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Human Gene Expression in Uncomplicated Plasmodium falciparum Malaria. J Immunol Res 2015; 2015:162639. [PMID: 26491700 PMCID: PMC4605373 DOI: 10.1155/2015/162639] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 12/30/2014] [Accepted: 01/02/2015] [Indexed: 11/17/2022] Open
Abstract
To examine human gene expression during uncomplicated P. falciparum malaria, we obtained three samples (acute illness, treatment, and recovery) from 10 subjects and utilized each subject's recovery sample as their baseline. At the time of acute illness (day 1), subjects had upregulation of innate immune response, cytokine, and inflammation-related genes (IL-1β, IL-6, TNF, and IFN-γ), which was more frequent with parasitemias >100,000 per μL and body temperatures ≥39°C. Apoptosis-related genes (Fas, BAX, and TP53) were upregulated acutely and for several days thereafter (days 1–3). In contrast, the expression of immune-modulatory (transcription factor 7, HLV-DOA, and CD6) and apoptosis inhibitory (c-myc, caspase 8, and Fas Ligand G) genes was downregulated initially and returned to normal with clinical recovery (days 7–10). These results indicate that the innate immune response, cytokine, and apoptosis pathways are upregulated acutely in uncomplicated malaria with concomitant downregulation of immune-modulatory and apoptosis inhibitory genes.
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Phagocytic uptake of oxidized heme polymer is highly cytotoxic to macrophages. PLoS One 2014; 9:e103706. [PMID: 25078090 PMCID: PMC4117526 DOI: 10.1371/journal.pone.0103706] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 07/06/2014] [Indexed: 11/26/2022] Open
Abstract
Apoptosis in macrophages is responsible for immune-depression and pathological effects during malaria. Phagocytosis of PRBC causes induction of apoptosis in macrophages through release of cytosolic factors from infected cells. Heme polymer or β-hematin causes dose-dependent death of macrophages with LC50 of 132 µg/ml and 182 µg/ml respectively. The toxicity of hemin or heme polymer was amplified several folds in the presence of non-toxic concentration of methemoglobin. β-hematin uptake in macrophage through phagocytosis is crucial for enhanced toxicological effects in the presence of methemoglobin. Higher accumulation of β-hematin is observed in macrophages treated with β-hematin along with methemoglobin. Light and scanning electron microscopic observations further confirm accumulation of β-hematin with cellular toxicity. Toxicological potentiation of pro-oxidant molecules toward macrophages depends on generation of H2O2 and independent to release of free iron from pro-oxidant molecules. Methemoglobin oxidizes β-hematin to form oxidized β-hematin (βH*) through single electron transfer mechanism. Pre-treatment of reaction mixture with spin-trap Phenyl-N-t-butyl-nitrone dose-dependently reverses the β-hematin toxicity, indicates crucial role of βH* generation with the toxicological potentiation. Acridine orange/ethidium bromide staining and DNA fragmentation analysis indicate that macrophage follows an oxidative stress dependent apoptotic pathway to cause death. In summary, current work highlights mutual co-operation between methemoglobin and different pro-oxidant molecules to enhance toxicity towards macrophages. Hence, methemoglobin peroxidase activity can be probed for subduing cellular toxicity of pro-oxidant molecules and it may in-turn make up for host immune response against the malaria parasite.
