title: Phenotypic diversity and selection maintain Leishmania amazonensis infectivity in BALB/c mouse model.
abstract: Leishmania are protozoan parasites that show remarkable diversity, as revealed by the various clinical forms of leishmaniasis, which can range from mild skin lesions to severe metastatic cutaneous/mucosal lesions. The exact nature and extent of Leishmania phenotypic diversity in establishing infection is not fully understood. In order to try to understand some aspects of this diversity, we subcutaneously infected BALB/c mice with first and second generation subclones of a L. amazonensis strain isolated from a patient (BA125) and examined in vivo lesion growth rate and antimony susceptibility. In vivo fast-, medium- and slow-growing subclones were obtained; moreover, fast-growing subclones could generate slow-growing subclones and inversely, revealing the continuous generation of diversity after passage into mice. No antimony-resistant subclone appeared, probably a rare occurrence. By tagging subclone cells with a L. amazonensis genomic cosmid library, we found that only a very small number of founding cells could produce lesions. Leishmania clones transfected with in vivo selected individual cosmids were also diverse in terms of lesion growth rate, revealing the cosmid-independent intrinsic characteristics of each clone. Our results suggest that only a few of the infecting parasites are able to grow and produce lesions; later, within the cell mixture of each lesion, there coexist several parasite populations with different potentialities to grow lesions during the next infection round. This may reflect a sort of programmed heterogeneity of individual parasites, favoring the survival of some individuals in various environmental conditions.
authors.affiliation: Université de Bordeaux, Laboratoire de Génomique Fonctionnelle des Trypanosomatidés, Bordeaux, France.|LabEx Corail, Papetoai, Moorea, Polynésie Française.
authors.forename: Benoît
authors.initials: B
authors.lastname: Espiau
authors.affiliation: Fundação Oswaldo Cruz, Instituto Gonçalo Moniz, Salvador, BA, Brasil.|Faculdade Anhanguera de Brasília, Brasília, DF, Brasil.
authors.forename: Virginia
authors.initials: V
authors.lastname: Vilhena
authors.affiliation: Université de Bordeaux, Laboratoire de Génomique Fonctionnelle des Trypanosomatidés, Bordeaux, France.|B Cell Design, Limoges, France.
authors.forename: Armelle
authors.initials: A
authors.lastname: Cuvillier
authors.affiliation: Fundação Oswaldo Cruz, Instituto Gonçalo Moniz, Salvador, BA, Brasil.|Instituto de Investigação em Imunologia, Salvador, BA, Brasil.
authors.forename: Aldina
authors.initials: A
authors.lastname: Barral
authors.affiliation: Université de Bordeaux, Laboratoire de Génomique Fonctionnelle des Trypanosomatidés, Bordeaux, France.|Instituto de Investigação em Imunologia, Salvador, BA, Brasil.
authors.forename: Gilles
authors.initials: G
authors.lastname: Merlin
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D007894:Leishmania mexicana / Q000235:genetics* / Q000472:pathogenicity; D016773:Leishmaniasis, Cutaneous / Q000469:parasitology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D013997:Time Factors