Plasmodium gallinaceum:Differential Killing of Some Mosquito Stages of the Parasite by Insect Defensin

Shahabuddin, Mohammed; Fields, Iesha; Bulet, Philippe; Hoffmann, Jules A.; Miller, Louis H.

doi:10.1006/expr.1998.4212

Cited by 137 publications

(83 citation statements)

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“…It should be stressed that R. prolixus infection with T. rangeli constitutes a very relevant natural model for studying parasite/vector interaction as most anti-parasite activity studies have been carried out on heterologous systems; molecules such as magainin isolated from frogs and cecropin isolated from silkworms have been proven against Plasmodium (Gwadz et al 1989), cecropin isolated from Drosophila against Trypanosoma (Durvasula et al 1997), insect defensins against Plasmodium (Shahabuddin et al 1998), cecropin from Drosophila against Leishmania (Akuffo et al 1998), diptericin isolated from Phormia against Trypanosoma sp. (Hao et al 2001) and stomoxyn isolated from S. calcitrans against T. brucei rhodesiense (Boulanger et al 2002b).…”

Section: Discussionmentioning

confidence: 99%

Preliminary characterization of a Rhodnius prolixus hemolymph trypanolytic protein, this being a determinant of Trypanosoma rangeli KP1(+) and KP1(-) subpopulations' vectorial ability

Pulido

Pérez

Vallejo

2008

Mem. Inst. Oswaldo Cruz

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Rhodnius prolixus is the main Trypanosoma rangeli vector in several Latin-American countries and is susceptible to infection with KP1(+) strains; however, it presents an invasion-resistant response to KP1(-) strains. The present work has identified a trypanolytic protein against T. rangeli KP1(-) in the R. prolixus hemolymph which was fractioned with ammonium sulfate (following dialysis). The results revealed a protein component which did not depend on divalent cations for its biological function whilst keeping its trypanolytic activity at temperatures ranging from -20ºC to 37ºC, at 7.0 to 10.5 pH. The protein was partially purified by gel filtration chromatography and ionic exchange chromatography. The major component presented a molecular weight of around 79 kDa and an isoelectric point between 4.9 and 6.3 and may be directly related to hemolymph trypanolytic activity against T. rangeli KP1(-) populations.Key words: Rhodnius prolixus -Trypanosoma rangeli KP1(+) -Trypanosoma rangeli KP1(-) -trypanolytic factorvectorial ability -insect immunity Trypanosoma rangeli is a hemoflagellate which is apparently apathogenous for humans, presenting pathogenicity for the invertebrate host. T. rangeli is of great interest due to its presence in mixed infection with Trypanosoma cruzi in vertebrates and invertebrate hosts, thereby interfering with a clear diagnosis of Chagas' disease and the epidemiology of these parasites in different Latin-American countries .T. rangeli vectors become infected by ingesting blood from wild or domestic reservoirs in natural conditions. The parasite develops in the digestive tract and then invades the hemolymph where it is recognized by the vector's immune system; however, some strains may escape host defense mechanisms, reaching the salivary glands where they become infective forms or metacyclic trypomastigotes (D'Alessandro-Bacigalupo & Gore-Saravia 1992). Salivary gland invasion is a necessary step for transmission, being mediated by one or several ligandreceptor interactions (Basseri et al. 2002).Previous work has revealed two phylogenetically different groups in T. rangeli called T. rangeli KP1(-) and T. rangeli KP1(+), these being mainly transmitted by the 16 Rhodnius species described so far (Vallejo et al. 2002(Vallejo et al. , 2007. Specificity between the vector and the parasite strain which it transmits has been pointed out; each Rhodnius species seems to select the T. rangeli subpopulation to which it is susceptible in nature so that it can then be transmitted to the vertebrate host via insect bite . Nevertheless, a close association has been observed between T. rangeli KP1(+) and vectors from the prolixus group (which includes Rhodnius prolixus and Rhodnius neglectus) and between T. rangeli KP1(-) and vectors from the pallescens group (including Rhodnius pallescens, Rhodnius colombiensis and Rhodnius ecuadoriensis) , Urrea et al. 2005. Recent parasite-vector interaction studies have shown a trypanolytic factor in R. prolixus hemolymph impeding the development of T. rangeli KP1(...

