AB, DeMatteo RP. Increased and long-term generation of dendritic cells with reduced function from IL-6-deficient bone marrow. THE JOURNAL OF IMMUNOLOGY 2004; 172:7408-16. [PMID: 15187118 DOI: 10.4049/jimmunol.172.12.7408] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The importance of IL-6 in dendritic cell (DC) development and function has not been well defined. To establish the role of IL-6, we studied bone marrow-derived DC (BMDC) and freshly isolated splenic DC from IL-6(-/-)-transgenic mice. We found that although IL-6(-/-) bone marrow had a similar composition to that of wild-type (WT) mice, it generated up to 10 times more DC when cultured in GM-CSF. The difference persisted even when IL-6(-/-) and WT bone marrow were cultured together, excluding the possibility that the effects were simply due to different cytokine microenvironments. In comparison to WT BMDC, IL-6(-/-) BMDC captured at least as much Ag, had an equivalent surface phenotype, and matured similarly in response to LPS or CpG. However, IL-6(-/-) BMDC induced less T cell allostimulation and Ag-specific T cell activation, but only the former was related to their inability to generate IL-6. Although WT bone marrow cultures died within 4 wk, IL-6(-/-) cultures continued to generate BMDC for >120 days, although the BMDC became immature and less functional. In vivo, we found that IL-6(-/-) mice had similar numbers and types of splenic DC as WT mice, both normally and after treatment with either Flt-3 ligand or GM-CSF. These findings demonstrate that IL-6 has profound effects on DC development in vitro, although the number and subtype composition of DC are unaffected by the absence of IL-6 in vivo. Furthermore, secretion of IL-6 is critical to certain DC functions.
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Affiliation(s)
- Joshua I Bleier
- Hepatobiliary Service, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10024, USA
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Stumbles PA, Upham JW, Holt PG. Airway dendritic cells: co-ordinators of immunological homeostasis and immunity in the respiratory tract. APMIS 2003; 111:741-55. [PMID: 12974776 DOI: 10.1034/j.1600-0463.2003.11107806.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The large quantities and complex mixtures of antigens encountered daily at airway mucosal and alveolar surfaces pose a major challenge to maintenance of immunological homeostasis in the respiratory tract. Amongst this myriad of antigens, the immune system must discriminate between innocuous components that can be tolerated by the host and potentially life-threatening pathogens that require a rapid immune response. Dendritic cells (DC) represent the principal cell type at these sites capable of processing antigens and delivering signals that initiate tolerogenic or immunogenic immune responses. This review will discuss the role of DC at the "front-line" of immune surveillance and homeostasis within the respiratory tract and their role in the pathogenesis of respiratory disease.
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Affiliation(s)
- Philip A Stumbles
- Telethon Institute for Child Health Research, Faculty of Medicine and Dentistry, The University of Western Australia, Perth, Western Australia.
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Holt PG, Stumbles PA. Regulation of immunologic homeostasis in peripheral tissues by dendritic cells: the respiratory tract as a paradigm. J Allergy Clin Immunol 2000; 105:421-9. [PMID: 10719288 DOI: 10.1067/mai.2000.105010] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Dendritic cells are now recognized as the gatekeepers of the immune response, possessing a unique potential for acquisition of antigens at extremely low exposure levels and for efficient presentation of these in an immunogenic form to the naive T-cell system. Dendritic cell populations throughout the body exhibit a wide range of features in common that are associated with their primary functions, and these are considered in the initial section of this review. In addition, it is becoming evident that the properties and functions of these cells are refined by microenvironmental factors unique to their tissues of residence, a prime example being mucosal microenvironments such as those in respiratory tract tissues, and the latter represents the focus of the second section of this review.
