Saurian-associated Leishmania tarentolae in dogs: Infectivity and immunogenicity evaluation in the canine model

• Published in: PLoS pathogens Vol. 20; no. 10; p. e1012598
• Main Authors: Mendoza-Roldan, Jairo Alfonso, Varotto-Boccazzi, Ilaria, Louzada-Flores, Viviane Noll, Evans, Alec, Cheikhi, Imad Bouzaidi, Carbonara, Mariaelisa, Zatelli, Andrea, Epis, Sara, Bandi, Claudio, Beugnet, Frédéric, Otranto, Domenico
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 09.10.2024
• Subjects: Analysis; Animals; Antibodies; Antibodies, Protozoan - immunology; Biology and Life Sciences; Care and treatment; Cytokines; Cytokines - immunology; Cytokines - metabolism; Diagnosis; Disease Models, Animal; Diseases; Dog Diseases - immunology; Dog Diseases - parasitology; Dogs; Enzyme-linked immunosorbent assay; Ethylenediaminetetraacetic acid; Female; Health aspects; Infection; Leishmania - immunology; Leishmania - pathogenicity; Leishmaniasis; Leishmaniasis - immunology; Leishmaniasis - parasitology; Lizards - immunology; Lizards - parasitology; Male; Medical research; Medicine and Health Sciences; Medicine, Experimental; Research and Analysis Methods; Testing; Viral antibodies; Italy
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1012598

In canine leishmaniosis endemic areas, Leishmania infantum may occur in sympatry with the non-pathogenic Leishmania tarentolae , which is associated to reptiles. The potential infectivity of L . tarentolae for mammals raises questions about the interactions between the two Leishmania species, and the potential cross-immune protection in dogs. This study aimed to assess the outcome of experimental L . tarentolae infection in dogs, determining: i) the anti- L . tarentolae antibody production, ii) the duration of the immunity and cytokine expression, and iii) the possible pathogenic effect in the canine host. Twelve purpose-bred beagle dogs were randomly allocated to three groups (intravenous inoculation, G1; intradermal inoculation, G2; negative control, G3). G1 and G2 dogs were inoculated twice (day 0, day 28) with 10 8 promastigotes of L . tarentolae strain (RTAR/IT/21/RI-325) isolated from a Tarentola mauritanica gecko. The animals were followed until day 206. Blood, serum, conjunctival swabs and lymph node aspirate samples were collected monthly and bone marrow, liver and spleen biopsies on day 91. Hematological and biochemical parameters were assessed monthly, as well as serology (IFAT and ELISA) and molecular identification of L . tarentolae . Mononuclear cells (PBMC) were obtained to assess the cytokine expression through in vitro stimulation or (re-) infection. Data from this study demonstrated that DNA from L . tarentolae is detectable up to 3 months post-infection, with seroconversion after day 28. Moreover, the non-pathogenic nature of L . tarentolae was confirmed, with a neutral Th1/Th2 polarization, and a possible shift to Th1 phenotype after derived macrophages (re-) infection, as demonstrated by the expression of IFN-gamma. Therefore, L . tarentolae demonstrated a great potential as a surrogate pathogen and/or immune-prophylaxis/immune-therapy against Leishmania infections in dogs and humans.