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Jangpatarapongsa K, Xia H, Fang Q, Hu K, Yuan Y, Peng M, Gao Q, Sattabongkot J, Cui L, Li B, Udomsangpetch R. Immunity to malaria in Plasmodium vivax infection: a study in central China. PLoS One 2012; 7:e45971. [PMID: 23049909 PMCID: PMC3457974 DOI: 10.1371/journal.pone.0045971] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 08/23/2012] [Indexed: 12/03/2022] Open
Abstract
Background P. vivax infection is characterised by relapsing fever, indicating reinfection by previously hidden parasites in the host. Relapsed infection can lead to the activation of the memory T cell pool, which may lead to protective immunity. This study aims to characterise immune responses in acute P. vivax-infected patients living in an area of central China characterised by only P. vivax infection. Methodology/Principal Findings We conducted a cross-sectional immune-phenotypic analysis of adults using the following inclusion criteria: acute P. vivax infection (N = 37), a history of P. vivax infection (N = 17), and no known history of P. vivax infection (N = 21). We also conducted a 2-week longitudinal analysis following acute P. vivax infection, in which PBMC proliferation was measured in response to P. vivax and P. falciparum blood stage lysates. Using flow cytometry, we showed elevated memory T cells in the blood during acute P. vivax infection. The levels of γδ T cells were two-fold higher than those measured in naive controls. This result suggested that in the two populations, memory and γδ T cells promptly responded to P. vivax parasites. Interestingly, P. falciparum antigens stimulated T cells obtained from P. vivax-infected patients during a day 14-convalescence, whereas lymphocytes from the naïve control group responded to a lower degree of convalescence. Conclusions/Significance Cell-mediated immunity during the convalescent period of the P. vivax-infected hosts was comprised of T cells that were specifically able to recognise P. falciparum antigens. Although the magnitude of the response was only half that measured after stimulation with P. vivax antigens, the matter of cross-antigenic stimulation is of great interest.
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Affiliation(s)
- Kulachart Jangpatarapongsa
- Center for Innovation Development and Technology Transfer, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Hui Xia
- Department of Parasitology, Bengbu Medical College, Anhui, China
- Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, China
| | - Qiang Fang
- Department of Parasitology, Bengbu Medical College, Anhui, China
- Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, China
| | - Kaiming Hu
- Department of Parasitology, Bengbu Medical College, Anhui, China
| | - Yuanying Yuan
- Department of Parasitology, Bengbu Medical College, Anhui, China
| | - Meiyu Peng
- Department of Immunology, Bengbu Medical College, Anhui, China
| | - Qi Gao
- Jiangsu Institute of Parasitic Disease, Wuxi, China
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Center, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, State College, Pennsylvania, United States of America
| | - Baiqing Li
- Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, China
- Department of Immunology, Bengbu Medical College, Anhui, China
- * E-mail: (RU); (BL)
| | - Rachanee Udomsangpetch
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
- Center of Neglected Infectious Diseases, Mahidol University, Bangkok, Thailand
- * E-mail: (RU); (BL)
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Abel S, Lückheide N, Westendorf AM, Geffers R, Roers A, Müller W, Sparwasser T, Matuschewski K, Buer J, Hansen W. Strong impact of CD4+ Foxp3+ regulatory T cells and limited effect of T cell-derived IL-10 on pathogen clearance during Plasmodium yoelii infection. THE JOURNAL OF IMMUNOLOGY 2012; 188:5467-77. [PMID: 22544931 DOI: 10.4049/jimmunol.1102223] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It is well established that CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) play a crucial role in the course of different infectious diseases. However, contradictory results have been published regarding to malaria infection. In this study, we report that specific ablation of Foxp3(+) Tregs in Plasmodium yoelii-infected DEREG-BALB/c mice leads to an increase in T cell activation accompanied by a significant decrease in parasitemia. To better understand how Foxp3(+) Tregs orchestrate this phenotype, we used microarrays to analyze CD4(+)CD25(+)Foxp3(+) Tregs and CD4(+)CD25(-)Foxp3(-) T cells in the course of P. yoelii infection. Using this approach we identified genes specifically upregulated in CD4(+)CD25(+)Foxp3(+) Tregs in the course of infection, such as G-protein-coupled receptor 83 and Socs2. This analysis also revealed that both CD4(+)CD25(+)Foxp3(+) Tregs and CD4(+)CD25(-)Foxp3(-) T cells upregulate CTLA-4, granzyme B, and, more strikingly, IL-10 during acute blood infection. Therefore, we aimed to define the function of T cell-derived IL-10 in this context by Cre/loxP-mediated selective conditional inactivation of the IL-10 gene in T cells. Unexpectedly, IL-10 ablation in T cells exerts only a minor effect on parasite clearance, even though CD8(+) T cells are more strongly activated, the production of IFN-γ and TNF-α by CD4(+)CD25(-) T cells is increased, and the suppressive activity of CD4(+)CD25(+) Tregs is reduced upon infection. In summary, these results suggest that CD4(+)Foxp3(+) Tregs modulate the course of P. yoelii infection in BALB/c mice. Moreover, CD4(+) T cell-derived IL-10 affects T effector function and Treg activity, but has only a limited direct effect on parasite clearance in this model.
