1
|
Wang Y, Nagase H, Tagawa YI, Taki S, Takamoto M. Endogenous IFN-γ facilitates Pneumocystis infection and downregulates carbohydrate receptors in CD4 + T cell-depleted mice. FEBS Lett 2024. [PMID: 38631897 DOI: 10.1002/1873-3468.14875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/09/2024] [Accepted: 02/24/2024] [Indexed: 04/19/2024]
Abstract
IFN-γ plays a critical role in host defense against intracellular pathogens. IFN-γ is produced in the bronchoalveolar lavage fluid of mice infected with Pneumocystis, but the role of IFN-γ in host defense against Pneumocystis remains controversial. It has been previously reported that although exogenous IFN-γ has beneficial effects on eradication of Pneumocystis, endogenous IFN-γ has a negative impact on innate immunity in immunocompromised hosts. Surprisingly, CD4+ T cell-depleted IFN-γ deficient (GKO) mice exhibit resistance to Pneumocystis. Alveolar macrophages (AM) from GKO mice exhibit higher expression of macrophage mannose receptor (MMR) and Dectin-1. Concomitantly, they exhibited greater ability to phagocytize Pneumocystis, and this activity was suppressed by inhibitors of these receptors. Incubation with IFN-γ resulted in a reduction in both the expression of these receptors on AM and their Pneumocystis-phagocytic activity. These results indicate that endogenous IFN-γ facilitates Pneumocystis to escape from host innate immunity by attenuating the phagocytic activity of AM via downregulation of MMR and Dectin-1.
Collapse
Affiliation(s)
- Yi Wang
- Department of Infection and Host Defense, Shinshu University School of Medicine, Matsumoto, Japan
| | - Hisashi Nagase
- Department of Infection and Host Defense, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yoh-Ichi Tagawa
- Department of Biomolecular Functional Engineering, Graduate School of Bioscience and Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Shinsuke Taki
- Department of Molecular and Cellular Immunology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Masaya Takamoto
- Department of Infection and Host Defense, Shinshu University School of Medicine, Matsumoto, Japan
- Community Health Care Research Center, Nagano University of Health and Medicine, Japan
| |
Collapse
|
2
|
Bath PM, Coleman CM, Gordon AL, Lim WS, Webb AJ. Nitric oxide for the prevention and treatment of viral, bacterial, protozoal and fungal infections. F1000Res 2021; 10:536. [PMID: 35685687 PMCID: PMC9171293 DOI: 10.12688/f1000research.51270.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/15/2021] [Indexed: 12/15/2022] Open
Abstract
Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts
in vitro. Therapeutic effects have been seen in animal models
in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from
in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections.
Collapse
Affiliation(s)
- Philip M. Bath
- Stroke Trials Unit, Division of Clinical Neuroscience, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
- Stroke, Nottingham University Hospitals NHS Trust, Nottingham, Notts, NG7 2UH, UK
| | - Christopher M. Coleman
- Division of Infection, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
| | - Adam L. Gordon
- Unit of Injury, Inflammation and Recovery Sciences, University of Nottingham, Derby, Derbyshire, DE22 3NE, UK
- NIHR Applied Research Collaboration-East Midlands (ARC-EM), Nottingham, Notts, UK
| | - Wei Shen Lim
- Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, NG5 1PB, UK
| | - Andrew J. Webb
- Clinical Pharmacology, School of Cardiovascular Medicine & Sciences, Kings College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, London, SE1 7EH, UK
| |
Collapse
|
3
|
Bath PM, Coleman CM, Gordon AL, Lim WS, Webb AJ. Nitric oxide for the prevention and treatment of viral, bacterial, protozoal and fungal infections. F1000Res 2021; 10:536. [PMID: 35685687 PMCID: PMC9171293 DOI: 10.12688/f1000research.51270.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/15/2021] [Indexed: 12/18/2023] Open
Abstract
Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts in vitro. Therapeutic effects have been seen in animal models in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections.
