A MONOCLONAL-ANTIBODY DIRECTED TO TERMINAL RESIDUE OF BETA-GALACTOFURANOSE OF A GLYCOLIPID ANTIGEN ISOLATED FROM PARACOCCIDIOIDES-BRASILIENSIS - CROSS-REACTIVITY WITH LEISHMANIA-MAJOR AND TRYPANOSOMA-CRUZI

A mouse monoclonal antibody, MEST-1, was produced against Band 1 glyco lipid antigen of Paracoccidioides brasiliensis, The glycan structure o f Band 1 antigen was recently elucidated and the monosaccharides seque nce was defined as: Galf beta 1-->6(Manp alpha 1-->3)Manp beta 1-->2In s. The reactivity of MEST-1 MAb was determined by solid-phase radioimm unoassay and high performance thin layer chromatography immunostaining . Selective oxidation of galactofuranose residues and inhibition assay s with different methyl-glycosides, revealed that MAb MEST-1 is direct ed against the terminal residue of beta-D-gaiactofuranose of Band 1, a phosphoglyceroglycolipid antigen of P.brasiliensis. By indirect immun ofluorescence, it was observed that the epitope recognized by MEST-1 i s accessible to the antibody in yeast forms of this fungus. Reactivity of MEST-1 with parasites known to express galactofuranose containing glycoconjugates was also analyzed by indirect immunofluorescence. A po sitive fluorescence was observed with promastigotes of Leishmania majo r and epimastigotes of Trypanosoma cruzi, GIPL-1 was identified as the antigen recognized by MEST-1 in Leishmania major, indicating that the MAb MEST-1 recognizes terminal galactofuranose residue in either beta 1-->6 or beta 1-->3 linkage to the mannose.