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Affiliation(s)
- P G Holt
- TVW Telethon Institute for Child Health Research, Department of Microbiology, University of Western Australia, Perth, Australia
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Cochand L, Isler P, Songeon F, Nicod LP. Human lung dendritic cells have an immature phenotype with efficient mannose receptors. Am J Respir Cell Mol Biol 1999; 21:547-54. [PMID: 10536111 DOI: 10.1165/ajrcmb.21.5.3785] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Dendritic cells (DC) can be present at distinct stages of differentiation within the immune system. Sallusto and colleagues have recently described an in vitro culture system suitable for analyzing the maturation processes of DC (Sallusto and colleagues, J. Exp. Med. 1994;179:1109-1118). Monocytes cultured for 6 d in the presence of granulocyte macrophage colony-stimulating factor and interleukin-4 develop into immature DC with a high endocytic capacity but a low capacity to stimulate T cells. When challenged by lipopolysaccharide, these cells upregulate costimulatory molecules, express CD83, and become mature DC. CCR1 and CCR5 chemokine receptors are highly expressed on immature DC and downregulated on mature DC. This in vitro system was used to characterize human lung DC. Lung DC were shown to express some characteristics of in vitro immature DC. These are: (1) low expression of the costimulatory molecules CD40, CD80, and CD86; (2) poor expression of the differentiation marker CD83 and no CD1a; and (3) good capacity to incorporate dextran. Lung DC express moderate levels of CCR1 and CCR5. However, lung DC, like in vitro mature DC, express high levels of major histocompatibility complex Class II molecules, show low expression of CD14 and CD64, and are characterized by their high capacity to stimulate allogeneic T cells to proliferate during mixed leukocyte reactions (MLRs). Although lung DC express low levels of CD80 and CD86, the important role of these costimulatory molecules in inducing high MLR was demonstrated by using blocking antibodies. Therefore, while lung DC have overall a phenotype and an endocytic capacity close to in vitro immature DC, they share, like in vitro mature DC, a powerful capacity to stimulate T cells.
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MESH Headings
- Antigens, CD/biosynthesis
- Antigens, T-Independent/immunology
- Antigens, T-Independent/metabolism
- Cells, Cultured
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Dextrans/pharmacokinetics
- Flow Cytometry
- Fluorescein-5-isothiocyanate/analogs & derivatives
- Fluorescein-5-isothiocyanate/pharmacokinetics
- Humans
- Immunophenotyping
- Lectins, C-Type
- Lung/immunology
- Lymphocyte Culture Test, Mixed
- Mannose Receptor
- Mannose-Binding Lectins
- Monocytes/immunology
- Receptors, CCR1
- Receptors, CCR5/biosynthesis
- Receptors, Cell Surface/metabolism
- Receptors, Chemokine/biosynthesis
- T-Lymphocytes/immunology
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Affiliation(s)
- L Cochand
- Division of Pneumology, University of Geneva, Geneva, Switzerland
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Simons PJ, Delemarre FG, Drexhage HA. Antigen-presenting dendritic cells as regulators of the growth of thyrocytes: a role of interleukin-1beta and interleukin-6. Endocrinology 1998; 139:3148-56. [PMID: 9645688 DOI: 10.1210/endo.139.7.6110] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An accumulation of antigen-presenting dendritic cells (DC) in the thyroid gland, followed by thyroid autoimmune reactivity, occurs in normal Wistar rats during iodine deficiency, and spontaneously in diabetic-prone Biobreeding rats. This intrathyroidal DC accumulation coincides with an enhanced growth rate and metabolism of the thyrocytes, suggesting that both phenomena are related. Because DC are known to regulate the hormone synthesis and growth in other endocrine systems (i.e. the pituitary, the ovary, and the testis), we tested the hypothesis that DC, known for their superb accessory cell function in T cell stimulation, act as regulators of thyrocyte proliferation (and hormone secretion). We investigated the effect of (Nycodenz density gradient) purified splenic DC from Wistar rats on the growth rate of and thyroid hormone secretion by Wistar thyroid