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Anopheles gambiae PRS1 modulates Plasmodium development at both midgut and salivary gland steps.

Chertemps T, Mitri C, Perrot S, Sautereau J, Jacques JC, Thiery I, Bourgouin C, Rosinski-Chupin I - PLoS ONE (2010)

Bottom Line: Furthermore, this induction is observed using either the rodent parasite Plasmodium berghei or the human pathogen Plasmodium falciparum.In the midgut, PRS1 overexpression is associated with a relocalization of the protein at the periphery of invaded cells.While providing insights into potential functions of DM9 proteins, our results reveal that PRS1 likely contributes to fundamental interactions between Plasmodium and mosquito epithelia, which do not depend on the specific Anopheles/P. falciparum coevolutionary history.

View Article: PubMed Central - PubMed

Affiliation: Unité de Biochimie et Biologie Moléculaire des Insectes, Département de Parasitologie et Mycologie, Centre National de la Recherche Scientifique URA 3012, Institut Pasteur, Paris, France.

ABSTRACT

Background: Invasion of the mosquito salivary glands by Plasmodium is a critical step for malaria transmission. From a SAGE analysis, we previously identified several genes whose expression in salivary glands was regulated coincident with sporozoite invasion of salivary glands. To get insights into the consequences of these salivary gland responses, here we have studied one of the genes, PRS1 (Plasmodium responsive salivary 1), whose expression was upregulated in infected glands, using immunolocalization and functional inactivation approaches.

Methodology/principal findings: PRS1 belongs to a novel insect superfamily of genes encoding proteins with DM9 repeat motifs of uncharacterized function. We show that PRS1 is induced in response to Plasmodium, not only in the salivary glands but also in the midgut, the other epithelial barrier that Plasmodium has to cross to develop in the mosquito. Furthermore, this induction is observed using either the rodent parasite Plasmodium berghei or the human pathogen Plasmodium falciparum. In the midgut, PRS1 overexpression is associated with a relocalization of the protein at the periphery of invaded cells. We also find that sporozoite invasion of salivary gland cells occurs sequentially and induces intra-cellular modifications that include an increase in PRS1 expression and a relocalization of the corresponding protein into vesicle-like structures. Importantly, PRS1 knockdown during the onset of midgut and salivary gland invasion demonstrates that PRS1 acts as an agonist for the development of both parasite species in the two epithelia, highlighting shared vector/parasite interactions in both tissues.

Conclusions/significance: While providing insights into potential functions of DM9 proteins, our results reveal that PRS1 likely contributes to fundamental interactions between Plasmodium and mosquito epithelia, which do not depend on the specific Anopheles/P. falciparum coevolutionary history.

