Limits...
Transcriptional signatures of BALB/c mouse macrophages housing multiplying Leishmania amazonensis amastigotes.

Osorio y Fortéa J, de La Llave E, Regnault B, Coppée JY, Milon G, Lang T, Prina E - BMC Genomics (2009)

Bottom Line: A total of 1,248 probe-sets showed significant differential expression.Our findings suggest that the amastigote growth relies on early coordinated gene expression of the MPhi lipid and polyamine pathways.Moreover, these MPhi hosting multiplying L. amazonensis amastigotes display a transcriptional profile biased towards parasite-and host tissue-protective processes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institut Pasteur, Unité d'Immunophysiologie et Parasitisme Intracellulaire, Département de Parasitologie et Mycologie, Paris, France. josorio@pasteur.fr

ABSTRACT

Background: Mammal macrophages (MPhi) display a wide range of functions which contribute to surveying and maintaining tissue integrity. One such function is phagocytosis, a process known to be subverted by parasites like Leishmania (L). Indeed, the intracellular development of L. amazonensis amastigote relies on the biogenesis and dynamic remodelling of a phagolysosome, termed the parasitophorous vacuole, primarily within dermal MPhi.

Results: Using BALB/c mouse bone marrow-derived MPhi loaded or not with amastigotes, we analyzed the transcriptional signatures of MPhi 24 h later, when the amastigote population was growing. Total RNA from MPhi cultures were processed and hybridized onto Affymetrix Mouse430_2 GeneChips, and some transcripts were also analyzed by Real-Time quantitative PCR (RTQPCR). A total of 1,248 probe-sets showed significant differential expression. Comparable fold-change values were obtained between the Affymetrix technology and the RTQPCR method. Ingenuity Pathway Analysis software pinpointed the up-regulation of the sterol biosynthesis pathway (p-value = 1.31e-02) involving several genes (1.95 to 4.30 fold change values), and the modulation of various genes involved in polyamine synthesis and in pro/counter-inflammatory signalling.

Conclusion: Our findings suggest that the amastigote growth relies on early coordinated gene expression of the MPhi lipid and polyamine pathways. Moreover, these MPhi hosting multiplying L. amazonensis amastigotes display a transcriptional profile biased towards parasite-and host tissue-protective processes.

Show MeSH

Related in: MedlinePlus

Modulation of the polyamine biosynthesis pathways in L. amazonensis-hosting MΦ. L. amazonensis-hosting MΦ display a gene expression coordination of several genes involved in polyamine biosynthesis (*, at least 2 probe-sets modulated; blue values determined by RTQPCR).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2666765&req=5

Figure 4: Modulation of the polyamine biosynthesis pathways in L. amazonensis-hosting MΦ. L. amazonensis-hosting MΦ display a gene expression coordination of several genes involved in polyamine biosynthesis (*, at least 2 probe-sets modulated; blue values determined by RTQPCR).

Mentions: Polyamines (e.g. putrescine) derived from arginine catabolism are essential compounds for amastigote growth [15]. Using the Affymetrix technology we failed to detect, at the 5% significance threshold, arginase-2 (arg2) and ornithine decarboxylase-1 (odc1), two enzymes leading to the formation of polyamines through arginine catabolism. Indeed, while for arg2 the raw fluorescence intensity values were below or close to the background level, for odc1 the raw fluorescence intensities before data processing displayed only a slight increase (+ 1.21) in presence of amastigotes (see Additional file 1). However, the up-regulation of SLC7A2 (+ 4.14) in MΦ hosting amastigotes was a strong incentive for monitoring the abundance of arg2 and odc1 transcripts with a validated RTQPCR method. Using this method we did detect a slight variation of the expression of arg2 (+ 1.91) and odc1 (+ 1.18) (Table 1). Therefore, in presence of amastigotes, arg2 could favour arginine transformation into ornithine, the latter being catalyzed in turn by odc1 to generate putrescine (Fig. 4).