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Rodrigues-da-Silva RN, Lima-Junior JDC, Fonseca BDPFE, Antas PRZ, Baldez A, Storer FL, Santos F, Banic DM, de Oliveira-Ferreira J. Alterations in cytokines and haematological parameters during the acute and convalescent phases of Plasmodium falciparum and Plasmodium vivax infections. Mem Inst Oswaldo Cruz 2014; 109:154-62. [PMID: 24676654 PMCID: PMC4015248 DOI: 10.1590/0074-0276140275] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 12/06/2013] [Indexed: 12/31/2022] Open
Abstract
Haematological and cytokine alterations in malaria are a broad and controversial subject in the literature. However, few studies have simultaneously evaluated various cytokines in a single patient group during the acute and convalescent phases of infection. The aim of this study was to sequentially characterise alterations in haematological patters and circulating plasma cytokine and chemokine levels in patients infected with Plasmodium vivax or Plasmodium falciparum from a Brazilian endemic area during the acute and convalescent phases of infection. During the acute phase, thrombocytopaenia, eosinopaenia, lymphopaenia and an increased number of band cells were observed in the majority of the patients. During the convalescent phase, the haematologic parameters returned to normal. During the acute phase, P. vivax and P. falciparum patients had significantly higher interleukin (IL)-6, IL-8, IL-17, interferon-γ, tumour necrosis factor (TNF)-α, macrophage inflammatory protein-1β and granulocyte-colony stimulating factor levels than controls and maintained high levels during the convalescent phase. IL-10 was detected at high concentrations during the acute phase, but returned to normal levels during the convalescent phase. Plasma IL-10 concentration was positively correlated with parasitaemia in P. vivax and P. falciparum-infected patients. The same was true for the TNF-α concentration in P. falciparum-infected patients. Finally, the haematological and cytokine profiles were similar between uncomplicated P. falciparum and P. vivax infections.
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Affiliation(s)
| | | | | | | | - Arlete Baldez
- Agência de Vigilância em Saúde, Secretaria de Estado da Saúde, Porto Velho, RO, Brasil
| | | | - Fátima Santos
- Odebrecht Energia/Usina Hidrelétrica Santo Antônio, Porto Velho, RO, Brasil
| | - Dalma Maria Banic
- Instituto Oswaldo Cruz, Laboratório de Simulídeos e Oncocercose, Instituto Oswaldo Cruz
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Hu X, Li JH, Lan L, Wu FF, Zhang EP, Song ZM, Huang HC, Luo FJ, Pan CW, Tan F. In vitro study of the effects of Angiostrongylus cantonensis larvae extracts on apoptosis and dysfunction in the blood-brain barrier (BBB). PLoS One 2012; 7:e32161. [PMID: 22393387 PMCID: PMC3290544 DOI: 10.1371/journal.pone.0032161] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 01/21/2012] [Indexed: 12/18/2022] Open
Abstract
It has been hypothesized that blood-brain barrier (BBB) dysfunction in Angiostrongylus cantonensis infection might be due to the apoptosis of the hosts' BBB cells. Here, we evaluated this hypothesis through several methods, all based on an in vitro mouse BBB model consisting of primary culture brain microvascular endothelial cells (BMECs) and brain astrocytic cells (BACs). In the present study, a four-hour percolation and HRP permeability experiment showed that A. cantonensis larvae extracts can increase the permeability of the BBB. Apoptosis among BMECs and BACs after exposure to larvae extracts was monitored by TUNEL and annexin-V-FITC/PI double staining. A. cantonensis larvae extracts were found to induce apoptosis in both BMECs and BACs. For this reason, we concluded that the induction of apoptosis might participate in the BBB dysfunction observed during angiostrongyliasis. Improved fundamental understanding of how A. cantonensis induces apoptosis may lead to new approaches to the treatment or prevention of this parasitic disease.
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Affiliation(s)
- Xin Hu
- School of Medical Laboratory Science and School of Life Science, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
| | - Jiang-Hui Li
- Institution of Health and Environment, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
| | - Lan Lan
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
| | - Fei-Fei Wu
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
| | - Er-Peng Zhang
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
| | - Zeng-Mei Song
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
| | - Hui-Cong Huang
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
| | - Fang-Jun Luo
- Department of Clinical Laboratory, Zhuji People's Hospital, Zhuji, Zhejiang, People's Republic of China
| | - Chang-Wang Pan
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
| | - Feng Tan
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, People's Republic of China
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Schuldt K, Kretz CC, Timmann C, Sievertsen J, Ehmen C, Esser C, Loag W, Ansong D, Dering C, Evans J, Ziegler A, May J, Krammer PH, Agbenyega T, Horstmann RD. A -436C>A polymorphism in the human FAS gene promoter associated with severe childhood malaria. PLoS Genet 2011; 7:e1002066. [PMID: 21625619 PMCID: PMC3098189 DOI: 10.1371/journal.pgen.1002066] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 03/18/2011] [Indexed: 11/29/2022] Open
Abstract