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Related in: MedlinePlus

PRS1 affects An. gambiae infection with Plasmodium.A. Effects of dsRNA injection on PRS1 expression in the midgut and the salivary glands. Expression of PRS1 was analyzed by qRT-PCR in the midgut and the salivary glands three days after injection of dsPRS1 or control dsGFP. For PRS1 silencing in salivary glands, three fold higher amounts of control or specific dsRNA were injected. B–E. Oocyst prevalences and oocyst intensities in P. berghei (B, C) or P. falciparum (D, E) infected mosquitoes after injection of GFP dsRNAs (controls) or PRS1 dsRNAs. For each infecting parasite, data from four independent experiments were pooled and analyzed for prevalence values (B, D) or distribution of oocyst intensities in positive midguts (C, E). In C and E, the black bar represents the cumulated median intensity value. Statistics were computed on each individual replicate (also see Sup. Table S3) and the p values were combined using the meta-analytical approach of Fisher as described in Experimental Procedures. Injection of PRS1 dsRNA significantly decreases prevalence in P. falciparum infections and oocyst intensities in P. berghei infections compared to injection of control dsRNA. F and G. Average parasite numbers in salivary glands after infection by P. berghei (F) or P. falciparum (G) of mosquitoes treated with PRS1 and GFP dsRNA. Data were collected from four independent experiments. The standard errors are indicated. Statistically significant differences between samples were evaluated using the Mann-Whitney and Student's tests. The p-values reveal significant differences between dsGFP controls and dsPRS1 KD.
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pone-0011538-g005: PRS1 affects An. gambiae infection with Plasmodium.A. Effects of dsRNA injection on PRS1 expression in the midgut and the salivary glands. Expression of PRS1 was analyzed by qRT-PCR in the midgut and the salivary glands three days after injection of dsPRS1 or control dsGFP. For PRS1 silencing in salivary glands, three fold higher amounts of control or specific dsRNA were injected. B–E. Oocyst prevalences and oocyst intensities in P. berghei (B, C) or P. falciparum (D, E) infected mosquitoes after injection of GFP dsRNAs (controls) or PRS1 dsRNAs. For each infecting parasite, data from four independent experiments were pooled and analyzed for prevalence values (B, D) or distribution of oocyst intensities in positive midguts (C, E). In C and E, the black bar represents the cumulated median intensity value. Statistics were computed on each individual replicate (also see Sup. Table S3) and the p values were combined using the meta-analytical approach of Fisher as described in Experimental Procedures. Injection of PRS1 dsRNA significantly decreases prevalence in P. falciparum infections and oocyst intensities in P. berghei infections compared to injection of control dsRNA. F and G. Average parasite numbers in salivary glands after infection by P. berghei (F) or P. falciparum (G) of mosquitoes treated with PRS1 and GFP dsRNA. Data were collected from four independent experiments. The standard errors are indicated. Statistically significant differences between samples were evaluated using the Mann-Whitney and Student's tests. The p-values reveal significant differences between dsGFP controls and dsPRS1 KD.

Mentions: QRT-PCR analysis of midgut and salivary gland RNA indicated a significant PRS1 silencing in both tissues (Fig. 5A). Nevertheless, gene silencing in the salivary gland was less efficient despite the use of larger amounts of dsRNA, in agreement with previous observations [21].


Anopheles gambiae PRS1 modulates Plasmodium development at both midgut and salivary gland steps.

Chertemps T, Mitri C, Perrot S, Sautereau J, Jacques JC, Thiery I, Bourgouin C, Rosinski-Chupin I - PLoS ONE (2010)

PRS1 affects An. gambiae infection with Plasmodium.A. Effects of dsRNA injection on PRS1 expression in the midgut and the salivary glands. Expression of PRS1 was analyzed by qRT-PCR in the midgut and the salivary glands three days after injection of dsPRS1 or control dsGFP. For PRS1 silencing in salivary glands, three fold higher amounts of control or specific dsRNA were injected. B–E. Oocyst prevalences and oocyst intensities in P. berghei (B, C) or P. falciparum (D, E) infected mosquitoes after injection of GFP dsRNAs (controls) or PRS1 dsRNAs. For each infecting parasite, data from four independent experiments were pooled and analyzed for prevalence values (B, D) or distribution of oocyst intensities in positive midguts (C, E). In C and E, the black bar represents the cumulated median intensity value. Statistics were computed on each individual replicate (also see Sup. Table S3) and the p values were combined using the meta-analytical approach of Fisher as described in Experimental Procedures. Injection of PRS1 dsRNA significantly decreases prevalence in P. falciparum infections and oocyst intensities in P. berghei infections compared to injection of control dsRNA. F and G. Average parasite numbers in salivary glands after infection by P. berghei (F) or P. falciparum (G) of mosquitoes treated with PRS1 and GFP dsRNA. Data were collected from four independent experiments. The standard errors are indicated. Statistically significant differences between samples were evaluated using the Mann-Whitney and Student's tests. The p-values reveal significant differences between dsGFP controls and dsPRS1 KD.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2902509&req=5

