Valley Fever: MS Based Diagnostics and Potential Vaccine Characterization

摘要

Coccidioidomycosis (Valley Fever) is a disease endemic to the Southwestern United States and Mexico. It is caused by the fungal pathogens Coccidioides immitis or C. posadasii. The pathogen is normally cleared in immunocompetent subjects; however immunocompromised subjects are at substantial risk for disease and disseminated infections. Available diagnostics are ～50% false negative, and a more robust diagnostic is desired. Also, a vaccine would help to alleviate the burden of Valley Fever. Described herein are the steps toward a mass spectrometry based diagnostic for Valley Fever and progress toward characterizing a potential vaccine candidate, Antigen 2/PRA. Diagnostic Development: Swiss Webster mice (SW) were administered ～500 spores intranasally and sacrificed 12 days post infection. Bronchoalveolar lavage fluid (BAL), lung homogenate (LH) and plasma samples were obtained and examined via proteomics based procedures utilizing Thermo Orbitrap Velos and Elite mass spectrometers. Both directed and undirected runs were used to observe three previously identified proteins, TP1, TP2 and TP3. Figure 1 shows the identification in-gel digest samples using a directed approach with an Orbitrap Elite. Identifications are found at the 10 ng / 50 ug host protein spike level. Two lower spikes, 1 and 0.1 ng/ 50 ug host protein were also performed; however target proteins were not identified at this level.