Human genetics and immune responses are considered to critically influence the outcome of malaria infections including life-threatening syndromes caused by Plasmodium falciparum. An important role in immune regulation is assigned to the apoptosis-signaling cell surface receptor CD95 (Fas, APO-1), encoded by the gene FAS. Here, a candidate-gene association study including variant discovery at the FAS gene locus was carried out in a case-control group comprising 1,195 pediatric cases of severe falciparum malaria and 769 unaffected controls from a region highly endemic for malaria in Ghana, West Africa. We found the A allele of c.−436C>A (rs9658676) located in the promoter region of FAS to be significantly associated with protection from severe childhood malaria (odds ratio 0.71, 95% confidence interval 0.58–0.88, pempirical = 0.02) and confirmed this finding in a replication group of 1,412 additional severe malaria cases and 2,659 community controls from the same geographic area. The combined analysis resulted in an odds ratio of 0.71 (95% confidence interval 0.62–0.80, p = 1.8×10−7, n = 6035). The association applied to c.−436AA homozygotes (odds ratio 0.47, 95% confidence interval 0.36–0.60) and to a lesser extent to c.−436AC heterozygotes (odds ratio 0.73, 95% confidence interval 0.63–0.84), and also to all phenotypic subgroups studied, including severe malaria anemia, cerebral malaria, and other malaria complications. Quantitative FACS analyses assessing CD95 surface expression of peripheral blood mononuclear cells of naïve donors showed a significantly higher proportion of CD69+CD95+ cells among persons homozygous for the protective A allele compared to AC heterozygotes and CC homozygotes, indicating a functional role of the associated CD95 variant, possibly in supporting lymphocyte apoptosis. Severe malaria caused by infection with the protozoan parasite Plasmodium falciparum is a major health burden, causing approximately one million fatalities annually, predominantly among young children in Sub-Saharan Africa. The occurrence of severe malaria may depend on a complex interplay of transmission dynamics and the development of a protective immune response but also on heritable differences in the susceptibility to the disease. In two large studies including a total of 2,607 affected children and 3,428 apparently healthy individuals from Ghana, West Africa, we investigated genetic variants of the FAS gene, which encodes CD95, a molecule critically involved in the programmed cell death of lymphocytes. We found that a single nucleotide variant in the FAS promoter was associated with a 29%–reduced risk of developing severe malaria. In individuals carrying two copies of the protective allele, a higher proportion of activated lymphocytes was found to express CD95. These findings indicate that a predisposition to an increased expression of CD95 may help to protect from severe malaria, possibly by rendering activated T-lymphocytes more susceptible to programmed cell death.
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Affiliation(s)
- Kathrin Schuldt
- Department of Molecular Medicine, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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Apoptosis of endothelial cells in bacterial sepsis and severe Plasmodium falciparum malaria: do we know enough to consider clinical trials? Crit Care Med 2008; 36:2690-2. [PMID: 18728485 DOI: 10.1097/ccm.0b013e3181833c6f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Wilson NO, Huang MB, Anderson W, Bond V, Powell M, Thompson WE, Armah HB, Adjei AA, Gyasi R, Tettey Y, Stiles JK. Soluble factors from Plasmodium falciparum-infected erythrocytes induce apoptosis in human brain vascular endothelial and neuroglia cells. Mol Biochem Parasitol 2008; 162:172-6. [PMID: 18848585 DOI: 10.1016/j.molbiopara.2008.09.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2008] [Revised: 08/29/2008] [Accepted: 09/08/2008] [Indexed: 11/28/2022]
Abstract
The severity of malaria is multi-factorial. It is associated with parasite-induced alteration in pro-inflammatory and anti-inflammatory cytokine and chemokine levels in host serum and cerebrospinal fluid. It is also associated with sequestration and cytoadherence of parasitized erythrocytes (pRBCs) in post-capillary venules and blood-brain barrier (BBB) dysfunction. The role of these factors in development of vascular injury and tissue damage in malaria patients is unclear. While some studies indicate a requirement for pRBC adhesion to vascular endothelial cells (ECs) in brain capillaries to induce apoptosis and BBB damage, others show no role of apoptosis resulting from adhesion of pRBC to EC. In the present study, the hypothesis that soluble factors from Plasmodium falciparum-infected erythrocytes induce apoptosis in human brain vascular endothelial (HBVEC) and neuroglia cells (cellular components of the BBB) was tested. Apoptotic effects of parasitized (pRBC) and non-parasitized erythrocyte (RBC) conditioned medium on HBVEC and neuroglia cells were determined in vitro by evaluating nuclear DNA fragmentation (TUNEL assay) in cultured cells. Soluble factors from P. falciparum-infected erythrocytes in conditioned medium induced extensive DNA fragmentation in both cell lines, albeit to a greater extent in HBVEC than neuroglia, indicating that extended exposure to high levels of these soluble factors in serum may be associated with vascular, neuronal and tissue injury in malaria patients.
