51
|
Silva MT. When two is better than one: macrophages and neutrophils work in concert in innate immunity as complementary and cooperative partners of a myeloid phagocyte system. J Leukoc Biol 2010; 87:93-106. [PMID: 20052802 DOI: 10.1189/jlb.0809549] [Citation(s) in RCA: 210] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The antimicrobial effector activity of phagocytes is crucial in the host innate defense against infection, and the classic view is that the phagocytes operating against intracellular and extracellular microbial pathogens are,respectively, macrophages and neutrophils. As a result of the common origin of the two phagocytes, they share several functionalities, including avid phagocytosis,similar kinetic behavior under inflammatory/infectious conditions, and antimicrobial and immunomodulatory activities. However, consequent to specialization during their differentiation, macrophages and neutrophils acquire distinctive, complementary features that originate different levels of antimicrobial capacities and cytotoxicity and different tissue localization and lifespan.This review highlights data suggesting the perspective that the combination of overlapping and complementary characteristics of the two professional phagocytes promotes their cooperative participation as effectors and modulators in innate immunity against infection and as orchestrators of adaptive immunity. In the concerted activities operating in antimicrobial innate immunity, macrophages and neutrophils are not able to replace each other. The common and complementary developmental,kinetic, and functional properties of neutrophils and macrophages make them the effector arms of a myeloid phagocyte system that groups neutrophils with members of the old mononuclear phagocyte system. The use by mammals of a system with two dedicated phagocytic cells working cooperatively represents an advantageous innate immune attack strategy that allows the efficient and safe use of powerful but dangerous microbicidal molecules.This crucial strategy is a target of key virulence mechanisms of successful pathogens.
Collapse
Affiliation(s)
- Manuel T Silva
- Instituto de Biologia Molecular e Celular, Rua do Campo Alegre 823, Porto, Portugal.
| |
Collapse
|
52
|
Laws TR, Davey MS, Titball RW, Lukaszewski R. Neutrophils are important in early control of lung infection by Yersinia pestis. Microbes Infect 2010; 12:331-5. [PMID: 20114086 DOI: 10.1016/j.micinf.2010.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Revised: 01/12/2010] [Accepted: 01/18/2010] [Indexed: 10/19/2022]
Abstract
In this paper we evaluate the role of neutrophils in pneumonic plague. Splenic neutrophils from naïve BALB/c mice were found to reduce numbers of culturable Yersinia pestis strain GB in suspension. A murine, BALB/c, intranasal model of pneumonic plague was used in conjunction with in vivo neutrophil ablation, using the GR-1 antibody. This treatment reduced neutrophil numbers without affecting other leukocyte numbers. Neutrophil ablated mice exhibited increased bacterial colonisation of the lung 24h post infection. Furthermore, exposure of Y. pestis to human neutrophils resulted in a 5-fold reduction in the number of viable bacterial cells, whereas, PBMCs had no effect.
Collapse
Affiliation(s)
- Thomas R Laws
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire, UK.
| | | | | | | |
Collapse
|
53
|
Chan ED, Bai X, Kartalija M, Orme IM, Ordway DJ. Host immune response to rapidly growing mycobacteria, an emerging cause of chronic lung disease. Am J Respir Cell Mol Biol 2010; 43:387-93. [PMID: 20081053 DOI: 10.1165/rcmb.2009-0276tr] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Rapidly growing mycobacteria (RGM) are environmental organisms classified under the broader category of nontuberculous mycobacteria. The most common RGM to cause human diseases are Mycobacterium abscessus, Mycobacterium chelonae, Mycobacterium fortuitum, and Mycobacterium massiliense. Infections due to the RGM are an emerging health problem in the United States. Chronic pulmonary disease and skin/soft-tissue infections are the two most common disorders due to these organisms. Clinical outcomes in the treatment of M. abscessus infections are generally disappointing. Because less is known about the nature of the immune response to M. abscessus than for tuberculosis, we herein highlight the major clinical features associated with infections due to M. abscessus and other RGM, and review the known host immune response to RGM, drawing from experimental animal and clinical studies. Based on in vitro and in vivo murine models, Toll-like receptor 2, dectin-1, tumor necrosis factor (TNF)-α, IFN-γ, leptin, T cells, and possibly neutrophils are important components in the host defense against RGM infections. However, excessive induction of TNF-α by the R morphotype of M. abscessus may allow it to be more pathogenic than the S morphotype. Clinical observations and/or genetic studies in humans corroborate many of the findings in animals in that those with cell-mediated immunodeficiency, genetic defects in IFN-γ-IL-12 axis, and those individuals on TNF-α blockers are at increased risk for nontuberculous mycobacteria infections, including the RGM. However, much remains to be discovered on why seemingly healthy individuals, particularly slender postmenopausal women with thoracic cage anomalies, appear to be at increased risk.
Collapse
Affiliation(s)
- Edward D Chan
- Division of Mycobacterial and Respiratory Infections, National Jewish Health, Denver, CO 80206, USA.
| | | | | | | | | |
Collapse
|
54
|
[The presence of mycobacteria in bronchoalveolar lavage fluid from an immunocompetent patient does not necessarily imply tuberculosis]. Ann Pathol 2009; 29:504-6. [PMID: 20005441 DOI: 10.1016/j.annpat.2009.10.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2009] [Indexed: 11/22/2022]
Abstract
Mycobacterium tuberculosis is the most frequently identified mycobacterium in the bronchoalveolar lavage fluid (BALF) of immunocompetent patients. Lung infections due to non-tuberculous mycobacteria (NTM) are rare in such patients and then often occur in the context of pre-existing chronic lung disease. We report the case of an immunocompetent 85-year-old woman without pre-existing lung disease in whom M. abscessus was recovered from BALF. Cytological examination of the BALF revealed an increased number of neutrophils and some acid-fast bacilli, all located within neutrophil cytoplasm. This case report contributes a cytological description of BALF in the context of M. abscessus infection, which is poorly detailed in the literature.
Collapse
|
55
|
Eum SY, Kong JH, Hong MS, Lee YJ, Kim JH, Hwang SH, Cho SN, Via LE, Barry CE. Neutrophils are the predominant infected phagocytic cells in the airways of patients with active pulmonary TB. Chest 2009; 137:122-8. [PMID: 19749004 DOI: 10.1378/chest.09-0903] [Citation(s) in RCA: 348] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The exact role of neutrophils in the pathogenesis of TB is poorly understood. Recent evidence suggests that neutrophils are not simply scavenging phagocytes in Mycobacterium tuberculosis (Mtb) infection. METHODS Three different types of clinical specimens from patients with active pulmonary TB who underwent lung surgery were examined: sputum, BAL fluid, and cavity contents. Differential cell separation and quantification were performed for intracellular and extracellular bacteria, and bacterial length was measured using microscopy. RESULTS Neutrophils were more abundant than macrophages in sputum (86.6% +/- 2.2% vs 8.4% +/- 1.3%) and in BAL fluid (78.8% +/- 5.8% vs 11.8% +/- 4.1%). Inside the cavity, lymphocytes (41.3% +/- 11.2%) were the most abundant cell type, followed by neutrophils (38.8% +/- 9.4%) and macrophages (19.5% +/- 7.5%). More intracellular bacilli were found in neutrophils than macrophages in sputum (67.6% +/- 5.6% vs 25.2% +/- 6.5%), in BAL fluid (65.1% +/- 14.4% vs 28.3% +/- 11.6%), and in cavities (61.8% +/- 13.3% vs 23.9% +/- 9.3%). The lengths of Mtb were shortest in cavities (1.9+/- 0.1 microm), followed by in sputum (2.9 +/- 0.1 microm) and in BAL fluid (3.6 +/- 0.2 microm). CONCLUSIONS Our results show that neutrophils are the predominant cell types infected with Mtb in patients with TB and that these intracellular bacteria appear to replicate rapidly. These results are consistent with a role for neutrophils in providing a permissive site for a final burst of active replication of the bacilli prior to transmission.
Collapse
Affiliation(s)
- Seok-Yong Eum
- International Tuberculosis Research Center, Division of Immunopathology and Cellular Immunology, 475-1, Gapo, Masan 631-320, Republic of Korea.
| | | | | | | | | | | | | | | | | |
Collapse
|
56
|
Yu C, Shi ZR, Chu CY, Lee KH, Zhao X, Lee JW. Expression of bovine granulocyte chemotactic protein-2 (GCP-2) in neutrophils and a mammary epithelial cell line (MAC-T) in response to various bacterial cell wall components. Vet J 2009; 186:89-95. [PMID: 19682932 DOI: 10.1016/j.tvjl.2009.07.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 07/10/2009] [Accepted: 07/12/2009] [Indexed: 10/20/2022]
Abstract
CXC chemokines are potential attractants for polymorphonuclear leucocytes (PMNs) and play an important role in resistance to infectious diseases, such as bovine mastitis. In this study, a bovine mammary epithelial cell line (MAC-T) and blood PMNs were stimulated with bacterial cell wall components of gram negative and gram positive bacteria, including lipopolysaccharide (LPS), lipoteichoic acid (LTA) and peptidoglycan (PGN). The expression of two CXC chemokines, interleukin (IL)-8 and granulocyte chemotactic protein (GCP)-2 was analysed by real-time PCR. High concentrations (1 or 10 μg/mL) of LPS and LTA, but not PGN, significantly increased the expression of GCP-2 and IL-8 in both MAC-T and PMNs. Biopsies from mammary glands of cattle with clinical Escherichia coli mastitis also had increased expression of GCP-2. Using an in vitro transepithelial migration assay, recombinant human GCP-2 (rhGCP-2) showed weak chemoattractant effects on bovine blood PMNs. It was concluded that PMNs and MAC-T cells can express GCP-2 in response to certain bacterial cell components during the course of mastitis.
Collapse
Affiliation(s)
- Chi Yu
- Department of Animal Science, National Pingtung University of Science and Technology, Neipu, Pingtung 91201, Taiwan
| | | | | | | | | | | |
Collapse
|
57
|
Persson A, Blomgran-Julinder R, Eklund D, Lundström C, Stendahl O. Induction of apoptosis in human neutrophils by Mycobacterium tuberculosis is dependent on mature bacterial lipoproteins. Microb Pathog 2009; 47:143-50. [PMID: 19501642 DOI: 10.1016/j.micpath.2009.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 05/15/2009] [Accepted: 05/27/2009] [Indexed: 10/20/2022]
Abstract
Modulation of immune cell apoptosis is a key evasion strategy utilized by Mycobacterium tuberculosis (Mtb). To be able to multiply within macrophages, the bacterium delays apoptosis and down-regulates pro-inflammatory activation in these cells, whereas apoptosis is rapidly induced in the potently bactericidal neutrophils. Initial host-pathogen interactions between neutrophils and Mtb, subsequently leading to apoptosis, need to be investigated to understand the early features during Mtb infections. Opsonized Mtb were readily phagocytosed, and the immuno-mediated phagocytosis triggered early activation of anti-apoptotic Akt in the neutrophils but the bacteria still induced apoptosis to the same extent as non-phagocytosed Mtb. Mtb-induced apoptosis was strictly dependent on NADPH oxidase-generated reactive oxygen species, compounds shown to damage lysosomal granules. Despite this, we found no involvement of damaged azurophilic granules in Mtb-induced apoptosis in human neutrophils. Instead, the Mtb-induced apoptosis was p38 MAPK dependent and induced through the mitochondrial pathway. Moreover, Mtb deficient of mature lipoproteins lacked the determinants required for induction of neutrophil apoptosis. These results show that Mtb exert a strong intrinsic capacity to induce apoptosis in neutrophils that is capable of overcoming the anti-apoptotic signaling in the cell.
