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Legorreta-Herrera M. The Influence of Prolactin on the Immune Response to Parasitic Diseases. ACTA ACUST UNITED AC 2018. [DOI: 10.3233/nib-170131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Martha Legorreta-Herrera
- Laboratorio de Inmunología Molecular, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México
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2
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Ghosh D, Stumhofer JS. Do you see what I see: Recognition of protozoan parasites by Toll-like receptors. ACTA ACUST UNITED AC 2014; 9:129-140. [PMID: 25383072 DOI: 10.2174/1573395509666131203225929] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Toll-like receptors (TLRs) are important for recognizing a variety of pathogens, including protozoan parasites, and initiating innate immune responses against them. TLRs are localized on the cell surface as well as in the endosome, and are implicated in innate sensing of these parasites. In this review, we will discuss recent findings on the identification of parasite-derived pathogen associated molecular patterns and the TLRs that bind them. The role of these TLRs in initiating the immune response against protozoan parasitic infections in vivo will be presented in the context of murine models of infection utilizing TLR-deficient mice. Additionally, we will explore evidence that TLRs and genetic variants of TLRs may impact the outcome of these parasitic infections in humans.
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Affiliation(s)
- Debopam Ghosh
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
| | - Jason S Stumhofer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
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Polimeni M, Prato M. Host matrix metalloproteinases in cerebral malaria: new kids on the block against blood-brain barrier integrity? Fluids Barriers CNS 2014; 11:1. [PMID: 24467887 PMCID: PMC3905658 DOI: 10.1186/2045-8118-11-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 01/24/2014] [Indexed: 12/23/2022] Open
Abstract
Cerebral malaria (CM) is a life-threatening complication of falciparum malaria, associated with high mortality rates, as well as neurological impairment in surviving patients. Despite disease severity, the etiology of CM remains elusive. Interestingly, although the Plasmodium parasite is sequestered in cerebral microvessels, it does not enter the brain parenchyma: so how does Plasmodium induce neuronal dysfunction? Several independent research groups have suggested a mechanism in which increased blood–brain barrier (BBB) permeability might allow toxic molecules from the parasite or the host to enter the brain. However, the reported severity of BBB damage in CM is variable depending on the model system, ranging from mild impairment to full BBB breakdown. Moreover, the factors responsible for increased BBB permeability are still unknown. Here we review the prevailing theories on CM pathophysiology and discuss new evidence from animal and human CM models implicating BBB damage. Finally, we will review the newly-described role of matrix metalloproteinases (MMPs) and BBB integrity. MMPs comprise a family of proteolytic enzymes involved in modulating inflammatory response, disrupting tight junctions, and degrading sub-endothelial basal lamina. As such, MMPs represent potential innovative drug targets for CM.
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Affiliation(s)
| | - Mauro Prato
- Dipartimento di Neuroscienze, Università di Torino, C,so Raffaello 30, 10125 Torino, Italy.
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Basu M, Das T, Ghosh A, Majumder S, Maji AK, Kanjilal SD, Mukhopadhyay I, Roychowdhury S, Banerjee S, Sengupta S. Gene-gene interaction and functional impact of polymorphisms on innate immune genes in controlling Plasmodium falciparum blood infection level. PLoS One 2012; 7:e46441. [PMID: 23071570 PMCID: PMC3470565 DOI: 10.1371/journal.pone.0046441] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 08/30/2012] [Indexed: 12/19/2022] Open
Abstract
Genetic variations in toll-like receptors and cytokine genes of the innate immune pathways have been implicated in controlling parasite growth and the pathogenesis of Plasmodium falciparum mediated malaria. We previously published genetic association of TLR4 non-synonymous and TNF-α promoter polymorphisms with P.falciparum blood infection level and here we extend the study considerably by (i) investigating genetic dependence of parasite-load on interleukin-12B polymorphisms, (ii) reconstructing gene-gene interactions among candidate TLRs and cytokine loci, (iii) exploring genetic and functional impact of epistatic models and (iv) providing mechanistic insights into functionality of disease-associated regulatory polymorphisms. Our data revealed that carriage of AA (P = 0.0001) and AC (P = 0.01) genotypes of IL12B 3′UTR polymorphism was associated with a significant increase of mean log-parasitemia relative to rare homozygous genotype CC. Presence of IL12B+1188 polymorphism in five of six multifactor models reinforced its strong genetic impact on malaria phenotype. Elevation of genetic risk in two-component models compared to the corresponding single locus and reduction of IL12B (2.2 fold) and lymphotoxin-α (1.7 fold) expressions in patients'peripheral-blood-mononuclear-cells under TLR4Thr399Ile risk genotype background substantiated the role of Multifactor Dimensionality Reduction derived models. Marked reduction of promoter activity of TNF-α risk haplotype (C-C-G-G) compared to wild-type haplotype (T-C-G-G) with (84%) and without (78%) LPS stimulation and the loss of binding of transcription factors detected in-silico supported a causal role of TNF-1031. Significantly lower expression of IL12B+1188 AA (5 fold) and AC (9 fold) genotypes compared to CC and under-representation (P = 0.0048) of allele A in transcripts of patients' PBMCs suggested an Allele-Expression-Imbalance. Allele (A+1188C) dependent differential stability (2 fold) of IL12B-transcripts upon actinomycin-D treatment and observed structural modulation (P = 0.013) of RNA-ensemble were the plausible explanations for AEI. In conclusion, our data provides functional support to the hypothesis that de-regulated receptor-cytokine axis of innate immune pathway influences blood infection level in P. falciparum malaria.