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Affiliation(s)
- Nana O Wilson
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, 720 Westview Drive SW, Atlanta, GA 30310, USA
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Mukherjee P, Devi YS, Chauhan VS. Blood stage malaria antigens induce different activation-induced cell death programs in splenic CD4+T cells. Parasite Immunol 2008; 30:497-514. [PMID: 18643960 DOI: 10.1111/j.1365-3024.2008.01050.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CD4(+) T cells respond to antigen immunization through a process of activation, clonal expansion to generate activated effector T cells followed by activation-induced clonal deletion of the responding T cells. While loss of responding T cells in post-activation death by apoptosis is a major factor regulating immune homeostasis, the precise pathways involved in downsizing of Plasmodium falciparum antigen-induced T cell expansions are not well characterized. We report in this study that splenic CD4(+) T cells from mice immunized with nonreplicating immunogens like OVA or recombinant blood stage P. falciparum antigens, PfMSP-3 and PfMSP-1(19) or crude parasite antigen (PfAg) undergo sequential T cell activation, proliferation followed by activation-induced cell death (AICD) in a dose- and time-dependent manner after Ag restimulation. While PfMSP-3 and OVA-induced AICD was mediated through a death receptor-dependent apoptotic program, PfMSP-1(19) and PfAg-induced AICD was via a mechanism dependent on the activation of mitochondria apoptosis signalling pathway through Bax activation. These results provide insights into the mechanism through which two blood stage merozoite antigens trigger different apoptotic programs of AICD in splenic CD4(+) T cells.
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Affiliation(s)
- P Mukherjee
- International Centre of Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi, India.
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Lovegrove FE, Gharib SA, Patel SN, Hawkes CA, Kain KC, Liles WC. Expression microarray analysis implicates apoptosis and interferon-responsive mechanisms in susceptibility to experimental cerebral malaria. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:1894-903. [PMID: 17991715 DOI: 10.2353/ajpath.2007.070630] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Specific local brain responses, influenced by parasite sequestration and host immune system activation, have been implicated in the development of cerebral malaria. This study assessed whole-brain transcriptional responses over the course of experimental cerebral malaria by comparing genetically resistant and susceptible inbred mouse strains infected with Plasmodium berghei ANKA. Computational methods were used to identify differential patterns of gene expression. Overall, genes that showed the most transcriptional activity were differentially expressed in susceptible mice 1 to 2 days before the onset of characteristic symptoms of cerebral malaria. Most of the differentially expressed genes identified were associated with immune-related gene ontology categories. Further analysis to identify interaction networks and to examine patterns of transcriptional regulation within the set of identified genes implicated a central role for both interferon-regulated processes and apoptosis in the pathogenesis of cerebral malaria. Biological relevance of these genes and pathways was confirmed using quantitative RT-PCR and histopathological examination of the brain for apoptosis. The application of computational biology tools to examine systematically the disease progression in cerebral malaria can identify important transcriptional programs activated during its pathogenesis and may serve as a methodological approach to identify novel targets for therapeutic intervention.