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Section: Discussionmentioning

confidence: 99%

Preliminary characterization of a Rhodnius prolixus hemolymph trypanolytic protein, this being a determinant of Trypanosoma rangeli KP1(+) and KP1(-) subpopulations' vectorial ability

Pulido

Pérez

Vallejo

2008

Mem. Inst. Oswaldo Cruz

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“…Parasite viability was assessed by staining with the fluorescent dyes calcein AM and ethidium homodimer (Molecular Probes; ref. 26). Briefly, parasites were incubated in PBS with or without gambicin (10-100 M) for 30-180 min at 21°C.…”

Section: Purification Of Antibacterial Peptides From Cell Culture Medmentioning

confidence: 99%

Gambicin: A novel immune responsive antimicrobial peptide from the malaria vector Anopheles gambiae

Vizioli

Bulet

Hoffmann

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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173

136

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A novel mosquito antimicrobial peptide, gambicin, and the corresponding gene were isolated in parallel through differential display-PCR, an expressed sequence tag (EST) project, and characterization of an antimicrobial activity in a mosquito cell line by reverse-phase chromatography. The 616-bp gambicin ORF encodes an 81-residue protein that is processed and secreted as a 61-aa mature peptide containing eight cysteines engaged in four disulfide bridges. Gambicin lacks sequence homology with other known proteins. Like other Anopheles gambiae antimicrobial peptide genes, gambicin is induced by natural or experimental infection in the midgut, fatbody, and hemocyte-like cell lines. Within the midgut, gambicin is predominantly expressed in the anterior part. Both local and systemic gambicin expression is induced during early and late stages of natural malaria infection. In vitro experiments showed that the 6.8-kDa mature peptide can kill both Gram-positive and Gram-negative bacteria, has a morphogenic effect on a filamentous fungus, and is marginally lethal to Plasmodium berghei ookinetes. An oxidized form of gambicin isolated from the cell line medium was more active against bacteria than the nonoxidized form from the same medium.Anopheles gambiae ͉ antimicrobial peptide ͉ innate immunity ͉ malaria

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“…Furthermore, studies using exogenous defensins demonstrated that these antibacterial peptides possess potent anti-Plasmodium activity (16,17). Moreover, defensin has been implicated in the local innate immune response of the Anopheles gambiae midgut to a Plasmodium infection (18).…”

mentioning

confidence: 99%

Engineering blood meal-activated systemic immunity in the yellow fever mosquito, Aedes aegypti

Kokoza

Ahmed

Cho

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

167

134

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Progress in molecular genetics makes possible the development of alternative disease control strategies that target the competence of mosquitoes to transmit pathogens. We tested the regulatory region of the vitellogenin (Vg) gene of Aedes aegypti for its ability to express potential antipathogen factors in transgenic mosquitoes. Hermes-mediated transformation was used to integrate a 2.1-kb Vg-promoter fragment driving the expression of the Defensin A (DefA) coding region, one of the major insect immune factors. PCR amplification of genomic DNA and Southern blot analyses, carried out through the ninth generation, showed that the Vg-DefA transgene insertion was stable. The Vg-DefA transgene was strongly activated in the fat body by a blood meal. The mRNA levels reached a maximum at 24-h postblood meal, corresponding to the peak expression time of the endogenous Vg gene. High levels of transgenic defensin were accumulated in the hemolymph of bloodfed female mosquitoes, persisting for 20 -22 days after a single blood feeding. Purified transgenic defensin showed antibacterial activity comparable to that of defensin isolated from bacterially challenged control mosquitoes. Thus, we have been able to engineer the genetically stable transgenic mosquito with an element of systemic immunity, which is activated through the blood meal-triggered cascade rather than by infection. This work represents a significant step toward the development of molecular genetic approaches to the control of vector competence in pathogen transmission.

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Plasmodium gallinaceum:Differential Killing of Some Mosquito Stages of the Parasite by Insect Defensin

Cited by 137 publications

References 0 publications

Preliminary characterization of a Rhodnius prolixus hemolymph trypanolytic protein, this being a determinant of Trypanosoma rangeli KP1(+) and KP1(-) subpopulations' vectorial ability

Preliminary characterization of a Rhodnius prolixus hemolymph trypanolytic protein, this being a determinant of Trypanosoma rangeli KP1(+) and KP1(-) subpopulations' vectorial ability

Gambicin: A novel immune responsive antimicrobial peptide from the malaria vector Anopheles gambiae

Engineering blood meal-activated systemic immunity in the yellow fever mosquito, Aedes aegypti

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