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Affiliation(s)
- Madhumita Basu
- Department of Biochemistry, University of Calcutta, Kolkata, West Bengal, India
| | - Tania Das
- Cancer & Cell Biology Division, Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Alip Ghosh
- Centre for Liver Research, The Institute of Post-Graduate Medical Education & Research, Kolkata, West Bengal, India
| | - Subhadipa Majumder
- Department of Biochemistry, University of Calcutta, Kolkata, West Bengal, India
| | - Ardhendu Kumar Maji
- Department of Protozoology, The Calcutta School of Tropical Medicine, Kolkata, West Bengal, India
| | - Sumana Datta Kanjilal
- Department of Pediatric Medicine, Calcutta National Medical College, Kolkata, West Bengal, India
| | | | - Susanta Roychowdhury
- Cancer & Cell Biology Division, Indian Institute of Chemical Biology, Kolkata, West Bengal, India
| | - Soma Banerjee
- Centre for Liver Research, The Institute of Post-Graduate Medical Education & Research, Kolkata, West Bengal, India
| | - Sanghamitra Sengupta
- Department of Biochemistry, University of Calcutta, Kolkata, West Bengal, India
- * E-mail:
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5
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Davenport GC, Hittner JB, Were T, Ong'echa JM, Perkins DJ. Relationship between inflammatory mediator patterns and anemia in HIV-1 positive and exposed children with Plasmodium falciparum malaria. Am J Hematol 2012; 87:652-8. [PMID: 22570198 DOI: 10.1002/ajh.23200] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 03/01/2012] [Accepted: 03/06/2012] [Indexed: 12/27/2022]
Abstract
Anemia is the primary hematological manifestation of both Plasmodium falciparum malaria and HIV-1 in pediatric populations in sub-Saharan Africa. We have previously shown that HIV-1 positive and exposed children have greater risk of developing severe anemia (hemoglobin, Hb <6.0 g dL⁻¹) during acute malaria. However, enhanced severity of anemia was unrelated to either erythropoietic suppression or parasite-driven red blood cell hemolysis. To further explore mechanisms of anemia, circulating inflammatory mediators (IMs) were determined using a 25-plex bead array in P. falciparum-infected (Pf[+]) children (3-36 month, n = 194) stratified into three groups: HIV-1 negative (HIV-1[-]/Pf[+]); HIV-1 exposed (HIV-1[exp]/Pf[+]); and HIV-1 infected (HIV-1[+]/Pf[+]). IL-12, MIG/CXCL9, eotaxin/CCL11, and GM-CSF differed significantly and progressively increased across the groups (HIV-1[-]→HIV-1[exp]→HIV-1[+]). To further explore the relationship between the inflammatory milieu (i.e., cytokines, chemokines, and growth factors) and HIV-1 status, the large panel of IMs was reduced into discrete groups by principal component factor analysis. Of the six principal components that emerged, three components were significantly higher in the HIV-1 [+]/pf[+] and HIV[exp]/Pf[+] groups, demonstrating that inflammatory profiles differ according to HIV-1 status. Additional analyses exploring the relationship between the components and anemia revealed significant positive correlations between Hb and Component 3 (IL-1Ra, IL-7, IL-17, IFN-α, IFN-γ, MIG/CXCL9) in the HIV-1[-]/Pf[+] group, and Component 4 (IL-4, IL-5, IL-12, Eotaxin/CCL11) in HIV-1[+]/Pf[+] children. Further analyses of the HIV-1[+]/Pf[+] group revealed that IL-12 had the strongest association with anemia. Results presented here demonstrate that there are unique relationships between the inflammatory environment and anemia in HIV-1 positive and exposed children with malaria.
