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163 results on '"Johnson, Wendell C."'

12. Comparison of high throughput RNA sequences between Babesia bigemina and Babesia bovis revealed consistent differential gene expression that is required for the Babesia life cycle in the vertebrate and invertebrate hosts

Author

Capelli-Peixoto, Janaina, primary, Saelao, Perot, additional, Johnson, Wendell C., additional, Kappmeyer, Lowell, additional, Reif, Kathryn E., additional, Masterson, Hayley E., additional, Taus, Naomi S., additional, Suarez, Carlos E., additional, Brayton, Kelly A., additional, and Ueti, Massaro W., additional

Published
2022
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13. Thrombospondin-Related Anonymous Protein (TRAP) Family Expression by Babesia bovis Life Stages within the Mammalian Host and Tick Vector

Author

Masterson, Hayley E., primary, Taus, Naomi S., additional, Johnson, Wendell C., additional, Kappmeyer, Lowell, additional, Capelli-Peixoto, Janaina, additional, Hussein, Hala E., additional, Mousel, Michelle R., additional, Hernandez-Silva, Diego J., additional, Laughery, Jacob M., additional, Mosqueda, Juan, additional, and Ueti, Massaro W., additional

Published
2022
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27. First report of Anaplasma marginale infection in goats, Brazil

Author

da Silva, Nayara B., primary, Taus, Naomi S., additional, Johnson, Wendell C., additional, Mira, Anabela, additional, Schnittger, Leonhard, additional, Valente, Jessica D. M., additional, Vidotto, Odilon, additional, Masterson, Hayley E., additional, Vieira, Thállitha S. W. J., additional, Ueti, Massaro W., additional, and Vieira, Rafael F. C., additional

Published
2018
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29. The Babesia bovis hap2 gene is not required for blood stage replication, but expressed upon in vitro sexual stage induction

Author

Hussein, Hala E., primary, Bastos, Reginaldo G., additional, Schneider, David A., additional, Johnson, Wendell C., additional, Adham, Fatma K., additional, Davis, William C., additional, Laughery, Jacob M., additional, Herndon, David R., additional, Alzan, Heba F., additional, Ueti, Massaro W., additional, and Suarez, Carlos E., additional

Published
2017
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34. Loss of Immunization-Induced Epitope-Specific CD4 T-Cell Response following Anaplasma marginale Infection Requires Presence of the T-Cell Epitope on the Pathogen and Is Not Associated with an Increase in Lymphocytes Expressing Known Regulatory Cell Phenotypes

Author

Brown, Wendy C., primary, Turse, Joshua E., additional, Lawrence, Paulraj K., additional, Johnson, Wendell C., additional, Scoles, Glen A., additional, Deringer, James R., additional, Sutten, Eric L., additional, Han, Sushan, additional, and Norimine, Junzo, additional

Published
2015
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39. Validation of a competitive enzyme-linked immunosorbent assay for detection of antibodies against Babesia bovis

Author

Goff, Will L., Molloy, John B., Johnson, Wendell C., Suarez, Carlos E., Pino, Ignacio, Rhalem, Abdelkebir, Sahibi, Hamid, Ceci, Luigi, Carelli, Grazia, Addams, D. Scott, McGuire, Travis C., Knowles, Donald P., McElwain, Terry F., Goff, Will L., Molloy, John B., Johnson, Wendell C., Suarez, Carlos E., Pino, Ignacio, Rhalem, Abdelkebir, Sahibi, Hamid, Ceci, Luigi, Carelli, Grazia, Addams, D. Scott, McGuire, Travis C., Knowles, Donald P., and McElwain, Terry F.

Abstract

A previously developed competitive enzyme-linked immunosorbent assay (cELISA) based on a species-specific, broadly conserved, and tandemly repeated B-cell epitope within the C terminus of rhoptry-associated protein 1 of Babesia bovis was refined and validated for use internationally. Receiver operating characteristic analysis revealed an assay with a specificity and positive predictive value of 100% and a sensitivity of 91.1%, with various negative predictive values depending on the level of disease prevalence. The cELISA was distributed to four different laboratories, along with a reference set of 100 defined bovine sera, including known-positive, known-negative, and field samples. Pairwise concordances among the four laboratories ranged from 94% to 88%. Analysis of variance of the resulting optical densities and a test of homogeneity indicated no significant difference among the laboratories. Overall, the cELISA appears to have the attributes necessary for international application.