Collapse
Affiliation(s)
- Alexander Persson
- Department of Molecular and Clinical Medicine, Linköping University, Sweden.
| | | | | | | | | |
Collapse
|
58
|
Korf H, Vander Beken S, Romano M, Steffensen KR, Stijlemans B, Gustafsson JA, Grooten J, Huygen K. Liver X receptors contribute to the protective immune response against Mycobacterium tuberculosis in mice. J Clin Invest 2009; 119:1626-37. [PMID: 19436111 DOI: 10.1172/jci35288] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Accepted: 03/11/2009] [Indexed: 12/21/2022] Open
Abstract
Liver X receptors (LXRs) are key regulators of macrophage function, controlling transcriptional programs involved in lipid homeostasis and inflammation. However, exactly how LXRs modulate inflammation during infection remains unknown. To explore this, we used a mouse model of Mycobacterium tuberculosis infection. Upon intratracheal infection with M. tuberculosis, LXRs and LXR target genes were induced in CD11c+ lung and alveolar cells. Furthermore, mice deficient in both LXR isoforms, LXRalpha and LXRbeta (Lxra-/-Lxrb-/- mice), were more susceptible to infection, developing higher bacterial burdens and an increase in the size and number of granulomatous lesions. Interestingly, mice solely deficient in LXRalpha, but not those lacking only LXRbeta, mirrored the susceptibility of the Lxra-/-Lxrb-/- animals. Lxra-/-Lxrb-/- mice failed to mount an effective early neutrophilic airway response to infection and showed dysregulation of both pro- and antiinflammatory factors in CD11c+ lung cells. T cell responses were strongly affected in Lxra-/-Lxrb-/- mice, showing near-complete abrogation of the infection-induced Th1 function - and even more so Th17 function - in the lungs. Treatment of WT mice with the LXR agonists TO901317 and GW3965 resulted in a 10-fold decrease of the pulmonary bacterial burden and a comparable increase of Th1/Th17 function in the lungs. The dependence of LXR signaling on the neutrophil IL-17 axis represents what we believe to be a novel function for these nuclear receptors in resistance to M. tuberculosis infection and may provide a new target for therapeutics.
Collapse
Affiliation(s)
- Hannelie Korf
- Laboratory of Mycobacterial Immunology, Scientific Institute of Public Health, Brussels, Belgium
| | | | | | | | | | | | | | | |
Collapse
|
59
|
Ramos-Kichik V, Mondragón-Flores R, Mondragón-Castelán M, Gonzalez-Pozos S, Muñiz-Hernandez S, Rojas-Espinosa O, Chacón-Salinas R, Estrada-Parra S, Estrada-García I. Neutrophil extracellular traps are induced by Mycobacterium tuberculosis. Tuberculosis (Edinb) 2008; 89:29-37. [PMID: 19056316 DOI: 10.1016/j.tube.2008.09.009] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 08/29/2008] [Accepted: 09/24/2008] [Indexed: 12/12/2022]
Abstract
Due to the intracellular nature of mycobacterial infections, little attention has been paid to the possible extracellular role that neutrophils might play in tuberculosis. The recent discovery of neutrophil extracellular traps (NETs), composed of DNA and antimicrobial proteins,(1) introduces a new perspective to our understanding of the mechanism used by the innate immune system to contain and kill microorganisms. In this study, we tested in vitro whether Mycobacterium tuberculosis, an intracellular pathogen, can induce NETs formation and if this newly discovered mechanism is involved in a control response during mycobacterial infection. We found that two different genotypes of M. tuberculosis exerted, in vitro, a cytotoxic effect and induced subcellular changes on infected neutrophils, leading to NETs formation in a time dependent manner. NETs trapped mycobacteria but were unable to kill them. NETs formation induced by M. tuberculosis could help understand the early stages of mycobacterial pathogenesis.
Collapse
Affiliation(s)
- Victoria Ramos-Kichik
- Depto. de Inmunología, Escuela Nacional de Ciencias Biológicas, I.P.N., Carpio y Plan de Ayala s/n. Col. Santo Tomás, México, D.F., México.
| | | | | | | | | | | | | | | | | |
Collapse
|
60
|
Abstract
Tuberculosis is the most important bacterial infection world wide. The causative agent, Mycobacterium tuberculosis survives and proliferates within macrophages. Immune mediators such as interferon gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha) activate macrophages and promote bacterial killing. IFN-gamma is predominantly secreted by innate cells (mainly natural killer (NK) cells) and by T cells upon instruction by interleukin 12 (IL-12) and IL-18. These cytokines are primarily produced by dendritic cells and macrophages in response to Toll-like receptor (TLR) signalling interaction with tubercle bacilli. These signals also induce pro-inflammatory cytokines (including IL-1beta and TNF-alpha), chemokines and defensins. The inflammatory environment further recruits innate effector cells such as macrophages, polymorphonuclear neutrophils (PMN) and NK cells to the infectious foci. This eventually leads to the downstream establishment of acquired T cell immunity which appears to be protective in more than 90% of infected individuals. Robust innate immune activation is considered an essential prerequisite for protective immunity and vaccine efficacy. However, data published so far provide a muddled view of the functional importance of innate immunity in tuberculosis. Here we critically discuss certain aspects of innate immunity, namely PMN, TLRs and NK cells, as characterised in tuberculosis to date, and their contribution to protection and pathology.
Collapse
Affiliation(s)
- Daniel S Korbel
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | | | | |
Collapse
|
61
|
Abstract
We demonstrate that apolipoprotein E -deficient (ApoE(-/-)) mice are highly susceptible to tuberculosis and that their susceptibility depends on the severity of hypercholesterolemia. Wild-type (WT) mice and ApoE(-/-) mice fed a low-cholesterol (LC) or high-cholesterol (HC) diet were infected with approximately 50 CFU Mycobacterium tuberculosis Erdman by aerosol. ApoE(-/-) LC mice were modestly more susceptible to tuberculosis than WT LC mice. In contrast, ApoE(-/-) HC mice were extremely susceptible, as evidenced by 100% mortality after 4 weeks with tuberculosis. The lung pathology of ApoE(-/-) HC mice was remarkable for giant abscess-like lesions, massive infiltration by granulocytes, elevated inflammatory cytokine production, and a mean bacterial load approximately 2 log units higher than that of WT HC mice. Compared to WT HC mice, the gamma interferon response of splenocytes restimulated ex vivo with M. tuberculosis culture filtrate protein was delayed in ApoE(-/-) HC mice, and they failed to control M. tuberculosis growth in the lung. OT-II cells adoptively transferred into uninfected ApoE(-/-) HC mice had a weak proliferative response to their antigen, indicating impaired priming of the adaptive immune response. Our studies show that ApoE(-/-) deficiency is associated with delayed expression of adaptive immunity to tuberculosis caused by defective priming of the adaptive immune response and that elevated serum cholesterol is responsible for this effect.
Collapse
|
62
|
de Noronha ALL, Báfica A, Nogueira L, Barral A, Barral-Netto M. Lung granulomas from Mycobacterium tuberculosis/HIV-1 co-infected patients display decreased in situ TNF production. Pathol Res Pract 2007; 204:155-61. [PMID: 18096327 DOI: 10.1016/j.prp.2007.10.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 10/19/2007] [Accepted: 10/22/2007] [Indexed: 10/22/2022]
Abstract
Tuberculosis/HIV-1 co-infection is responsible for thousands of deaths each year, and previous studies have reported that co-infected individuals display major morphological alterations in tissue granulomas. The purpose of this study was to evaluate immunohistopathological characteristics in lung tissues from pulmonary TB/HIV-1-co-infected individuals. Following autopsy, tuberculosis-positive HIV-1-negative cases displayed granulomas with normal architecture, mainly composed of a mononuclear infiltrate with typical epithelioid, as well as giant cells, and exhibiting caseous necrosis. In contrast, lesions from the TB/HIV-1-co-infected group showed extensive necrosis, poorly formed granulomas, and a marked presence of polymorphonuclear cells. More importantly, TNF staining was greatly reduced in the TB/HIV-1-co-infected individuals. Our data suggest that HIV-1 infection alters the organization of pulmonary granulomas by modulating TNF and, possibly, cell trafficking, leading to an impaired anti-tuberculosis response.
Collapse
Affiliation(s)
- Almério L L de Noronha
- Centro de Pesquisas Goncalo Moniz, Fiocruz, Bahia, Brazil; Faculdade de Medicina da Bahia, UFBA, Salvador, Bahia, Brazil
| | | | | | | | | |
Collapse
|
63
|
Widdison S, Watson M, Piercy J, Howard C, Coffey TJ. Granulocyte chemotactic properties of M. tuberculosis versus M. bovis-infected bovine alveolar macrophages. Mol Immunol 2007; 45:740-9. [PMID: 17698194 DOI: 10.1016/j.molimm.2007.06.357] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 06/26/2007] [Accepted: 06/29/2007] [Indexed: 10/23/2022]
Abstract
The incidence of bovine tuberculosis (TB) continues to rise, and causes significant economic losses worldwide. The causative agent of bovine TB, Mycobacterium bovis, is closely related to the human pathogen M. tuberculosis, and yet these two organisms differ profoundly in their ability to cause disease in cattle. The innate immune system is primarily responsible for controlling disease, with the alveolar macrophage (AlvMvarphi) acting as one of the first points of contact between host and respiratory pathogens. In this study we have examined some of the differences in this component of the host immune response to M. bovis and M. tuberculosis, with the aim of improving our understanding of why M. bovis is able to cause disease in cattle whereas M. tuberculosis is efficiently controlled. Initial studies using microarray technology revealed that chemokines represented some of the most differentially expressed genes between M. tuberculosis and M. bovis-infected bovine AlvMvarphi. M. tuberculosis-infected bovine AlvMvarphi expressed significantly higher levels of the chemokines CCL3, CCL4, CCL5 and CXCL8, whereas M. bovis-infected AlvMvarphi were shown to express higher levels of CCL23. We further demonstrated the role of chemokines in bovine TB by showing that supernatants from AlvMvarphi infected with M. tuberculosis were significantly more effective than those from M. bovis-infected cells at attracting bovine granulocytes in an in vitro chemotaxis assay. These results have significant implications in vivo as they suggest that the M. bovis-infected macrophage is able to circumvent activation of the host chemotactic response and thereby evade killing by the host immune system.
