Metacyclic neutralizing effect of monoclonal antibody 10D8 directed to the 35- and 50-kilodalton surface glycoconjugates of Trypanosoma cruzi

Abstract

It was shown in this work that the infectivity of metacyclic forms of Trypanosoma cruzi was affected upon interaction with the monoclonal antibody (10D8), which reacts with a carbohydrate epitope of the 35-and 50-kilodalton (kDa) surface glycoconjugates. The invasion of Vero cells by metacyclic forms of strains Tulahuen and G was inhibited 50 to 67% in the presence of 10D8 (10 ,g/ml), whereas a nonrelated monoclonal antibody to Plasmodium berghei had no such effect. In mice that were inoculated with metacyclic forms preincubated with 10D8 or that had passively received 10D8 before challenge with metacyclic forms, a considerable decrease in the parasitemia levels was observed. The 35-and 50-kDa antigens were detectable by the galactose oxidase and sodium boro[3HJhydride procedure but not by surface iodination or metabolic labeling with [35S]methionine, suggesting that they may be of glycolipid nature. The finding that the 35-and 50-kDa antigens are major bands recognized by sera of mice immunized with killed metacyclic forms and protected against acute infection, in addition to the results with 10D8, indicate that these glycoconjugates may play an important role in the metacyclic form-host cell association that initiates T. cruzi infection.

Lysosome biogenesis/scattering increases host cell susceptibility to invasion by Trypanosoma cruzi metacyclic forms and resistance to tissue culture trypomastigotes

“…HeLa cells, the human carcinomaderived epithelial cells, were grown at 37°C in D10 (Dulbecco's minimum essential medium supplemented with 10% FBS, 100 μg ml À1 streptomycin and 100 U ml À1 penicillin), in a humidified 5% CO 2 atmosphere. Cell invasion assays were performed as detailed elsewhere (Yoshida et al, 1989), by seeding the parasites (moi = 10 for MT and 20 for TCT) onto each well of 24well plates containing 13-mm-diameter round glass coverslips coated with 1.5 × 10 5 HeLa cells.…”

Flagellar protein localization mediated by a calcium-myristoyl/palmitoyl switch mechanism

“…Samples were boiled and approximately equal amounts of each protein fraction were analyzed by one-dimensional 12% SDS-PAGE (Laemmli, 1970). Gels were either stained with GelCode (Pierce, Rockford, IL) or transferred to nitrocellulose (Towbin et al, 1979) and probed with FCaBP-specific (Godsel et al, 1995), Hsp70specific (Olson et al, 1994) or gp35/gp50 surface mucin-specific (Yoshida et al, 1989) mouse sera and alkaline phosphatase-conjugated goat antimouse IgG ϩ IgM (Caltag Laboratories, San Francisco, CA), and blots were developed using BCIP/NBT (Life Technologies, Gaithersburg, MD).…”

Glycoconjugates of Trypanosoma cruzi: A 74 kD antigen of trypomastigotes specifically reacts with lytic anti‐α‐galactosyl antibodies from patients with chronic Chagas disease

“…Glycoconjugates play an important role in the biology of Trypanosomatidae. They act as mediators of parasite interactions with host cells and with soluble ligands (1)(2)(3)(4), regulate morphological transitions or are specific to the various developmental stages of the parasite (S- 8), elicit or modulate the host immune response (9)(10)(11)(12), and display enzymatic activities important for the parasite invasion of host cells ( I [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. In American trypanosomiasis, surface glycoconjugates of Tkypanosoma cruzi have been characterized and shown to react with patients' sera in different assay systems, involving parasite agglutination, complement-mediated lysis, solid-phase immunosorbent reactions, irnmunoprecipitation, and immunofluorescence (7,12,(17)(18)(19).…”