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Affiliation(s)
- Simone Abel
- Institute of Medical Microbiology, University Hospital Essen, University Duisburg-Essen, 45122 Essen, Germany
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53
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Freitas do Rosario AP, Langhorne J. T cell-derived IL-10 and its impact on the regulation of host responses during malaria. Int J Parasitol 2012; 42:549-55. [PMID: 22549022 DOI: 10.1016/j.ijpara.2012.03.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 03/02/2012] [Accepted: 03/24/2012] [Indexed: 02/04/2023]
Abstract
Despite intense research, malaria still is the one of the most devastating diseases killing more people than any other parasitic infection. In an attempt to control the infection, the host immune system produces a potent pro-inflammatory response. However, this response is also associated with complications, such as severe anaemia, hypoglycaemia and cerebral malaria. This pronounced production of pro-inflammatory cytokines response is a common feature of malaria caused by parasites infecting humans as well as rodents and primates. A balance between pro- and anti-inflammatory responses may be fundamental to the elimination of the parasite without inducing excessive host pathology. IL-10 is a key cytokine that has been shown to have an important regulatory function in establishing this balance in malaria. Here we discuss which cells can produce IL-10 during infection, and present an overview of the evidence showing that T-cell derived IL-10 plays an important role in regulating malaria pathology. Many different subsets of T cells can produce IL-10, however, evidence is accumulating that it is effector Th1 CD4(+) T cells which provide the crucial source that down-regulates inflammatory pathology during blood-stage malaria infections.
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54
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Liu Y, Xing X, Wang J, Xing L, Su Y, Yao Z, Yan X, Wang J, Zhang X. Sterigmatocystin alters the number of FoxP3+ regulatory T cells and plasmacytoid dendritic cells in BALB/c mice. Food Chem Toxicol 2012; 50:1920-6. [PMID: 22429820 DOI: 10.1016/j.fct.2012.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Revised: 03/02/2012] [Accepted: 03/03/2012] [Indexed: 12/19/2022]
Abstract
Sterigmatocystin (ST), a mycotoxin with mutagenic, cytotoxic and carcinogenic properties, is commonly found as the contaminant in grains and animal feeds. Of particular interest is the capacity of ST to alter normal immune function when presented in foods. As part of an on-going investigation of ST toxicological effects, we attempt to explore the short-term immunotoxic effects of ST, specifically on FoxP3(+) regulatory T cells (FoxP3(+) Tregs) and plasmacytoid dendritic cells (pDCs), by observing changes in number/expression of FoxP3(+) Tregs, pDCs and CD4(+), CD8(+) T cells in BALB/c mice 24h after a single intraperitoneal administration of ST at different dosages (3, 30, 300 and 3000 μg/kg body weight). The present study showed that 24h after ST treatment, the proportion of CD8(+) T cells was decreased in the thymus in ST 3 μg/kg group, while that of CD4(+) and CD8(+) T cells was increased in the spleen in two treatment groups (3 and 30 μg/kg). The proportion of FoxP3(+) Tregs and FoxP3 expressions were all significantly increased in mPBMCs, the thymus and the spleen. It is noteworthy that the population of pDCs significantly decreased in the thymus as we expected but increased in the spleen as compared with control, which we suspect is resulted from a temporary immune response triggered by the ST inhibition. We believe that ST may exert its immunotoxic effects by stimulating Treg, but inhibiting pDCs in the long-term to contribute its carcinogenic effects.