Published
2006

40. Validation of a Competitive Enzyme-Linked Immunosorbent Assay for Detection of Babesia bigemina Antibodies in Cattle

Author

Goff, Will L., primary, Johnson, Wendell C., additional, Molloy, John B., additional, Jorgensen, Wayne K., additional, Waldron, Susan J., additional, Figueroa, Julio V., additional, Matthee, Olivier, additional, Adams, D. Scott, additional, McGuire, Travis C., additional, Pino, Ignacio, additional, Mosqueda, Juan, additional, Palmer, Guy H., additional, Suarez, Carlos E., additional, Knowles, Donald P., additional, and McElwain, Terry F., additional

Published
2008
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41. Validation of a Competitive Enzyme-Linked Immunosorbent Assay for Detection of Antibodies against Babesia bovis

Author

Goff, Will L., primary, Molloy, John B., additional, Johnson, Wendell C., additional, Suarez, Carlos E., additional, Pino, Ignacio, additional, Rhalem, Abdelkebir, additional, Sahibi, Hamid, additional, Ceci, Luigi, additional, Carelli, Grazia, additional, Adams, D. Scott, additional, McGuire, Travis C., additional, Knowles, Donald P., additional, and McElwain, Terry F., additional

Published
2006
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45. Analysis of Stage-Specific Protein Expression during Babesia BovisDevelopment within Female Rhipicephalus Microplus

Author

Johnson, Wendell C., Taus, Naomi S., Reif, Kathryn E., Bohaliga, Gamila A.R., Kappmeyer, Lowell S., and Ueti, Massaro W.

Abstract

Arthropod-borne protozoan pathogens have a complex life cycle that includes asexual reproduction of haploid stages in mammalian hosts and the development of diploid stages in invertebrate hosts. The ability of pathogens to invade, survive, and replicate within distinct cell types is required to maintain their life cycle. In this study, we describe a comparative proteomic analysis of a cattle pathogen, Babesia bovis, during its development within the mammalian and tick hosts with the goal of identifying cell-surface proteins expressed by B. boviskinetes as potential targets for the development of a transmission blocking vaccine. To determine parasite tick-stage-specific cell-surface proteins, CyDye labeling was performed with B. bovisblood stages from the bovine host and kinetes from the tick vector. Cell-surface kinete-stage-specific proteins were identified using 2D difference in gel electrophoresis and analyzed by mass spectrometry. Ten proteins were identified as kinete-stage-specific, with orthologs found in closely related Apicomplexan pathogens. Transcriptional analysis revealed two genes were highly expressed by kinetes as compared with blood stages. Immunofluorescence using antibodies against the two proteins confirmed kinete-stage-specific expression. The identified cell-surface kinete proteins are potential candidates for the development of a B. bovistransmission blocking vaccine.

Published
2017
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46. Loss of Immunization-Induced Epitope-Specific CD4 T-Cell Response following Anaplasma marginaleInfection Requires Presence of the T-Cell Epitope on the Pathogen and Is Not Associated with an Increase in Lymphocytes Expressing Known Regulatory Cell Phenotypes

Author

Brown, Wendy C., Turse, Joshua E., Lawrence, Paulraj K., Johnson, Wendell C., Scoles, Glen A., Deringer, James R., Sutten, Eric L., Han, Sushan, and Norimine, Junzo

Abstract

ABSTRACTWe have shown that in cattle previously immunized with outer membrane proteins, infection with Anaplasma marginaleinduces a functionally exhausted CD4 T-cell response to the A. marginaleimmunogen. Furthermore, T-cell responses following infection in nonimmunized cattle had a delayed onset and were sporadic and transient during persistent infection. The induction of an exhausted T-cell response following infection presumably facilitates pathogen persistence. In the current study, we hypothesized that the loss of epitope-specific T-cell responses requires the presence of the immunizing epitope on the pathogen, and T-cell dysfunction correlates with the appearance of regulatory T cells. In limited studies in cattle, regulatory T cells have been shown to belong to ?d T-cell subsets rather than be CD4 T cells expressing forkhead box protein P3 (FoxP3). Cattle expressing the DRB3*1101 haplotype were immunized with a truncated A. marginalemajor surface protein (MSP) 1a that contains a DRB3*1101-restricted CD4 T-cell epitope, F2-5B. Cattle either remained unchallenged or were challenged with A. marginalebacteria that express the epitope or with A. marginalesubsp. centralethat do not. Peripheral blood and spleen mononuclear cells were monitored for MSP1a epitope F2-5B-specfic T-cell proliferative responses and were stained for ?d T-cell subsets or CD4+CD25+FoxP3+T cells before and during infection. As hypothesized, the induction of T-cell exhaustion occurred only following infection with A. marginale, which did not correlate with an increase in either CD4+CD25+FoxP3+T cells or any ?d T-cell subset examined.

