Infect. Immun., 07 1997, 2548-2554, Vol 65, No. 7
Copyright © 1997, American Society for Microbiology

Passive transfer of a monoclonal antibody specific for a sialic acid- dependent epitope on the surface of Trypanosoma cruzi trypomastigotes reduces infection in mice

G Franchin, VL Pereira-Chioccola, S Schenkman and MM Rodrigues
Department of Microbiology, Immunology, and Parasitology, Federal University of Sao Paulo-Escola Paulista de Medicina, S.P. Brazil.

Trypanosoma cruzi, the parasite that causes Chagas' disease, proliferates in the cytosol of mammalian cells. When the trypomastigote forms exit the infected cell, they become extensively sialylated because the parasite contains an enzyme called trans-sialidase. This enzyme efficiently catalyzes the transfer of bound sialic acid residues from host glycoconjugates to acceptors containing terminal beta- galactosyl residues on the parasite surface. The sialic acid acceptors are developmentally regulated mucin-like glycoproteins that are extremely abundant on the trypomastigote surface. In the present study, we determined whether passive transfer of monoclonal antibodies specific for sialic acid acceptors could reduce the acute infection induced by T. cruzi in a highly susceptible mouse strain. We found that passive transfer to naive mice of an immunoglobulin G1 monoclonal antibody directed to a sialylated epitope of these mucin-like glycoproteins significantly decreased parasitemia and the number of tissue parasites as measured by a DNA probe specific for T. cruzi. Upon challenge with trypomastigotes, mice which received this antibody also had a significant increase in survival. A statistically significant reduction in parasitemia could be accomplished with relatively small doses of immunoglobulin, and Fab fragments alone could not mediate protective immunity. The precise mechanism of parasite elimination is unknown; however, this monoclonal antibody does not lyse trypomastigotes in vitro in the presence of human complement or mouse spleen cells.

This article has been cited by other articles:

• Alcaide, P., Fresno, M. (2004). The Trypanosoma cruzi membrane mucin AgC10 inhibits T cell activation and IL-2 transcription through L-selectin. Int Immunol 16: 1365-1375 [Abstract] [Full Text]  
• Pitcovsky, T. A., Mucci, J., Alvarez, P., Leguizamon, M. S., Burrone, O., Alzari, P. M., Campetella, O. (2001). Epitope Mapping of trans-Sialidase from Trypanosoma cruzi Reveals the Presence of Several Cross-Reactive Determinants. Infect. Immun. 69: 1869-1875 [Abstract] [Full Text]  
• Di Noia, J. M., D'Orso, I., Sanchez, D. O., Frasch, A. C. C. (2000). AU-rich Elements in the 3'-Untranslated Region of a New Mucin-type Gene Family of Trypanosoma cruzi Confers mRNA Instability and Modulates Translation Efficiency. J. Biol. Chem. 275: 10218-10227 [Abstract] [Full Text]  
• Pereira-Chioccola, V., Acosta-Serrano, A, Correia de Almeida, I, Ferguson, M., Souto-Padron, T, Rodrigues, M., Travassos, L., Schenkman, S (2000). Mucin-like molecules form a negatively charged coat that protects Trypanosoma cruzi trypomastigotes from killing by human anti-alpha-galactosyl antibodies. J. Cell Sci. 113: 1299-1307 [Abstract]  
• Saavedra, E., Herrera, M., Gao, W., Uemura, H., Pereira, M. A. (1999). The Trypanosoma cruzi trans-Sialidase, through Its COOH-terminal Tandem Repeat, Upregulates Interleukin 6 Secretion in Normal Human Intestinal Microvascular Endothelial Cells and Peripheral Blood Mononuclear Cells. J. Exp. Med. 190: 1825-1836 [Abstract] [Full Text]  
• Miyahira, Y., Kobayashi, S., Takeuchi, T., Kamiyama, T., Nara, T., Nakajima-Shimada, J., Aoki, T. (1999). Induction of CD8+ T cell-mediated protective immunity against Trypanosoma cruzi. Int Immunol 11: 133-141 [Abstract] [Full Text]  
• Di Noia, J. M., D'Orso, I., Aslund, L., Sanchez, D. O., Frasch, A. C.C. (1998). The Trypanosoma cruzi Mucin Family Is Transcribed from Hundreds of Genes Having Hypervariable Regions. J. Biol. Chem. 273: 10843-10850 [Abstract] [Full Text]