follicles (collagenase dispersion) in culture. Various numbers of DC and follicles were cocultured during 24 h. The proliferative capacity of thyrocytes was measured by adding tritiated thymidine (3H-TdR) and bromodeoxyuridine, the hormone secretion into the culture fluid was measured by using a conventional T3 RIA. Furthermore, antibodies directed against interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor-alpha (TNF-alpha) were added to these cocultures to determine the role of these cytokines in a possible DC regulation of thyrocyte growth. Cocultures were also carried out in the presence of antimajor histocompatibility complex-class I (MHC I), anti-MHC II, antiintercellular adhesion molecule-1 (ICAM-1), and antilymphocyte function-associated antigen-1alpha (LFA-1alpha) antibodies to possibly interfere with DC-thyrocyte interactions. The addition of DC to thyroid follicles clearly inhibited their 3H-TdR uptake, particularly at a 10:1 ratio, in comparison to follicle cultures alone, both under basal conditions and after TSH stimulation (75 +/- 7% and 49 +/- 11% reduction, respectively, n = 4). The follicle T3 secretion (after TSH stimulation) was also suppressed by DC in this system, but to a lesser extent (at best at an 1:1 ratio, 25 +/- 7% reduction, n = 4). The DC-induced inhibition of thyroid follicle growth was totally abrogated after addition of anti-IL-1beta antibodies; anti-IL-6 only had effect on the DC inhibition of non-TSH-stimulated thyrocytes, whereas anti-TNF-alpha demonstrated no effect at all. The antibodies to MHC and to adhesion molecules had also no effect on this DC-induced growth inhibition. The effect of the different anti-cytokine and anti-adhesion antibodies on the T3 secretion from thyroid follicles was not investigated. The clear inhibition of thyrocyte growth by splenic DC (classical antigen-presenting cells) again demonstrates the regulatory role of DC in endocrine systems. Proinflammatory cytokines such as IL-1beta and IL-6 are important mediators in this regulation. The here shown dual role of DC represents a link between the immune and endocrine system, which may form the gateway to the understanding of the initiation of thyroid autoimmune reactions and the thyroid autoimmune phenomena seen in iodine deficiency.
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Affiliation(s)
- P J Simons
- Department of Immunology, Erasmus University Rotterdam, The Netherlands.
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O'Doherty U, Steinman RM, Peng M, Cameron PU, Gezelter S, Kopeloff I, Swiggard WJ, Pope M, Bhardwaj N. Dendritic cells freshly isolated from human blood express CD4 and mature into typical immunostimulatory dendritic cells after culture in monocyte-conditioned medium. J Exp Med 1993; 178:1067-76. [PMID: 8102389 PMCID: PMC2191184 DOI: 10.1084/jem.178.3.1067] [Citation(s) in RCA: 305] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A procedure has been developed to isolate dendritic cells to a high degree of purity from fresh blood. Prior enrichment methods have relied upon an initial 1-2-d culture period. Purified fresh isolates lack the characteristic morphology, phenotype, and immunostimulatory function of dendritic cells. The purified cells have the appearance of medium sized lymphocytes and express substantial levels of CD4, but lack the T cell molecules CD3, CD8, and T cell receptor. When placed in culture, the cells mature in a manner resembling the previously described, cytokine-dependent maturation of epidermal dendritic cells (Langerhans cells). The cells enlarge and exhibit many cell processes, express much higher levels of major histocompatibility complex class II and a panel of accessory molecules for T cell activation, and become potent stimulators of the mixed leukocyte reaction. Among the many changes during this maturation process are a fall in CD4 and the appearance of high levels of B7/BB1, the costimulator for enhanced interleukin 2 production in T cells. These changes are not associated with cell proliferation, but are dependent upon the addition of monocyte-conditioned medium. We suggest that the freshly isolated CD4-positive blood dendritic cells are recent migrants from the bone marrow, and that subsequent maturation of the lineage occurs in tissues in situ upon appropriate exposure to cytokines.