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Affiliation(s)
- Gregory C Davenport
- Center for Global Health, Department of Internal Medicine, University of New Mexico, Albuquerque, NM 87131-0001, USA
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Fauconnier M, Palomo J, Bourigault ML, Meme S, Szeremeta F, Beloeil JC, Danneels A, Charron S, Rihet P, Ryffel B, Quesniaux VFJ. IL-12Rβ2 Is Essential for the Development of Experimental Cerebral Malaria. THE JOURNAL OF IMMUNOLOGY 2012; 188:1905-14. [DOI: 10.4049/jimmunol.1101978] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Quintero JP, Siqueira AM, Tobón A, Blair S, Moreno A, Arévalo-Herrera M, Lacerda MVG, Valencia SH. Malaria-related anaemia: a Latin American perspective. Mem Inst Oswaldo Cruz 2011; 106 Suppl 1:91-104. [PMID: 21881762 PMCID: PMC4830680 DOI: 10.1590/s0074-02762011000900012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 07/04/2011] [Indexed: 11/22/2022] Open
Abstract
Malaria is the most important parasitic disease worldwide, responsible for an estimated 225 million clinical cases each year. It mainly affects children, pregnant women and non-immune adults who frequently die victims of cerebral manifestations and anaemia. Although the contribution of the American continent to the global malaria burden is only around 1.2 million clinical cases annually, there are 170 million inhabitants living at risk of malaria transmission in this region. On the African continent, where Plasmodium falciparum is the most prevalent human malaria parasite, anaemia is responsible for about half of the malaria-related deaths. Conversely, in Latin America (LA), malaria-related anaemia appears to be uncommon, though there is a limited knowledge about its real prevalence. This may be partially explained by several factors, including that the overall malaria burden in LA is significantly lower than that of Africa, that Plasmodium vivax, the predominant Plasmodium species in the region, appears to display a different clinical spectrus and most likely because better health services in LA prevent the development of severe malaria cases. With the aim of contributing to the understanding of the real importance of malaria-related anaemia in LA, we discuss here a revision of the available literature on the subject and the usefulness of experimental animal models, including New World monkeys, particularly for the study of the mechanisms involved in the pathogenesis of malaria.
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Affiliation(s)
- Juan Pablo Quintero
- Caucaseco Scientific Research Center, Cali, Colômbia
- Centro Latino Americano de Investigación en Malaria, Cali, Colombia
| | - André Machado Siqueira
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Manaus, AM, Brasil
- Universidade do Estado do Amazonas, Manaus, AM, Brasil
| | | | | | - Alberto Moreno
- Emory Vaccine Centre, Yerkes National Primate Research Centre, Atlanta, GA, USA
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, USA
| | - Myriam Arévalo-Herrera
- Caucaseco Scientific Research Center, Cali, Colômbia
- Centro Latino Americano de Investigación en Malaria, Cali, Colombia
| | | | - Sócrates Herrera Valencia
- Caucaseco Scientific Research Center, Cali, Colômbia
- Centro Latino Americano de Investigación en Malaria, Cali, Colombia
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Gammadelta T cells but not NK cells are essential for cell-mediated immunity against Plasmodium chabaudi malaria. Infect Immun 2010; 78:4331-40. [PMID: 20660608 DOI: 10.1128/iai.00539-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Blood-stage Plasmodium chabaudi infections are suppressed by antibody-mediated immunity and/or cell-mediated immunity (CMI). To determine the contributions of NK cells and γδ T cells to protective immunity, C57BL/6 (wild-type [WT]) mice and B-cell-deficient (J(H(-/-))) mice were infected with P. chabaudi and depleted of NK cells or γδ T cells with monoclonal antibody. The time courses of parasitemia in NK-cell-depleted WT mice and J(H(-/-)) mice were similar to those of control mice, indicating that deficiencies in NK cells, NKT cells, or CD8(+) T cells had little effect on parasitemia. In contrast, high levels of noncuring parasitemia occurred in J(H(-/-)) mice depleted of γδ T cells. Depletion of γδ T cells during chronic parasitemia in B-cell-deficient J(H(-/-)) mice resulted in an immediate and marked exacerbation of parasitemia, suggesting that γδ T cells have a direct killing effect in vivo on blood-stage parasites. Cytokine analyses revealed that levels of interleukin-10, gamma interferon (IFN-γ), and macrophage chemoattractant protein 1 (MCP-1) in the sera of γδ T-cell-depleted mice were significantly (P < 0.05) decreased compared to hamster immunoglobulin-injected controls, but these cytokine levels were similar in NK-cell-depleted mice and their controls. The time courses of parasitemia in CCR2(-/-) and J(H(-/-)) × CCR2(-/-) mice and in their controls were nearly identical, indicating that MCP-1 is not required for the control of parasitemia. Collectively, these data indicate that the suppression of acute P. chabaudi infection by CMI is γδ T cell dependent, is independent of NK cells, and may be attributed to the deficient IFN-γ response seen early in γδ T-cell-depleted mice.