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Affiliation(s)
- Yaling Liu
- Laboratory of Pathology, Hebei Medical University, Shijiazhuang, China
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55
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Wykes MN. Are plasmacytoid dendritic cells the misguided sentinels of malarial immunity? Trends Parasitol 2012; 28:182-6. [PMID: 22365902 DOI: 10.1016/j.pt.2012.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 01/28/2012] [Accepted: 01/30/2012] [Indexed: 12/23/2022]
Abstract
Dendritic cells (DCs), the sentinels of immunity, reside in almost every organ of the body. These cells are responsible for initiating immune responses against infectious agents. DCs are divided into different subsets based on their biological functions, with plasmacytoid DCs (pDCs) and conventional DCs (cDCs) being two major populations. The ability of DCs to protect against malaria infection was recently questioned when pDCs were reported to be a reservoir for rodent Plasmodium spp. in the spleen. This opinion article explores how the occupation of pDCs by the parasite may corrupt immunity against malaria.
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Affiliation(s)
- Michelle N Wykes
- The Queensland Institute of Medical Research, The Bancroft Centre, 300 Herston Road, Brisbane, Queensland 4006, Australia.
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Gautam S, Kumar R, Maurya R, Nylén S, Ansari N, Rai M, Sundar S, Sacks D. IL-10 neutralization promotes parasite clearance in splenic aspirate cells from patients with visceral leishmaniasis. J Infect Dis 2011; 204:1134-7. [PMID: 21881130 PMCID: PMC3164427 DOI: 10.1093/infdis/jir461] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 05/19/2011] [Indexed: 11/12/2022] Open
Abstract
The mechanisms underlying the failure to contain the growth of Leishmania parasites in human visceral leishmaniasis (VL) are not understood. L donovani amastigotes were quantified in cultured splenic aspirate cells to assess the function of IL-10 in lesional tissue ex vivo. In 67 patients with active VL, IL-10 neutralization promoted parasite killing in 73% and complete clearance in 30%, while 18% had more parasites and 9% did not change. The splenic cells secreted increased levels of both tumor necrosis factor α (TNFα) and interferon γ (IFNγ) under IL-10-neutralizing conditions. These findings provide direct support for targeting IL-10 as an approach to therapy in human VL.
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Affiliation(s)
- Shalini Gautam
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi
| | - Rajiv Kumar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi
| | - Radheshyam Maurya
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi
- Department of Animal Sciences, School of Life-Sciences, University of Hyderabad, India
| | - Susanne Nylén
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Nasim Ansari
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Madhukar Rai
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi
| | - Shyam Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi
| | - David Sacks
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
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Increased interleukin-10 and interferon-γ levels in Plasmodium vivax malaria suggest a reciprocal regulation which is not altered by IL-10 gene promoter polymorphism. Malar J 2011; 10:264. [PMID: 21917128 PMCID: PMC3196927 DOI: 10.1186/1475-2875-10-264] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 09/14/2011] [Indexed: 01/01/2023] Open
Abstract
Background In human malaria, the naturally-acquired immune response can result in either the elimination of the parasite or a persistent response mediated by cytokines that leads to immunopathology. The cytokines are responsible for all the symptoms, pathological alterations and the outcome of the infection depends on the reciprocal regulation of the pro and anti-inflammatory cytokines. IL-10 and IFN-gamma are able to mediate this process and their production can be affected by single nucleotide polymorphisms (SNPs) on gene of these cytokines. In this study, the relationship between cytokine IL-10/IFN-gamma levels, parasitaemia, and their gene polymorphisms was examined and the participation of pro-inflammatory and regulatory balance during a natural immune response in Plasmodium vivax-infected individuals was observed. Methods The serum levels of the cytokines IL-4, IL-12, IFN-gamma and IL-10 from 132 patients were evaluated by indirect enzyme-linked immunosorbent assays (ELISA). The polymorphism at position +874 of the IFN-gamma gene was identified by allele-specific polymerase chain reaction (ASO-PCR) method, and the polymorphism at position -1082 of the IL-10 gene was analysed by PCR-RFLP (PCR-Restriction Fragment Length Polymorphism). Results The levels of a pro- (IFN-gamma) and an anti-inflammatory cytokine (IL-10) were significantly higher in P. vivax-infected individuals as compared to healthy controls. The IFN-gamma levels in primoinfected patients were significantly higher than in patients who had suffered only one and more than one previous episode. The mutant alleles of both IFN-gamma and IL-10 genes were more frequent than the wild allele. In the case of the IFNG+874 polymorphism (IFN-gamma) the frequencies of the mutant (A) and wild (T) alleles were 70.13% and 29.87%, respectively. Similar frequencies were recorded in IL-10-1082, with the mutant (A) allele returning a frequency of 70.78%, and the wild (G) allele a frequency of 29.22%. The frequencies of the alleles associated with reduced production of both IFN-gamma and IL-10 were high, but this effect was only observed in the production of IFN-gamma. Conclusions This study has shown evidence of reciprocal regulation of the levels of IL-10 and IFN-gamma cytokines in P. vivax malaria, which is not altered by the presence of polymorphism in the IL-10 gene.
