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


CONCLUSIONS
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.
Osorio y Fortéa
José
J
Institut Pasteur, Unité d'Immunophysiologie et Parasitisme Intracellulaire, Département de Parasitologie et Mycologie, Paris, France. josorio@pasteur.fr
de La Llave
Emilie
E
Regnault
Béatrice
B
Coppée
Jean-Yves
JY
Milon
Geneviève
G
Lang
Thierry
T
Prina
Eric
E
D000818:Animals; D015870:Gene Expression; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007891:Leishmania; D008264:Macrophages / Q000378:metabolism* / Q000469:parasitology*; D051379:Mice; D008807:Mice, Inbred BALB C; D020411:Oligonucleotide Array Sequence Analysis; D010587:Phagocytosis / Q000502:physiology; D010588:Phagosomes / Q000469:parasitology; D020133:Reverse Transcriptase Polymerase Chain Reaction