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Zhang L, Prather D, Vanden Eng J, Crawford S, Kariuki S, ter Kuile F, Terlouw D, Nahlen B, Lal AA, Slutsker L, Udhayakumar V, Shi YP. Polymorphisms in genes of interleukin 12 and its receptors and their association with protection against severe malarial anaemia in children in western Kenya. Malar J 2010; 9:87. [PMID: 20350312 PMCID: PMC2858737 DOI: 10.1186/1475-2875-9-87] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 03/29/2010] [Indexed: 01/21/2023] Open
Abstract
Background Malarial anaemia is characterized by destruction of malaria infected red blood cells and suppression of erythropoiesis. Interleukin 12 (IL12) significantly boosts erythropoietic responses in murine models of malarial anaemia and decreased IL12 levels are associated with severe malarial anaemia (SMA) in children. Based on the biological relevance of IL12 in malaria anaemia, the relationship between genetic polymorphisms of IL12 and its receptors and SMA was examined. Methods Fifty-five tagging single nucleotide polymorphisms covering genes encoding two IL12 subunits, IL12A and IL12B, and its receptors, IL12RB1 and IL12RB2, were examined in a cohort of 913 children residing in Asembo Bay region of western Kenya. Results An increasing copy number of minor variant (C) in IL12A (rs2243140) was significantly associated with a decreased risk of SMA (P = 0.006; risk ratio, 0.52 for carrying one copy of allele C and 0.28 for two copies). Individuals possessing two copies of a rare variant (C) in IL12RB1 (rs429774) also appeared to be strongly protective against SMA (P = 0.00005; risk ratio, 0.18). In addition, children homozygous for another rare allele (T) in IL12A (rs22431348) were associated with reduced risk of severe anaemia (SA) (P = 0.004; risk ratio, 0.69) and of severe anaemia with any parasitaemia (SAP) (P = 0.004; risk ratio, 0.66). In contrast, AG genotype for another variant in IL12RB1 (rs383483) was associated with susceptibility to high-density parasitaemia (HDP) (P = 0.003; risk ratio, 1.21). Conclusions This study has shown strong associations between polymorphisms in the genes of IL12A and IL12RB1 and protection from SMA in Kenyan children, suggesting that human genetic variants of IL12 related genes may significantly contribute to the development of anaemia in malaria patients.
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Affiliation(s)
- Lyna Zhang
- Malaria Branch, Division of Parasitic Diseases, National Center for Zoonotic, Vector-Borne & Enteric Diseases, Coordinating Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30341, USA.
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Naka I, Patarapotikul J, Tokunaga K, Hananantachai H, Tsuchiya N, Ohashi J. A replication study of the association between the IL12B promoter allele CTCTAA and susceptibility to cerebral malaria in Thai population. Malar J 2009; 8:290. [PMID: 20003322 PMCID: PMC2797809 DOI: 10.1186/1475-2875-8-290] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Accepted: 12/11/2009] [Indexed: 11/22/2022] Open
Abstract
Background Interleukin-12 (IL-12), a heterodimeric cytokine composed of p35 and p40 subunits, has been thought to play an important role in the pathogenesis of malaria. The IL-12p40 subunit is encoded by the IL12B gene. An IL12B promoter allele, CTCTAA, at rs17860508 has been reported to be associated with susceptibility to cerebral malaria in African populations. However, this association has not so far been replicated in non-African populations. Methods To examine whether the CTCTAA allele is associated with susceptibility to cerebral malaria in Asian populations, 303 Thai patients with Plasmodium falciparum malaria (109 cerebral malaria and 194 mild malaria patients) were genotyped for rs17860508 by PCR-direct sequencing. Results The CTCTAA allele showed a significant association with susceptibility to cerebral malaria in the Thai population (allelic OR = 1.37; one sided P-value = 0.030). Conclusions The existence of a significant association between the CTCTAA allele and susceptibility to cerebral malaria was confirmed in Southeast Asian population, which was previously reported in African populations.
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Affiliation(s)
- Izumi Naka
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan.
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Scorza T, Grubb K, Cambos M, Santamaria C, Tshikudi Malu D, Spithill TW. Vaccination with a Plasmodium chabaudi adami multivalent DNA vaccine cross-protects A/J mice against challenge with P. c. adami DK and virulent Plasmodium chabaudi chabaudi AS parasites. Int J Parasitol 2007; 38:819-27. [PMID: 18062974 DOI: 10.1016/j.ijpara.2007.10.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 10/13/2007] [Accepted: 10/15/2007] [Indexed: 10/22/2022]
Abstract
A current goal of malaria vaccine research is the development of vaccines that will cross-protect against multiple strains of malaria. In the present study, the breadth of cross-reactivity induced by a 30K multivalent DNA vaccine has been evaluated in susceptible A/J mice (H-2a) against infection with the Plasmodium chabaudi adami DK strain and a virulent parasite subspecies, Plasmodium chabaudi chabaudi AS. Immunized A/J mice were significantly protected against infection with both P. c. adami DK (31-40% reduction in cumulative parasitemia) and P. c. chabaudi AS parasites, where a 30-39% reduction in cumulative parasitemia as well as enhanced survival was observed. The 30K vaccine-induced specific IFN-gamma production by splenocytes in response to native antigens from both P. c. chabaudi AS and P. c. adami DK. Specific antibodies reacting with surface antigens expressed on P. c. adami DS and P. c. chabaudi AS infected red blood cells, and with opsonizing properties, were detected. These results suggest that multivalent vaccines encoding conserved antigens can feasibly induce immune cross-reactivity that span Plasmodium strains and subspecies and can protect hosts of distinct major histocompatibility complex haplotypes.