pone-0011538-g005: PRS1 affects An. gambiae infection with Plasmodium.A. Effects of dsRNA injection on PRS1 expression in the midgut and the salivary glands. Expression of PRS1 was analyzed by qRT-PCR in the midgut and the salivary glands three days after injection of dsPRS1 or control dsGFP. For PRS1 silencing in salivary glands, three fold higher amounts of control or specific dsRNA were injected. B–E. Oocyst prevalences and oocyst intensities in P. berghei (B, C) or P. falciparum (D, E) infected mosquitoes after injection of GFP dsRNAs (controls) or PRS1 dsRNAs. For each infecting parasite, data from four independent experiments were pooled and analyzed for prevalence values (B, D) or distribution of oocyst intensities in positive midguts (C, E). In C and E, the black bar represents the cumulated median intensity value. Statistics were computed on each individual replicate (also see Sup. Table S3) and the p values were combined using the meta-analytical approach of Fisher as described in Experimental Procedures. Injection of PRS1 dsRNA significantly decreases prevalence in P. falciparum infections and oocyst intensities in P. berghei infections compared to injection of control dsRNA. F and G. Average parasite numbers in salivary glands after infection by P. berghei (F) or P. falciparum (G) of mosquitoes treated with PRS1 and GFP dsRNA. Data were collected from four independent experiments. The standard errors are indicated. Statistically significant differences between samples were evaluated using the Mann-Whitney and Student's tests. The p-values reveal significant differences between dsGFP controls and dsPRS1 KD.
Mentions: QRT-PCR analysis of midgut and salivary gland RNA indicated a significant PRS1 silencing in both tissues (Fig. 5A). Nevertheless, gene silencing in the salivary gland was less efficient despite the use of larger amounts of dsRNA, in agreement with previous observations [21].

Bottom Line: Furthermore, this induction is observed using either the rodent parasite Plasmodium berghei or the human pathogen Plasmodium falciparum.In the midgut, PRS1 overexpression is associated with a relocalization of the protein at the periphery of invaded cells.While providing insights into potential functions of DM9 proteins, our results reveal that PRS1 likely contributes to fundamental interactions between Plasmodium and mosquito epithelia, which do not depend on the specific Anopheles/P. falciparum coevolutionary history.

View Article: PubMed Central - PubMed

Affiliation: Unité de Biochimie et Biologie Moléculaire des Insectes, Département de Parasitologie et Mycologie, Centre National de la Recherche Scientifique URA 3012, Institut Pasteur, Paris, France.

ABSTRACT

Background: Invasion of the mosquito salivary glands by Plasmodium is a critical step for malaria transmission. From a SAGE analysis, we previously identified several genes whose expression in salivary glands was regulated coincident with sporozoite invasion of salivary glands. To get insights into the consequences of these salivary gland responses, here we have studied one of the genes, PRS1 (Plasmodium responsive salivary 1), whose expression was upregulated in infected glands, using immunolocalization and functional inactivation approaches.

Methodology/principal findings: PRS1 belongs to a novel insect superfamily of genes encoding proteins with DM9 repeat motifs of uncharacterized function. We show that PRS1 is induced in response to Plasmodium, not only in the salivary glands but also in the midgut, the other epithelial barrier that Plasmodium has to cross to develop in the mosquito. Furthermore, this induction is observed using either the rodent parasite Plasmodium berghei or the human pathogen Plasmodium falciparum. In the midgut, PRS1 overexpression is associated with a relocalization of the protein at the periphery of invaded cells. We also find that sporozoite invasion of salivary gland cells occurs sequentially and induces intra-cellular modifications that include an increase in PRS1 expression and a relocalization of the corresponding protein into vesicle-like structures. Importantly, PRS1 knockdown during the onset of midgut and salivary gland invasion demonstrates that PRS1 acts as an agonist for the development of both parasite species in the two epithelia, highlighting shared vector/parasite interactions in both tissues.

Conclusions/significance: While providing insights into potential functions of DM9 proteins, our results reveal that PRS1 likely contributes to fundamental interactions between Plasmodium and mosquito epithelia, which do not depend on the specific Anopheles/P. falciparum coevolutionary history.

Show MeSH
Related in: MedlinePlus