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58
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Clemente A, Caporale R, Sannella AR, Majori G, Severini C, Fadigati G, Cirelli D, Bonini P, Garaci E, Cozzolino F, Torcia MG. Plasmodium falciparum soluble extracts potentiate the suppressive function of polyclonal T regulatory cells through activation of TGFβ-mediated signals. Cell Microbiol 2011; 13:1328-38. [DOI: 10.1111/j.1462-5822.2011.01622.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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59
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Salwati E, Minigo G, Woodberry T, Piera KA, de Silva HD, Kenangalem E, Tjitra E, Coppel RL, Price RN, Anstey NM, Plebanski M. Differential cellular recognition of antigens during acute Plasmodium falciparum and Plasmodium vivax malaria. J Infect Dis 2011; 203:1192-1199. [PMID: 21451007 DOI: 10.1093/infdis/jiq166] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Plasmodium falciparum and Plasmodium vivax are co-endemic in the Asia-Pacific region. Their capacity to induce and sustain diverse T-cell responses underpins protective immunity. We compared T-cell responses to the largely conserved merozoite surface protein-5 (PfMSP5) during acute and convalescent falciparum and vivax malaria. METHODS Lymphoproliferation and IFN--γ secretion to PfMSP5 and purified protein derivate were quantified in adults with falciparum (n=34), and vivax malaria (n=12) or asymptomatic residents (n=10) of Papua, Indonesia. Responses were reassessed 7-28 days following treatment. RESULTS The frequency of IFN-γ responders to PfMSP5 was similar in acute falciparum (63%) or vivax (67%) malaria. However, significantly more IFN-γ-secreting cells were detectable during vivax compared with falciparum infection. Purified protein derivative responses showed a similarly enhanced pattern. While rapidly lost in vivax patients, PfMSP5-specific responses in falciparum malaria remained to day 28. By contrast, frequency and magnitude of lymphoproliferation to PfMSP5 were similar for falciparum and vivax infections. CONCLUSION Cellular PfMSP5-specific responses are most frequent during either acute falciparum or vivax malaria, indicating functional T-cell responses to conserved antigens. Both effector and central memory T-cell functions are increased. Greater IFN-γ responses in acute P. vivax, suggest enhancement of pre-existing effector T-cells during acute vivax infection.