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Affiliation(s)
- T Scorza
- Department of Biological Sciences, Université du Québec à Montréal, Case postale 8888, Succursale Centre-Ville, Montréal, Quebec, Canada
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Namangala B, Sugimoto C, Inoue N. Effects of exogenous transforming growth factor beta on Trypanosoma congolense infection in mice. Infect Immun 2007; 75:1878-85. [PMID: 17261602 PMCID: PMC1865695 DOI: 10.1128/iai.01452-06] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The socioeconomic implications of trypanosomosis in sub-Saharan Africa and the limitations of its current control regimes have stimulated research into alternative control methods. Considering the pro- and anti-inflammatory properties of transforming growth factor beta1 (TGF-beta1) and its potential to enhance immunity against protozoan parasites, we examined the effects of intraperitoneally delivered TGF-beta1 in C57BL/6 mice infected with Trypanosoma congolense, the hemoprotozoan parasite causing nagana in cattle. A triple dose of 10 ng TGF-beta1 significantly reduced the first parasitemic peak and delayed mortality of infected mice. Furthermore, exogenous TGF-beta1 significantly decreased the development of trypanosome-induced anemia and splenomegaly. The apparent TGF-beta1-induced antitrypanosome protection, occurring mainly during the early stage of infection, correlated with an enhanced parasite antigen-specific Th1 cell response characterized by a skewed type I cytokine response and a concomitant stronger antitrypanosome immunoglobulin G2a antibody response. Infected TGF-beta1-pretreated mice exhibited a significant reduction in the trypanosome-induced hyperexpansion of B cells. Furthermore, evidence is provided herein that exogenous TGF-beta1 activates macrophages that may contribute to parasite control. Collectively, these data indicate that exogenous TGF-beta1 is immunostimulative, inducing partial protection against T. congolense infection, possibly through mechanisms involving innate immune responses.
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Affiliation(s)
- Boniface Namangala
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan
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Abstract
Natural killer cells derived from pluripotent hematopoietic stem cells are important cells of the immune system that have two main functions: a cytolytic activity and a cytokine-producing capacity. These functions are tightly regulated by numerous activating and inhibitory receptors, including newly discovered receptors that selectively trigger the cytolytic activity in a major histocompatibility complex independent manner. Based on their defining function of spontaneous cytotoxicity without prior immunization, natural killer (NK) cells have been thought to play a critical role in immune surveillance and cancer therapy. New insights into NK cell biology have suggested their major roles in the control of infections, particularly in Plasmodium falciparum infection and in fetal implantation. P. falciparum is the main protozoan parasite responsible for malaria causing 200-300 million clinical cases and killing over 3 million people each year. This review provides an update on NK cell function, ontogeny and biology in order to better understand the role of NK cells in pregnancy in regions where malaria is endemic. Understanding mechanisms of NK cell functions may lead to novel therapeutic strategies for the treatment of human disease, in general, and particularly in the fight against malaria.
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Affiliation(s)
- Elie Mavoungou
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon, c/o Institute for Tropical Medicine, Department of Parasitology, University of Tübingen, Wilhelmstrasse 27, 72074, Tübingen, Germany.
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14
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Urban BC, Ing R, Stevenson MM. Early interactions between blood-stage plasmodium parasites and the immune system. Curr Top Microbiol Immunol 2005; 297:25-70. [PMID: 16265902 DOI: 10.1007/3-540-29967-x_2] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Accumulating evidence provides strong support for the importance of innate immunity in shaping the subsequent adaptive immune response to blood-stage Plasmodium parasites, the causative agents of malaria. Early interactions between blood-stage parasites and cells of the innate immune system, including dendritic cells, monocytes/macrophages, natural killer (NK) cells, NKT cells, and gamma6 T cells, are important in the timely control of parasite replication and in the subsequent elimination and resolution of the infection. The major role of innate immunity appears to be the production of immunoregulatory cytokines, such as interleukin (IL)-12 and interferon (IFN)-gamma, which are critical for the development of type 1 immune responses involving CD4+ Thl cells, B cells, and effector cells which mediate cell-mediated and antibody-dependent adaptive immune responses. In addition, it is likely that cells of the innate immune system, especially dendritic cells, serve as antigen-presenting cells. Here, we review recent data from rodent models of blood-stage malaria and from human studies, and outline the early interactions of infected red blood cells with the innate immune system. We compare and contrast the results derived from studies in infected laboratory mice and humans. These host species are sufficiently different with respect to the identity of the infecting Plasmodium species, the resulting pathologies, and immune responses, particularly where the innate immune response is concerned. The implications of these findings for the development of an effective and safe malaria vaccine are also discussed.