Collapse
Affiliation(s)
- Philip M. Bath
- Stroke Trials Unit, Division of Clinical Neuroscience, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
- Stroke, Nottingham University Hospitals NHS Trust, Nottingham, Notts, NG7 2UH, UK
| | - Christopher M. Coleman
- Division of Infection, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
| | - Adam L. Gordon
- Unit of Injury, Inflammation and Recovery Sciences, University of Nottingham, Derby, Derbyshire, DE22 3NE, UK
- NIHR Applied Research Collaboration-East Midlands (ARC-EM), Nottingham, Notts, UK
| | - Wei Shen Lim
- Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, NG5 1PB, UK
| | - Andrew J. Webb
- Clinical Pharmacology, School of Cardiovascular Medicine & Sciences, Kings College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, London, SE1 7EH, UK
| |
Collapse
|
4
|
Rayavara K, Kurosky A, Stafford SJ, Garg NJ, Brasier AR, Garofalo RP, Hosakote YM. Proinflammatory Effects of Respiratory Syncytial Virus-Induced Epithelial HMGB1 on Human Innate Immune Cell Activation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2018; 201:2753-2766. [PMID: 30275049 PMCID: PMC6200588 DOI: 10.4049/jimmunol.1800558] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 08/29/2018] [Indexed: 01/21/2023]
Abstract
High mobility group box 1 (HMGB1) is a multifunctional nuclear protein that translocates to the cytoplasm and is subsequently released to the extracellular space during infection and injury. Once released, it acts as a damage-associated molecular pattern and regulates immune and inflammatory responses. Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infections in infants and elderly, for which no effective treatment or vaccine is currently available. This study investigated the effects of HMGB1 on cytokine secretion, as well as the involvement of NF-κB and TLR4 pathways in RSV-induced HMGB1 release in human airway epithelial cells (AECs) and its proinflammatory effects on several human primary immune cells. Purified HMGB1 was incubated with AECs (A549 and small alveolar epithelial cells) and various immune cells and measured the release of proinflammatory mediators and the activation of NF-κB and P38 MAPK. HMGB1 treatment significantly increased the phosphorylation of NF-κB and P38 MAPK but did not induce the release of cytokines/chemokines from AECs. However, addition of HMGB1 to immune cells did significantly induce the release of cytokines/chemokines and activated the NF-κB and P38 MAPK pathways. We found that activation of NF-κB accounted for RSV-induced HMGB1 secretion in AECs in a TLR4-dependent manner. These results indicated that HMGB1 secreted from AECs can facilitate the secretion of proinflammatory mediators from immune cells in a paracrine mechanism, thus promoting the inflammatory response that contributes to RSV pathogenesis. Therefore, blocking the proinflammatory function of HMGB1 may be an effective approach for developing novel therapeutics.
Collapse
Affiliation(s)
- Kempaiah Rayavara
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Alexander Kurosky
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Susan J Stafford
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Nisha J Garg
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Allan R Brasier
- Division of Endocrinology, Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 77555
- Institute for Translational Sciences, The University of Texas Medical Branch, Galveston, TX 77555
| | - Roberto P Garofalo
- Department of Pediatrics, The University of Texas Medical Branch, Galveston, TX 77555; and
- Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, TX 77555
| | - Yashoda M Hosakote
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555;
- Institute for Translational Sciences, The University of Texas Medical Branch, Galveston, TX 77555
| |
Collapse
|
5
|
Mechanisms of Action of Vitamin D as Supplemental Therapy for Pneumocystis Pneumonia. Antimicrob Agents Chemother 2017; 61:AAC.01226-17. [PMID: 28760906 DOI: 10.1128/aac.01226-17] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/24/2017] [Indexed: 12/18/2022] Open
Abstract
The combination of trimethoprim and sulfamethoxazole (TMP-SMX) is the most effective regimen for therapy of Pneumocystis pneumonia (PCP). As many patients with PCP are allergic or do not respond to it, efforts have been devoted to develop alternative therapies for PCP. We have found that the combination of vitamin D3 (VitD3) (300 IU/kg/day) and primaquine (PMQ) (5 mg/kg/day) was as effective as TMP-SMX for therapy of PCP. In this study, we investigated the mechanisms by which vitamin D enhances the efficacy of PMQ. C57BL/6 mice were immunosuppressed by CD4+ cell depletion, infected with Pneumocystismurina for 8 weeks, and then treated for 9 days with the combination of VitD3 and PMQ (VitD3-PMQ) or with TMP-SMX or PMQ to serve as controls. The results showed that vitamin D supplementation increased the number of CD11c+ cells, suppressed the production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], gamma interferon [IFN-γ], and interleukin-6 [IL-6]) and inducible nitric oxide synthase (iNOS), and enhanced the expression of genes related to antioxidation (glutathione reductase and glutamate-cysteine ligase modifier subunit), antimicrobial peptides (cathelicidin), and autophagy (ATG5 and beclin-1). These results suggest that the main action of vitamin D is enhancing the ability of the host to defend against Pneumocystis infection.
Collapse
|
6
|
Passive transfer of interferon-γ over-expressing macrophages enhances resistance of SCID mice to Mycobacterium tuberculosis infection. Cytokine 2017; 95:70-79. [DOI: 10.1016/j.cyto.2017.02.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/07/2017] [Accepted: 02/10/2017] [Indexed: 01/06/2023]
|
7
|
Differential Macrophage Polarization from Pneumocystis in Immunocompetent and Immunosuppressed Hosts: Potential Adjunctive Therapy during Pneumonia. Infect Immun 2017; 85:IAI.00939-16. [PMID: 27993972 DOI: 10.1128/iai.00939-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 12/09/2016] [Indexed: 11/20/2022] Open
Abstract
We explored differential polarization of macrophages during infection using a rat model of Pneumocystis pneumonia. We observed enhanced pulmonary M1 macrophage polarization in immunosuppressed (IS) hosts, but an M2 predominant response in immunocompetent (IC) hosts following Pneumocystis carinii challenge. Increased inflammation and inducible nitric oxide synthase (iNOS) levels characterized the M1 response. However, macrophage ability to produce nitric oxide was defective. In contrast, the lungs of IC animals revealed a prominent M2 gene signature, and these macrophages effectively elicited an oxidative burst associated with clearance of Pneumocystis In addition, during P. carinii infection the expression of Dectin-1, a critical receptor for recognition and clearance of P. carinii, was upregulated in macrophages of IC animals but suppressed in IS animals. In the absence of an appropriate cytokine milieu for M2 differentiation, Pneumocystis induced an M1 response both in vitro and in vivo The M1 response induced by P. carinii was plastic in nature and reversible with appropriate cytokine stimuli. Finally, we tested whether macrophage polarization can be modulated in vivo and used to help manage the pathogenesis of Pneumocystis pneumonia by adoptive transfer. Treatment with both M1 and M2 cells significantly improved survival of P. carinii-infected IS hosts. However, M2 treatment provided the best outcomes with efficient clearance of P. carinii and reduced inflammation.