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Affiliation(s)
- Ervi Salwati
- National Institute of Health Research and Development (NIHRD), Ministry of Health, Jakarta, Indonesia
| | - Gabriela Minigo
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Department of Immunology, Monash University, Victoria, Australia
| | - Tonia Woodberry
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Kim A Piera
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | | | - Enny Kenangalem
- Menzies-NIHRD Collaborative Research Program and District Health Authority, Timika, Papua, Indonesia
| | - Emiliana Tjitra
- National Institute of Health Research and Development (NIHRD), Ministry of Health, Jakarta, Indonesia
| | - Ross L Coppel
- Department of Microbiology, Monash University, Victoria, Australia
| | - Ric N Price
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Centre for Vaccinology and Tropical Medicine, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford.,Division of Medicine, Royal Darwin Hospital, Darwin, Australia
| | - Nicholas M Anstey
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Division of Medicine, Royal Darwin Hospital, Darwin, Australia
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60
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Kushwah R, Hu J. Role of dendritic cells in the induction of regulatory T cells. Cell Biosci 2011; 1:20. [PMID: 21711933 PMCID: PMC3125210 DOI: 10.1186/2045-3701-1-20] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 05/24/2011] [Indexed: 12/12/2022] Open
Abstract
Dendritic cells (DCs) play a key role in initiating immune responses and maintaining immune tolerance. In addition to playing a role in thymic selection, DCs play an active role in tolerance under steady state conditions through several mechanisms which are dependent on IL-10, TGF-β, retinoic acid, indoleamine-2,3,-dioxygenase along with vitamin D. Several of these mechanisms are employed by DCs in induction of regulatory T cells which are comprised of Tr1 regulatory T cells, natural and inducible foxp3+ regulatory T cells, Th3 regulatory T cells and double negative regulatory T cells. It appears that certain DC subsets are highly specialized in inducing regulatory T cell differentiation and in some tissues the local microenvironment plays a role in driving DCs towards a tolerogenic response. In this review we discuss the recent advances in our understanding of the mechanisms underlying DC driven regulatory T cell induction.
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Affiliation(s)
- Rahul Kushwah
- Physiology and Experimental Medicine Research Program, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, M5G 1X8, Canada.
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61
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Abstract
Infectious agents have intimately co-evolved with the host immune system, acquiring a portfolio of highly sophisticated mechanisms to modulate immunity. Among the common strategies developed by viruses, bacteria, protozoa, helminths, and fungi is the manipulation of the regulatory T cell network in order to favor pathogen survival and transmission. Treg activity also benefits the host in many circumstances by controlling immunopathogenic reactions to infection. Interestingly, some pathogens are able to directly induce the conversion of naive T cells into suppressive Foxp3-expressing Tregs, while others activate pre-existing natural Tregs, in both cases repressing pathogen-specific effector responses. However, Tregs can also act to promote immunity in certain settings, such as in initial stages of infection when effector cells must access the site of infection, and subsequently in ensuring generation of effector memory. Notably, there is little current information on whether infections selectively drive pathogen-specific Tregs, and if so whether these cells are also reactive to self-antigens. Further analysis of specificity, together with a clearer picture of the relative dynamics of Treg subsets over the course of disease, should lead to rational strategies for immune intervention to optimize immunity and eliminate infection.
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Coban C, Horii T, Akira S, Ishii KJ. TLR9 and endogenous adjuvants of the whole blood-stage malaria vaccine. Expert Rev Vaccines 2010; 9:775-84. [PMID: 20624050 DOI: 10.1586/erv.10.60] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Vaccination has been a successful tool in the protection against many infectious diseases, and recent advances in biotechnology have created new techniques and strategies to produce safe and efficacious vaccines for human use. However, developing a protective vaccine against malaria has been a challenge. In this article, we focus on an old approach with some new modifications, the so-called whole-parasite vaccination strategy against blood-stage Plasmodium falciparum, the deadliest human malarial agent. In addition, we discuss recent developments in our understanding of how the endogenous adjuvant activity in the parasites, which functions via Toll-like receptor 9, acts as a double-edged sword between protective vaccination and pathological responses against malaria infection.
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Affiliation(s)
- Cevayir Coban
- Immunology Frontier Research Center, World Premier Institute for Immunology, Osaka University, Suita, Osaka 565-0871, Japan.
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63
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Zheng W, Wang QH, Liu YJ, Liu J, Feng H, Wu JJ, Cao YM. Distinct host-related dendritic cell responses during the early stage of Plasmodium yoelii infection in susceptible and resistant mice. Parasite Immunol 2010; 32:324-34. [PMID: 20500661 DOI: 10.1111/j.1365-3024.2009.01190.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The diverse outcomes of experimental murine infection with Plasmodium parasites, ranging from spontaneous cure to death, depend largely on the establishment of an effective Th1 immune response during the early stages of infection. However, the molecular and cellular factors responsible for the induction and regulation of this response are poorly understood. As immunity is initiated by dendritic cells (DCs), we compared their phenotype and function during the early stages of infection with Plasmodium yoelii 17XL (P.y 17XL) strain in susceptible (BALB/c) and resistant (DBA/2) mice. Resistant DBA/2 mice developed a greater number of myeloid (CD11c(+)CD11b(+)) and mature DCs, which were fully functional and capable of secreting IL-12p40. In contrast, susceptible BALB/c mice produced more plasmacytoid (CD11c(+)CD45R/B220(+)) and less mature DCs, resulting in high levels of IL-10 and TGF-beta1. In addition, an in vitro experiment confirmed that splenic DCs from the two strains of mice differ in their ability to prime CD4(+)T cells in response to P.y 17XL stimulation. These findings indicate that the subset, the phenotype and the type of inflammatory and anti-inflammatory signals of splenic DCs are critical factors responsible for the discrepancy in the ability to induce or regulate Th1 immune responses in different hosts.