Published
2015
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47. Lymphocytes and Macrophages Are Infected by Theileria equi, but T Cells and B Cells Are Not Required to Establish Infection In Vivo.

Author

Ramsay, Joshua D., Ueti, Massaro W., Johnson, Wendell C., Scoles, Glen A., Knowles, Donald P., and Mealey, Robert H.

Subjects
HORSES, LYMPHOCYTES, MACROPHAGES, THEILERIA, T cells, B cells, LEUKOCYTES, ERYTHROCYTES
Abstract

Theileria equi has a biphasic life cycle in horses, with a period of intraleukocyte development followed by patent erythrocytic parasitemia that causes acute and sometimes fatal hemolytic disease. Unlike Theileria spp. that infect cattle (Theileria parva and Theileria annulata), the intraleukocyte stage (schizont) of Theileria equi does not cause uncontrolled host cell proliferation or other significant pathology. Nevertheless, schizont-infected leukocytes are of interest because of their potential to alter host cell function and because immune responses directed against this stage could halt infection and prevent disease. Based on cellular morphology, Theileria equi has been reported to infect lymphocytes in vivo and in vitro, but the specific phenotype of schizont-infected cells has yet to be defined. To resolve this knowledge gap in Theileria equi pathogenesis, peripheral blood mononuclear cells were infected in vitro and the phenotype of infected cells determined using flow cytometry and immunofluorescence microscopy. These experiments demonstrated that the host cell range of Theileria equi was broader than initially reported and included B lymphocytes, T lymphocytes and monocyte/macrophages. To determine if B and T lymphocytes were required to establish infection in vivo, horses affected with severe combined immunodeficiency (SCID), which lack functional B and T lymphocytes, were inoculated with Theileria equi sporozoites. SCID horses developed patent erythrocytic parasitemia, indicating that B and T lymphocytes are not necessary to complete the Theileria equi life cycle in vivo. These findings suggest that the factors mediating Theileria equi leukocyte invasion and intracytoplasmic differentiation are common to several leukocyte subsets and are less restricted than for Theileria annulata and Theileria parva. These data will greatly facilitate future investigation into the relationships between Theileria equi leukocyte tropism and pathogenesis, breed susceptibility, and strain virulence. [ABSTRACT FROM AUTHOR]

Published
2013
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48. A Divergent Artiodactyl MYADM-like Repeat Is Associated with Erythrocyte Traits and Weight of Lamb Weaned in Domestic Sheep.

Author

Gonzalez, Michael V., Mousel, Michelle R., Herndon, David R., Jiang, Yu, Dalrymple, Brian P., Reynolds, James O., Johnson, Wendell C., Herrmann-Hoesing, Lynn M., and White, Stephen N.

Subjects
ARTIODACTYLA microbiology, ERYTHROCYTES, DOMESTIC animals, SHEEP as laboratory animals, INFANT weaning, GENOMES, SINGLE nucleotide polymorphisms
Abstract

A genome-wide association study (GWAS) was performed to investigate seven red blood cell (RBC) phenotypes in over 500 domestic sheep (Ovis aries) from three breeds (Columbia, Polypay, and Rambouillet). A single nucleotide polymorphism (SNP) showed genome-wide significant association with increased mean corpuscular hemoglobin concentration (MCHC, P = 6.2×10−14) and genome-wide suggestive association with decreased mean corpuscular volume (MCV, P = 2.5×10−6). The ovine HapMap project found the same genomic region and the same peak SNP has been under extreme historical selective pressure, demonstrating the importance of this region for survival, reproduction, and/or artificially selected traits. We observed a large (>50 kb) variant haplotype sequence containing a full-length divergent artiodactyl MYADM-like repeat in strong linkage disequilibrium with the associated SNP. MYADM gene family members play roles in membrane organization and formation in myeloid cells. However, to our knowledge, no member of the MYADM gene family has been identified in development of morphologically variant RBCs. The specific RBC differences may be indicative of alterations in morphology. Additionally, erythrocytes with altered morphological structure often exhibit increased structural fragility, leading to increased RBC turnover and energy expenditure. The divergent artiodactyl MYADM-like repeat was also associated with increased ewe lifetime kilograms of lamb weaned (P = 2×10−4). This suggests selection for normal RBCs might increase lamb weights, although further validation is required before implementation in marker-assisted selection. These results provide clues to explain the strong selection on the artiodactyl MYADM-like repeat locus in sheep, and suggest MYADM family members may be important for RBC morphology in other mammals. [ABSTRACT FROM AUTHOR]