Collapse
Affiliation(s)
- Stephanie Widdison
- Division of Immunology, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
| | | | | | | | | |
Collapse
|
64
|
Wick MJ. Monocyte and dendritic cell recruitment and activation during oral Salmonella infection. Immunol Lett 2007; 112:68-74. [PMID: 17720254 DOI: 10.1016/j.imlet.2007.07.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 07/13/2007] [Accepted: 07/15/2007] [Indexed: 12/24/2022]
Abstract
Immunity to bacterial infection involves the joint effort of the innate and adaptive immune systems. The innate immune response is triggered when the body senses bacterial components, such as lipopolysaccharide, that alarm the body of the invader. An array of cell types function in the innate response. These cells are rapidly recruited to the infection site and activated to optimally perform their functions. The adaptive immune response follows the innate response, and one cell type in particular, dendritic cells (DCs), are the critical link between the innate and adaptive responses. This review will summarize recent data concerning the events that occur early during oral infection with the intracellular pathogen Salmonella, with emphasis on the phagocytic cells involved in combating the infection in the gut-associated lymphoid tissues. In particular, recent findings concerning the recruitment and activation of mononuclear phagocyte populations and dendritic cell subsets will be presented after an overview of the Salmonella infection model.
Collapse
Affiliation(s)
- Mary Jo Wick
- Department of Microbiology and Immunology, Göteborg University, Box 435, S-405 30 Göteborg, Sweden.
| |
Collapse
|
65
|
Umemura M, Yahagi A, Hamada S, Begum MD, Watanabe H, Kawakami K, Suda T, Sudo K, Nakae S, Iwakura Y, Matsuzaki G. IL-17-mediated regulation of innate and acquired immune response against pulmonary Mycobacterium bovis bacille Calmette-Guerin infection. THE JOURNAL OF IMMUNOLOGY 2007; 178:3786-96. [PMID: 17339477 DOI: 10.4049/jimmunol.178.6.3786] [Citation(s) in RCA: 417] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-17 is a cytokine that induces neutrophil-mediated inflammation, but its role in protective immunity against intracellular bacterial infection remains unclear. In the present study, we demonstrate that IL-17 is an important cytokine not only in the early neutrophil-mediated inflammatory response, but also in T cell-mediated IFN-gamma production and granuloma formation in response to pulmonary infection by Mycobacterium bovis bacille Calmette-Guérin (BCG). IL-17 expression in the BCG-infected lung was detected from the first day after infection and the expression depended on IL-23. Our observations indicated that gammadelta T cells are a primary source of IL-17. Lung-infiltrating T cells of IL-17-deficient mice produced less IFN-gamma in comparison to those from wild-type mice 4 wk after BCG infection. Impaired granuloma formation was also observed in the infected lungs of IL-17-deficient mice, which is consistent with the decreased delayed-type hypersensitivity response of the infected mice against mycobacterial Ag. These data suggest that IL-17 is an important cytokine in the induction of optimal Th1 response and protective immunity against mycobacterial infection.
Collapse
MESH Headings
- Animals
- Cytokines/immunology
- Hypersensitivity, Delayed/genetics
- Hypersensitivity, Delayed/immunology
- Hypersensitivity, Delayed/pathology
- Immunity, Cellular
- Immunity, Innate/genetics
- Inflammation/genetics
- Inflammation/immunology
- Inflammation/pathology
- Interleukin-17/deficiency
- Interleukin-17/immunology
- Mice
- Mycobacterium bovis/immunology
- Neutrophils/immunology
- Neutrophils/pathology
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Th1 Cells/immunology
- Th1 Cells/pathology
- Time Factors
- Tuberculoma/genetics
- Tuberculoma/immunology
- Tuberculoma/pathology
- Tuberculoma/veterinary
- Tuberculosis, Pulmonary/genetics
- Tuberculosis, Pulmonary/immunology
- Tuberculosis, Pulmonary/veterinary
Collapse
Affiliation(s)
- Masayuki Umemura
- Molecular Microbiology Group, Center of Molecular Biosciences, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
66
|
Torrado E, Adusumilli S, Fraga AG, Small PLC, Castro AG, Pedrosa J. Mycolactone-mediated inhibition of tumor necrosis factor production by macrophages infected with Mycobacterium ulcerans has implications for the control of infection. Infect Immun 2007; 75:3979-88. [PMID: 17517872 PMCID: PMC1951989 DOI: 10.1128/iai.00290-07] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The pathogenicity of Mycobacterium ulcerans, the agent of Buruli ulcer, depends on the cytotoxic exotoxin mycolactone. Little is known about the immune response to this pathogen. Following the demonstration of an intracellular growth phase in the life cycle of M. ulcerans, we investigated the production of tumor necrosis factor (TNF) induced by intramacrophage bacilli of diverse toxigenesis/virulence, as well as the biological relevance of TNF during M. ulcerans experimental infections. Our data show that murine bone marrow-derived macrophages infected with mycolactone-negative strains of M. ulcerans (nonvirulent) produce high amounts of TNF, while macrophages infected with mycolactone-positive strains of intermediate or high virulence produce intermediate or low amounts of TNF, respectively. These results are in accordance with the finding that TNF receptor P55-deficient (TNF-P55 KO) mice are not more susceptible than wild-type mice to infection by the highly virulent strains but are more susceptible to nonvirulent and intermediately virulent strains, demonstrating that TNF is required to control the proliferation of these strains in animals experimentally infected by M. ulcerans. We also show that mycolactone produced by intramacrophage M. ulcerans bacilli inhibits, in a dose-dependent manner, but does not abrogate, the production of macrophage inflammatory protein 2, which is consistent with the persistent inflammatory responses observed in experimentally infected mice.
Collapse
Affiliation(s)
- Egídio Torrado
- Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, 4710-057 Braga, Portugal
| | | | | | | | | | | |
Collapse
|
67
|
Kibiki GS, Myers LC, Kalambo CF, Hoang SB, Stoler MH, Stroup SE, Houpt ER. Bronchoalveolar neutrophils, interferon gamma-inducible protein 10 and interleukin-7 in AIDS-associated tuberculosis. Clin Exp Immunol 2007; 148:254-9. [PMID: 17286802 PMCID: PMC1868885 DOI: 10.1111/j.1365-2249.2007.03330.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
During advanced AIDS tuberculosis (TB) often presents atypically with
smear-negative and non-cavitary disease, yet immune features associated with
this change are poorly characterized. We examined the local immune response in a
cohort of Tanzanian AIDS-associated TB patients who underwent bronchoalveolar
lavage. TB infection was confirmed in bronchoalveolar lavage (BAL) fluid by
culture, probe and polymerase chain reaction (PCR). Among TB patients CD4 count
correlated positively with the extent of cavitary disease as well as BAL TB load
(qPCR CT). TB patients had significantly higher
granulocyte–macrophage colony-stimulating factor (GM-CSF) than non-TB
patients, and those with non-cavitary TB had significantly higher BAL interferon
gamma-inducible protein (IP-10) and interleukin (IL)-7 than those with cavities.
BAL neutrophils were as prevalent as monocytes/macrophages or epithelial
cells, and immunohistochemistry revealed that neutrophils,
monocytes/macrophages, and epithelial cells were major sources of the
IP-10 and IL-7. These data suggest a dysregulated cytokine profile may
contribute to the TB of advanced AIDS.
Collapse
Affiliation(s)
- G S Kibiki
- Medical Department and Radiology Department, Kilimanjaro Christian Medical Centre, Moshi, Tanzania
| | | | | | | | | | | | | |
Collapse
|
68
|
Sá-Nunes A, Medeiros AI, Sorgi CA, Soares EG, Maffei CML, Silva CL, Faccioli LH. Gr-1+ cells play an essential role in an experimental model of disseminated histoplasmosis. Microbes Infect 2006; 9:1393-401. [PMID: 17296322 DOI: 10.1016/j.micinf.2006.10.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 09/07/2006] [Accepted: 10/06/2006] [Indexed: 11/21/2022]
Abstract
Recent studies have shown the participation of Gr-1(+) cells in many types of infections; however, the role played by these cells in the immune response to fungal pathogens is controversial. In this study we determined whether Gr-1(+) cells are involved in the protective immune response in systemic Histoplasma capsulatum infection. Depletion of Gr-1(+) cells using the monoclonal antibody (MAb) RB6-8C5 increased histoplasmosis severity and inhibited the subsequent development of a protective immune response. In addition to the increased fungal burden in lungs and spleens, the Th1 response was found to be unbalanced in these mice and the suppression of the cellular immune response seemed to be associated with increased nitric oxide production. Taken together, these results indicate that Gr-1(+) cell depletion at the beginning of infection allows yeast multiplication and increases mice mortality. This study improves the understanding of the role of Gr-1(+) cells on the protective immunity in histoplasmosis.
Collapse
Affiliation(s)
- Anderson Sá-Nunes
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/no, Ribeirão Preto, São Paulo 14040-903, Brazil
| | | | | | | | | | | | | |
Collapse
|
69
|
Wang T, Tian L, Haino M, Gao JL, Lake R, Ward Y, Wang H, Siebenlist U, Murphy PM, Kelly K. Improved antibacterial host defense and altered peripheral granulocyte homeostasis in mice lacking the adhesion class G protein receptor CD97. Infect Immun 2006; 75:1144-53. [PMID: 17158902 PMCID: PMC1828551 DOI: 10.1128/iai.00869-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
CD97 is a member of the adhesion family of G protein-coupled receptors. Alternatively spliced forms of CD97 bind integrins alpha5beta1 and alphavbeta3, decay accelerating factor, or dermatan sulfate. CD97 is expressed on myeloid cells at high levels and a variety of other cell types at lower levels. Little is known about the physiological function of CD97. To begin dissecting the function of CD97, we evaluated the immune response of CD97 null mice to systemic infection by Listeria monocytogenes. CD97 null mice were significantly more resistant to listeriosis than matched wild-type mice. A major determinant of the difference in survival appeared to be the comparatively more robust accumulation of granulocytes in the blood and in infected livers of CD97 null mice within 18 h of inoculation, correlating with a decrease in the number of bacteria. CD97 null mice also displayed a mild granulocytosis in the nonchallenged state. Because there is a strong suggestion that CD97 functions in an adhesive capacity, we examined the migratory properties of granulocytes in CD97 null mice. In chimeric animals, CD97 null and wild-type granulocytes migrated similarly, as determined by inflammation-induced emigration from the bone marrow and accumulation in the peritoneum. Granulocyte development in the bone marrow of CD97 null mice was comparable to that of wild-type mice, and CD97 deficiency did not appear to stimulate granulocytosis secondary to peripheral inflammation and resultant granulocyte colony-stimulating factor induction, unlike various other models of adhesion deficiencies. Our results suggest that CD97 plays a role in peripheral granulocyte homeostasis.
