Advances in experimental medicine and biology, 1981
Complement profiles were tested in outbred (LVG) Syrian hamsters (Mesocricetus auratus) and compa... more Complement profiles were tested in outbred (LVG) Syrian hamsters (Mesocricetus auratus) and compared to the MHA, LHC, PD4, and CB inbred strains. The total C and C component concentrations in the sera varied among the strains and were in the following ranges in untreated animals (in CH50 units per ml): total C, 140-260 (undetectable in PD4 and CB); Cl, 14,000-25,000; C2, 200-800 (except PD 4 and CB); C3, 40,000 and 80,000; C4, 2,000-2,800 (except PD4 and CB); C4, 40,000-80,000; C6, 3,600-6,000 (undetectable in PD4 and CB); C7, 50,000-350,000; C8, 10,000-30,000; C9, 30,000-60,000. The PD4 and CB strains had undetectable total C and C6, and their exact C2 and C4 levels could not be determined, but were lower than in the other strains. The MHA strain had the highest total C levels, but had significantly lower (1/3 or less) C7 levels than the other strains of hamsters. Infection of hamsters with the filarid nematode Brugia pahangi for four to five months produced moderate decreases in t...
Host suitability, reproduction, effects of temperature on reproduction and pupal development, eff... more Host suitability, reproduction, effects of temperature on reproduction and pupal development, effects of humidity on pupal development and the effects of photoperoid on puparial deposition, pupal development and adult emergence were studied in a laboratory colony of Pseudolynchia canariensis. Flies were observed to lack strong host specificity. Puparia were produced at regular 24 h intervals by flies maintained at 30 °C, averaging 8·8 puparia per female. Optimum temperature for colony maintenance was observed to range between 26·6 and 30·0 °C. Temperatures of 13 and 37 °C were lethal to pupae. Humidity and photoperiod did not markedly affect pupal development. Puparial deposition and adult emergence occurred only during the photoperiod.
Parasitic nematodes produce an unusual class of fatty acid and retinol (FAR)-binding proteins tha... more Parasitic nematodes produce an unusual class of fatty acid and retinol (FAR)-binding proteins that may scavenge host fatty acids and retinoids. Two FARs from Brugia malayi (Bm-FAR-1 and Bm-FAR-2) were expressed as recombinant proteins, and their ligand binding, structural characteristics, and immunogenicities examined. Circular dichroism showed that rBm-FAR-1 and rBm-FAR-2 are similarly rich in α-helix structure. Unexpectedly, however, their lipid binding activities were found to be readily differentiated. Both FARs bound retinol and cis-parinaric acid similarly, but, while rBm-FAR-1 induced a dramatic increase in fluorescence emission and blue shift in peak emission by the fluorophore-tagged fatty acid (dansyl-undecanoic acid), rBm-FAR-2 did not. Recombinant forms of the related proteins from Onchocerca volvulus, rOv-FAR-1 and rOv-FAR-2, were found to be similarly distinguishable. This is the first FAR-2 protein from parasitic nematodes that is being characterized. The relative pro...
In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administr... more In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administration, although there is concern based on several factors that onchocerciasis cannot be eliminated solely through this approach. A vaccine against Onchocerca volvulus would provide a critical tool for the ultimate elimination of this infection. Previous studies have demonstrated that immunization of mice with Ov-103 and Ov-RAL-2, when formulated with alum, induced protective immunity. It was hypothesized that the levels of protective immunity induced with the two recombinant antigens formulated with alum would be improved by formulation with other adjuvants known to enhance different types of antigen-specific immune responses. Immunizing mice with Ov-103 and Ov-RAL-2 in conjunction with alum, Advax 2 and MF59 induced significant levels of larval killing and host protection. The immune response was biased towards Th2 with all three of the adjuvants, with IgG1 the dominant antibody. Improv...