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Affiliation(s)
- Fiona E Lovegrove
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada M5G 2C4
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10
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Schaumburg F, Hippe D, Vutova P, Lüder CGK. Pro- and anti-apoptotic activities of protozoan parasites. Parasitology 2006; 132 Suppl:S69-85. [PMID: 17018167 DOI: 10.1017/s0031182006000874] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
During infection, programmed cell death, i.e. apoptosis, is an important effector mechanism of innate and adaptive host responses to parasites. In addition, it fulfils essential functions in regulating host immunity and tissue homeostasis. Not surprisingly, however, adaptation of parasitic protozoa to their hosts also involves modulation or even exploitation of cell death in order to facilitate parasite survival in a hostile environment. During recent years, considerable progress has been made in our understanding of apoptosis during parasitic infections and there is now convincing evidence that apoptosis and its modulation by protozoan parasites has a major impact on the parasite-host interaction and on the pathogenesis of disease. This review updates our current knowledge on the diverse functions apoptosis may fulfil during infections with diverse protozoan parasites including apicomplexans, kinetoplastids and amoebae. Furthermore, we also summarize common mechanistic themes of the pro- and anti-apoptotic activities of protozoan parasites. The diverse and complex effects which parasitic protozoa exert on apoptotic cell death within the host highlight fascinating interactions of parasites and their hosts. Importantly, they also stress the importance of further investigations before the modulation of host cell apoptosis can be exploited to combat parasitic infections.
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Affiliation(s)
- F Schaumburg
- Institute for Medical Microbiology, Georg-August-University, Kreuzbergring 57, 37075 Göttingen, Germany
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11
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Weidanz WP, Batchelder JM, Flaherty P, LaFleur G, Wong C, van der Heyde HC. Plasmodium chabaudi adami: use of the B-cell-deficient mouse to define possible mechanisms modulating parasitemia of chronic malaria. Exp Parasitol 2005; 111:97-104. [PMID: 16087175 DOI: 10.1016/j.exppara.2005.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 06/23/2005] [Accepted: 06/26/2005] [Indexed: 11/25/2022]
Abstract
Our previous observation that B-cell-deficient JH-/- mice utilize T cell-dependent immunity to suppress acute Plasmodium chabaudi adami-induced malaria but then develop chronic low-level parasitemia prompted this study of control mechanisms for chronic parasitemia. When we infected JH-/- mice with blood-stage parasites, chronic parasitemia exacerbated after the 6th month and persisted for up to 17 months. This exacerbation of parasitemia could not be attributed to host aging because the time-course of acute infection in naïve aged mice was nearly identical to that seen in young mice. Nor could exacerbated parasitemia be attributed to mutation in the parasite genome resulting in increased virulence; when subinoculated into naïve JH-/- mice, parasites from chronically infected JH-/- mice with exacerbated parasitemia produced acute stage parasitemia profiles in most recipients comparable to those seen in JH-/- mice upon infection with the original stabilate material. Of the pro-inflammatory cytokines measured, including IFNgamma, TNFalpha, IL-12p70, and MCP-1beta, none were significantly different in the sera of mice with exacerbated parasitemia compared to uninfected controls. Levels of IL-6 were significantly (P=0.002) less in the sera of mice with exacerbated parasitemia. Serum levels of the anti-inflammatory cytokine, TGFbeta, were significantly depressed in chronically infected JH-/- mice compared to uninfected controls. In contrast, IL-10 levels were markedly increased. These findings suggest that the cytokine balance may be disturbed during chronic malaria, thereby impacting on mechanisms that modulate levels of parasitemia.
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Affiliation(s)
- William P Weidanz
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706 1532, USA.
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12
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Abstract
It is widely perceived that immunity to malaria is, to an extent, defective and that one component of this defective immune response is the inability to induce or maintain long-term memory responses. If true, this is likely to pose problems for development of an effective vaccine against malaria. In this article, we critically review and challenge this interpretation of the epidemiological and experimental evidence. While evasion and modulation of host immune responses clearly occurs and naturally acquired immunity is far from optimal, mechanisms to control blood-stage parasites are acquired and maintained by individuals living in endemic areas, allowing parasite density to be kept below the threshold for induction of acute disease. Furthermore, protective immunity to severe pathology is achieved relatively rapidly and is maintained in the absence of boosting by re-infection. Nevertheless, there are significant challenges to overcome. The need for multiple infections to acquire immunity means that young children remain at risk of infection for far too long. Persistent or frequent exposure to antigen seems to be required to maintain anti-parasite immunity (premunition). Lastly, pre-erythrocytic and sexual stages of the life cycle are poorly immunogenic, and there is little evidence of effective pre-erythrocytic or transmission-blocking immunity at the population level. While these problems might theoretically be due to defective immunological memory, we suggest alternative explanations. Moreover, we question the extent to which these problems are malaria-specific rather than generic (i.e. result from inherent limitations of the vertebrate immune system).