Collapse
Affiliation(s)
- Tao Wang
- Cell and Cancer Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
70
|
Sohn EJ, Paape MJ, Bannerman DD, Connor EE, Fetterer RH, Peters RR. Shedding of sCD14 by bovine neutrophils following activation with bacterial lipopolysaccharide results in down-regulation of IL-8. Vet Res 2006; 38:95-108. [PMID: 17156740 DOI: 10.1051/vetres:2006052] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Accepted: 10/03/2006] [Indexed: 12/29/2022] Open
Abstract
CD14, the leukocyte co-receptor for lipopolysaccharide (LPS), is important in the response of bovine polymorphonuclear neutrophil leukocytes (PMN) to Gram-negative bacteria. In other species, the expression of CD14 on the surface of PMN was shown to increase after exposure to inflammatory stimuli. These newly expressed molecules may originate from either an intracellular pool or through new gene expression. We sought to characterize bovine PMN cell surface expression and shedding of CD14 molecules, and CD14's effect on secretion of the chemoattractants IL-8 and IL-1beta by PMN. Bovine PMN were incubated in RPMI for 20 h at 37 degrees C with LPS (1, 10, 100 microg/mL). IL-8 release increased with treatment of 1 microg/mL LPS, but decreased 41.5 and 95% at the 10 and 100 microg/mL concentrations of LPS, respectively. In contrast, shedding of CD14 from the surface of PMN only increased at the highest concentration of LPS (100 microg/mL). Secretion of IL-1beta was similar regardless of the LPS concentration used to stimulate PMN. The effect of PMN concentration (1 x 10(7), 2.5 x 10(7), 5 x 10(7), and 10 x 10(7)/mL) on CD14 cell surface expression and shedding of IL-8 and IL-1beta were also determined. Shedding of CD14 by PMN increased with increasing concentration of PMN after exposure to 0.1 and 10 microg/mL of LPS, while secretion of IL-8 decreased. IL-1beta increased at the highest concentration of PMN. The use of real time polymerase chain reaction showed that CD14 mRNA expression was not different between control and LPS-stimulated cells, indicating that the sCD14 came from either membrane bound CD14 or a preformed pool. Our results demonstrate that release of CD14 from PMN suppresses secretion of IL-8, and may be an important regulatory mechanism for controlling excessive migration of PMN into the bovine mammary gland.
Collapse
Affiliation(s)
- Eun J Sohn
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD 20742, USA
| | | | | | | | | | | |
Collapse
|
71
|
Gumenscheimer M, Balkow S, Simon MM, Jirillo E, Galanos C, Freudenberg MA. Stage of primary infection with lymphocytic choriomeningitis virus determines predisposition or resistance of mice to secondary bacterial infections. Med Microbiol Immunol 2006; 196:79-88. [PMID: 17136407 DOI: 10.1007/s00430-006-0030-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Indexed: 10/23/2022]
Abstract
We investigated the effect of a primary non-lethal infection with lymphocytic choriomeningitis virus (LCMV) on the course and outcome of a secondary infection with the Gram-negative Salmonella enterica serovar Typhimurium or the Gram-positive Listeria monocytogenes in mice. We found that at each stage of the viral infection the susceptibility of mice to bacterial super-infections changes dramatically and depends also on whether the secondary infection is a Gram-positive or Gram-negative one. The study shows that the outcome of the secondary infection is determined by a delicate balance between the overproduction of and the hypersensitivity to inflammatory cytokines (TNF-alpha and IFN-gamma), as well as by the changes in blood leukocytes occurring in mice in the course of viral infection.
Collapse
|
72
|
Navarini AA, Recher M, Lang KS, Georgiev P, Meury S, Bergthaler A, Flatz L, Bille J, Landmann R, Odermatt B, Hengartner H, Zinkernagel RM. Increased susceptibility to bacterial superinfection as a consequence of innate antiviral responses. Proc Natl Acad Sci U S A 2006; 103:15535-9. [PMID: 17030789 PMCID: PMC1622858 DOI: 10.1073/pnas.0607325103] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The reason why severe localized or systemic virus infections enhance and aggravate bacterial superinfection is poorly understood. Here we show that virus-induced IFN type I caused apoptosis in bone marrow granulocytes, drastically reduced granulocyte infiltrates at the site of bacterial superinfection, caused up to 1,000-fold higher bacterial titers in solid organs, and increased disease susceptibility. The finding that the innate antiviral immune response reduces the antibacterial granulocyte defense offers an explanation for enhanced susceptibility to bacterial superinfection during viral disease.
Collapse
Affiliation(s)
- Alexander A. Navarini
- *Institute for Experimental Immunology, University Hospital Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland
- To whom correspondence may be addressed. E-mail:
or
| | - Mike Recher
- *Institute for Experimental Immunology, University Hospital Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland
| | - Karl S. Lang
- *Institute for Experimental Immunology, University Hospital Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland
| | - Panco Georgiev
- Department of Visceral and Transplantation Surgery, University Hospital Zurich, Rämistrasse 100, CH-8091 Zurich, Switzerland
| | - Susanne Meury
- University Children's Hospital, Roemergasse 12, CH-4058 Basel, Switzerland
| | - Andreas Bergthaler
- *Institute for Experimental Immunology, University Hospital Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland
| | - Lukas Flatz
- *Institute for Experimental Immunology, University Hospital Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland
| | - Jacques Bille
- Faculté de Biologie et Médecine, Institut de Microbiologie, Rue du Bugnon 48, CH-1011 Lausanne, Switzerland
| | - Regine Landmann
- Division of Infectious Diseases, Department of Research, University Hospital, Hebelstrasse 20, CH-4031 Basel, Switzerland; and
| | - Bernhard Odermatt
- **Department of Pathology, University Hospital Zurich, CH-8091 Zurich, Switzerland
| | - Hans Hengartner
- *Institute for Experimental Immunology, University Hospital Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland
| | - Rolf M. Zinkernagel
- *Institute for Experimental Immunology, University Hospital Zurich, Schmelzbergstrasse 12, CH-8091 Zurich, Switzerland
- To whom correspondence may be addressed. E-mail:
or
| |
Collapse
|
73
|
Keller C, Hoffmann R, Lang R, Brandau S, Hermann C, Ehlers S. Genetically determined susceptibility to tuberculosis in mice causally involves accelerated and enhanced recruitment of granulocytes. Infect Immun 2006; 74:4295-309. [PMID: 16790804 PMCID: PMC1489748 DOI: 10.1128/iai.00057-06] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Classical twin studies and recent linkage analyses of African populations have revealed a potential involvement of host genetic factors in susceptibility or resistance to Mycobacterium tuberculosis infection. In order to identify the candidate genes involved and test their causal implication, we capitalized on the mouse model of tuberculosis, since inbred mouse strains also differ substantially in their susceptibility to infection. Two susceptible and two resistant mouse strains were aerogenically infected with 1,000 CFU of M. tuberculosis, and the regulation of gene expression was examined by Affymetrix GeneChip U74A array with total lung RNA 2 and 4 weeks postinfection. Four weeks after infection, 96 genes, many of which are involved in inflammatory cell recruitment and activation, were regulated in common. One hundred seven genes were differentially regulated in susceptible mouse strains, whereas 43 genes were differentially expressed only in resistant mice. Data mining revealed a bias towards the expression of genes involved in granulocyte pathophysiology in susceptible mice, such as an upregulation of those for the neutrophil chemoattractant LIX (CXCL5), interleukin 17 receptor, phosphoinositide kinase 3 delta, or gamma interferon-inducible protein 10. Following M. tuberculosis challenge in both airways or peritoneum, granulocytes were recruited significantly faster and at higher numbers in susceptible than in resistant mice. When granulocytes were efficiently depleted by either of two regimens at the onset of infection, only susceptible mice survived aerosol challenge with M. tuberculosis significantly longer than control mice. We conclude that initially enhanced recruitment of granulocytes contributes to susceptibility to tuberculosis.
Collapse
Affiliation(s)
- Christine Keller
- Molecular Infection Biology, Research Center Borstel, Parkallee 22, D-23845 Borstel, Germany.
| | | | | | | | | | | |
Collapse
|
74
|
Johansson C, Ingman M, Jo Wick M. Elevated neutrophil, macrophage and dendritic cell numbers characterize immune cell populations in mice chronically infected with Salmonella. Microb Pathog 2006; 41:49-58. [PMID: 16782300 DOI: 10.1016/j.micpath.2006.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 03/15/2006] [Accepted: 03/16/2006] [Indexed: 01/22/2023]
Abstract
The present study characterizes immune cell populations in mice chronically infected with Salmonella. Mice were characterized as chronically infected based on persistently high titers of Salmonella-reactive immunoglobulins in the serum >6 months after a single oral dose of S. enterica serovar Typhimurium. These mice had a visibly enlarged spleen but not liver, while both organs harbored bacteria and had increased total cellularity up to 11 months post-infection. Flow cytometry analysis revealed significantly elevated numbers of neutrophils, dendritic cells (DC) and macrophages in the spleen of chronically infected mice. In contrast, no significant increase in the absolute number of T and B cells was apparent in the spleen and DX5+ cells, which includes NK cells, some NK T cells and possibly some activated T cells, appears to correlate with chronic Salmonella infection in the liver but not the spleen. In situ analyses revealed that CD8alpha+ DC and Gr-1+ cells (neutrophils) increased in the splenic red pulp of chronically infected mice. In addition, Gr-1+ cells, CD68+ cells and CD11c+ cells (DC), the latter lacking detectable staining for CD8alpha and CD4, accumulated around hepatic blood vessels and in the hepatic network in the liver of mice chronically harboring bacteria. These data provide insight into changes that occur within immune cell populations, most notably within splenic and hepatic phagocytic cell populations, that accompany chronic infection with the intracellular bacterium Salmonella.
Collapse
Affiliation(s)
- Cecilia Johansson
- Department of Cell and Molecular Biology, Section for Immunology, Lund University, 221 84 Lund, Sweden
| | | | | |
Collapse
|
75
|
Logsdon LK, Mecsas J. A non-invasive quantitative assay to measure murine intestinal inflammation using the neutrophil marker lactoferrin. J Immunol Methods 2006; 313:183-90. [PMID: 16806255 DOI: 10.1016/j.jim.2006.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 05/01/2006] [Accepted: 05/04/2006] [Indexed: 10/24/2022]
Abstract
Intestinal inflammation in mice is most frequently assessed by histology or FACS, processes that necessitate sacrificing mice. We developed a lactoferrin ELISA for murine feces to quantify intestinal inflammation in mice with enteric infections or colitis. Levels of fecal lactoferrin, a protein secreted by activated neutrophils, were consistent with neutrophil infiltration as assessed by histology, indicating that this fecal lactoferrin ELISA is a good alternative to histology. The fecal lactoferrin ELISA provides a non-invasive, quantitative assessment of intestinal inflammation, which should facilitate longitudinal studies of the development of and/or therapies reducing intestinal inflammation in individual mice and reduce the number of mice needed for such studies.
