Sexual forms obtained in a continuous in vitro cultured Colombian strain of Plasmodium falciparum (FCB2)

Background: The epidemiological control of malaria has been hampered by the appearance of parasite resistance to anti-malarial drugs and by the resistance of mosquito vectors to control measures. This has also been associated with weak transmission control, mostly due to poor control of asymptomatic patients associated with host-vector transmission. This highlights the importance of studying the parasite's sexual forms (gametocytes) which are involved in this phase of the parasite's life-cycle. Some African and Asian strains of Plasmodium falciparum have been fully characterized regarding sexual forms' production; however, few Latin-American strains have been so characterized. This study was aimed at characterizing the Colombian FCB2 strain as a gametocyte producer able to infect mosquitoes. Methods: Gametocyte production was induced in in vitro cultured P. falciparum FCB2 and 3D7 strains. Pfap2g and Pfs25 gene expression was detected in FCB2 strain gametocyte culture by RT-PCR. Comparative analysis of gametocytes obtained from both strains was made (counts and morphological changes). In vitro zygote formation from FCB2 gametocytes was induced by incubating a gametocyte culture sample at 27 °C for 20 min. A controlled Anopheles albimanus infection was made using an artificial feed system with cultured FCB2 gametocytes (14-15 days old). Mosquito midgut dissection was then carried out for analyzing oocysts. Results: The FCB2 strain expressed Pfap2g, Pfs16, Pfg27/25 and Pfs25 sexual differentiation-related genes after in vitro sexual differentiation induction, producing gametocytes that conserved the expected morphological features. The amount of FCB2 gametocytes produced was similar to that from the 3D7 strain. FCB2 gametocytes were differentiated into zygotes and ookinetes after an in vitro low-temperature stimulus and infected An. albimanus mosquitoes, developing to oocyst stage. Conclusions: Even with the history of long-term FCB2 strain in vitro culture maintenance, it has retained its sexual differentiation ability. The gametocytes produced here preserved these parasite forms' usual characteristics and An. albimanus infection capability, thus enabling its use as a tool for studying sexual form biology, An. albimanus infection comparative analysis and anti-malarial drug and vaccine development. © 2020 The Author(s).

• Fecha de publicación: 2020
• Institución: Universidad del Rosario
• Repositorio: Repositorio EdocUR - U. Rosario
• Idioma: eng
• OAI Identifier: oai:repository.urosario.edu.co:10336/22550
• Acceso en línea: https://doi.org/10.1186/s12936-020-3142-y; https://repository.urosario.edu.co/handle/10336/22550
• Palabra clave: Antimalarial agent; Malaria vaccine; Animal cell; Anopheles; Anopheles albimanus; Anopheles albimanus infection; Article; Colombia; Comparative study; Controlled study; Erythrocyte; Female; Gametocyte; Gene; Gene expression; Genetic analysis; Human; Human cell; In vitro study; Incubation time; Infection; Low temperature; Microbial morphology; Midgut; Nonhuman; Oocyst; Parasite examination; Parasite transmission; Pfap2g gene; Pfg25 gene; Pfg27 gene; Pfs16 gene; Pfs25 gene; Plasmodium falciparum; Plasmodium falciparum 3d7; Plasmodium falciparum fcb2; Real time polymerase chain reaction; Sex differentiation; Stimulus; Fcb2; Gametocyte; Malaria; Mosquito infectivity; Oocyst; Plasmodium falciparum; Sexual differentiation
• License: Abierto (Texto Completo)