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Affiliation(s)
- Siske S Struik
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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Struik SS, Omer FM, Artavanis-Tsakonas K, Riley EM. Uninfected erythrocytes inhibit Plasmodium falciparum–induced cellular immune responses in whole-blood assays. Blood 2004; 103:3084-92. [PMID: 15070689 DOI: 10.1182/blood-2003-08-2867] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Abstract
Whole-blood assays (WBAs) have been successfully used as a simple tool for immuno-epidemiological field studies evaluating cellular immune responses to mycobacterial and viral antigens. Rather unexpectedly, we found very poor cytokine responses to malaria antigens in WBAs in 2 immuno-epidemiological studies carried out in malaria endemic populations in Africa. We have therefore conducted a detailed comparison of cellular immune responses to live (intact) and lysed malaria-infected erythrocytes in WBAs and in peripheral blood mononuclear cell (PBMC) cultures. We observed profound inhibition of both proliferative and interferon-γ responses to malarial antigens in WBAs as compared with PBMC cultures. This inhibition was seen only for malaria antigens and could not be overcome by increasing either antigen concentration or responder cell numbers. Inhibition was mediated by intact erythrocytes and occurred early in the culture period, suggesting that failure of antigen uptake might underlie the lack of T-cell responses. In support of this hypothesis, we have shown that intact uninfected erythrocytes specifically inhibit phagocytosis of infected red blood cells by peripheral blood monocytes. We propose that specific biochemical interactions with uninfected erythrocytes inhibit the phagocytosis of malaria-infected erythrocytes and that this may impede T-cell recognition in vivo. (Blood. 2004; 103:3084-3092)
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Affiliation(s)
- Siske S Struik
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
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López-Briones S, Sciutto E, Ventura JL, Zentella A, Fragoso G. CD4+ and CD19+ splenocytes undergo apoptosis during an experimental murine infection with Taenia crassiceps. Parasitol Res 2003; 90:157-63. [PMID: 12756553 DOI: 10.1007/s00436-003-0829-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2002] [Accepted: 12/16/2002] [Indexed: 10/25/2022]
Abstract
The Taenia crassiceps cysticercus is a cestode that naturally and experimentally infects rodents in which it reproduces by budding. In the laboratory, a persistent cellular immunosuppression with a concomitant increasing load of parasites has been observed in experimentally infected BALB/cAnN mice. In this study, enhanced apoptosis was found in spleen cells from 30-day infected mice with a typical "ladder-patterned" DNA fragmentation and an increase in phosphatidylserine expression. A characteristic poly-(ADP-ribose) polymerase cleavage indicates that this cell death is caspase-mediated. Apoptosis was detected in the CD4(+) and CD19(+) splenocytes of infected mice after in vitro stimulation with cysticercal antigens. Considering previous results on the crucial role that CD4(+) T cells play in controlling the extent of infection, apoptosis in this T-lymphocyte subpopulation induced by T. crassiceps cysticerci could be responsible for the immunosuppression that underlies parasite success.
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Affiliation(s)
- Sergio López-Briones
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), AP 70228, C.P. 04510, Mexico City, Mexico
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15
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Riccio EKP, Júnior IN, Riccio LRP, das Graças Alecrim M, Corte-Real S, Morgado M, Daniel-Ribeiro CT, de Fátima Ferreira-da-Cruz M. Malaria associated apoptosis is not significantly correlated with either parasitemia or the number of previous malaria attacks. Parasitol Res 2003; 90:9-18. [PMID: 12743799 DOI: 10.1007/s00436-002-0816-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2002] [Accepted: 11/21/2002] [Indexed: 10/21/2022]
Abstract
The occurrence and intensity of lymphocyte apoptosis in blood samples from 79 outclinic patients with uncomplicated Plasmodium falciparum or Plasmodium vivax malaria and 30 healthy individuals were investigated. No difference in apoptosis percentages was detected between healthy individuals and malaria patients when ex vivo lymphocytes were analyzed. However, significantly increased apoptosis levels were observed in lymphocytes from both P. falciparum- and P. vivax-infected patients when the cells were cultured for 24 h. CD4(+)and CD8(+) T cells were affected to a comparable extent in P.falciparum- and P.vivax-infected patients. However, when we compared apoptosis values in infected and non-infected individuals it appeared that CD4(+) T cells were more susceptible than CD8(+) T cells. A significant increase in the sIL-2R plasma levels was observed in malaria patients when compared with healthy individuals and a positive correlation was observed between sIL-2R levels and apoptosis rates in infected patients presenting increased rates of apoptosis. An increased expression of Fas antigen was recorded after stimulation with P. falciparum antigen or anti-CD3 monoclonal antibody. These data show that a consistent proportion of the lymphocyte population dies by apoptosis during a malaria infection and that a period of time is necessary before in vivo activated cells can express the apoptotic process in vitro.