Collapse
Affiliation(s)
- Lauren K Logsdon
- Department of Molecular Biology and Microbiology, Tufts University, 136 Harrison Ave, Boston, MA 02111, USA
| | | |
Collapse
|
76
|
Martens RJ, Cohen ND, Jones SL, Moore TA, Edwards JF. Protective role of neutrophils in mice experimentally infected with Rhodococcus equi. Infect Immun 2005; 73:7040-2. [PMID: 16177388 PMCID: PMC1230988 DOI: 10.1128/iai.73.10.7040-7042.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neutrophils are important in controlling early infections with the intracellular bacterium Rhodococcus equi. Antineutrophil monoclonal antibody (RB6-8C5)-induced neutrophil deficiency during the first week after experimental infection of mice with R. equi resulted in more severe disease and significantly increased tissue concentrations of R. equi.
Collapse
Affiliation(s)
- Ronald J Martens
- Equine Infectious Disease Laboratory, Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, 77843, USA.
| | | | | | | | | |
Collapse
|
77
|
Oliveira MS, Fraga AG, Torrado E, Castro AG, Pereira JP, Filho AL, Milanezi F, Schmitt FC, Meyers WM, Portaels F, Silva MT, Pedrosa J. Infection with Mycobacterium ulcerans induces persistent inflammatory responses in mice. Infect Immun 2005; 73:6299-310. [PMID: 16177301 PMCID: PMC1230890 DOI: 10.1128/iai.73.10.6299-6310.2005] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Buruli ulcer (BU) is a devastating, necrotizing, tropical skin disease caused by infections with Mycobacterium ulcerans. In contrast to other mycobacterioses, BU has been associated with minimal or absent inflammation. However, here we show that in the mouse M. ulcerans induces persistent inflammatory responses with virulence-dependent patterns. Mycolactone-positive, cytotoxic strains are virulent for mice and multiply progressively, inducing both early and persistent acute inflammatory responses. The cytotoxicity of these strains leads to progressive destruction of the inflammatory infiltrates by postapoptotic secondary necrosis, generating necrotic acellular areas with extracellular bacilli released by the lysis of infected phagocytes. The necrotic areas, always surrounded by acute inflammatory infiltrates, expand through the progressive invasion of healthy tissues around the initial necrotic lesions by bacteria and by newly recruited acute inflammatory cells. Our observations show that the lack of inflammatory infiltrates in the extensive areas of necrosis seen in advanced infections results from the destruction of continuously produced inflammatory infiltrates and not from M. ulcerans-induced local or systemic immunosuppression. Whether this is the mechanism behind the predominance of minimal or absent inflammatory responses in BU biopsies remains to be elucidated.
Collapse
Affiliation(s)
- Martinha S Oliveira
- Life and Health Sciences Research Institute, School of Health Sciences (ICVS), University of Minho, Braga, Portugal
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
78
|
Kirimanjeswara GS, Mann PB, Pilione M, Kennett MJ, Harvill ET. The Complex Mechanism of Antibody-Mediated Clearance ofBordetellafrom the Lungs Requires TLR4. THE JOURNAL OF IMMUNOLOGY 2005; 175:7504-11. [PMID: 16301658 DOI: 10.4049/jimmunol.175.11.7504] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although the antibacterial effects of Abs are well studied in in vitro systems, the in vivo effects of Abs cannot always be accurately predicted. Complicated cross-talk between different effector functions of Abs and various arms of the immune system can affect their activities in vivo. Using the mouse respiratory pathogen Bordetella bronchiseptica, we examined the mechanisms of Ab-mediated clearance of bacteria from the respiratory tract. Interestingly, although TLR4 was not necessary for protective immunity following infection, it was required for rapid bacterial clearance in mice that were vaccinated or adoptively transferred Abs. TLR4 was important for the rapid recruitment of neutrophils that are necessary for Ab-mediated bacterial clearance via a mechanism that requires both FcgammaR and CR3. These data are consistent with a model in which TLR4-mediated inflammatory responses aid in the recruitment of neutrophils, which phagocytose Ab- and complement-opsonized bacteria via FcgammaRs and CR3. Although pattern recognition receptors are known to be involved in innate immunity and the generation of adaptive immunity, their contributions to specific adaptive immune functions should be considered in ongoing efforts to improve vaccine-induced protective immunity.
Collapse
Affiliation(s)
- Girish S Kirimanjeswara
- Immunology Research Laboratories, Department of Biomedical Veterinary Sciences, Pennsylvania State University, University Park 16802, USA
| | | | | | | | | |
Collapse
|
79
|
Kirimanjeswara GS, Agosto LM, Kennett MJ, Bjornstad ON, Harvill ET. Pertussis toxin inhibits neutrophil recruitment to delay antibody-mediated clearance of Bordetella pertussis. J Clin Invest 2005; 115:3594-601. [PMID: 16294220 PMCID: PMC1283938 DOI: 10.1172/jci24609] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 09/20/2005] [Indexed: 11/17/2022] Open
Abstract
Whooping cough is considered a childhood disease, although there is growing evidence that children are infected by adult carriers. Additionally, increasing numbers of vaccinated adults are being diagnosed with Bordetella pertussis disease. Thus it is critical to understand how B. pertussis remains endemic even in highly vaccinated or immune populations. Here we used the mouse model to examine the nature of sterilizing immunity to B. pertussis. Antibodies were necessary to control infection but did not rapidly clear B. pertussis from the lungs. However, antibodies affected B. pertussis after a delay of at least a week by a mechanism that involved neutrophils and Fc receptors, suggesting that neutrophils phagocytose and clear antibody-opsonized bacteria via Fc receptors. B. pertussis blocked migration of neutrophils and inhibited their recruitment to the lungs during the first week of infection by a pertussis toxin-dependent (PTx-dependent) mechanism; a PTx mutant of B. pertussis induced rapid neutrophil recruitment and was rapidly cleared from the lungs by adoptively transferred antibodies. Depletion of neutrophils abrogated the defects of the PTx mutant. Together these results indicate that PTx inhibits neutrophil recruitment, which consequently allows B. pertussis to avoid rapid antibody-mediated clearance and therefore successfully infect immune hosts.
Collapse
Affiliation(s)
- Girish S Kirimanjeswara
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | | | | | | | | |
Collapse
|
80
|
Godaly G, Young DB. Mycobacterium bovis bacille Calmette Guerin infection of human neutrophils induces CXCL8 secretion by MyD88-dependent TLR2 and TLR4 activation. Cell Microbiol 2005; 7:591-601. [PMID: 15760459 DOI: 10.1111/j.1462-5822.2004.00489.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
To investigate the potential role of neutrophils in initiation of immune responses to mycobacteria, we have characterized the response of human neutrophils to infection with Mycobacterium bovis bacille Calmette Guerin, the BCG vaccine. BCG induced transcription and secretion of the chemokine CXCL8, by signalling through Toll-like receptors TLR2 and TLR4, in conjunction with the adaptor protein myeloid differentiation factor 88 (MyD88). Blocking of responses with antibodies revealed a difference in the kinetics of signalling through the different TLRs. Anti-TLR2 antibody blocked the early phase of CXCL8 and MyD88 induction. Anti-TLR4 antibody blocked the late phase of induction occurring 2 h after infection. The existence of a TLR/MyD88 pathway for recognition and response to mycobacterial ligands provides neutrophils with the ability to drive the recruitment and activation of inflammatory cells during the early phase of mycobacterial infection and immunization.
Collapse
Affiliation(s)
- Gabriela Godaly
- Department of Infectious Diseases and Microbiology, Division of Investigative Science, Faculty of Medicine, Imperial College London, UK.
| | | |
Collapse
|
81
|
Abadie V, Badell E, Douillard P, Ensergueix D, Leenen PJM, Tanguy M, Fiette L, Saeland S, Gicquel B, Winter N. Neutrophils rapidly migrate via lymphatics after Mycobacterium bovis BCG intradermal vaccination and shuttle live bacilli to the draining lymph nodes. Blood 2005; 106:1843-50. [PMID: 15886329 DOI: 10.1182/blood-2005-03-1281] [Citation(s) in RCA: 275] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The early innate response after Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination is poorly characterized but probably decisive for subsequent protective immunity against tuberculosis. Therefore, we vaccinated mice with fluorescent BCG strains in the ear dorsum, as a surrogate of intradermal vaccination in humans. During the first 3 days, we tracked BCG host cells migrating out of the dermis to the auricular draining lymph nodes (ADLNs). Resident skin dendritic cells (DCs) or macrophages did not play a predominant role in early BCG capture and transport to ADLNs. The main BCG host cells rapidly recruited both in the dermis and ADLNs were neutrophils. Fluorescent green or red BCG strains injected into nonoverlapping sites were essentially sheltered by distinct neutrophils in the ADLN capsule, indicating that neutrophils had captured bacilli in peripheral tissue and transported them to the lymphoid organ. Strikingly, we observed BCG-infected neutrophils in the lumen of lymphatic vessels by confocal microscopy on ear dermis. Fluorescence-labeled neutrophils injected into the ears accumulated exclusively into the ipsilateral ADLN capsule after BCG vaccination. Thus, we provide in vivo evidence that neutrophils, like DCs or inflammatory monocytes, migrate via afferent lymphatics to lymphoid tissue and can shuttle live microorganisms.
Collapse
Affiliation(s)
- Valérie Abadie
- Mycobacterial Genetics Unit, Institut Pasteur, 25 rue du Docteur Roux, 7724 Paris Cedex 15, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
82
|
Eruslanov EB, Lyadova IV, Kondratieva TK, Majorov KB, Scheglov IV, Orlova MO, Apt AS. Neutrophil responses to Mycobacterium tuberculosis infection in genetically susceptible and resistant mice. Infect Immun 2005; 73:1744-53. [PMID: 15731075 PMCID: PMC1064912 DOI: 10.1128/iai.73.3.1744-1753.2005] [Citation(s) in RCA: 209] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Revised: 08/17/2004] [Accepted: 09/27/2004] [Indexed: 12/21/2022] Open
Abstract
The role of neutrophils in tuberculosis (TB) resistance and pathology is poorly understood. Neutrophil reactions are meant to target the offending pathogen but may lead to destruction of the host lung tissue, making the defending cells an enemy. Here, we show that mice of the I/St strain which are genetically susceptible to TB show an unusually high and prolonged neutrophil accumulation in their lungs after intratracheal infection. Compared to neutrophils from more resistant A/Sn mice, I/St neutrophils display an increased mobility and tissue influx, prolonged lifespan, low expression of the CD95 (Fas) apoptotic receptor, relative resistance to apoptosis, and an increased phagocytic capacity for mycobacteria. Segregation genetic analysis in (I/St x A/Sn)F2 hybrids indicates that the alleles of I/St origin at the chromosome 3 and 17 quantitative trait loci which are involved in the control of TB severity also determine a high level of neutrophil influx. These features, along with the poor ability of neutrophils to restrict mycobacterial growth compared to that of lung macrophages, indicate that the prevalence of neutrophils in TB inflammation contributes to the development of pathology, rather than protection of the host, and that neutrophils may play the role of a "Trojan horse" for mycobacteria.
