Limits...
Wolbachia infections in Anopheles gambiae cells: transcriptomic characterization of a novel host-symbiont interaction.

Hughes GL, Ren X, Ramirez JL, Sakamoto JM, Bailey JA, Jedlicka AE, Rasgon JL - PLoS Pathog. (2011)

Bottom Line: We used Affymetrix GeneChip microarrays to investigate the effect of wAlbB and wRi infection on the transcriptome of cultured Anopheles Sua5B cells, and for a subset of genes used quantitative PCR to validate results in somatically-infected Anopheles mosquitoes.Very strikingly, infection resulted in a significant down-regulation of many immune, stress and detoxification-related transcripts.The data show that Wolbachia has a profound and unique effect on Anopheles gene expression in cultured cells, and has important implications for mechanistic understanding of Wolbachia-induced phenotypes and potential novel strategies to control malaria.

View Article: PubMed Central - PubMed

Affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.

ABSTRACT
The endosymbiotic bacterium Wolbachia is being investigated as a potential control agent in several important vector insect species. Recent studies have shown that Wolbachia can protect the insect host against a wide variety of pathogens, resulting in reduced transmission of parasites and viruses. It has been proposed that compromised vector competence of Wolbachia-infected insects is due to up-regulation of the host innate immune system or metabolic competition. Anopheles mosquitoes, which transmit human malaria parasites, have never been found to harbor Wolbachia in nature. While transient somatic infections can be established in Anopheles, no stable artificially-transinfected Anopheles line has been developed despite numerous attempts. However, cultured Anopheles cells can be stably infected with multiple Wolbachia strains such as wAlbB from Aedes albopictus, wRi from Drosophila simulans and wMelPop from Drosophila melanogaster. Infected cell lines provide an amenable system to investigate Wolbachia-Anopheles interactions in the absence of an infected mosquito strain. We used Affymetrix GeneChip microarrays to investigate the effect of wAlbB and wRi infection on the transcriptome of cultured Anopheles Sua5B cells, and for a subset of genes used quantitative PCR to validate results in somatically-infected Anopheles mosquitoes. Wolbachia infection had a dramatic strain-specific effect on gene expression in this cell line, with almost 700 genes in total regulated representing a diverse array of functional classes. Very strikingly, infection resulted in a significant down-regulation of many immune, stress and detoxification-related transcripts. This is in stark contrast to the induction of immune genes observed in other insect hosts. We also identified genes that may be potentially involved in Wolbachia-induced reproductive and pathogenic phenotypes. Somatically-infected mosquitoes had similar responses to cultured cells. The data show that Wolbachia has a profound and unique effect on Anopheles gene expression in cultured cells, and has important implications for mechanistic understanding of Wolbachia-induced phenotypes and potential novel strategies to control malaria.

Show MeSH

Related in: MedlinePlus

Anopheles gambiae gene regulation in response to Wolbachia infection.A. Venn diagram of 690 Anopheles transcripts which display differential expression due to wAlbB or wRi infection. 104 transcripts were common to both strains, while 389 were down regulated and 320 up regulated due to Wolbachia infection. B. Scatter plot of regulated significant genes (>2 fold regulation; False discovery rate P value <0.05). Blue dots represent significant genes regulated by wRi only, red regulated by wAlbB only and purple, genes commonly regulated. C. Number of genes in each functional classes class up or down regulated in response to either wAlbB or wRi infection. Genes were classified into groups; transport (TRP), replication, transcription and translation (RTT), redox, stress and mitochondrial (RSM) proteolysis and digestion (PROT), metabolism (M) cytoskeletal and structural (CS) and immune (I) depicted in the first column, and diverse (D) and unknown (U), in the second column.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3040664&req=5

ppat-1001296-g001: Anopheles gambiae gene regulation in response to Wolbachia infection.A. Venn diagram of 690 Anopheles transcripts which display differential expression due to wAlbB or wRi infection. 104 transcripts were common to both strains, while 389 were down regulated and 320 up regulated due to Wolbachia infection. B. Scatter plot of regulated significant genes (>2 fold regulation; False discovery rate P value <0.05). Blue dots represent significant genes regulated by wRi only, red regulated by wAlbB only and purple, genes commonly regulated. C. Number of genes in each functional classes class up or down regulated in response to either wAlbB or wRi infection. Genes were classified into groups; transport (TRP), replication, transcription and translation (RTT), redox, stress and mitochondrial (RSM) proteolysis and digestion (PROT), metabolism (M) cytoskeletal and structural (CS) and immune (I) depicted in the first column, and diverse (D) and unknown (U), in the second column.