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Affiliation(s)
- Evelyn K P Riccio
- Department of Immunology--WHO Collaborating Center for Research and Training in Immunology of Parasitic Diseases, Instituto Oswaldo Cruz Fiocruz, RJ, Brazil
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Aubouy A, Deloron P, Migot-Nabias F. Plasma and in vitro levels of cytokines during and after a Plasmodium falciparum malaria attack in Gabon. Acta Trop 2002; 83:195-203. [PMID: 12204392 DOI: 10.1016/s0001-706x(02)00094-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Fifty subjects living in a malaria endemic area were studied at diagnosis of a Plasmodium falciparum attack and 3 weeks later. Absolute numbers of CD3(+), CD4(+) and CD8(+) lymphocytes as well as plasma cytokines and secreted cytokines after in vitro mitogenic stimulation were measured. At enrollment, lymphopenia was observed, lending support to the reallocation hypothesis during the acute phase. A significant elevation of the number of CD8(+) cells was present in the peripheral blood during the recovery phase. During the acute phase, plasma IL-6 levels peaked while in vitro production capacity was high at both phases. Plasma IL-6 concentrations were positively related to blood parasite density at D0, as IL-4 and IFN-gamma, suggesting an early intervention of these cytokines. Plasma IL-2 levels were low at diagnosis although cells retained their ability to produce IL-2, which was found more frequently in plasma after cure. Acquisition of immunity with age was in relation with greater secretion abilities of cells for type 1 and type 2 cytokines during the parasite clearance phase. We conclude to an early implication of type 2 cytokines and IFN-gamma, with particularly high levels of IL-6.
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Affiliation(s)
- Agnès Aubouy
- Centre International de Recherches Médicales de Franceville, Unité de Parasitologie Médicale, Gabon.
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Garraud O, Diouf A, Nguer CM, Tall A, Marrama L, Perraut R. Experimental IgG antibody production in vitro by peripheral blood and tonsil surface gamma+ B lymphocytes from Plasmodium falciparum-immune West Africans. Scand J Immunol 2001; 54:606-12. [PMID: 11902336 DOI: 10.1046/j.1365-3083.2001.01011.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Antigen reactive B cells in tonsil specimens from teenagers from a region moderately exposed to P. falciparum were capable of being differentiated in vitro and producing specific immunoglobulin (Ig)G in up to 33% of individual experiments. Mononuclear cells or purified (s)gamma+ CD19+ B cells from peripheral blood or tonsil specimens from P falciparum-immune Senegalese subjects produced antigen-specific IgG upon appropriate stimulation in vitro. One fraction of this IgG was produced de novo by differentiated B cells and another fraction was likely bound on the surface of circulating or resident CD19+ sgamma+ B cells which were found in significantly greater numbers in individuals from rural Senegal as compared to nonimmune European controls. This study further documents the baseline levels of in vitro driven anti-P. falciparum IgG antibody production by mononuclear cells from blood and tonsils in immune populations exposed to P. falciparum differentially. Furthermore, this study demonstrates the relevance and potential utility of tonsils as a source of B lymphocytes to characterize further specific antibody responses to P. falciparum antigens in immune populations.
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Affiliation(s)
- O Garraud
- Laboratoire d'Immunologie, Institut Pasteur de Dakar, Senegal.