Collapse
Affiliation(s)
- Evgenyi B Eruslanov
- Laboratory for Immunogenetics, Central Institute for Tuberculosis, Yauza Alley 2, Moscow 107564, Russia
| | | | | | | | | | | | | |
Collapse
|
83
|
Currie BJ, Jacups SP, Cheng AC, Fisher DA, Anstey NM, Huffam SE, Krause VL. Melioidosis epidemiology and risk factors from a prospective whole-population study in northern Australia. Trop Med Int Health 2004; 9:1167-74. [PMID: 15548312 DOI: 10.1111/j.1365-3156.2004.01328.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The aims of this study were to describe the epidemiology of melioidosis in tropical northern Australia and to assess the importance of defined risk factors. METHODS The data were taken from a 14-year prospective study of 364 cases of melioidosis in the 'Top End' of the Northern Territory. A whole-population logistic regression model was used to estimate the crude and adjusted relative risk (RR) for the defined risk factors. RESULTS The mean age of the study population was 46.8 years, 264 (72.5%) were male, 178 (49%) were aboriginal Australians and 59 (16.2%) died from melioidosis. Average annual incidence was 19.6 cases per 100 000 population, with an estimated rate of 260 cases per 100,000 diabetics per year. Using a whole-population logistic regression model, the estimated crude and adjusted RR [95% confidence intervals (CI)] for melioidosis were 6.3 (5.1-7.8) and 4.0 (3.2-5.1) for those aged > or = 45 years, 2.3 (1.8-2.9) and 2.4 (1.9-3.0) for males, 2.9 (2.3-3.5) and 3.0 (2.3-4.0) for aboriginal Australians, 21.2 (17.1-26.3) and 13.1 (9.4-18.1) for diabetics, 2.7 (2.2-3.4) and 2.1 (1.6-2.6) for those with excess alcohol consumption, 6.8 (5.4-8.6) and 4.3 (3.4-5.5) for chronic lung disease and 6.7 (4.7-9.6) and 3.2 (2.2-4.8) for chronic renal disease, respectively. CONCLUSIONS Diabetes, excess alcohol intake, chronic renal disease and chronic lung disease are each independent risk factors for melioidosis. In tropical northern Australia, male sex, aboriginal ethnicity and age of > or = 45 years are also independent predictors for melioidosis. Impaired polymorph function may be critical in the predisposition to melioidosis.
Collapse
Affiliation(s)
- Bart J Currie
- Menzies School of Health Research, Charles Darwin University, Darwin, Australia.
| | | | | | | | | | | | | |
Collapse
|
84
|
Lyons MJ, Yoshimura T, McMurray DN. Interleukin (IL)-8 (CXCL8) induces cytokine expression and superoxide formation by guinea pig neutrophils infected with Mycobacterium tuberculosis. Tuberculosis (Edinb) 2004; 84:283-92. [PMID: 15207803 DOI: 10.1016/j.tube.2003.09.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
SETTING Interleukin (IL)-8, a neutrophil attracting chemokine, is known to be made by a variety of leukocyte populations following stimulation by Mycobacterium tuberculosis. OBJECTIVE The effect of recombinant guinea pig IL-8 on the ability of neutrophils to generate a cytokine response after infection with M. tuberculosis H37Ra was examined. DESIGN Recombinant gpIL-8 was produced by subcloning the gene into Escherichia coli and purification over a nickel column. The identity of the rgpIL-8 was confirmed by sequencing. Neutrophils were harvested from the blood of non-vaccinated or M. bovis BCG-vaccinated guinea pigs and tested for their ability to migrate toward media alone, 10 microg/ml PPD, f-Met-Leu-Phe (f-MLP), or rgpIL-8 in 96-well chemotactic chambers. Neutrophils were also pre-stimulated with rgpIL-8 then restimulated with LPS (10 microg/ml) or infected in vitro with M. tuberculosis H37Ra (MOI 1:1). RESULTS Recombinant gpIL-8 and f-MLP induced significant chemotaxis in neutrophils from both non-vaccinated and BCG-vaccinated guinea pigs, with the best chemotaxis occurring at a concentration of 10(-7)M. Real-time PCR analysis revealed that pre-treatment of neutrophils induced elevated levels of IL-8 and TNF-alpha mRNA and protein as well as superoxide, but not mRNA for MCP-1, IFN-gamma, or TGF-beta when compared to neutrophils pre-stimulated with media alone. CONCLUSIONS The presence of IL-8 early in the host response to M. tuberculosis infection may be an important contributor to a successful immune response. How essential a role IL-8 plays remains unknown and merits further study.
Collapse
Affiliation(s)
- Mark J Lyons
- Department of Medical Microbiology and Immunology, Texas A&M University, System Health Science Center, Reynolds Medical Building Room 463, University Drive, College Station, TX 77843-1114, USA
| | | | | |
Collapse
|
85
|
al-Ramadi BK, Bashir G, Rizvi TA, Fernandez-Cabezudo MJ. Poor survival but high immunogenicity of IL-2-expressing Salmonella typhimurium in inherently resistant mice. Microbes Infect 2004; 6:350-9. [PMID: 15050962 DOI: 10.1016/j.micinf.2003.12.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2003] [Accepted: 12/24/2003] [Indexed: 10/26/2022]
Abstract
An IL-2-expressing, attenuated strain of Salmonella typhimurium (strain GIDIL2) was previously shown to survive poorly and to have lower immunogenicity in susceptible mice than its parental, non-cytokine-expressing strain (designated BRD509). In the present study, we compared the immune responses induced by both bacterial strains in inherently Salmonella-resistant C3H/HeN mice. Analysis of the bacterial loads in the peritoneum and spleen revealed that colony-forming units (CFUs) of GIDIL2 were consistently lower than the corresponding BRD509 CFUs. As early as 48 h after inoculation, there were 60-fold lower CFUs of GIDIL2 than BRD509 organisms in the peritoneal cavity. Similarly, the differences in splenic CFUs of GIDIL2 were 20- to 50-fold lower than those of BRD509 over a period of 3-21 days post-injection. This rapid rate of clearance of the GIDIL2 organisms correlated with significantly decreased infection-induced splenomegaly and nitric oxide production by spleen cells. However, despite the poor survival of GIDIL2 organisms in vivo, they could activate peritoneal NK cells efficiently. As early as 48 h after immunization, equivalent levels of NK-mediated cellular cytotoxicity were induced by BRD509 and GIDIL2 strains. Direct evidence for priming of the immune response was shown by demonstrating increased production of IFN-gamma in a recall response by spleen memory T cells obtained 3 weeks after immunization. Finally, mice inoculated with a single dose of either BRD509 or GIDIL2 organisms were fully protected against a challenge of >100-fold the LD50 dose of virulent Salmonella. Taken together, our data demonstrate that despite their rapid clearance from the reticuloendothelial system, IL-2-expressing Salmonella are immunogenic and fully capable of affording excellent protection against virulent challenge in Salmonella-resistant C3H/HeN mice.
Collapse
Affiliation(s)
- Basel K al-Ramadi
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE.
| | | | | | | |
Collapse
|
86
|
Abstract
To understand the role of neutrophils in the development of rat tuberculosis in vivo, we utilized lipopolysaccharide (LPS)-induced neutrophilia in the lungs. LPS (50 micro g/ml) was administered intratracheally to male Fischer rats. Rats were then infected with Mycobacterium tuberculosis by an airborne route. Intratracheal injection of LPS significantly blocked the development of pulmonary granulomas and significantly reduced pulmonary CFU (P < 0.01). LPS treatment with amphotericin B (an LPS inhibitor) or neutralizing anti-rat neutrophil antibody reversed the development of pulmonary lesions. LPS-induced transient neutrophilia prevented early mycobacterial infection. The timing of LPS administration was important. When given intratracheally at least 10 days after aerial infection, LPS did not prevent development of tuberculosis. Neutrophils obtained by bronchoalveolar lavage killed M. tuberculosis cells. These results indicate clearly that neutrophils participate actively in defense against early-phase tuberculosis.
Collapse
Affiliation(s)
- Isamu Sugawara
- Mycobacterial Reference Center, The Research Institute of Tuberculosis, Tokyo 204-0022, Japan.
| | | | | |
Collapse
|
87
|
Abstract
Pathogenic mycobacteria, including the causative agents of tuberculosis and leprosy, are responsible for considerable morbidity and mortality worldwide. A hallmark of these pathogens is their tendency to establish chronic infections that produce similar pathologies in a variety of hosts. During infection, mycobacteria reside in macrophages and induce the formation of granulomas, organized immune complexes of differentiated macrophages, lymphocytes, and other cells. This review summarizes our understanding of Mycobacterium-host cell interactions, the bacterial-granuloma interface, and mechanisms of bacterial virulence and persistence. In addition, we highlight current controversies and unanswered questions in these areas.
Collapse
Affiliation(s)
- Christine L Cosma
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA.
| | | | | |
Collapse
|
88
|
Emoto M, Miyamoto M, Emoto Y, Yoshizawa I, Brinkmann V, van Rooijen N, Kaufmann SHE. Highly biased type 1 immune responses in mice deficient in LFA-1 in Listeria monocytogenes infection are caused by elevated IL-12 production by granulocytes. THE JOURNAL OF IMMUNOLOGY 2004; 171:3970-6. [PMID: 14530315 DOI: 10.4049/jimmunol.171.8.3970] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
LFA-1 (CD11a/CD18) plays a key role in various inflammatory responses. Here we show that the acquired immune response to Listeria monocytogenes is highly biased toward type 1 in the absence of LFA-1. At the early stage of listeriosis, numbers of IFN-gamma producers in the liver and spleen of LFA-1(-/-) mice were markedly increased compared with heterozygous littermates and Valpha14(+)NKT cell-deficient mice, and NK cells were major IFN-gamma producers. Numbers of IL-12 producers were also markedly elevated in LFA-1(-/-) mice compared with heterozygous littermates, and endogenous IL-12 neutralization impaired IFN-gamma production by NK cells. Granulocyte depletion diminished numbers of IL-12 producers and IFN-gamma-secreting NK cells in the liver of LFA-1(-/-) mice. Granulocytes from the liver of L. monocytogenes-infected LFA-1(-/-) mice were potent IL-12 producers. Thus, in the absence of LFA-1, granulocytes are a major source of IL-12 at the early stage of listeriosis. We assume that highly biased type 1 immune responses in LFA-1(-/-) mice are caused by increased levels of IL-12 from granulocytes and that granulocytes play a major role in IFN-gamma secretion by NK cells. In conclusion, LFA-1 regulates type 1 immune responses by controlling prompt infiltration of IL-12-producing granulocytes into sites of inflammation.