Collapse
|
8
|
B cell production of tumor necrosis factor in response to Pneumocystis murina infection in mice. Infect Immun 2013; 81:4252-60. [PMID: 24002064 DOI: 10.1128/iai.00744-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pneumocystis species are opportunistic fungal pathogens that induce tumor necrosis factor (TNF) production by alveolar macrophages. Here we report that B cells from the draining lymph nodes as well as lung CD4(+) T cells are important producers of TNF upon Pneumocystis murina infection. To determine the importance of B cell-derived TNF in the primary response to P. murina, we generated bone marrow chimeras whose B cells were unable to produce TNF. The lung P. murina burden at 10 days postinfection in TNF knockout (TNFKO) chimeras was significantly higher than that in wild-type (WT) chimeras, which corresponded to reduced numbers of activated CD4(+) T cells in the lungs at this early time point. Furthermore, CD4(+) T cells isolated from P. murina-infected TNFKO chimeras were unable to stimulate clearance of P. murina upon adoptive transfer to recombinase-deficient (RAG1KO) hosts. Together, these data indicate that B cell-derived TNF plays an important function in promoting CD4(+) T cell expansion and production of TNF and facilitating protection against P. murina infection.
Collapse
|
9
|
Schwartz YS, Svistelnik AV. Functional phenotypes of macrophages and the M1-M2 polarization concept. Part I. Proinflammatory phenotype. BIOCHEMISTRY (MOSCOW) 2013; 77:246-60. [PMID: 22803942 DOI: 10.1134/s0006297912030030] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Current concepts concerning the main functional phenotypes of mononuclear phagocytes are systematized, molecular mechanisms of their formation are considered, and the functional polarization concept of macrophages is critically analyzed. Mechanisms of macrophage priming activation mediated by pattern recognition receptors TLR, NLR, RLR, and CLR are described, and the features of each phenotype acquired via various pattern recognition receptors are emphasized. It is concluded that there is a huge variety of proinflammatory phenotypes from highly to poorly polarized ones. Thus the widespread notion of "classical activation" of macrophage concerns just a particular case of proinflammatory phenotype formation.
Collapse
Affiliation(s)
- Y Sh Schwartz
- Research Institute of Internal Medicine, Siberian Branch of the Russian Academy of Medical Sciences, Novosibirsk, 630089, Russia.
| | | |
Collapse
|
10
|
Abstract
Although the incidence of Pneumocystis pneumonia (PCP) has decreased since the introduction of combination antiretroviral therapy, it remains an important cause of disease in both HIV-infected and non-HIV-infected immunosuppressed populations. The epidemiology of PCP has shifted over the course of the HIV epidemic both from changes in HIV and PCP treatment and prevention and from changes in critical care medicine. Although less common in non-HIV-infected immunosuppressed patients, PCP is now more frequently seen due to the increasing numbers of organ transplants and development of novel immunotherapies. New diagnostic and treatment modalities are under investigation. The immune response is critical in preventing this disease but also results in lung damage, and future work may offer potential areas for vaccine development or immunomodulatory therapy. Colonization with Pneumocystis is an area of increasing clinical and research interest and may be important in development of lung diseases such as chronic obstructive pulmonary disease. In this review, we discuss current clinical and research topics in the study of Pneumocystis and highlight areas for future research.
Collapse
|
11
|
Brown SD, Brown LAS. Ethanol (EtOH)-induced TGF-β1 and reactive oxygen species production are necessary for EtOH-induced alveolar macrophage dysfunction and induction of alternative activation. Alcohol Clin Exp Res 2012; 36:1952-62. [PMID: 22551312 DOI: 10.1111/j.1530-0277.2012.01825.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 02/26/2012] [Indexed: 01/17/2023]
Abstract
BACKGROUND Previous studies have shown that chronic ethanol (EtOH) ingestion results in impaired alveolar macrophage function, increased TGF-β(1) production, and decreased antioxidant availability. Similarly, alternative activation (M2 activation) of alveolar macrophages also induces TGF-β(1) production and impairs macrophage function. However, the potential links between EtOH-induced alveolar macrophage derangements, M2 activation, TGF-β(1) production signaling, and oxidant stress have yet to be examined. We hypothesized that EtOH-induced oxidant stress and induction of TGF-β(1) signaling result in alternative activation which subsequently impairs the phagocytic capacity of alveolar macrophages. METHODS Primary rat alveolar macrophages and the alveolar macrophages cell line NR8383 were treated with 0.08% EtOH ± the antioxidant glutathione (GSH) or a TGF-β(1) neutralizing antibody for 5 days. Outcome measures included TGF-β(1) production, reactive oxygen species (ROS) production, phagocytic capacity, and expression of markers of M2 activation. RESULTS Chronic EtOH treatment greatly decreased alveolar macrophage phagocytic function, increased ROS production, increased TGF-β(1) , and increased expression of markers of M2 activation. GSH supplementation and inhibition of TGF-β(1) signaling during EtOH treatment prevented these alterations. CONCLUSIONS EtOH treatment increased oxidant stress, TGF-β(1) production, and alternative activation in NR8383 cells. However, GSH supplementation and ablation of TGF-β(1) signaling prevented these effects. This suggested that the EtOH-induced switch to an M2 phenotype was a result of decreased antioxidant availability and increased TGF-β(1) signaling. Preventing EtOH-induced induction of alternative activation may improve alveolar macrophage function in alcoholic subjects and decrease the risk of respiratory infections.