Rates of trypomastigote adherence, interiorization, amastigote division in, and trypomastigote re... more Rates of trypomastigote adherence, interiorization, amastigote division in, and trypomastigote release from Vero cells were measured for Trypanosoma cruzi isolates from a dog (Tc-D), opossum (Tc-O), and an armadillo (Tc-A) from Louisiana. Because the Tc-O and Tc-A (wild isolates) trypomastigotes became interiorized rapidly, the media were quickly depleted of trypomastigotes thus reducing the numbers available to adhere to cells. In contrast, the Tc-D trypomastigote interiorization rate was slower. Intracellular amastigote division rate was slower for the Tc-D than the wild isolates. The Tc-D trypomastigotes were released from cells approximately 2 days later than wild isolate trypomastigotes, but twice the number were released. Growth rate for Tc-D epimastigotes in liver infusion tryptose media was faster than that of wild isolates. The doubling times for Tc-D, Tc-O, and Tc-A were 48.0, 69.0, and 67.4 hr, respectively. Soluble parasite extract was produced from epimastigotes of each isolate by freeze/thawing, sonication, and high-speed centrifugation. Proteins were separated on an SDS-PAGE slab gel and stained with Coomassie blue. Although similar bands were present in each preparation, the general pattern of staining was similar only between the Tc-O and Tc-A preparations, which showed some differences from the Tc-D preparation. Each isolate was zymodeme typed using 5 enzymes in lysates produced from epimastigotes of each isolate. Enzymes were separated electrophoretically and stained. Wild isolates showed similar patterns as zymodeme 1 reference stock, whereas the Tc-D isolate produced a pattern that did not resemble any of the reference stocks examined.
The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and ... more The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and B...
Trypanosoma cruzi isolates from a dog (Tc-D), opossum (Tc-O), and an armadillo (Tc-A) from southe... more Trypanosoma cruzi isolates from a dog (Tc-D), opossum (Tc-O), and an armadillo (Tc-A) from southern Louisiana were inoculated into 6 inbred mouse strains. None of the isolates produced fatal infections in the mouse strains tested. Parasitemias were quantified over 34 days and found to be similar in mouse strains infected with Tc-O and Tc-A. Parasitemias in Tc-D-infected mice were detectable only by blood culture. Pseudocyst numbers, inflammatory changes, and weight changes were quantified in CF1 mice infected with the 3 isolates. Tc-O- and Tc-A-infected CF1 mice were shown to be myotropic and produced comparable weight increases, pseudocyst numbers, and inflammatory changes in similar tissues. Tissues found to contain pseudocysts were muscles of the bladder, abdominal wall, thigh, heart, and diaphragm. Clinical signs of infection, pseudocyst numbers, and inflammatory changes were minimal in Tc-D-infected CF1 mice. Tissue tropism of this isolate was not determined. The in vivo infectivity characteristics of these isolates suggests that Tc-O and Tc-A are similar and differ markedly from Tc-D.
Advances in experimental medicine and biology, 1981
Complement profiles were tested in outbred (LVG) Syrian hamsters (Mesocricetus auratus) and compa... more Complement profiles were tested in outbred (LVG) Syrian hamsters (Mesocricetus auratus) and compared to the MHA, LHC, PD4, and CB inbred strains. The total C and C component concentrations in the sera varied among the strains and were in the following ranges in untreated animals (in CH50 units per ml): total C, 140-260 (undetectable in PD4 and CB); Cl, 14,000-25,000; C2, 200-800 (except PD 4 and CB); C3, 40,000 and 80,000; C4, 2,000-2,800 (except PD4 and CB); C4, 40,000-80,000; C6, 3,600-6,000 (undetectable in PD4 and CB); C7, 50,000-350,000; C8, 10,000-30,000; C9, 30,000-60,000. The PD4 and CB strains had undetectable total C and C6, and their exact C2 and C4 levels could not be determined, but were lower than in the other strains. The MHA strain had the highest total C levels, but had significantly lower (1/3 or less) C7 levels than the other strains of hamsters. Infection of hamsters with the filarid nematode Brugia pahangi for four to five months produced moderate decreases in t...
Host suitability, reproduction, effects of temperature on reproduction and pupal development, eff... more Host suitability, reproduction, effects of temperature on reproduction and pupal development, effects of humidity on pupal development and the effects of photoperoid on puparial deposition, pupal development and adult emergence were studied in a laboratory colony of Pseudolynchia canariensis. Flies were observed to lack strong host specificity. Puparia were produced at regular 24 h intervals by flies maintained at 30 °C, averaging 8·8 puparia per female. Optimum temperature for colony maintenance was observed to range between 26·6 and 30·0 °C. Temperatures of 13 and 37 °C were lethal to pupae. Humidity and photoperiod did not markedly affect pupal development. Puparial deposition and adult emergence occurred only during the photoperiod.