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Affiliation(s)
- W Zheng
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
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CD4+ CD25+ Foxp3+ regulatory T cells, dendritic cells, and circulating cytokines in uncomplicated malaria: do different parasite species elicit similar host responses? Infect Immun 2010; 78:4763-72. [PMID: 20713627 DOI: 10.1128/iai.00578-10] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Clearing blood-stage malaria parasites without inducing major host pathology requires a finely tuned balance between pro- and anti-inflammatory responses. The interplay between regulatory T (Treg) cells and dendritic cells (DCs) is one of the key determinants of this balance. Although experimental models have revealed various patterns of Treg cell expansion, DC maturation, and cytokine production according to the infecting malaria parasite species, no studies have compared all of these parameters in human infections with Plasmodium falciparum and P. vivax in the same setting of endemicity. Here we show that during uncomplicated acute malaria, both species induced a significant expansion of CD4(+) CD25(+) Foxp3(+) Treg cells expressing the key immunomodulatory molecule CTLA-4 and a significant increase in the proportion of DCs that were plasmacytoid (CD123(+)), with a decrease in the myeloid/plasmacytoid DC ratio. These changes were proportional to parasite loads but correlated neither with the intensity of clinical symptoms nor with circulating cytokine levels. One-third of P. vivax-infected patients, but no P. falciparum-infected subjects, showed impaired maturation of circulating DCs, with low surface expression of CD86. Although vivax malaria patients overall had a less inflammatory cytokine response, with a higher interleukin-10 (IL-10)/tumor necrosis factor alpha (TNF-α) ratio, this finding did not translate to milder clinical manifestations than those of falciparum malaria patients. We discuss the potential implications of these findings for species-specific pathogenesis and long-lasting protective immunity to malaria.
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65
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Abstract
Plasmodium falciparum malaria causes 500 million clinical cases with approximately one million deaths each year. After many years of exposure, individuals living in endemic areas develop a form of clinical immunity to disease known as premunition, which is characterised by low parasite burdens rather than sterilising immunity. The reason why malaria parasites persist under a state of premunition is unknown but it has been suggested that suppression of protective immunity might be a mechanism leading to parasite persistence. Although acquired immunity limits the clinical impact of infection and provides protection against parasite replication, experimental evidence indicates that cell-mediated immune responses also result in detrimental inflammation and contribute to the aetiology of severe disease. Thus, an appropriate regulatory balance between protective immune responses and immune-mediated pathology is required for a favourable outcome of infection. As natural regulatory T (Treg) cells are identified as an immunosuppressive lineage able to modulate the magnitude of effector responses, several studies have investigated whether this cell population plays a role in balancing protective immunity and pathogenesis during malaria. The main findings to date are summarised in this review and the implication for the induction of pathogenesis and immunity to malaria is discussed.