Mentions: Wolbachia infection of Anopheles cells resulted in the regulation of 690 genes relative to uninfected Sua5B cells (False discovery rate (FDR) P<0.05, ≥ 2.0 fold-change (FC)) (Table S1). When comparing Wolbachia strains, 255 genes were uniquely regulated by wAlbB infection, while 331 were regulated specifically by wRi infection (Figure 1A). Of the 104 genes regulated by both strains, the majority (74 genes) were down-regulated, 11 were similarly up-regulated and the remainder had alternating regulation patterns between the two Wolbachia strains (Figure 1B). Interestingly, we observed a greater number of genes regulated by wRi compared to wAlbB even though the cell infection density of wRi was much less than wAlbB (wRi∼10% cells infected, wAlbB >90% of cells infected) [14]. It is possible that since wRi was purified from live flies, it has a greater impact that wAlbB which was purified from another cell line [14]. Of the regulated genes, a diverse range of functional classes was represented with a large proportion being genes of unknown or diverse function, which was consistent for both Wolbachia strains. Among the genes assigned to specific known functional classes, immune-, transport- and metabolism-related transcripts were the most abundant categories regulated by Wolbachia (Figure 1C). Strikingly, over 75% of the immune related transcripts were down-regulated, which was consistent between both strains. Overall, down-regulation was a common theme, with only redox/stess/mitochondrial (RSM) and replication/transcription/translation (RTT) classes not down-regulated in wRi infected cells and RTT in wAlbB. Microarray data is available at gene expression omnibus (accession number GSE23215) [32].


Wolbachia infections in Anopheles gambiae cells: transcriptomic characterization of a novel host-symbiont interaction.

Hughes GL, Ren X, Ramirez JL, Sakamoto JM, Bailey JA, Jedlicka AE, Rasgon JL - PLoS Pathog. (2011)

Anopheles gambiae gene regulation in response to Wolbachia infection.A. Venn diagram of 690 Anopheles transcripts which display differential expression due to wAlbB or wRi infection. 104 transcripts were common to both strains, while 389 were down regulated and 320 up regulated due to Wolbachia infection. B. Scatter plot of regulated significant genes (>2 fold regulation; False discovery rate P value <0.05). Blue dots represent significant genes regulated by wRi only, red regulated by wAlbB only and purple, genes commonly regulated. C. Number of genes in each functional classes class up or down regulated in response to either wAlbB or wRi infection. Genes were classified into groups; transport (TRP), replication, transcription and translation (RTT), redox, stress and mitochondrial (RSM) proteolysis and digestion (PROT), metabolism (M) cytoskeletal and structural (CS) and immune (I) depicted in the first column, and diverse (D) and unknown (U), in the second column.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3040664&req=5