Collapse
Affiliation(s)
- Masashi Emoto
- Department of Immunology, Max-Planck- Institute for Infection Biology, Berlin, Germany.
| | | | | | | | | | | | | |
Collapse
|
89
|
Emoto M, Emoto Y, Brinkmann V, Miyamoto M, Yoshizawa I, Stäber M, van Rooijen N, Hamann A, Kaufmann SHE. Increased resistance of LFA-1-deficient mice to lipopolysaccharide-induced shock/liver injury in the presence of TNF-alpha and IL-12 is mediated by IL-10: a novel role for LFA-1 in the regulation of the proinflammatory and anti-inflammatory cytokine balance. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:584-93. [PMID: 12847222 DOI: 10.4049/jimmunol.171.2.584] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Challenge with low doses of LPS together with D-galactosamine causes severe liver injury, resulting in lethal shock (low dose LPS-induced shock). We examined the role of LFA-1 in low dose LPS-induced shock. LFA-1(-/-) mice were more resistant to low dose LPS-induced shock/liver injury than their heterozygous littermates, although serum levels of TNF-alpha and IL-12 were higher in these mice. C57BL/6 mice were not rescued from lethal effects of LPS by depletion of NK1(+) cells, granulocytes, or macrophages, and susceptibility of NKT cell-deficient mice was comparable to that of controls. High numbers of platelets were detected in the liver of LFA-1(+/-) mice after low dose LPS challenge, whereas liver accumulation of platelets was only marginal in LFA-1(-/-) mice. Following low dose LPS challenge, serum levels of IL-10 were higher in LFA-1(-/-) mice than in LFA-1(+/-) mice, and susceptibility to low dose LPS-induced shock as well as platelet accumulation in the liver of LFA-1(-/-) mice were markedly increased by IL-10 neutralization. Serum levels of IL-10 in LFA-1(+/-) mice were only marginally affected by macrophage depletion. However, in LFA-1(-/-) mice macrophage depletion markedly reduced serum levels of IL-10, and as a corollary, susceptibility of LFA-1(-/-) mice to low dose LPS-induced shock was markedly elevated despite the fact that TNF-alpha levels were also diminished. We conclude that LFA-1 participates in LPS-induced lethal shock/liver injury by regulating IL-10 secretion from macrophages and that IL-10 plays a decisive role in resistance to shock/liver injury. Our data point to a novel role of LFA-1 in control of the proinflammatory/anti-inflammatory cytokine network.
Collapse
MESH Headings
- Animals
- Antibodies, Monoclonal/administration & dosage
- Clodronic Acid/administration & dosage
- Cytokines/biosynthesis
- Cytokines/metabolism
- Dose-Response Relationship, Immunologic
- Down-Regulation/genetics
- Down-Regulation/immunology
- Female
- Granulocytes/immunology
- Granulocytes/metabolism
- Immunity, Innate/genetics
- Inflammation Mediators/antagonists & inhibitors
- Inflammation Mediators/metabolism
- Injections, Intravenous
- Interleukin-10/blood
- Interleukin-10/immunology
- Interleukin-10/metabolism
- Interleukin-10/physiology
- Interleukin-12/blood
- Interleukin-12/physiology
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Leukocytosis/genetics
- Leukocytosis/immunology
- Leukocytosis/pathology
- Lipopolysaccharides/administration & dosage
- Liver/immunology
- Liver/metabolism
- Liver/pathology
- Lymphocyte Function-Associated Antigen-1/genetics
- Lymphocyte Function-Associated Antigen-1/physiology
- Macrophages/drug effects
- Macrophages/immunology
- Macrophages/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Platelet Count
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Shock, Septic/genetics
- Shock, Septic/immunology
- Shock, Septic/mortality
- Shock, Septic/pathology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Tumor Necrosis Factor-alpha/metabolism
- Tumor Necrosis Factor-alpha/physiology
- Up-Regulation/genetics
- Up-Regulation/immunology
Collapse
Affiliation(s)
- Masashi Emoto
- Department of Immunology and. Central Core Facility Microscopy, Max-Planck-Institute for Infection Biology, Berlin, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
90
|
Lee JW, Paape MJ, Elsasser TH, Zhao X. Recombinant soluble CD14 reduces severity of intramammary infection by Escherichia coli. Infect Immun 2003; 71:4034-9. [PMID: 12819092 PMCID: PMC161972 DOI: 10.1128/iai.71.7.4034-4039.2003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The interaction among gram-negative bacteria, the innate immune system, and soluble CD14 (sCD14) has not been well documented. The effect of recombinant bovine sCD14 (rbosCD14) on milk somatic cell count (SCC), bacterial clearance, and cytokine production was investigated by using a bovine intramammary Escherichia coli infection model. We first determined whether rbosCD14 would increase the SCC during a lipopolysaccharide (LPS) challenge. Three quarters of each of six healthy lactating cows were injected with either 0.3 microg of LPS, 0.3 microg of LPS plus 100 micro g of rbosCD14, or saline. In comparison with quarters injected with LPS alone, the SCC was twofold higher (P < 0.05) in quarters injected with LPS plus rbosCD14 after the challenge. We therefore hypothesized that when E. coli bacteria invade the mammary gland, sCD14 in milk would interact with LPS and rapidly recruit neutrophils from the blood to eliminate the bacteria before establishment of infection. To test this hypothesis, two quarters of each of nine healthy cows were challenged with either 50 CFU of E. coli plus saline or 50 CFU of E. coli plus 100 microg of rbosCD14. Quarters challenged with E. coli plus rbosCD14 had a more rapid recruitment of neutrophils, which was accompanied by a faster clearance of bacteria, lower concentrations of tumor necrosis factor alpha and interleukin-8 in milk, and milder clinical symptoms, than challenged quarters injected with saline. Results indicate that increasing the concentration of sCD14 in milk may be a potential strategy with which to prevent or reduce the severity of infection by coliform bacteria.
Collapse
Affiliation(s)
- Jai-Wei Lee
- Department of Animal Science, McGill University, Ste-Anne-de-Bellevue, Quebec H9X 3V9, Canada
| | | | | | | |
Collapse
|
91
|
Miyamoto M, Emoto M, Emoto Y, Brinkmann V, Yoshizawa I, Seiler P, Aichele P, Kita E, Kaufmann SHE. Neutrophilia in LFA-1-deficient mice confers resistance to listeriosis: possible contribution of granulocyte-colony-stimulating factor and IL-17. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:5228-34. [PMID: 12734371 DOI: 10.4049/jimmunol.170.10.5228] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
LFA-1 (CD11a/CD18) plays a crucial role in various inflammatory responses. In this study, we show that LFA-1(-/-) mice are far more resistant to Listeria monocytogenes infection than LFA-1(+/-) mice. Consistent with this, we found the following: 1) the numbers of granulocytes infiltrating the liver were markedly higher in LFA-1(-/-) mice than in LFA-1(+/-) mice, 2) increased antilisterial resistance in LFA-1(-/-) mice was abrogated by depletion of granulocytes, and 3) the numbers of granulocytes in peripheral blood, and the serum levels of both G-CSF and IL-17 were higher in LFA-1(-/-) mice than in LFA-1(+/-) mice. Neither spontaneous apoptosis nor survival of granulocytes from LFA-1(-/-) mice were affected by physiological concentrations of G-CSF. Our data suggest regulatory effects of LFA-1 on G-CSF and IL-17 secretion, and as a corollary on neutrophilia. Consequently, we conclude that increased resistance of LFA-1(-/-) mice to listeriosis is due to neutrophilia facilitating liver infiltration by granulocytes promptly after L. monocytogenes infection, although it is LFA-1 independent.
Collapse
Affiliation(s)
- Mamiko Miyamoto
- Department of Immunology, Max-Planck Institute for Infection Biology, Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
92
|
Peters W, Ernst JD. Mechanisms of cell recruitment in the immune response to Mycobacterium tuberculosis. Microbes Infect 2003; 5:151-8. [PMID: 12650773 DOI: 10.1016/s1286-4579(02)00082-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recent advances in understanding cell traffic, especially the roles of adhesion proteins, chemokines, and chemokine receptors, provide the opportunity for understanding mechanisms involved in the immune response to tuberculosis. This review concentrates on the roles of these molecules and the immune response in tuberculosis, based on studies of humans and mice infected with Mycobacterium tuberculosis.
Collapse
Affiliation(s)
- Wendy Peters
- Gladstone Institute of Cardiovascular Disease, PO Box 419100, San Francisco, CA 94141-9100, USA
| | | |
Collapse
|
93
|
Linehan SA, Holden DW. The interplay between Salmonella typhimurium and its macrophage host--what can it teach us about innate immunity? Immunol Lett 2003; 85:183-92. [PMID: 12527226 DOI: 10.1016/s0165-2478(02)00227-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Salmonella enterica sv. Typhimurium (S. typhimurium) is a genetically tractable, facultative intracellular pathogen, whose capacity to cause systemic disease in mice depends upon its ability to survive and replicate within macrophages. The identification of Salmonella mutants that lack this activity, has provided a tool with which to dissect the mechanisms used by Salmonella to establish a permissive niche, and identify host activities which it must overcome in order to achieve this. Salmonella actively maintains itself within an intracellular vacuole, thereby shielding itself from an antibacterial activity of host macrophage cytosol. Salmonella controls the maturation of its vacuole, segregating itself from the macrophage degradative pathway. Like several other pathogens, Salmonella reduces the effectiveness of bacteriocidal and bacteriostatic free radicals generated by macrophages, by synthesising enzymes and products that counteract them. Recent evidence indicates that Salmonella also avoids free radical-dependent macrophage antimicrobial mechanisms by more novel means. Here, we review recent studies of the interplay between pathogen and host, with particular emphasis on those areas that suggest new facets to the cell biology of macrophages, and their innate immune functions.