Parasitic nematodes produce an unusual class of fatty acid and retinol (FAR)-binding proteins tha... more Parasitic nematodes produce an unusual class of fatty acid and retinol (FAR)-binding proteins that may scavenge host fatty acids and retinoids. Two FARs from Brugia malayi (Bm-FAR-1 and Bm-FAR-2) were expressed as recombinant proteins, and their ligand binding, structural characteristics, and immunogenicities examined. Circular dichroism showed that rBm-FAR-1 and rBm-FAR-2 are similarly rich in α-helix structure. Unexpectedly, however, their lipid binding activities were found to be readily differentiated. Both FARs bound retinol and cis-parinaric acid similarly, but, while rBm-FAR-1 induced a dramatic increase in fluorescence emission and blue shift in peak emission by the fluorophore-tagged fatty acid (dansyl-undecanoic acid), rBm-FAR-2 did not. Recombinant forms of the related proteins from Onchocerca volvulus, rOv-FAR-1 and rOv-FAR-2, were found to be similarly distinguishable. This is the first FAR-2 protein from parasitic nematodes that is being characterized. The relative pro...
In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administr... more In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administration, although there is concern based on several factors that onchocerciasis cannot be eliminated solely through this approach. A vaccine against Onchocerca volvulus would provide a critical tool for the ultimate elimination of this infection. Previous studies have demonstrated that immunization of mice with Ov-103 and Ov-RAL-2, when formulated with alum, induced protective immunity. It was hypothesized that the levels of protective immunity induced with the two recombinant antigens formulated with alum would be improved by formulation with other adjuvants known to enhance different types of antigen-specific immune responses. Immunizing mice with Ov-103 and Ov-RAL-2 in conjunction with alum, Advax 2 and MF59 induced significant levels of larval killing and host protection. The immune response was biased towards Th2 with all three of the adjuvants, with IgG1 the dominant antibody. Improv...
Rates of trypomastigote adherence, interiorization, amastigote division in, and trypomastigote re... more Rates of trypomastigote adherence, interiorization, amastigote division in, and trypomastigote release from Vero cells were measured for Trypanosoma cruzi isolates from a dog (Tc-D), opossum (Tc-O), and an armadillo (Tc-A) from Louisiana. Because the Tc-O and Tc-A (wild isolates) trypomastigotes became interiorized rapidly, the media were quickly depleted of trypomastigotes thus reducing the numbers available to adhere to cells. In contrast, the Tc-D trypomastigote interiorization rate was slower. Intracellular amastigote division rate was slower for the Tc-D than the wild isolates. The Tc-D trypomastigotes were released from cells approximately 2 days later than wild isolate trypomastigotes, but twice the number were released. Growth rate for Tc-D epimastigotes in liver infusion tryptose media was faster than that of wild isolates. The doubling times for Tc-D, Tc-O, and Tc-A were 48.0, 69.0, and 67.4 hr, respectively. Soluble parasite extract was produced from epimastigotes of each isolate by freeze/thawing, sonication, and high-speed centrifugation. Proteins were separated on an SDS-PAGE slab gel and stained with Coomassie blue. Although similar bands were present in each preparation, the general pattern of staining was similar only between the Tc-O and Tc-A preparations, which showed some differences from the Tc-D preparation. Each isolate was zymodeme typed using 5 enzymes in lysates produced from epimastigotes of each isolate. Enzymes were separated electrophoretically and stained. Wild isolates showed similar patterns as zymodeme 1 reference stock, whereas the Tc-D isolate produced a pattern that did not resemble any of the reference stocks examined.
The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and ... more The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and B...
Trypanosoma cruzi isolates from a dog (Tc-D), opossum (Tc-O), and an armadillo (Tc-A) from southe... more Trypanosoma cruzi isolates from a dog (Tc-D), opossum (Tc-O), and an armadillo (Tc-A) from southern Louisiana were inoculated into 6 inbred mouse strains. None of the isolates produced fatal infections in the mouse strains tested. Parasitemias were quantified over 34 days and found to be similar in mouse strains infected with Tc-O and Tc-A. Parasitemias in Tc-D-infected mice were detectable only by blood culture. Pseudocyst numbers, inflammatory changes, and weight changes were quantified in CF1 mice infected with the 3 isolates. Tc-O- and Tc-A-infected CF1 mice were shown to be myotropic and produced comparable weight increases, pseudocyst numbers, and inflammatory changes in similar tissues. Tissues found to contain pseudocysts were muscles of the bladder, abdominal wall, thigh, heart, and diaphragm. Clinical signs of infection, pseudocyst numbers, and inflammatory changes were minimal in Tc-D-infected CF1 mice. Tissue tropism of this isolate was not determined. The in vivo infectivity characteristics of these isolates suggests that Tc-O and Tc-A are similar and differ markedly from Tc-D.
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