Bovine antibody against Cryptosporidium parvum elicits a circumsporozoite precipitate-like reaction and has immunotherapeutic effect against persistent cryptosporidiosis in SCID mice.

摘要: Control of cryptosporidiosis is currently hampered by the absence drugs or vaccines proven consistently effective against Cryptosporidium parvum. On basis observations that anti-C. parvum antibody has therapeutic effect cryptosporidiosis, cows were immunized with C. to produce hyperimmune colostral antibody. An antibody-rich fraction was prepared and differentiated from control (nonhyperimmune) enzyme-linked immunosorbent assay, immunofluorescence immunoelectron microscopy, in vitro neutralizing titer DEAE-cellulose-isolated sporozoites. Oocyst, purified sporozoite, merozoite antigens recognized defined Western blot (immunoblot). Hyperimmune common oocysts, sporozoites, merozoites, as well stage-specific antigens. Upon incubation antibody, sporozoites underwent distinct morphologic changes characterized progressive formation eventual release membranous sporozoite surface antigen-antibody complexes, similar malaria circumsporozoite precipitate reaction. The infectivity having undergone this reaction neutralized. minimal absent on incubated To determine vivo, persistent infection established adult severe combined immune-deficient (SCID) mice oral inoculation 10(7) oocysts. At 5 weeks postinfection, infected treated for 10 days inclusion drinking water daily gavage. Fecal oocyst shedding scores gastrointestinal tract gall bladder/common bile duct antibody-treated significantly lower than those mice. bovine may provide a first-generation therapy cryptosporidiosis. Additionally, can be evaluated subunit immunogens better-characterized polyclonal targets monoclonal antibody-based immunotherapy.