Collapse
Affiliation(s)
- Sheena D Brown
- Department of Pediatrics, Emory University, and Center for Developmental Lung Biology, Children's Healthcare of Atlanta, Georgia 30322, USA
| | | |
Collapse
|
12
|
Lasbury ME, Liao CP, Hage CA, Durant PJ, Tschang D, Wang SH, Zhang C, Lee CH. Defective nitric oxide production by alveolar macrophages during Pneumocystis pneumonia. Am J Respir Cell Mol Biol 2010; 44:540-7. [PMID: 20558778 DOI: 10.1165/rcmb.2009-0367oc] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The effect of nitric oxide (NO) on Pneumocystis (Pc) organisms, the role of NO in the defense against infection with Pc, and the production of NO by alveolar macrophages (AMs) during Pneumocystis pneumonia (PCP) were investigated. The results indicate that NO was toxic to Pc organisms and inhibited their proliferation in culture. When the production of NO was inhibited by intraperitoneal injection of rats with the nitric oxide synthase inhibitor L-N(5)-(1-iminoethyl) ornithine, progression of Pc infection in immunocompetent rats was enhanced. Concentrations of NO in bronchoalveolar lavage fluids from immunosuppressed, Pc-infected rats and mice were greatly reduced, compared with those from uninfected animals, and AMs from these animals were defective in NO production. However, inducible nitric oxide synthase (iNOS) mRNA and protein concentrations were high in AMs from Pc-infected rats and mice. Immunoblot analysis showed that iNOS in AMs from Pc-infected rats existed primarily as a monomer, but the homo-dimerization of iNOS monomers was required for the production of NO. When iNOS dimerization cofactors, including calmodulin, were added to macrophage lysates, iNOS dimerization increased, whereas incubation of the same lysates with all cofactors except calmodulin did not rescue iNOS dimer formation. These data suggest that NO is important in the defense against Pc infection, but that the production of NO in AMs during PCP is defective because of the reduced dimerization of iNOS.
Collapse
Affiliation(s)
- Mark E Lasbury
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202-5113, USA
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Abstract
Pneumocystis jirovecii is the opportunistic fungal organism that causes Pneumocystis pneumonia (PCP) in humans. Similar to other opportunistic pathogens, Pneumocystis causes disease in individuals who are immunocompromised, particularly those infected with HIV. PCP remains the most common opportunistic infection in patients with AIDS. Incidence has decreased greatly with the advent of HAART. However, an increase in the non-HIV immunocompromised population, noncompliance with current treatments, emergence of drug-resistant strains and rise in HIV(+) cases in developing countries makes Pneumocystis a pathogen of continued interest and a public health threat. A great deal of research interest has addressed therapeutic interventions to boost waning immunity in the host to prevent or treat PCP. This article focuses on research conducted during the previous 5 years regarding the host immune response to Pneumocystis, including innate, cell-mediated and humoral immunity, and associated immunotherapies tested against PCP.
Collapse
Affiliation(s)
- Michelle N Kelly
- Section of Pulmonary/Critical Care Medicine, LSU Health Sciences Center, Medical Education Building 3205, 1901 Perdido Street, New Orleans, LA 70112, USA.
| | | |
Collapse
|
14
|
Hu T, Takamoto M, Hida S, Tagawa YI, Sugane K. IFN-gamma deficiency worsen Pneumocystis pneumonia with Th17 development in nude mice. Immunol Lett 2009; 127:55-9. [PMID: 19733591 DOI: 10.1016/j.imlet.2009.08.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 08/27/2009] [Accepted: 08/30/2009] [Indexed: 10/20/2022]
Abstract
Pneumocystis pneumonia (PCP) occurs frequently in patients with immunodeficiency syndromes, especially AIDS. In order to investigate the role of IFN-gamma on PCP, nude mice deficient in IFN-gamma (GKO nude) and their wild-type ones (WT nude) were infected with murine Pneumocystis. Nine weeks later they were sacrificed, and cytokines in BALF and lung histopathology were compared between them. Cyst burden was greater in GKO than in WT nude mice. Histopathology in the lung was severer and granulomatous lesions were observed more frequently in GKO nude mice. Levels of IL-17 were higher in BALF of GKO than in that of WT nude mice. Greater number of CD4(+) T cells from lungs of infected GKO nude mice produced IL-17 than those from WT ones. These results suggest that deficiency in IFN-gamma induces the differentiation of Th17 and that IL-17 is responsible for inflammatory response in PCP.
