Experimental infection of Leishmania (L.) chagasi in a cell line derived from Lutzomyia longipalpis (Diptera:Psychodidae)

• Published in: Memórias do Instituto Oswaldo Cruz 2005-10, Vol.100 (6), p.519-525
• Main Authors: Bello, Felio J, Mejía, Astrid J, Corena, María del Pilar, Ayala, Martha, Sarmiento, Ladys, Zuñiga, Claudio, Palau, María T
• Format: Article
• Language: English
• Subjects: Animals; Cell Line - parasitology; Humans; infection percentages; J774 cell line; Leishmania chagasi; Leishmania chagasi - Lulo cell line - J774 cell line - infection percentages - parasitophorous vacuoles; Leishmania infantum - growth & development; Leishmania infantum - ultrastructure; Lulo cell line; Lutzomyia longipalpis; Microscopy, Electron, Transmission; PARASITOLOGY; parasitophorous vacuoles; Psychodidae - cytology; Psychodidae - parasitology; TROPICAL MEDICINE
• ISSN: 1678-8060; 0074-0276; 0074-0276
• DOI: 10.1590/s0074-02762005000600004

The present work describes the in vitro infection of a cell line Lulo, derived from Lutzomyia longipalpis embryonic tissue, by Leishmania (L.) chagasi promastigotes. This infection process is compared with a parallel one developed using the J774 cell line. The L. chagasi MH/CO/84/CI-044B strain was used for experimental infection in two cell lines. The cells were seeded on glass coverslips in 24-well plates to reach a final number of 2x105 cells/well. Parasites were added to the adhered Lulo and J774 cells in a 10:1 ratio and were incubated at 28 and 37°C respectively. After 2, 4, 6, 8, and 10 days post-infection, the cells were extensively washed with PBS, fixed with methanol, and stained with Giemsa. The number of internalized parasites was determined by counting at least 400 cultured cells on each coverslip. The results showed continuous interaction between L. chagasi promastigotes with the cell lines. Some ultrastructural characteristics of the amastigote forms were observed using transmission electron microscopy. The highest percentage of infection in Lulo cells was registered on day 6 post-infection (29.6%) and on day 4 in the J774 cells (51%). This work shows similarities and differences in the L. chagasi experimental infection process in the two cell lines. However, Lulo cells emerge as a new model to study the life-cycle of this parasite.