title: Lysis and immobilization of Giardia muris trophozoites in vitro by immune serum from susceptible and resistant mice.
abstract: To define the potential role of antibody in host defence against Giardia muris, comparative assessment of in-vitro anti-trophozoite effects of immune serum obtained from susceptible (A/J) and resistant (B10.A) mice was done. Two anti-parasite effects of serum were identified and quantified: lysis and immobilization of trophozoites. These giardicidal activities were present in the serum from both A/J and B10.A mice. Maximal lysis of trophozoites by serum from A/J or B10.A mice was 40 to 50%. The lysis of trophozoites was abolished after incubation of serum at 56 degrees C for 30 min. The addition of exogenous complement restored lytic activity of heat-inactivated serum. The immobilization of trophozoites was dependent on both the duration of incubation and concentration of serum. After 30 min of incubation, over 98% of trophozoites were immobilized by immune serum from A/J or B10.A mice. There was no apparent relationship between the capacity of immune sera from A/J and B10.A mice to kill trophozoites in vitro and the ability of these strains of mice to control the infection with G. muris.
mesh_terms: D000818:Animals; D004198:Disease Susceptibility; D005260:Female; D005872:Giardia / Q000276:immunology*; D005873:Giardiasis / Q000276:immunology*; D007106:Immune Sera / Q000276:immunology*; D007113:Immunity, Innate; D051379:Mice; D008805:Mice, Inbred A
chemical_list: D007106:Immune Sera