Collapse
Affiliation(s)
- Tao Hu
- Department of Infection and Host Defense, Shinshu University Graduate School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan
| | | | | | | | | |
Collapse
|
15
|
Komano Y, Harigai M, Koike R, Sugiyama H, Ogawa J, Saito K, Sekiguchi N, Inoo M, Onishi I, Ohashi H, Amamoto F, Miyata M, Ohtsubo H, Hiramatsu K, Iwamoto M, Minota S, Matsuoka N, Kageyama G, Imaizumi K, Tokuda H, Okochi Y, Kudo K, Tanaka Y, Takeuchi T, Miyasaka N. Pneumocystis jirovecipneumonia in patients with rheumatoid arthritis treated with infliximab: A retrospective review and case-control study of 21 patients. ACTA ACUST UNITED AC 2009; 61:305-12. [DOI: 10.1002/art.24283] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
16
|
Haque AK, Adegboyega PA. Pneumocystis jiroveci Pneumonia. DAIL AND HAMMAR’S PULMONARY PATHOLOGY 2008. [PMCID: PMC7121032 DOI: 10.1007/978-0-387-68792-6_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Pneumocystis pneumonia (PCP) is one of the most common pulmonary infections in persons with impaired cell-mediated immunity, and particularly those infected with human immunodeficiency virus (HIV).1–7 Pneumocystis was first described in the lungs of guinea pigs, during experiments on American trypanosomiasis by Carlos Chagas8 in 1909 and by Antonio Carinii9 in 1910. Both considered the cysts of Pneumocystis as part of the trypanosome’s life cycle. Shortly afterward the Delanoes10 found identical forms in the lungs of rats that had not been infected with trypanosomes and recognized the organism as a separate species. The name Pneumocystis carinii, was given to this organism as a generic name (Greek:pneumon, “lung”; kystis, “cyst”), honoring Carinii.11
Collapse
|
17
|
Wang SH, Zhang C, Lasbury ME, Liao CP, Durant PJ, Tschang D, Lee CH. Decreased inflammatory response in Toll-like receptor 2 knockout mice is associated with exacerbated Pneumocystis pneumonia. Microbes Infect 2007; 10:334-41. [PMID: 18400546 DOI: 10.1016/j.micinf.2007.12.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Revised: 12/10/2007] [Accepted: 12/17/2007] [Indexed: 11/19/2022]
Abstract
Pneumocystis pneumonia (PcP) is marked by substantial inflammatory damage to the lung. We have found that Toll-like receptor 2 (TLR2) mediates macrophage inflammatory responses to Pneumocystis and hypothesized that TLR2 deficiency would lead to less severe inflammation and milder lung injury during PcP. Histopathology examination showed that TLR2-/- mice with PcP indeed exhibited milder pulmonary inflammation. TLR2-/- mouse lungs contained less TNF-alpha and displayed lower levels of NF-kappaB activation during PcP. However, TLR2-/- mice with PcP displayed increased severity in symptoms and organism burden. The increased organism burden is likely due to defects in protective mechanisms in TLR2-/- mice. mRNA levels of the inducible nitric oxide synthase and NADPH oxidase p47phox, as well as nitric oxide levels in the lungs, were decreased in TLR2-/- PcP mice. Taken together, this study shows that TLR2-mediated inflammatory responses contribute to a certain degree to the clearance of Pneumocystis organism in mice.
Collapse
Affiliation(s)
- Shao-Hung Wang
- Department of Medical Research, E-DA Hospital, I-Shou University, Kaohsiung 824, Taiwan, ROC
| | | | | | | | | | | | | |
Collapse
|
18
|
Mori S, Imamura F, Kiyofuji C, Ito K, Koga Y, Honda I, Sugimoto M. Pneumocystis jiroveci pneumonia in a patient with rheumatoid arthritis as a complication of treatment with infliximab, anti-tumor necrosis factor alpha neutralizing antibody. Mod Rheumatol 2006; 16:58-62. [PMID: 16622728 DOI: 10.1007/s10165-005-0454-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Accepted: 12/21/2005] [Indexed: 10/25/2022]
Abstract
We report that a-63-year-old woman developed Pneumocystis jiroveci pneumonia (PCP) as a complication from treatment with infliximab for rheumatoid arthritis. Although there was neither symptoms of dyspnea nor typical observations on a chest X-ray examination, low levels of oxygen saturation and findings of high-resolution chest computed tomographic scanning suggested a possibility of interstitial pneumonia. A polymerase chain reaction-based detection of Pneumocystis jiroveci in induced sputum allowed an early diagnosis of PCP and subsequent effective treatment.
Collapse
Affiliation(s)
- Shunsuke Mori
- Division of Rheumatology, Department of Medicine, National Hospital Organization, Kumamoto Saishunso National Hospital, Suya 2659 Nishigohshi-machi, Kikuchi-gun, Kumamoto 860-1196, Japan.