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Affiliation(s)
- Diana S Hansen
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
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Gupta V, Jaiswal A, Behera D, Prasad HK. Disparity in circulating peripheral blood dendritic cell subsets and cytokine profile of pulmonary tuberculosis patients compared with healthy family contacts. Hum Immunol 2010; 71:682-91. [PMID: 20381566 DOI: 10.1016/j.humimm.2010.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 03/25/2010] [Accepted: 03/29/2010] [Indexed: 11/15/2022]
Abstract
Dendritic cell (DC) subsets, myeloid DCs (mDCs), and plasmacytoid DCs (pDCs) play a fundamental role in immune response to Mycobacterium tuberculosis (M. tuberculosis). Flow-cytometric estimation of DC subsets showed differences in the ratio of these subsets in untreated, smear-positive pulmonary tuberculosis patients compared with healthy family contacts (HFC, p < 0.05). The percentage of pDCs (0.14 +/- 0.01) was higher than mDCs (0.12 +/- 0.01) in patients, whereas in HFC, mDCs (0.15 +/- 0.01) was higher than pDCs (0.1 +/- 0.01). The percentage of mDCs (0.15 +/- 0.01) and pDCs (0.11 +/- 0.01) was restored in treated patients. Alteration in the DC subsets before and after chemotherapy was confirmed in the follow-up of acid-fast bacilli (AFB)-positive patients. This reversal in the percentage of mDC vs pDCs implicates the influence of active disease on circulating DC subsets. The cytokine bead array revealed an inverse relationship in the circulating levels of IL-12 and IFN-gamma. High IL-12 (37.9 +/- 15.2) and low IFN-gamma (11.09 +/- 3.6) was seen in HFCs derived serum samples compared with that of patients (p < 0.05). The higher percentage of mDCs and elevated IL-12 levels was found to be associated with high risk HFCs investigated. Furthermore CpG/LPS-stimulated whole-blood culture of untreated patients expressed high IFN-alpha in pDCs and less IL-12 in mDCs compared with those of treated patients.
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Affiliation(s)
- Vinay Gupta
- TB Immunology Laboratory, Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
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Bueno LL, Morais CG, Araújo FF, Gomes JAS, Corrêa-Oliveira R, Soares IS, Lacerda MV, Fujiwara RT, Braga ÉM. Plasmodium vivax: induction of CD4+CD25+FoxP3+ regulatory T cells during infection are directly associated with level of circulating parasites. PLoS One 2010; 5:e9623. [PMID: 20224778 PMCID: PMC2835751 DOI: 10.1371/journal.pone.0009623] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 02/19/2010] [Indexed: 11/29/2022] Open
Abstract
Circulation CD4+CD25+FoxP3+ regulatory T cells (Tregs) have been associated with the delicate balancing between control of overwhelming acute malaria infection and prevention of immune pathology due to disproportionate inflammatory responses to erythrocytic stage of the parasite. While the role of Tregs has been well-documented in murine models and P. falciparum infection, the phenotype and function of Tregs in P. vivax infection is still poorly characterized. In the current study, we demonstrated that patients with acute P. vivax infection presented a significant augmentation of circulating Tregs producing anti-inflammatory (IL-10 and TGF-β) as well as pro-inflammatory (IFN-γ, IL-17) cytokines, which was further positively correlated with parasite burden. Surface expression of GITR molecule and intracellular expression of CTLA-4 were significantly upregulated in Tregs from infected donors, presenting also a positive association between either absolute numbers of CD4+CD25+FoxP3+GITR+ or CD4+CD25+FoxP3+CTLA-4+ and parasite load. Finally, we demonstrate a suppressive effect of Treg cells in specific T cell proliferative responses of P. vivax infected subjects after antigen stimulation with Pv-AMA-1. Our findings indicate that malaria vivax infection lead to an increased number of activated Treg cells that are highly associated with parasite load, which probably exert an important contribution to the modulation of immune responses during P. vivax infection.
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Affiliation(s)
- Lilian Lacerda Bueno
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Cristiane Guimarães Morais
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Fernanda Fortes Araújo
- Laboratório de Imunologia Celular e Molecular, Instituto René Rachou, FIOCRUZ, Belo Horizonte, Brazil
| | - Juliana Assis Silva Gomes
- Laboratório de Imunologia Celular e Molecular, Instituto René Rachou, FIOCRUZ, Belo Horizonte, Brazil
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Rodrigo Corrêa-Oliveira
- Laboratório de Imunologia Celular e Molecular, Instituto René Rachou, FIOCRUZ, Belo Horizonte, Brazil
| | - Irene Silva Soares
- Departamento de Análises Clínicas e Toxicológicas, Universidade de São Paulo, São Paulo, Brazil
| | | | - Ricardo Toshio Fujiwara
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Laboratório de Imunologia Celular e Molecular, Instituto René Rachou, FIOCRUZ, Belo Horizonte, Brazil
| | - Érika Martins Braga
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- * E-mail:
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68
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Modulation of dendritic cell responses by parasites: a common strategy to survive. J Biomed Biotechnol 2010; 2010:357106. [PMID: 20204070 PMCID: PMC2829630 DOI: 10.1155/2010/357106] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Accepted: 11/18/2009] [Indexed: 12/28/2022] Open
Abstract
Parasitic infections are one of the most important causes of morbidity and mortality in our planet and the immune responses triggered by these organisms are critical to determine their outcome. Dendritic cells are key elements for the development of immunity against parasites; they control the responses required to eliminate these pathogens while maintaining host homeostasis. However, there is evidence showing that parasites can influence and regulate dendritic cell function in order to promote a more permissive environment for their survival. In this review we will focus on the strategies protozoan and helminth parasites have developed to interfere with dendritic cell activities as well as in the possible mechanisms involved.
