Reduced invasion of cultured cells pretreated with a monoclonal antibody elicited against refractile body antigens of avian coccidial sporozoites.
The effect of a monoclonal antibody (1209-C2) elicited against sporozoite refractile-body antigen on invasion of cultured baby hamster kidney cells by avian Eimeria species was examined in vitro. Pretreatment of sporozoites with 1209-C2 for 45 min before inoculation into cultures or simultaneous introduction of sporozoites and 1209-C2 into cultures had no significant effect on invasion. However, pretreatment of cultures for 45 min with 1209-C2 (also with media from other cloned 1209 cell lines) significantly inhibited invasion by sporozoites of Eimeria tenella and E. adenoeides. Pretreatment of cultures with 2 unrelated monoclonal antibodies with the same isotype as 1209-C2 did not inhibit invasion by E. tenella. There was a significant correlation between time of exposure of the cultures to 1209-C2 and invasion (r = -0.80924; p = 0.0001), with inhibition of invasion occurring after 20 min exposure, but not after 10 min. There was also a significant correlation between the titer of 1209-C2 and invasion (r = 0.62291; p = 0.0305). Monoclonal antibody 1209-C2 cross-reacted with epitopes of baby hamster kidney cells by both immunofluorescence and Western blot. The fluorescent labeling of the cells differed according to the fixative that was used. In formalin-fixed cultures labeled with 1209-C2, fluorescent foci were distributed over the entire cell; after methanol fixation, 1209-C2 reacted with only discrete foci in the nucleus. On Western blots of sporozoites, 1209-C2 reacted with antigens having molecular sizes of approximately 8, 17, 23, 30, and 45-60 kDa, and with several minor bands. On baby hamster kidney cells, the antibody reacted primarily with bands of approximately 30, 45-60, and slightly with other bands. The data suggest that interactions among similar molecules in the sporozoites and host cells may play a role in cellular invasion.
Augustine
P C
PC
United States Department of Agriculture, Livestock and Poultry Sciences Institute, Beltsville, Maryland 20705, USA. paugusti@ggpl.arsusda.gov
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000494:pharmacology; D000953:Antigens, Protozoan / Q000276:immunology*; D015153:Blotting, Western; D002460:Cell Line; D006224:Cricetinae; D004539:Eimeria / Q000254:growth & development / Q000276:immunology* / Q000472:pathogenicity*; D016786:Eimeria tenella / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity; D005455:Fluorescent Antibody Technique; D006790:Host-Parasite Interactions
D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan