TOXOPLASMA-GONDII - A MONOCLONAL-ANTIBODY THAT INHIBITS INTRACELLULARREPLICATION

Citation
Jr. Mineo et al., TOXOPLASMA-GONDII - A MONOCLONAL-ANTIBODY THAT INHIBITS INTRACELLULARREPLICATION, Experimental parasitology, 79(3), 1994, pp. 351-361
Citations number
24
Categorie Soggetti
Parasitiology
Journal title
ISSN journal
00144894
Volume
79
Issue
3
Year of publication
1994
Pages
351 - 361
Database
ISI
SICI code
0014-4894(1994)79:3<351:T-AMTI>2.0.ZU;2-B
Abstract
During its intracellular life cycle within the infected host cell, Tox oplasma gondii is able to undergo rapid asexual replication. Neither t he mechanism by which the parasite initiates this process nor the requ irements for maintaining it are understood. We produced a monoclonal a ntibody, 1B8, that identifies a parasite antigen of approximate M(r) 9 7 kDa as determined by SDS-PAGE. The epitope recognized by mAb 1B8 app ears as a collection of vesicular structures scattered throughout the cell cytoplasm. When RH strain parasites are incubated with mAb 1B8 in the absence of serum complement, parasite growth is inhibited by >90% as determined by radioisotope incorporation. Both attachment and inva sion assays show that neither of these parasite-host cell interactions are inhibited by the mAb. However, a marked reduction in the number o f intracellular rosettes was observed following mAb treatment of the p arasites. Viable extracellular parasites are able to endocytose mAb 1B 8. Once within the parasite cytosol the antibody recognizes the vesicu lar structures similar to those observed with fixed parasites. Immunof luorescence assays with Besnoitia jellisoni and Plasmodium falciparum show that the epitope recognized by mAb 1B8 is conserved among Coccidi ae but not the kinetoplastid Leishmania. (C) 1994 Academic Press, Inc.