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69
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Finney OC, Riley EM, Walther M. Regulatory T cells in malaria – friend or foe? Trends Immunol 2010; 31:63-70. [DOI: 10.1016/j.it.2009.12.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 12/06/2009] [Accepted: 12/08/2009] [Indexed: 10/20/2022]
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70
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Scholzen A, Minigo G, Plebanski M. Heroes or villains? T regulatory cells in malaria infection. Trends Parasitol 2010; 26:16-25. [DOI: 10.1016/j.pt.2009.10.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 10/09/2009] [Accepted: 10/15/2009] [Indexed: 12/14/2022]
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71
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Bueno LL, Morais CG, da Silva Soares I, Bouillet LEM, Bruna-Romero O, Fontes CJ, Fujiwara RT, Braga ÉM. Plasmodium vivax recombinant vaccine candidate AMA-1 plays an important role in adaptive immune response eliciting differentiation of dendritic cells. Vaccine 2009; 27:5581-8. [DOI: 10.1016/j.vaccine.2009.07.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 07/06/2009] [Accepted: 07/14/2009] [Indexed: 11/16/2022]
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72
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Singh M, Mukherjee P, Narayanasamy K, Arora R, Sen SD, Gupta S, Natarajan K, Malhotra P. Proteome analysis of Plasmodium falciparum extracellular secretory antigens at asexual blood stages reveals a cohort of proteins with possible roles in immune modulation and signaling. Mol Cell Proteomics 2009; 8:2102-18. [PMID: 19494339 DOI: 10.1074/mcp.m900029-mcp200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The highly co-evolved relationship of parasites and their hosts appears to include modulation of host immune signals, although the molecular mechanisms involved in the host-parasite interplay remain poorly understood. Characterization of these key genes and their cognate proteins related to the host-parasite interplay should lead to a better understanding of this intriguing biological phenomenon. The malaria agent Plasmodium falciparum is predicted to export a cohort of several hundred proteins to remodel the host erythrocyte. However, proteins actively exported by the asexual intracellular parasite beyond the host red blood cell membrane (before merozoite egress) have been poorly investigated so far. Here we used two complementary methodologies, two-dimensional gel electrophoresis/MS and LC-MS/MS, to examine the extracellular secreted antigens at asexual blood stages of P. falciparum. We identified 27 novel antigens exported by P. falciparum in the culture medium of which some showed clustering with highly polymorphic genes on chromosomes, suggesting that they may encode putative antigenic determinants of the parasite. Immunolocalization of four novel secreted proteins confirmed their export beyond the infected red blood cell membrane. Of these, preliminary functional characterization of two novel (Sel1 repeat-containing) parasite proteins, PfSEL1 and PfSEL2 revealed that they down-regulate expression of cell surface Notch signaling molecules in host cells. Also a novel protein kinase (PfEK) and a novel protein phosphatase (PfEP) were found to, respectively, phosphorylate/dephosphorylate parasite-specific proteins in the extracellular culture supernatant. Our study thus sheds new light on malaria parasite extracellular secreted antigens of which some may be essential for parasite development and could constitute promising new drug targets.
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Affiliation(s)
- Meha Singh
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
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73
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Casares S, Richie TL. Immune evasion by malaria parasites: a challenge for vaccine development. Curr Opin Immunol 2009; 21:321-30. [DOI: 10.1016/j.coi.2009.05.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 04/26/2009] [Accepted: 05/12/2009] [Indexed: 11/26/2022]
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74
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Biotech paper watch. Biotechnol J 2008. [DOI: 10.1002/biot.200890111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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