Transcriptional signatures of BALB/c mouse macrophages housing multiplying Leishmania amazonensis amastigotes.

Osorio y Fortéa J, de La Llave E, Regnault B, Coppée JY, Milon G, Lang T, Prina E - BMC Genomics (2009)

Modulation of the polyamine biosynthesis pathways in L. amazonensis-hosting MΦ. L. amazonensis-hosting MΦ display a gene expression coordination of several genes involved in polyamine biosynthesis (*, at least 2 probe-sets modulated; blue values determined by RTQPCR).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2666765&req=5

Figure 4: Modulation of the polyamine biosynthesis pathways in L. amazonensis-hosting MΦ. L. amazonensis-hosting MΦ display a gene expression coordination of several genes involved in polyamine biosynthesis (*, at least 2 probe-sets modulated; blue values determined by RTQPCR).
Mentions: Polyamines (e.g. putrescine) derived from arginine catabolism are essential compounds for amastigote growth [15]. Using the Affymetrix technology we failed to detect, at the 5% significance threshold, arginase-2 (arg2) and ornithine decarboxylase-1 (odc1), two enzymes leading to the formation of polyamines through arginine catabolism. Indeed, while for arg2 the raw fluorescence intensity values were below or close to the background level, for odc1 the raw fluorescence intensities before data processing displayed only a slight increase (+ 1.21) in presence of amastigotes (see Additional file 1). However, the up-regulation of SLC7A2 (+ 4.14) in MΦ hosting amastigotes was a strong incentive for monitoring the abundance of arg2 and odc1 transcripts with a validated RTQPCR method. Using this method we did detect a slight variation of the expression of arg2 (+ 1.91) and odc1 (+ 1.18) (Table 1). Therefore, in presence of amastigotes, arg2 could favour arginine transformation into ornithine, the latter being catalyzed in turn by odc1 to generate putrescine (Fig. 4).

Bottom Line: A total of 1,248 probe-sets showed significant differential expression.Our findings suggest that the amastigote growth relies on early coordinated gene expression of the MPhi lipid and polyamine pathways.Moreover, these MPhi hosting multiplying L. amazonensis amastigotes display a transcriptional profile biased towards parasite-and host tissue-protective processes.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institut Pasteur, Unité d'Immunophysiologie et Parasitisme Intracellulaire, Département de Parasitologie et Mycologie, Paris, France. josorio@pasteur.fr

ABSTRACT

Background: Mammal macrophages (MPhi) display a wide range of functions which contribute to surveying and maintaining tissue integrity. One such function is phagocytosis, a process known to be subverted by parasites like Leishmania (L). Indeed, the intracellular development of L. amazonensis amastigote relies on the biogenesis and dynamic remodelling of a phagolysosome, termed the parasitophorous vacuole, primarily within dermal MPhi.

Results: Using BALB/c mouse bone marrow-derived MPhi loaded or not with amastigotes, we analyzed the transcriptional signatures of MPhi 24 h later, when the amastigote population was growing. Total RNA from MPhi cultures were processed and hybridized onto Affymetrix Mouse430_2 GeneChips, and some transcripts were also analyzed by Real-Time quantitative PCR (RTQPCR). A total of 1,248 probe-sets showed significant differential expression. Comparable fold-change values were obtained between the Affymetrix technology and the RTQPCR method. Ingenuity Pathway Analysis software pinpointed the up-regulation of the sterol biosynthesis pathway (p-value = 1.31e-02) involving several genes (1.95 to 4.30 fold change values), and the modulation of various genes involved in polyamine synthesis and in pro/counter-inflammatory signalling.

Conclusion: Our findings suggest that the amastigote growth relies on early coordinated gene expression of the MPhi lipid and polyamine pathways. Moreover, these MPhi hosting multiplying L. amazonensis amastigotes display a transcriptional profile biased towards parasite-and host tissue-protective processes.

Show MeSH
Related in: MedlinePlus