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Affiliation(s)
- B C Urban
- Centre for Clinical Vaccinology and Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Churchill Hospital, Old Road, Oxford, UK.
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Ing R, Gros P, Stevenson MM. Interleukin-15 enhances innate and adaptive immune responses to blood-stage malaria infection in mice. Infect Immun 2005; 73:3172-7. [PMID: 15845528 PMCID: PMC1087354 DOI: 10.1128/iai.73.5.3172-3177.2005] [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] [Indexed: 11/20/2022] Open
Abstract
Compared to C57BL/6 wild-type mice, interleukin-15(-/-) (IL-15(-/-)) mice showed delayed clearance of Plasmodium chabaudi AS infection, lower type 1 cytokine production, impaired dendritic cell and NK cell functions, and lower titers of malaria-specific antibodies. Thus, IL-15 supports early control and timely resolution of blood-stage malaria through promotion of Th1-dependent innate and adaptive immune responses.
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Affiliation(s)
- Rebecca Ing
- Centre for the Study of Host Resistance, Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada
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Chang KH, Stevenson MM. Malarial anaemia: mechanisms and implications of insufficient erythropoiesis during blood-stage malaria. Int J Parasitol 2005; 34:1501-16. [PMID: 15582527 DOI: 10.1016/j.ijpara.2004.10.008] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Revised: 09/23/2004] [Accepted: 10/08/2004] [Indexed: 12/15/2022]
Abstract
It has been proposed that the basis of severe malarial anaemia, a major cause of morbidity and mortality in endemic areas, is multifactorial. Inappropriately low reticulocytosis is observed in malaria patients suggesting that insufficient erythropoiesis is a major factor. Clinical studies provide conflicting data concerning the production of adequate levels of erythropoietin (EPO) during malaria. Plasmodium chabaudi AS causes non-lethal infection in resistant C57BL/6 mice, and lethal infection in susceptible A/J mice. In P. chabaudi AS infected C57BL/6 and A/J mice, which experience varying degrees of severity of anaemia, kidney EPO production is appropriate to the severity of anaemia and is regulated by haematocrit level. Neutralisation of endogenous EPO during infection leads to lethal anaemia while timely administration of exogenous EPO rescues mice although reticulocytosis is suppressed in proportion to the parasitemia level. Characterisation of alterations in splenic erythroid compartments in naive and P. chabaudi AS infected A/J mice revealed that infection, with or without EPO treatment, leads to sub-optimal increases in TER119+ erythroblasts compared to EPO-treated naive mice. A lower percentage of TER119+ erythroblasts in infected mice undergo terminal differentiation to become mature haemoglobin-producing cells. Furthermore, there is a shift in transferrin receptor (CD71) expression from TER119+ cells to a non-erythroid population. Deficiencies in the number and maturation of TER119+ erythroblasts during infection coincide with blunted proliferation to EPO stimulation in vitro by splenocytes, although a high frequency express EPO receptor (EPOR). Together, these data suggest that during malaria, EPO-induced proliferation of early EPOR+ erythroid progenitors is suppressed, leading to sub-optimal generation of TER119+ erythroblasts. Moreover, a shift in CD71 expression may result in impaired terminal maturation of erythroblasts. Thus, suppressed proliferation, differentiation, and maturation of erythroid precursors in association with inadequate reticulocytosis may be the basis of insufficient erythropoiesis during malaria.
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Affiliation(s)
- Kai-Hsin Chang
- Centre for Host-Parasite Interactions, Institute of Parasitology, McGill University, Ste. Anne de Bellevue, Que., Canada
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Korbel DS, Finney OC, Riley EM. Natural killer cells and innate immunity to protozoan pathogens. Int J Parasitol 2004; 34:1517-28. [PMID: 15582528 DOI: 10.1016/j.ijpara.2004.10.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Revised: 09/16/2004] [Accepted: 10/06/2004] [Indexed: 10/26/2022]
Abstract
Natural killer (NK) cells are lymphoid cells that mediate significant cytotoxic activity and produce high levels of pro-inflammatory cytokines in response to infection. During viral infection, NK cell cytotoxicity and cytokine production is induced principally by monocyte-macrophage- and dendritic cell-derived cytokines but virally encoded ligands for NK cells are also beginning to be described. NK derived interferon-gamma (IFN-gamma) production is also essential for control of several protozoal infections including toxoplasmosis, trypanosomiasis, leishmaniasis and malaria. The activation of NK cells by protozoan pathogens is also believed to be cytokine-mediated although some recent studies suggest that direct recognition of parasites by NK cells also occurs. Both indirect signalling via accessory cell-derived cytokines and direct signalling, presumably through NK receptors, are needed in order for human malaria parasites (Plasmodium falciparum) to optimally stimulate NK activity.
