Objective To determine the length of protection by murine immunization with living third stage hookworm larvae (L 3) as measured by reduction in worm burden and host serologic antibody responses Methods Outbred male (...Objective To determine the length of protection by murine immunization with living third stage hookworm larvae (L 3) as measured by reduction in worm burden and host serologic antibody responses Methods Outbred male (Kunming strain) mice were immunized subcutaneously with 500 L 3 once every 2 weeks for a total of immunization for 3 times, and then challenged orally with 1000 L 3 for 1 to 8 weeks after the final immunization Host protective immunity was determined both by the reduction in worm burden as measured by the number of L 3 recovered from murine lungs 48 hour post challenge, as well as by measurement of circulating antibodies Histopathological responses were also examined Non immunized mice served as negative controls Results The protection by L 3 immunization declined over time One or 2 weeks after the final immunization, worm burdens were reduced 72% and 77 5% after challenge respectively In contrast, only 37% reduction in worm burden was observed when the L 3 challenge was delayed by 4 weeks and protection was almost entirely lost when there was an 8 week delay between the time of final immunization and challenge The reduced level of protection over time partially correlated with diminishing L 3 specific antibody responses Host inflammation in the lungs of immunized mice also diminished Conclusion The protection afforded by living L 3 immunization is maximal for the first two weeks after immunization, but then declines significantly over the ensuing展开更多
Abstract This work was supported by Tropical Medicine Research Center (TMRC) grant 1 P50 AI39461 awarded to the Institute of Parasitic Diseases, Chinese Academy of Preventive Medicine. Dr. Hotez is further supporte...Abstract This work was supported by Tropical Medicine Research Center (TMRC) grant 1 P50 AI39461 awarded to the Institute of Parasitic Diseases, Chinese Academy of Preventive Medicine. Dr. Hotez is further supported by a clinical research grant from the March of Dimes, NIH AI32726, and an Established Investigator Grant from the American Heart Association. Objective To elucidate the mechanisms of protective immunity in mice elicited by living hookworm ( Ancylostoma caninum third stage infective larvae (L 3). Methods The number of migrating infective larvae recovered from the lungs was used as an endpoint for vaccine immunity. The timing of maximal L 3 lung entry was determined by counting the number of lung larvae at several time points after infection with 500 or 1000 L 3. Mice were immunized either orally or subcutaneously with 500 L 3, followed by two boosts of L 3 once every two weeks. The immunized mice were challenged orally with 500 L 3 one week after the final boost. To evaluate the protective immunity, the number of L 3 recovered from the lungs of the immunized mice during the time of maximal larval entry was compared with that of controls. Host immunity was also evaluated by comparing circulating anti L 3 antibodies between immunized and controlled mice, using both enzyme immunoassays and immunoblotting techniques, and by lung histopathology. Results The peak time of larval entry into the lungs occurred 48 hours after infection. Mice immunized either orally or subcutaneously with L 3 exhibited a marked reduction (90.2% and 86.2% respectively) in the number of recovered lung larvae in comparison to controls ( P <0.01). The protection might be associated with circulating anti L 3 antibodies, including antibodies directed against 132 200 kDa L 3 antigens, as well as three major antigens ranging from 28 to 51 kDa. Larvae migrating through the lungs of vaccinated mice showed cuticular damages accompanied with host inflammatory cell invasion. Conclusions Immunization with living L 3 protects mice against lung invasion after challenged with hookworm infection. Vaccine immunity is associated with circulating antibodies against L 3 antigens and lung inflammatory responses. The mouse model is potentially useful for developing a hookworm vaccine.展开更多
Objective To explore the possibility of using specific antigens for immunodiagnosis of hookworm desease in endemic area. Method Infective third stage larvae of the canine hookworm, Ancylostoma caninum (A. Cani...Objective To explore the possibility of using specific antigens for immunodiagnosis of hookworm desease in endemic area. Method Infective third stage larvae of the canine hookworm, Ancylostoma caninum (A. Caninum) , were prepared as the source of antigen. Enzyme linked immunoelectrotransfer blotting (EITB) was enployed as an immunodiagnostic method. Results Two immunodominant bands of hookworm antigens (42 kDa and 55 kDa) were recognized by the sera of hookworm infected patients (serum dilution 1∶200; antigen centrifuged at 36 000 r/m for 20 minutes, but not by sera from negative controls. Conclusion The 42 kDa and 55 kDa A. caninum antigens might be the specific antigens that could be used for immunodiagnosis of hookworm disease in endemic area.展开更多