Published
2013
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49. Differential Expression of Three Members of the Multidomain Adhesion CCp Family in Babesia bigemina, Babesia bovis and Theileria equi.

Author

Bastos, Reginaldo G., Suarez, Carlos E., Laughery, Jacob M., Johnson, Wendell C., Ueti, Massaro W., and Knowles, Donald P.

Subjects
GENE expression, BABESIA bigemina, BABESIA, THEILERIA, GERM cells, APICOMPLEXA, COMPUTATIONAL biology, PROTOZOOLOGY, VETERINARY medicine
Abstract

Members of the CCp protein family have been previously described to be expressed on gametocytes of apicomplexan Plasmodium parasites. Knocking out Plasmodium CCp genes blocks the development of the parasite in the mosquito vector, making the CCp proteins potential targets for the development of a transmission-blocking vaccine. Apicomplexans Babesia bovis and Babesia bigemina are the causative agents of bovine babesiosis, and apicomplexan Theileria equi causes equine piroplasmosis. Bovine babesiosis and equine piroplasmosis are the most economically important parasite diseases that affect worldwide cattle and equine industries, respectively. The recent sequencing of the B. bovis and T. equi genomes has provided the opportunity to identify novel genes involved in parasite biology. Here we characterize three members of the CCp family, named CCp1, CCp2 and CCp3, in B. bigemina, B. bovis and T. equi. Using B. bigemina as an in vitro model, expression of all three CCp genes and proteins was demonstrated in temperature-induced sexual stages. Transcripts for all three CCp genes were found in vivo in blood stages of T. equi, and transcripts for CCp3 were detected in vivo in blood stages of B. bovis. However, no protein expression was detected in T. equi blood stages or B. bovis blood stages or B. bovis tick stages. Collectively, the data demonstrated a differential pattern of expression of three orthologous genes of the multidomain adhesion CCp family by B. bigemina, B. bovis and T. equi. The novel CCp members represent potential targets for innovative approaches to control bovine babesiosis and equine piroplasmosis. [ABSTRACT FROM AUTHOR]

Published
2013
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50. Validation of a Competitive Enzyme-Linked Immunosorbent Assay for Detection of Babesia bigeminaAntibodies in Cattle

Author

Goff, Will L., Johnson, Wendell C., Molloy, John B., Jorgensen, Wayne K., Waldron, Susan J., Figueroa, Julio V., Matthee, Olivier, Adams, D. Scott, McGuire, Travis C., Pino, Ignacio, Mosqueda, Juan, Palmer, Guy H., Suarez, Carlos E., Knowles, Donald P., and McElwain, Terry F.

Abstract

ABSTRACTA competitive enzyme-linked immunosorbent assay (cELISA) based on a broadly conserved, species-specific, B-cell epitope within the C terminus of Babesia bigeminarhoptry-associated protein 1a was validated for international use. Receiver operating characteristic analysis revealed 16% inhibition as the threshold for a negative result, with an associated specificity of 98.3% and sensitivity of 94.7%. Increasing the threshold to 21% increased the specificity to 100% but modestly decreased the sensitivity to 87.2%. By using 21% inhibition, the positive predictive values ranged from 90.7% (10% prevalence) to 100% (95% prevalence) and the negative predictive values ranged from 97.0% (10% prevalence) to 48.2% (95% prevalence). The assay was able to detect serum antibody as early as 7 days after intravenous inoculation. The cELISA was distributed to five different laboratories along with a reference set of 100 defined bovine serum samples, including known positive, known negative, and field samples. The pairwise concordance among the five laboratories ranged from 100% to 97%, and all kappa values were above 0.8, indicating a high degree of reliability. Overall, the cELISA appears to have the attributes necessary for international application.

Published
2008
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