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Affiliation(s)
- Daniel S Korbel
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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Pouniotis DS, Proudfoot O, Bogdanoska V, Apostolopoulos V, Fifis T, Plebanski M. Dendritic cells induce immunity and long-lasting protection against blood-stage malaria despite an in vitro parasite-induced maturation defect. Infect Immun 2004; 72:5331-9. [PMID: 15322030 PMCID: PMC517485 DOI: 10.1128/iai.72.9.5331-5339.2004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Dendritic cells (DC) suffer a maturation defect following interaction with erythrocytes infected with malaria parasites and become unable to induce protective malaria liver-stage immunity. Here we show that, by contrast, maturation-arrested DC in vitro are capable of the successful induction of antigen-specific gamma interferon (IFN-gamma) and interleukin 4 (IL-4) T-cell responses, antibody responses, and potent protection against lethal blood-stage malaria challenge in vivo. Similar results were found with DC pulsed with intact parasitized Plasmodium yoelii or Plasmodium chabaudi erythrocytes. Cross-strain protection was also induced. High levels of protection (80 to 100%) against lethal challenge were evident from 10 days after a single immunization and maintained up to 120 days. Interestingly, correlation studies versus blood-stage protection at different time points suggest that the immune effector mechanisms associated with protection could change over time. Antibody-independent, T-cell- and IL-12-associated protection was observed early after immunization, followed by antibody and IL-4-associated, IFN-gamma-independent protection in long-term studies. These results indicate that DC, even when clearly susceptible to parasite-induced maturation defect effects in vitro, can be central to the induction of protection against blood-stage malaria in vivo.
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Affiliation(s)
- Dodie S Pouniotis
- Vaccine and Infectious Diseases Unit, The Austin Research Institute, Austin Campus Heidelberg, Victoria 3084, Australia
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Affiliation(s)
- Mary M Stevenson
- Centre for the Study of Host Resistance, McGill University Health Centre Research Institute and Department of Medicine, McGill University, 1650 Cedar Avenue, Montreal, Quebec, H3G 1A4, Canada.
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Boutlis CS, Lagog M, Chaisavaneeyakorn S, Misukonis MA, Bockarie MJ, Mgone CS, Wang Z, Morahan G, Weinberg JB, Udhayakumar V, Anstey NM. Plasma interleukin-12 in malaria-tolerant papua new guineans: inverse correlation with Plasmodium falciparum parasitemia and peripheral blood mononuclear cell nitric oxide synthase activity. Infect Immun 2003; 71:6354-7. [PMID: 14573655 PMCID: PMC219590 DOI: 10.1128/iai.71.11.6354-6357.2003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interleukin-12 (IL-12) has been inversely associated with disease severity in human and murine malaria, and a polymorphism in the IL-12 p40 subunit gene (IL12B) has been associated with susceptibility to human cerebral malaria and reduced nitric oxide (NO) production. To better define the relationships between IL-12, NO, malaria parasitemia, and IL12B polymorphisms during malarial tolerance, plasma IL-12 levels and peripheral blood mononuclear cell NO synthase (NOS) activity were measured in asymptomatic Papua New Guineans exposed to intense malaria transmission. The IL-12 level was strongly inversely correlated with the density of Plasmodium falciparum parasitemia (rho = -0.45; P < 0.001) and was predicted to decrease by 19% (95% confidence interval [CI], 10 to 27%) for each twofold increase in P. falciparum parasitemia. This is consistent with a suppressive effect of parasitemia on IL-12 production, an effect previously shown in vitro and in rodent models of disease. The IL-12 level was inversely correlated with NOS activity (r = -0.22; P = 0.007), with each twofold increase in NOS activity being predictive of a 25% (95% CI, 7 to 38%) decrease in plasma IL-12 levels. This probably reflects additional down-regulation of IL-12 by the high basal NO production and monocyte NOS expression found in the malaria-tolerant state. Neither the IL-12 level nor NOS activity was associated with either of two IL12B polymorphisms, reflecting the diversity of genetic control over immune responses in different populations.
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Affiliation(s)
- Craig S Boutlis
- International Health Program, Division of Infectious Diseases, Menzies School of Health Research, Northern Territory University, Flinders University Northern Territory Clinical School, Darwin, Australia
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Abstract
Combating pathogenic organisms by combinatorial approaches involving appropriate immune response molecules and antimicrobial drugs represents a progessively more apparent and successful therapeutic paradigm for the treatment of acute and chronic persistent infectious diseases. This review explores areas of current innovation and provides an update of the present state of knowledge concerning combination of chemotherapy with several immune-based interventions in infections. In the future, a better understanding of microbial immune modulation and evasion may continue to open new avenues of inquiry and carefully targeted application of adjunctive immunotherapies.
