Coccidioides spp. are fungal pathogens that normally causes a pneumonia associated with considerable morbidity and attendant economic or medical care costs. Some infections produce respiratory failure, soft tissue abscesses, osteomyelitis or meningitis. Even in otherwise healthy persons, inhalation of a single spore is sufficient to result in death from one or more of these complications, and this degree of infectivity was responsible, in part, for past development programs by the U.S. and the Soviet Union to use Coccidioides spp. as biological weapons. Coccidioides spp., recently classified as Category C agents by NIAID, are also considered emerging public health pathogens. Because coccidioidal infection so often produces life-long protection against reinfection, it is likely that a preventative vaccine could be effective. A screening program of approximately two dozen coccidioidal proteins identified a recombinant vaccine that was recommended for clinical trials. However, manufacturing difficulties related to the antigen's specific sequence has impeded its further development. In this project, we shall use in vitro protein expression to permit antigen screening on a larger scale as a means of identifying equally protective antigens that are more amenable to formulation. A proteomic analysis of spherule cell walls has identified 650 proteins and of these we shall screen approximately 1,000 exons with the least similarity to mammalian proteins, using first seroreactivity and subsequently reactivity of lymphocytes from mice previously infected with Coccidioides or immunized with protective whole cell vaccines. Our goal is to identify a second-generation recombinant vaccine candidate that could be developed for clinical testing. This project will also use tandem mass spectrometry to develop antigen-detecting assays as a more sensitive diagnostic for early Valley Fever. We have recently detected in the lungs of infected mice dozens of coccidioidal proteins. Three of these have no similarity to mammalian proteins and <45% similarity to other fungal proteins. We shall express these biosignature targets by recombinant methods and use the purified proteins to raise high-affinity antibodies. Tandem mass spectrometry will also be used to characterize the strength and specificity of antigen-antibody interactions to serve as independent analyses for the rational and optimal design of direct fluorescent staining or ELISA methods to detect antigens in clinical specimens.
A protective vaccine against coccidioidomycosis could be used to prevent this disease in the general public. A more sensitive diagnostic test would also be an advance in distinguishing Valley Fever pneumonia from pneumonia from other causes since current antibody tests are falsely negative in half of first blood tests.
|Tsai, Wen-Yang; Youn, Han Ha; Tyson, Jasmine et al. (2018) Use of Urea Wash ELISA to Distinguish Zika and Dengue Virus Infections. Emerg Infect Dis 24:1355-1359|
|Thongsripong, Panpim; Chandler, James Angus; Green, Amy B et al. (2018) Mosquito vector-associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod-borne diseases. Ecol Evol 8:1352-1368|
|Katzelnick, Leah C; Ben-Shachar, Rotem; Mercado, Juan Carlos et al. (2018) Dynamics and determinants of the force of infection of dengue virus from 1994 to 2015 in Managua, Nicaragua. Proc Natl Acad Sci U S A 115:10762-10767|
|Clemens, Daniel L; Lee, Bai-Yu; Horwitz, Marcus A (2018) The Francisella Type VI Secretion System. Front Cell Infect Microbiol 8:121|
|Huwyler, Camille; Heiniger, Nadja; Chomel, Bruno B et al. (2017) Dynamics of Co-Infection with Bartonella henselae Genotypes I and II in Naturally Infected Cats: Implications for Feline Vaccine Development. Microb Ecol 74:474-484|
|Norris, Michael H; Heacock-Kang, Yun; Zarzycki-Siek, Jan et al. (2017) Burkholderia pseudomallei natural competency and DNA catabolism: Identification and characterization of relevant genes from a constructed fosmid library. PLoS One 12:e0189018|
|Marques, Adriana R; Yang, Xiuli; Smith, Alexis A et al. (2017) Citrate Anticoagulant Improves the Sensitivity of Borreliella (Borrelia) burgdorferi Plasma Culture. J Clin Microbiol 55:3297-3299|
|Nualnoi, Teerapat; Norris, Michael H; Tuanyok, Apichai et al. (2017) Development of Immunoassays for Burkholderia pseudomallei Typical and Atypical Lipopolysaccharide Strain Typing. Am J Trop Med Hyg 96:358-367|
|Parameswaran, Poornima; Wang, Chunling; Trivedi, Surbhi Bharat et al. (2017) Intrahost Selection Pressures Drive Rapid Dengue Virus Microevolution in Acute Human Infections. Cell Host Microbe 22:400-410.e5|
|Bortell, Nikki; Flynn, Claudia; Conti, Bruno et al. (2017) Osteopontin Impacts West Nile virus Pathogenesis and Resistance by Regulating Inflammasome Components and Cell Death in the Central Nervous System at Early Time Points. Mediators Inflamm 2017:7582437|
Showing the most recent 10 out of 467 publications