| | | | | | | | | | | | | |
Collapse
|
19
|
Bhagwat SP, Gigliotti F, Xu H, Wright TW. Contribution of T cell subsets to the pathophysiology of Pneumocystis-related immunorestitution disease. Am J Physiol Lung Cell Mol Physiol 2006; 291:L1256-66. [PMID: 16891394 PMCID: PMC4161614 DOI: 10.1152/ajplung.00079.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Immune-mediated lung injury is an important component of Pneumocystis pneumonia (PcP)-related immunorestitution disease (IRD). However, the individual contribution of CD4(+) and CD8(+) T cells to the pathophysiology of IRD remains undetermined. Therefore, IRD was modeled in severe combined immunodeficient mice, and specific T cell depletion was used to determine how T cell subsets interact to affect the nature and severity of disease. CD4(+) cells were more abundant than CD8(+) cells during the acute stage of IRD that coincided with impaired pulmonary physiology and organism clearance. Conversely, CD8(+) cells were more abundant during the resolution phase following P. carinii clearance. Depletion of CD4(+) T cells protected mice from the acute pathophysiology of IRD. However, these mice could not clear the infection and developed severe PcP at later time points when a pathological CD8(+) T cell response was observed. In contrast, mice depleted of CD8(+) T cells efficiently cleared the infection but developed more severe disease, an increased frequency of IFN-gamma-producing CD4(+) cells, and a prolonged CD4(+) T cell response than mice with both CD4(+) and CD8(+) cells. These data suggest that CD4(+) T cells mediate the acute respiratory disease associated with IRD. In contrast, CD8(+) T cells contributed to neither lung injury nor organism clearance when CD4(+) cells were present, but instead served to modulate CD4 function. In the absence of CD4(+) cells, CD8(+) T cells produced a nonprotective, pathological immune response. These data suggest that the interplay of CD4(+) and CD8(+) T cells affects the ultimate outcome of PcP-related IRD.
Collapse
Affiliation(s)
- Samir P. Bhagwat
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642
| | - Francis Gigliotti
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue Rochester, NY 14642
| | - Haodong Xu
- Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642
| | - Terry W. Wright
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue Rochester, NY 14642
- Corresponding Author: Terry W. Wright, Ph.D., Department of Pediatrics, P.O. Box 850, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave., Rochester, NY 14642., TEL: (585) 275-4246, FAX: (585) 756-7780,
| |
Collapse
|
20
|
Abstract
Species of the genus Pneumocystis exist as opportunistic fungal pathogens and are associated with severe pneumonia and pulmonary complications in immunocompromised individuals. Although prophylactic therapy for Pneumocystis has significantly decreased the overall incidence of infection, more than 80% of cases in current patient populations are considered breakthrough cases. In the HIV-infected population, in the years following the initiation of highly active antiretroviral therapy (HAART), significant reductions in the incidence of Pneumocystis infection were observed, although trends over the last several years suggest that the incidence of Pneumocystis has plateaued rather than decreased. Furthermore, with the more prominent usage of immunosuppressive therapies, the frequency of Pneumocystis infection in the HIV-negative population, such as those with hematologic malignancies and those who have undergone transplantation, has risen significantly. Investigating host defense mechanisms against P. carinii has historically been problematic due to the difficulty in achieving continuous in vitro propagation of proliferating Pneumocytis organisms. Nevertheless, clinical and experimental studies have documented that host defense against Pneumocystis involves a concerted effort between innate, cell-mediated (T lymphocyte) and humoral (B lymphocyte) responses. However, the pulmonary environment is a tissue site where heightened inflammatory responses can often lead to inflammation-mediated injury, thereby contributing to the pathogenesis of Pneumocystis infection. Accordingly, clearance of Pneumocystis from the pulmonary environment is dependent on a delicate equilibrium between the inflammatory response and immune-mediated clearance of the organism. Furthermore, innate and adaptive responses against Pneumocystis are strikingly similar to those against other medically-important fungi, thus providing additional evidence that Pneumocystis exists as a fungal organism.
Collapse
Affiliation(s)
- Chad Steele
- Department of Pediatrics, Division of Pulmonology Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
| | | | | |
Collapse
|
21
|
Affiliation(s)
- Charles F Thomas
- Thoracic Diseases Research Unit, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minn, USA
| | | |
Collapse
|
22
|
Wright TW, Pryhuber GS, Chess PR, Wang Z, Notter RH, Gigliotti F. TNF Receptor Signaling Contributes to Chemokine Secretion, Inflammation, and Respiratory Deficits duringPneumocystisPneumonia. THE JOURNAL OF IMMUNOLOGY 2004; 172:2511-21. [PMID: 14764724 DOI: 10.4049/jimmunol.172.4.2511] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD8(+) T cells contribute to the pathophysiology of Pneumocystis pneumonia (PcP) in a murine model of AIDS-related disease. The present studies were undertaken to more precisely define the mechanisms by which these immune cells mediate the inflammatory response that leads to lung injury. Experimental mice were depleted of either CD4(+) T cells or both CD4(+) and CD8(+) T cells and then infected with Pneumocystis: The CD4(+)-depleted mice had significantly greater pulmonary TNF-alpha levels than mice depleted of both CD4(+) and CD8(+) T cells. Elevated TNF-alpha levels were associated with increased lung concentrations of the chemokines RANTES, monocyte chemoattractant protein 1, macrophage-inflammatory protein 2, and cytokine-induced neutrophil chemoattractant. To determine whether TNFR signaling was involved in the CD8(+) T cell-dependent chemokine response, TNFRI- and II-deficient mice were CD4(+) depleted and infected with Pneumocystis: TNFR-deficient mice had significantly reduced pulmonary RANTES, monocyte chemoattractant protein 1, macrophage-inflammatory protein 2, and cytokine-induced neutrophil chemoattractant responses, reduced inflammatory cell recruitment to the alveoli, and reduced histological evidence of PcP-related alveolitis as compared with infected wild-type mice. Diminished pulmonary inflammation correlated with improved surfactant activity and improved pulmonary function in the TNFR-deficient mice. These data indicate that TNFR signaling is required for maximal CD8(+) T cell-dependent pulmonary inflammation and lung injury during PcP and also demonstrate that CD8(+) T cells can use TNFR signaling pathways to respond to an extracellular fungal pathogen.