文摘Objective To determine the length of protection by murine immunization with living third stage hookworm larvae (L 3) as measured by reduction in worm burden and host serologic antibody responses Methods Outbred male (Kunming strain) mice were immunized subcutaneously with 500 L 3 once every 2 weeks for a total of immunization for 3 times, and then challenged orally with 1000 L 3 for 1 to 8 weeks after the final immunization Host protective immunity was determined both by the reduction in worm burden as measured by the number of L 3 recovered from murine lungs 48 hour post challenge, as well as by measurement of circulating antibodies Histopathological responses were also examined Non immunized mice served as negative controls Results The protection by L 3 immunization declined over time One or 2 weeks after the final immunization, worm burdens were reduced 72% and 77 5% after challenge respectively In contrast, only 37% reduction in worm burden was observed when the L 3 challenge was delayed by 4 weeks and protection was almost entirely lost when there was an 8 week delay between the time of final immunization and challenge The reduced level of protection over time partially correlated with diminishing L 3 specific antibody responses Host inflammation in the lungs of immunized mice also diminished Conclusion The protection afforded by living L 3 immunization is maximal for the first two weeks after immunization, but then declines significantly over the ensuing
文摘Abstract This work was supported by Tropical Medicine Research Center (TMRC) grant 1 P50 AI39461 awarded to the Institute of Parasitic Diseases, Chinese Academy of Preventive Medicine. Dr. Hotez is further supported by a clinical research grant from the March of Dimes, NIH AI32726, and an Established Investigator Grant from the American Heart Association. Objective To elucidate the mechanisms of protective immunity in mice elicited by living hookworm ( Ancylostoma caninum third stage infective larvae (L 3). Methods The number of migrating infective larvae recovered from the lungs was used as an endpoint for vaccine immunity. The timing of maximal L 3 lung entry was determined by counting the number of lung larvae at several time points after infection with 500 or 1000 L 3. Mice were immunized either orally or subcutaneously with 500 L 3, followed by two boosts of L 3 once every two weeks. The immunized mice were challenged orally with 500 L 3 one week after the final boost. To evaluate the protective immunity, the number of L 3 recovered from the lungs of the immunized mice during the time of maximal larval entry was compared with that of controls. Host immunity was also evaluated by comparing circulating anti L 3 antibodies between immunized and controlled mice, using both enzyme immunoassays and immunoblotting techniques, and by lung histopathology. Results The peak time of larval entry into the lungs occurred 48 hours after infection. Mice immunized either orally or subcutaneously with L 3 exhibited a marked reduction (90.2% and 86.2% respectively) in the number of recovered lung larvae in comparison to controls ( P <0.01). The protection might be associated with circulating anti L 3 antibodies, including antibodies directed against 132 200 kDa L 3 antigens, as well as three major antigens ranging from 28 to 51 kDa. Larvae migrating through the lungs of vaccinated mice showed cuticular damages accompanied with host inflammatory cell invasion. Conclusions Immunization with living L 3 protects mice against lung invasion after challenged with hookworm infection. Vaccine immunity is associated with circulating antibodies against L 3 antigens and lung inflammatory responses. The mouse model is potentially useful for developing a hookworm vaccine.
文摘Objective To explore the possibility of using specific antigens for immunodiagnosis of hookworm desease in endemic area. Method Infective third stage larvae of the canine hookworm, Ancylostoma caninum (A. Caninum) , were prepared as the source of antigen. Enzyme linked immunoelectrotransfer blotting (EITB) was enployed as an immunodiagnostic method. Results Two immunodominant bands of hookworm antigens (42 kDa and 55 kDa) were recognized by the sera of hookworm infected patients (serum dilution 1∶200; antigen centrifuged at 36 000 r/m for 20 minutes, but not by sera from negative controls. Conclusion The 42 kDa and 55 kDa A. caninum antigens might be the specific antigens that could be used for immunodiagnosis of hookworm disease in endemic area.