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Affiliation(s)
- U O'Doherty
- Laboratory of Cellular Physiology and Immunology, Rockefeller University, New York, New York 10021
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Nicod LP, el Habre F. Adhesion molecules on human lung dendritic cells and their role for T-cell activation. Am J Respir Cell Mol Biol 1992; 7:207-13. [PMID: 1379822 DOI: 10.1165/ajrcmb/7.2.207] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Human lung parenchyma contains potent accessory cells to stimulate T cells with many features of dendritic cells (DC), including a strong tendency to form aggregates with T cells. As contact phenomena may be crucial for T-cell activation, phenotypic and functional studies were conducted on adhesion molecules. DC from minced lung were isolated by their loose adherence and by their absence of autofluorescent inclusions by flow cytometry. DC compared with peripheral blood monocytes (Mo) show an increased density of Class I and II major histocompatibility antigens. Unexpectedly, the leukocyte integrins (beta 2 group) are decreased in density on DC. CD11a (LFA-1) and CD11b are less expressed, whereas CD11c is preserved. In contrast, the beta 1 chains are denser on DC with an increase in the alpha 5 chain (CD49e) on their surface. The alpha 4 chain of this later group (CD49d) is only weakly present and its ligand VCAM (INCAM-110) is not detected. DC-induced allogeneic T-cell proliferation is suppressed by antibodies against both the beta 1 and the beta 2 chains with a slight additive effect. Among the adhesins, LFA-3 and ICAM-1 are increased on DC compared with Mo. Antibodies against LFA-3, and to a lesser extent against ICAM-1, block T-cell activation. These data improve our knowledge of the phenotype expressed by DC and provide some clues as to how DC adhere with T cells and may transduce signals for T-cell activation by cell-cell interactions.
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Affiliation(s)
- L P Nicod
- Respiratory Division, University Hospital, Geneva, Switzerland
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Rodriguez ER, Nasim S, Hsia J, Sandin RL, Ferreira A, Hilliard BA, Ross AM, Garrett CT. Cardiac myocytes and dendritic cells harbor human immunodeficiency virus in infected patients with and without cardiac dysfunction: detection by multiplex, nested, polymerase chain reaction in individually microdissected cells from right ventricular endomyocardial biopsy tissue. Am J Cardiol 1991; 68:1511-20. [PMID: 1746436 DOI: 10.1016/0002-9149(91)90288-v] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Two hundred fifteen patients infected with human immunodeficiency virus (HIV) participated in a prospective longitudinal study of HIV-related heart disease. Evaluation included signal-averaged electrocardiography and echocardiography. Fifteen patients underwent endomyocardial biopsy, 5 had cardiovascular symptoms and 10 did not. Cardiac myocytes or dendritic cells were prepared by individual cell microdissection to sort them from other cell types such as interstitial cells or circulating blood elements. HIV proviral sequences were amplified in samples of 15 to 20 cells of each type by multiplex, nested, polymerase chain reaction and hybridized to 32P-labeled probes specific for regions within the gag and pol genes of HIV-1. The results showed the presence of HIV sequences in myocytes of 2 of 5 patients with cardiac symptoms and in 6 of 10 without. Thus, symptomatic HIV cardiomyopathy did not appear to be a direct consequence of the virus on myocardial cells. In dendritic cells, HIV sequences were detected in 5 of 5 patients with cardiac symptoms and in 8 of 10 with apparently normal ventricular function. Furthermore, dendritic cells were somewhat more numerous in the myocardium of symptomatic than asymptomatic patients. Our studies are the first to directly detect the HIV genome in purified cardiac myocytes from patients with and without cardiac dysfunction. Our findings do not support a direct role of the virus in myocardial dysfunction. However, the results do suggest that the interstitial dendritic cells may be involved in some manner in the development of cardiac dysfunction observed in HIV-infected patients.
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Affiliation(s)
- E R Rodriguez
- Department of Pathology, George Washington University Medical Center, D.C
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Abstract
It has been customary to consider that antigen-presenting cells provide, in addition to the presented antigen, a second or co-stimulatory signal that leads to T-cell growth and effector function. The recent literature indicates that this two-signal notion oversimplifies the function of antigen-presenting cells. Instead it is useful to consider four groups of events: the formation of peptide-MHC complexes, the role of soluble cytokines, the action of antigen-presenting cell-T cell molecular couples distinct from the receptor for peptide MHC, and the function of antigen-presenting cells in situ.
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Affiliation(s)
- R M Steinman
- Laboratory of Cellular Physiology and Immunology, The Rockefeller University, New York, New York 10021
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