Collapse
MESH Headings
- Animals
- Bronchoalveolar Lavage Fluid/chemistry
- Bronchoalveolar Lavage Fluid/cytology
- Bronchoalveolar Lavage Fluid/immunology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/pathology
- Cell Movement/immunology
- Chemokines/biosynthesis
- Chemokines/metabolism
- Dose-Response Relationship, Immunologic
- Female
- Inflammation Mediators/physiology
- Lung/blood supply
- Lung/immunology
- Lung/pathology
- Lung/physiopathology
- Lung Compliance
- Mice
- Mice, SCID
- Mice, Transgenic
- Pneumonia, Pneumocystis/genetics
- Pneumonia, Pneumocystis/immunology
- Pneumonia, Pneumocystis/pathology
- Pneumonia, Pneumocystis/physiopathology
- Pulmonary Surfactants/metabolism
- Receptors, Tumor Necrosis Factor/deficiency
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/physiology
- Respiratory Function Tests
- Signal Transduction/genetics
- Signal Transduction/immunology
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/physiology
- Up-Regulation/genetics
- Up-Regulation/immunology
Collapse
Affiliation(s)
- Terry W Wright
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
| | | | | | | | | | | |
Collapse
|
23
|
Steele C, Marrero L, Swain S, Harmsen AG, Zheng M, Brown GD, Gordon S, Shellito JE, Kolls JK. Alveolar macrophage-mediated killing of Pneumocystis carinii f. sp. muris involves molecular recognition by the Dectin-1 beta-glucan receptor. ACTA ACUST UNITED AC 2004; 198:1677-88. [PMID: 14657220 PMCID: PMC2194130 DOI: 10.1084/jem.20030932] [Citation(s) in RCA: 238] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Innate immune mechanisms against Pneumocystis carinii, a frequent cause of pneumonia in immunocompromised individuals, are not well understood. Using both real time polymerase chain reaction as a measure of organism viability and fluorescent deconvolution microscopy, we show that nonopsonic phagocytosis of P. carinii by alveolar macrophages is mediated by the Dectin-1 β-glucan receptor and that the subsequent generation of hydrogen peroxide is involved in alveolar macrophage–mediated killing of P. carinii. The macrophage Dectin-1 β-glucan receptor colocalized with the P. carinii cyst wall. However, blockage of Dectin-1 with high concentrations of anti–Dectin-1 antibody inhibited binding and concomitant killing of P. carinii by alveolar macrophages. Furthermore, RAW 264.7 macrophages overexpressing Dectin-1 bound P. carinii at a higher level than control RAW cells. In the presence of Dectin-1 blockage, killing of opsonized P. carinii could be restored through FcγRII/III receptors. Opsonized P. carinii could also be efficiently killed in the presence of FcγRII/III receptor blockage through Dectin-1–mediated phagocytosis. We further show that Dectin-1 is required for P. carinii–induced macrophage inflammatory protein 2 production by alveolar macrophages. Taken together, these results show that nonopsonic phagocytosis and subsequent killing of P. carinii by alveolar macrophages is dependent upon recognition by the Dectin-1 β-glucan receptor.
Collapse
Affiliation(s)
- Chad Steele
- Department of Pediatrics, Division of Pulmonology, Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Lasbury ME, Tang X, Durant PJ, Bartlett MS, Smith JW, Lee CH. Production and role of nitric oxide in the alveolar immune response to Pneumocystis carinii. J Eukaryot Microbiol 2002; Suppl:165S-166S. [PMID: 11906046 DOI: 10.1111/j.1550-7408.2001.tb00503.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M E Lasbury
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis 46202, USA.
| | | | | | | | | | | |
Collapse
|
25
|
Wu M, Hussain S, He YH, Pasula R, Smith PA, Martin WJ. Genetically engineered macrophages expressing IFN-gamma restore alveolar immune function in scid mice. Proc Natl Acad Sci U S A 2001; 98:14589-94. [PMID: 11724936 PMCID: PMC64726 DOI: 10.1073/pnas.251451498] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2001] [Indexed: 11/18/2022] Open
Abstract
Reversal of immunodeficiency in the lung by gene therapy is limited in part by the difficulty of transfecting lung cells in vivo. Many options exist for successfully transfecting cells in vitro, but they are not easily adapted to the in vivo condition. To overcome this limitation, we transduced macrophages in vitro with the murine IFN-gamma (mIFN-gamma) gene and intratracheally delivered the macrophages to express mIFN-gamma in vivo. A recombinant retroviral vector pSF91 system was modified to encode mIFN-gamma and enhanced green fluorescent protein (EGFP). A murine macrophage cell line J774A.1 transduced with the retroviral supernatant increased secretion from undetectable levels to 131.6 +/- 4.2 microg/ml mIFN-gamma at 24 h in vitro. The mIFN-gamma-producing macrophages were intratracheally instilled into mechanically ventilated scid mice. mIFN-gamma levels in the bronchoalveolar lavage increased from undetectable levels at baseline to 158.8 +/- 5.1 pg/ml at 48 h (P < 0.001). Analysis of the lavaged cells for EGFP expression revealed that EGFP expression was directly proportional to the number of transduced macrophages instilled into the lung. Immune function was partially restored in the alveolar spaces of scid mice with evidence of enhanced MHC class II antigen expression and increased phagocytosis (P < 0.05). Tumor necrosis factor alpha was increased from undetectable at baseline to 103.5 +/- 11.4 pg/ml. In contrast, i.p. administration of the engineered macrophages did not enhance IFN-gamma levels in the lung. Our study suggests airway delivery of genetically engineered macrophages expressing mIFN-gamma gene can partially restore significant immune activity in the lungs of immunodeficient mice.
