Inhibition of macrophage invasion by monoclonal antibodies specific to Leishmania (Viannia) braziliensis promastigotes and characterisation of their antigens

• Published in: International journal for parasitology 2001-11, Vol.31 (13), p.1451-1458
• Main Authors: Silveira, Thaı́s G.V, Suzuki, Erika, Takahashi, Helio K, Straus, Anita H
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Monoclonal - immunology; Antibody Specificity; Antigens, Protozoan - chemistry; Antigens, Protozoan - immunology; Biological and medical sciences; Blotting, Western; Chromatography, Agarose; Epitopes - chemistry; Epitopes - immunology; Flagella; Fluorescent Antibody Technique, Indirect; Fundamental and applied biological sciences. Psychology; Immunoglobulin Fab Fragments - immunology; Infectivity; Leishmania; Leishmania (Viannia) braziliensis; Leishmania braziliensis; Leishmania braziliensis - immunology; Macrophages, Peritoneal - immunology; Macrophages, Peritoneal - parasitology; Male; Mice; Mice, Inbred BALB C; Monoclonal antibody; Precipitin Tests; Protozoa; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/S0020-7519(01)00269-7

Monoclonal antibodies that specifically recognise Leishmania (Viannia) braziliensis promastigotes were produced and termed SST-2, SST-3 and SST-4. SST-2 recognises a conformational epitope present in a 24–28 kDa doublet and in a 72 kDa component, as verified by Western blotting. Indirect immunofluorescence showed that the antigen recognised by SST-2 is distributed homogeneously on the parasite surface. SST-3 recognises a flagellar glycoprotein of ∼180 kDa. The reactivity of this mAb was abolished by sodium m-periodate treatment, indicating that SST-3 reacts with a carbohydrate epitope of the 180 kDa antigen. SST-4 recognises a conformational epitope of a 98 kDa antigen. SST-2, SST-3 and SST-4 were specific to L. (V.) braziliensis promastigote forms. Indirect immunofluorescence did not show reactivity of SST-2 or SST-3 with amastigotes of L. (V.) braziliensis, or with promastigotes of Leishmania (Viannia) panamensis, Leishmania (Viannia) guyanensis, Leishmania (Viannia) naiffi, Leishmania (Viannia) lainsoni, Leishmania (Leishmania) amazonensis, Leishmania (Leishmania) major, or Leishmania (Leishmania) chagasi. We also evaluated the involvement of SST-2, SST-3 and SST-4 antigens in parasite–macrophage interaction. Fab fragments of SST-3 and SST-4 significantly inhibited the infectivity of L. (V.) braziliensis promastigotes to mouse peritoneal macrophages.