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Affiliation(s)
- Hartmut Hengel
- Robert Koch Institute, Nordufer 20, D-13353 Berlin, Germany
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Affiliation(s)
- K Noel Masihi
- Robert Koch Institute, Nordufer 20, 13353 Berlin, Germany.
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Rogerson SJ, Brown HC, Pollina E, Abrams ET, Tadesse E, Lema VM, Molyneux ME. Placental tumor necrosis factor alpha but not gamma interferon is associated with placental malaria and low birth weight in Malawian women. Infect Immun 2003; 71:267-70. [PMID: 12496175 PMCID: PMC143363 DOI: 10.1128/iai.71.1.267-270.2003] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Malaria in pregnancy predisposes to maternal anemia and low birth weight (LBW). We examined the possible roles of the cytokines tumor necrosis factor alpha (TNF-alpha) and gamma interferon (IFN-gamma) in these adverse outcomes. We measured cytokine concentrations in placental, peripheral, and cord blood plasma in relation to malaria parasitemia and placental monocyte accumulation in 276 Malawian women. Maternal hemoglobin concentration, human immunodeficiency virus status, and infant birth weight were determined. Concentrations of TNF-alpha in placental blood were correlated with densities of Plasmodium falciparum-infected erythrocytes (P < 0.0001) and of intervillous monocyte infiltrates (P < 0.0001) on placental histology. Peripheral blood TNF-alpha concentrations were relatively low and were weakly associated with malaria. TNF-alpha concentrations were higher in placental blood, where they were strongly associated with malaria. Placental plasma TNF-alpha levels were higher in women who had LBW babies (P = 0.0027), women with febrile symptoms (P < 0.0001), and teenage mothers (P = 0.04) than in other women. The presence of TNF-alpha in cord blood was not associated with malaria infection. IFN-gamma levels were infrequently elevated, and elevated IFN-gamma levels were not associated with poor pregnancy outcomes. Placental production of TNF-alpha, but not of IFN-gamma, may be implicated in impaired fetal growth in Malawian women.
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Affiliation(s)
- Stephen J Rogerson
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Department of Obstetrics and Gynaecology, College of Medicine, University of Malawi, Blantyre, Malawi.
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Morahan G, Boutlis CS, Huang D, Pain A, Saunders JR, Hobbs MR, Granger DL, Weinberg JB, Peshu N, Mwaikambo ED, Marsh K, Roberts DJ, Anstey NM. A promoter polymorphism in the gene encoding interleukin-12 p40 (IL12B) is associated with mortality from cerebral malaria and with reduced nitric oxide production. Genes Immun 2002; 3:414-8. [PMID: 12424623 DOI: 10.1038/sj.gene.6363909] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Interleukin-12 (IL-12) is an important regulatory cytokine in infection and immunity. Administration of IL-12 may reduce complications of severe malaria in rodents. Polymorphisms in IL12B, the gene encoding the IL-12 p40 subunit, influence the secretion of IL-12 and susceptibility to Type 1 diabetes. We therefore investigated whether IL12B polymorphisms may affect the outcome of severe malaria. Homozygosity for a polymorphism in the IL12B promoter was associated with increased mortality in Tanzanian children having cerebral malaria but not in Kenyan children with severe malaria. Furthermore, homozygotes for the IL12B promotor polymorphism had decreased production of nitric oxide, which is in part regulated by IL-12 activity. These studies suggest that IL12B polymorphisms, via regulation of IL-12 production, may influence the outcome of malaria infection in at least one African population.
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Affiliation(s)
- G Morahan
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.
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Abstract
PURPOSE OF REVIEW The present review addresses recent developments that relate to the clinical management and prevention of childhood salmonellosis in developed and developing countries. RECENT FINDINGS Invasive disease due to serovar Typhi as well as nontyphoidal salmonellae (NTS) is common in children younger than 5 years old in developing countries, and multidrug resistance is an increasingly difficult problem to manage. A new conjugate vaccine was found to be very effective in preventing typhoid fever in young Vietnamese children and was well tolerated, showing great promise for the future. Antibiotic use in the food animal industry is an important source of disease with multidrug resistant NTS strains in the developed world. Efforts for prevention are aimed at immunization of animals, control of antibiotic use in the food animal industry and careful monitoring of food-borne outbreaks. On the other hand, although the burden of NTS disease in children is far greater in developing countries, especially in tropical Africa, knowledge of even basic epidemiology is lacking. Importantly, it may be that, as spp. acquire increasing resistance, they also acquire increasing virulence that will lead to even greater morbidity and mortality. SUMMARY Recent developments include a better knowledge of clinical aspects of invasive salmonellosis, an increasing response to the problem of multiple antibiotic resistance (including quinolones), and excellent results from the use of a recently developed conjugate vaccine for typhoid fever in children as young as 2 years old.
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