Collapse
Affiliation(s)
- M Wu
- Division of Pulmonary, Allergy, Critical Care and Occupational Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | | | | | | | | |
Collapse
|
26
|
Saio M, Radoja S, Marino M, Frey AB. Tumor-infiltrating macrophages induce apoptosis in activated CD8(+) T cells by a mechanism requiring cell contact and mediated by both the cell-associated form of TNF and nitric oxide. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:5583-93. [PMID: 11698429 DOI: 10.4049/jimmunol.167.10.5583] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have investigated the ability of different cells present in murine tumors to induce apoptosis of activated CD8(+) T cells in vitro. Tumor cells do not induce apoptosis of T cells; however, macrophages that infiltrate tumors are potent inducers of apoptosis. Tumor macrophages express cell surface-associated TNF, TNF type I (CD120a) and II (CD120b) receptors, and, upon contact with T cells which induces release of IFN-gamma from T cells, secrete nitric oxide. Killing of T cells in vitro is blocked by Abs to IFN-gamma, TNF, CD120a, or CD120b, or N-methyl-L-arginine. In concert with that finding, tumor macrophages isolated from either TNF type I or type II receptor -/- mice are not proapoptotic and do not produce nitric oxide upon contact with activated T cells. Control macrophages do not express TNF receptors or release nitric oxide. Tumor cells or tumor-derived macrophages do not express FasL, and blocking Abs to either Fas or FasL have no effect on macrophage-mediated T cell killing. These results demonstrate that macrophages which infiltrate tumors are highly proapoptotic and may be responsible for elimination of activated antitumor T cells within the tumor bed.
Collapse
Affiliation(s)
- M Saio
- Department of Cell Biology and Kaplan Cancer Center, New York University School of Medicine, New York, NY 10016, USA
| | | | | | | |
Collapse
|
27
|
Martin WJ, Pasula R. Role of alveolar macrophages in host defense against Pneumocystis carinii. Am J Respir Cell Mol Biol 2000; 23:434-5. [PMID: 11017906 DOI: 10.1165/ajrcmb.23.4.f203] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- W J Martin
- Division of Pulmonary, Allergy, Critical Care and Occupational Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202-2879, USA.
| | | |
Collapse
|
28
|
Behnia M, Robertson KA, Martin WJ. Lung infections: role of apoptosis in host defense and pathogenesis of disease. Chest 2000; 117:1771-7. [PMID: 10858414 DOI: 10.1378/chest.117.6.1771] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Apoptosis is a form of cell death that has gained enormous attention during the past few years, and its mechanisms, important to biology and medicine, are being unraveled at an accelerating pace. Apoptosis of lung cells occurs during lung infections and may be either a host defense mechanism or reflect the pathogenesis of the infection. In the first part of this review, the biochemistry and physiology of apoptotic pathways and its regulators are discussed. This is followed by an overview of apoptotic mechanisms in selected lung infections. The implications of apoptosis in host immunity, pathogenesis, and treatment of pulmonary infections will be discussed in this context.
Collapse
Affiliation(s)
- M Behnia
- Department of Medicine, and Herman B. Wells Center for Pediatric Research, and Stem Cell Transplantation Program, Indiana University School of Medicine, Indianapolis, USA
| | | | | |
Collapse
|
29
|
Ouadrhiri Y, Sibille Y. Phagocytosis and killing of intracellular pathogens: interaction between cytokines and antibiotics. Curr Opin Infect Dis 2000; 13:233-240. [PMID: 11964792 DOI: 10.1097/00001432-200006000-00006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Phagocytosis and bacterial killing are the primary functions of macrophages. Among the mechanisms involved in the phagocytic process, cytokines, especially those of T-helper 1 profile, appear to influence considerably the internalization and the intracellular fate of the pathogen within the macrophage. In particular, the evidence for a cooperation of cytokines with antibiotics in intracellular infection could provide new therapeutic approaches to intracellular infectious diseases in the future.
Collapse
Affiliation(s)
- Youssef Ouadrhiri
- Unit of Experimental Medicine, Christian de Duve International Institute of Cellular and Molecular Pathology, Brussels, Belgium
| | | |
Collapse
|
30
|
Martin WJ, Wright JR. Pneumocystis carinii pneumonia and pulmonary surfactant. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1999; 133:406-7. [PMID: 10235122 DOI: 10.1016/s0022-2143(99)90016-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|