ppat-1001296-g001: Anopheles gambiae gene regulation in response to Wolbachia infection.A. Venn diagram of 690 Anopheles transcripts which display differential expression due to wAlbB or wRi infection. 104 transcripts were common to both strains, while 389 were down regulated and 320 up regulated due to Wolbachia infection. B. Scatter plot of regulated significant genes (>2 fold regulation; False discovery rate P value <0.05). Blue dots represent significant genes regulated by wRi only, red regulated by wAlbB only and purple, genes commonly regulated. C. Number of genes in each functional classes class up or down regulated in response to either wAlbB or wRi infection. Genes were classified into groups; transport (TRP), replication, transcription and translation (RTT), redox, stress and mitochondrial (RSM) proteolysis and digestion (PROT), metabolism (M) cytoskeletal and structural (CS) and immune (I) depicted in the first column, and diverse (D) and unknown (U), in the second column.
Mentions: Wolbachia infection of Anopheles cells resulted in the regulation of 690 genes relative to uninfected Sua5B cells (False discovery rate (FDR) P<0.05, ≥ 2.0 fold-change (FC)) (Table S1). When comparing Wolbachia strains, 255 genes were uniquely regulated by wAlbB infection, while 331 were regulated specifically by wRi infection (Figure 1A). Of the 104 genes regulated by both strains, the majority (74 genes) were down-regulated, 11 were similarly up-regulated and the remainder had alternating regulation patterns between the two Wolbachia strains (Figure 1B). Interestingly, we observed a greater number of genes regulated by wRi compared to wAlbB even though the cell infection density of wRi was much less than wAlbB (wRi∼10% cells infected, wAlbB >90% of cells infected) [14]. It is possible that since wRi was purified from live flies, it has a greater impact that wAlbB which was purified from another cell line [14]. Of the regulated genes, a diverse range of functional classes was represented with a large proportion being genes of unknown or diverse function, which was consistent for both Wolbachia strains. Among the genes assigned to specific known functional classes, immune-, transport- and metabolism-related transcripts were the most abundant categories regulated by Wolbachia (Figure 1C). Strikingly, over 75% of the immune related transcripts were down-regulated, which was consistent between both strains. Overall, down-regulation was a common theme, with only redox/stess/mitochondrial (RSM) and replication/transcription/translation (RTT) classes not down-regulated in wRi infected cells and RTT in wAlbB. Microarray data is available at gene expression omnibus (accession number GSE23215) [32].

Bottom Line: We used Affymetrix GeneChip microarrays to investigate the effect of wAlbB and wRi infection on the transcriptome of cultured Anopheles Sua5B cells, and for a subset of genes used quantitative PCR to validate results in somatically-infected Anopheles mosquitoes.Very strikingly, infection resulted in a significant down-regulation of many immune, stress and detoxification-related transcripts.The data show that Wolbachia has a profound and unique effect on Anopheles gene expression in cultured cells, and has important implications for mechanistic understanding of Wolbachia-induced phenotypes and potential novel strategies to control malaria.

View Article: PubMed Central - PubMed

Affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.

ABSTRACT
The endosymbiotic bacterium Wolbachia is being investigated as a potential control agent in several important vector insect species. Recent studies have shown that Wolbachia can protect the insect host against a wide variety of pathogens, resulting in reduced transmission of parasites and viruses. It has been proposed that compromised vector competence of Wolbachia-infected insects is due to up-regulation of the host innate immune system or metabolic competition. Anopheles mosquitoes, which transmit human malaria parasites, have never been found to harbor Wolbachia in nature. While transient somatic infections can be established in Anopheles, no stable artificially-transinfected Anopheles line has been developed despite numerous attempts. However, cultured Anopheles cells can be stably infected with multiple Wolbachia strains such as wAlbB from Aedes albopictus, wRi from Drosophila simulans and wMelPop from Drosophila melanogaster. Infected cell lines provide an amenable system to investigate Wolbachia-Anopheles interactions in the absence of an infected mosquito strain. We used Affymetrix GeneChip microarrays to investigate the effect of wAlbB and wRi infection on the transcriptome of cultured Anopheles Sua5B cells, and for a subset of genes used quantitative PCR to validate results in somatically-infected Anopheles mosquitoes. Wolbachia infection had a dramatic strain-specific effect on gene expression in this cell line, with almost 700 genes in total regulated representing a diverse array of functional classes. Very strikingly, infection resulted in a significant down-regulation of many immune, stress and detoxification-related transcripts. This is in stark contrast to the induction of immune genes observed in other insect hosts. We also identified genes that may be potentially involved in Wolbachia-induced reproductive and pathogenic phenotypes. Somatically-infected mosquitoes had similar responses to cultured cells. The data show that Wolbachia has a profound and unique effect on Anopheles gene expression in cultured cells, and has important implications for mechanistic understanding of Wolbachia-induced phenotypes and potential novel strategies to control malaria.

Show MeSH
Related in: MedlinePlus