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18
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Wipasa J, Xu H, Stowers A, Good MF. Apoptotic deletion of Th cells specific for the 19-kDa carboxyl-terminal fragment of merozoite surface protein 1 during malaria infection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:3903-9. [PMID: 11564808 DOI: 10.4049/jimmunol.167.7.3903] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immunity induced by the 19-kDa fragment of merozoite surface protein 1 is dependent on CD4+ Th cells. However, we found that adoptively transferred CFSE-labeled Th cells specific for an epitope on Plasmodium yoelii 19-kDa fragment of merozoite surface protein 1 (peptide (p)24), but not OVA-specific T cells, were deleted as a result of P. yoelii infection. As a result of infection, spleen cells recovered from infected p24-specific T cell-transfused mice demonstrated reduced response to specific Ag. A higher percentage of CFSE-labeled p24-specific T cells stained positive with annexin and anti-active caspase-3 in infected compared with uninfected mice, suggesting that apoptosis contributed to deletion of p24-specific T cells during infection. Apoptosis correlated with increased percentages of p24-specific T cells that stained positive for Fas from infected mice, suggesting that P. yoelii-induced apoptosis is, at least in part, mediated by Fas. However, bystander cells of other specificities also showed increased Fas expression during infection, suggesting that Fas expression alone is not sufficient for apoptosis. These data have implications for the development of immunity in the face of endemic parasite exposure.
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Affiliation(s)
- J Wipasa
- Cooperative Research Center for Vaccine Technology, Queensland Institute of Medical Research, Royal Brisbane Hospital, Queensland, 4029 Australia
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Lüder CG, Gross U, Lopes MF. Intracellular protozoan parasites and apoptosis: diverse strategies to modulate parasite-host interactions. Trends Parasitol 2001; 17:480-6. [PMID: 11587962 DOI: 10.1016/s1471-4922(01)02016-5] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Programmed cell death (apoptosis) is an important regulator of the host's response during infection with a variety of intracellular protozoan parasites. Parasitic pathogens have evolved diverse strategies to induce or inhibit host-cell apoptosis, thereby modulating the host's immune response, aiding dissemination within the host or facilitating intracellular survival. Here, we review the molecular and cell-biological mechanisms of the pathogen-induced modulation of host-cell apoptosis and its effects on the parasite-host interaction and the pathogenesis of parasitic diseases. We also discuss the previously unrecognized phenomenon of apoptotic cell death in (unicellular) protozoan parasites and its potential implications.
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Affiliation(s)
- C G Lüder
- Department Bacteriology, Georg August University of Göttingen, Kreuzbergring 57, D-37075 Göttingen, Germany.
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McNamee JP, Bellier PV, McLean JR. Differential rates of cytokine production and apoptosis in venipuncture and finger-stab derived blood cultures. Cytokine 2001; 15:274-80. [PMID: 11594793 DOI: 10.1006/cyto.2001.0929] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The collection of finger-stab (FS) blood is a convenient and non-invasive method of rapidly acquiring human blood and is becoming increasingly popular for use in human biomonitoring studies. This study compared whole blood (WB) and peripheral blood mononuclear cell (PBMC) cultures derived from venipuncture (VP) and FS blood, to determine whether they respond similarly under culture conditions. The rates of spontaneous- and radiation-induced apoptosis and pro-inflammatory cytokine production were monitored over 72 h in each of four culture conditions. In non-irradiated WB cultures, the spontaneous rate of apoptosis was significantly lower in cultures from FS-derived blood than from VP-derived blood. However, FS- and VP-derived cultures responded similarly to radiation-induced apoptosis. PBMC cultures, regardless of the source, were the most responsive to radiation. When the levels of pro-inflammatory cytokines were measured, a significant time-dependent increase in TNF-alpha, IL-6 and IL-1beta production was observed in FS-derived cultures, but not in VP-derived cultures. While VP and FS blood cultures were found to respond similarly to radiation-induced apoptosis, there was a significant difference in the rate of spontaneous apoptosis in non-irradiated WB cultures and in the in situ production of pro-inflammatory cytokines between VP- and FS-derived blood cultures.
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Affiliation(s)
- J P McNamee
- Consumer and Clinical Radiation Protection Bureau, Product Safety Programme, Health Canada, 775 Brookfield Rd, Ottawa, Ontario, Canada K1A 1C1.
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