Development of monoclonal antibodies against axenic amastigotes of Leishmania infantum strain in Iran: implication for diagnosis of Kala-azar

Objectives: Leishmaniasis is endemic in 88 countries. Amastigote forms of Leishmania are experts at exploiting host cell processes to establish infection. Monoclonal antibodies are key reagents used in the diagnosis of infectious and non-infectious diseases. The aim of this study was to produce monoclonal antibodies against axenic amastigotes of the Leishmaniainfantum strain in Iran.

Materials and methods: First, standard strains were cultured and axenic amastigote antigens of L. infantum were obtained. Since then, BALB/c smice were immunized and antibody titers were determined. For hybridoma cell formation, lymphocytes isolated from spleen of immunized mice and myeloma cells were fused at a ratio of 10 to 1 in the presence of polyethylene glycol, followed by limiting dilution for the isolation of monoclones. Subsequently, antibody isotypes were determined by using the isotyping kit. The best clone was injected intraperitoneally to pristane-primed mice for large scale production of monoclonal antibodies. The specificity of antibody was determined with Western blotting.

Results: Approximately 25 positive monoclones were obtained, of which four hybrids producing anti-amastigotes L. infantum monoclonal antibodies with high optical density (OD), selected and designated as 8D2 FVI6, 8D2 FVI3, 6G2 FV4 and 6G2 FV3. Results from isotype determination showed the IgG2b sub-class in 6G2FV2 and 8D2FVI6 monoclones.

Conclusion: This study produced monoclonal antibody against amastigotes of Iranian strain of L. infantum for the first time. These antibodies have reactivity against Iranian strain of L. infantum and can be used in the diagnosis of Kala-azar.