Collapse
Affiliation(s)
- Sheena A Linehan
- The Department of Infectious Diseases, Centre for Molecular Microbiology and Infection, Imperial College of Science, Technology and Medicine, The Flowers Building, Armstrong Road, London SW7 2AZ, UK.
| | | |
Collapse
|
94
|
Yang KK, Dorner BG, Merkel U, Ryffel B, Schütt C, Golenbock D, Freeman MW, Jack RS. Neutrophil influx in response to a peritoneal infection with Salmonella is delayed in lipopolysaccharide-binding protein or CD14-deficient mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:4475-80. [PMID: 12370383 DOI: 10.4049/jimmunol.169.8.4475] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The induction of an adaptive immune response to a previously unencountered pathogen is a time-consuming process and initially the infection must be held in check by the innate immune system. In the case of an i.p. infection with Salmonella typhimurium, survival requires both CD14 and LPS-binding protein (LBP) which, together with Toll-like receptor 4 and myeloid differentiation protein 2, provide a sensitive means to detect bacterial LPS. In this study, we show that in the first hours after i.p. infection with Salmonella a local inflammatory response is evident and that concomitantly neutrophils flood into the peritoneum. This rapid neutrophil influx is dependent on TNF since it is 1) abolished in TNF KO mice and 2) can be induced by i.p. injection of TNF in uninfected animals. Neutrophil influx is not strictly dependent on the presence of either LBP or CD14. However, in their absence, no local inflammatory response is evident, neutrophil migration is delayed, and the mice succumb to the infection. Using confocal microscopy, we show that the neutrophils which accumulate in CD14 and LBP null mice, albeit with delayed kinetics, are nevertheless fully capable of ingesting the bacteria. We suggest that the short delay in neutrophil influx gives the pathogen a decisive advantage in this infection model.
Collapse
Affiliation(s)
- Kang K Yang
- Department of Immunology, Klinikum der Universität Greifswald, Sauerbruchstrasse, D-17489 Greifswald, Germany
| | | | | | | | | | | | | | | |
Collapse
|
95
|
Kirby AC, Yrlid U, Wick MJ. The innate immune response differs in primary and secondary Salmonella infection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:4450-9. [PMID: 12370380 DOI: 10.4049/jimmunol.169.8.4450] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study examines innate immunity to oral Salmonella during primary infection and after secondary challenge of immune mice. Splenic NK and NKT cells plummeted early after primary infection, while neutrophils and macrophages (Mphi) increased 10- and 3-fold, respectively. In contrast, immune animals had only a modest reduction in NK cells, no loss of NKT cells, and a slight increase in phagocytes following secondary challenge. During primary infection, the dominant sources of IFN-gamma were, unexpectedly, neutrophils and Mphi, the former having intracellular stores of IFN-gamma that were released during infection. IFN-gamma-producing phagocytes greatly outnumbered IFN-gamma-producing NK cells, NKT cells, and T cells during the primary response. TNF-alpha production was also dominated by neutrophils and Mphi, which vastly outnumbered NKT cells producing this cytokine. Neither T cells nor NK cells produced TNF-alpha early during primary infection. The TNF-alpha response was reduced in a secondary response, but remained dominated by neutrophils and Mphi. Moreover, no significant IFN-gamma production by Mphi was associated with the secondary response. Indeed, only NK1.1(+) cells and T cells produced IFN-gamma in these mice. These studies provide a coherent view of innate immunity to oral Salmonella infection, reveal novel sources of IFN-gamma, and demonstrate that immune status influences the nature of the innate response.
Collapse
Affiliation(s)
- Alun C Kirby
- Department of Cell and Molecular Biology, Section for Immunology, Lund University, Lund, Sweden
| | | | | |
Collapse
|
96
|
Lyons MJ, Yoshimura T, McMurray DN. Mycobacterium bovis BCG vaccination augments interleukin-8 mRNA expression and protein production in guinea pig alveolar macrophages infected with Mycobacterium tuberculosis. Infect Immun 2002; 70:5471-8. [PMID: 12228272 PMCID: PMC128323 DOI: 10.1128/iai.70.10.5471-5478.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Alveolar macrophages are likely the first cell type to encounter Mycobacterium tuberculosis in a pulmonary infection, resulting in the production of chemokines. In order to evaluate this response, alveolar macrophages harvested from nonvaccinated and Mycobacterium bovis BCG-vaccinated guinea pigs were infected in vitro with live M. tuberculosis H37Ra or H37Rv (multiplicity of infection, 1:1) or cultured with lipopolysaccharide (10 micro g/ml) for 3, 12, and 24 h. Interleukin-8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) mRNA expression was determined by real-time PCR. Culture supernatants were assayed for guinea pig IL-8 protein by using a human IL-8 enzyme-linked immunosorbent assay kit. Alveolar macrophages harvested from BCG-vaccinated guinea pigs produced significantly more mRNA and protein for IL-8 than alveolar macrophages harvested from nonvaccinated guinea pigs at 12 and 24 h poststimulation or postinfection. Infection with attenuated M. tuberculosis (H37Ra) stimulated alveolar macrophages isolated from BCG-vaccinated guinea pigs to produce significantly more IL-8 mRNA than did alveolar macrophages infected with a virulent strain (H37Rv) at 12 and 24 h postinfection. Significant MCP-1 mRNA production was also detected in stimulated or infected alveolar macrophages; however, prior vaccination did not significantly affect levels of MCP-1 mRNA. Alveolar macrophages isolated from BCG-vaccinated guinea pigs produced significantly more IL-8 mRNA and protein when stimulated for 24 h with heat-killed H37Ra, heat-killed H37Rv, and H37Rv cell wall, but not mannose-capped lipoarabinomannan (ManLAM), than did cells stimulated with media alone. These observations indicate that prior vaccination may alter very early events in the M. tuberculosis-infected lung.
Collapse
MESH Headings
- Animals
- BCG Vaccine/pharmacology
- Chemokine CCL2/genetics
- Disease Models, Animal
- Gene Expression
- Guinea Pigs
- In Vitro Techniques
- Interleukin-8/biosynthesis
- Interleukin-8/genetics
- Lipopolysaccharides/pharmacology
- Macrophages, Alveolar/immunology
- Macrophages, Alveolar/metabolism
- Macrophages, Alveolar/microbiology
- Mycobacterium tuberculosis/pathogenicity
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Tuberculosis, Pulmonary/genetics
- Tuberculosis, Pulmonary/immunology
- Tuberculosis, Pulmonary/metabolism
- Tuberculosis, Pulmonary/prevention & control
- Virulence
Collapse
Affiliation(s)
- Mark J Lyons
- Department of Medical Microbiology and Immunology, Texas A&M University System Health Science Center, College Station, Texas 77843, USA
| | | | | |
Collapse
|
97
|
Fulton SA, Reba SM, Martin TD, Boom WH. Neutrophil-mediated mycobacteriocidal immunity in the lung during Mycobacterium bovis BCG infection in C57BL/6 mice. Infect Immun 2002; 70:5322-7. [PMID: 12183593 PMCID: PMC128293 DOI: 10.1128/iai.70.9.5322-5327.2002] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Although neutrophils have been identified as sources of inflammatory cytokines and chemokines, little is known about their immunologic function during mycobacterial infection in the lungs. In this study, we examined the growth of Mycobacterium bovis BCG in the lungs under experimental conditions that altered neutrophil recruitment to the lungs. Depletion and recruitment of neutrophils was associated with respective increases and decreases in M. bovis BCG growth. Thus, neutrophils may enhance mycobacteriocidal immunity in the lungs.
Collapse
Affiliation(s)
- S A Fulton
- Division of Infectious Diseases, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, Ohio 44106-4984, USA.
| | | | | | | |
Collapse
|
98
|
Faldt J, Dahlgren C, Ridell M. Difference in neutrophil cytokine production induced by pathogenic and non-pathogenic mycobacteria. APMIS 2002; 110:593-600. [PMID: 12529011 DOI: 10.1034/j.1600-0463.2002.1100901.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study shows differences between Mycobacterium tuberculosis and Mycobacterium avium (opportunistic) and Mycobacterium smegmatis (non-pathogenic), with respect to their abilities to induce cytokine/chemokine release from human neutrophils. Neutrophils incubated with live cells of M. tuberculosis, M. avium, or M. smegmatis produced and released TNF-alpha, IL-6, and IL-8. No or very small amounts of these cytokines/chemokines were found in resting neutrophils, suggesting that they were newly synthesised. The levels of TNF-alpha, IL-6, and IL-8 produced/released from neutrophils incubated with M. tuberculosis were markedly lower than those of the opportunistic or non-pathogenic bacterial species. The production of TNF-alpha reached a maximum level at a time (4 h) when the production of IL-8 had only just started, and this was true for all three mycobacteria tested. However, the time course for IL-6 production differed between the species, reaching a peak value after 8 h for M. tuberculosis not seen with the other bacteria. It is likely that the relatively high levels of cytokines induced by opportunistic/non-pathogenic mycobacteria are of importance for the induction of an innate immune response through which these organisms are eliminated, while the low levels of cytokines released by neutrophils interfering with M. tuberculosis might help the bacteria to persist.
Collapse
Affiliation(s)
- J Faldt
- Department of Medical Microbiology and Immunology, Göteborg University, Sweden.
| | | | | |
Collapse
|
99
|
Abstract
Rapidly growing mycobacteria are widespread saprophytes, but approximately one-third of identified species are also opportunistic pathogens in humans and animals, associated with skin, soft tissue, bone, and pulmonary infections as well as disseminated disease. Clinical and experimental evidence indicates a major role for the cell-mediated immune response in the pathogenesis of infection.
Collapse
Affiliation(s)
- S T Howard
- I.D.I.P. Department, The University of New Mexico School of Medicine, Albuquerque, NM 87131, USA.
| | | |
Collapse
|
100
|
Montes de Oca R, Buendía AJ, Sánchez J, Del Río L, Seva J, Navarro JA, Salinas J. Limited role of polymorphonuclear neutrophils in a pregnant mouse model of secondary infection by Chlamydophila abortus (Chlamydia psittaci serotype 1). Microb Pathog 2000; 29:319-27. [PMID: 11095917 DOI: 10.1006/mpat.2000.0396] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this work was to study the role of polymorphonuclear neutrophils (PMNs) in the clearance of infection, and in the development of specific immunity against Chlamydophila abortus (Chlamydia psittaci serotype 1) secondary infection. A pregnant mouse model depleted of neutrophils by the RB6-8C5 monoclonal antibody was used. No clinical signs were observed in depleted or non-depleted mice after secondary infection and no significant differences were observed in the litter size between the infected and control groups. In PMN-depleted mice C. abortus was not detected in the materno-fetal unit but merely produced low, persistent levels of infection in spleen and liver. In the non-depleted mice the level of infection was significantly lower, being resolved during the first few days post-reinfection. In both infected mice groups the immune response in the liver was quickly established and was seen to be composed mainly of CD4(+)T lymphocytes and macrophages. A Th1 response characterized by the presence of IFN-gamma and TNF-alpha in serum was observed during early infection, with significantly higher levels in the non-depleted animals. Our results suggest that PMNs have little influence on the control of C. abortus secondary infection, although they are a first line of defense and may influence the early production of TNF-alpha and IFN-gamma.
Collapse
Affiliation(s)
- R Montes de Oca
- Departamento de Histología y Anatomía Patológica, Universidad de Murcia, Spain
| | | | | | | | | | | | | |
Collapse
|