Abstract Details

Title Proteome-wide Humoral Immune Profiling in Central Nervous System Coccidioidomycosis Using Programmable Phage Display

Topic Infectious Disease

Presentation(s) S25 - Diagnostics and Therapies in Infectious Diseases (4:06 PM-4:18 PM)

Poster/Presentation
Number 004

Background Valley Fever is caused by inhalation of the soil-based fungus Coccidioides, which is endemic to the southwestern U.S. Most infections are asymptomatic, but 5-10% result in chronic complications, and sometimes death. CNS dissemination often necessitates surgical interventions and lifelong anti-fungal therapy. Because few Coccidioides antigens are known a) current diagnostic assays are variably sensitive and specific, b) vaccine design efforts are limited, and c) differences in the humoral immune response between patients with and without disseminated disease are unknown.

Objective

Comprehensively assess the humoral immune response to Coccidioides infection using a new high-resolution, proteome-wide antibody profiling assay in patients with and without coccidioidal meningitis.

Design/Methods

Known protein and predicted protein coding regions of the C. immitis and C. posadasii genomes were computationally tiled into overlapping 50 amino acid segments and collapsed on 95% sequence similarity. Oligonucleotides were synthesized, cloned, and packaged into T7 bacteriophage so the encoded peptides would be displayed on the phage surface. Multiple rounds of immunoprecipitation with patient-matched cerebrospinal fluid (CSF) and serum were performed (n=20 patients), and immunoprecipitated phage were sequenced. Peptides were counted by aligning sequences to the synthetic Coccidioides peptide library. Peptide enrichment was calculated relative to uninfected and no template controls.

Results

To assess the quality of the new Coccidioides phage display library, the library was sequenced. On average, 94% of the 202,919 designed Coccidioides peptides were displayed. Preliminary immunoprecipitations with coccidioidal meningitis CSF enriched multiple proteins, including two known extracellular antigens: SOWgp and a CFEM domain containing extracellular membrane protein.

Conclusions We successfully designed and built a new assay that enables agnostic anti-Coccidioides antibody profiling. In preliminary experiments, we validated the immunogenicity of two Coccidioides cell surface proteins and anticipate future experiments will provide significant insights into the humoral response to coccidioidomycosis, especially in patients with CNS disseminated disease.

Authors/Disclosures
Christine Boutros PRESENTER	The institution of Ms. Boutros has received research support from NIH.
Ravi Dandekar	No disclosure on file
Mark Voorhies (UCSF)	No disclosure on file
Christina Homer (UCSF)	No disclosure on file
George Thompson (George Thompson, Professor of Medicine)	No disclosure on file
Satya Dandekar (UC Davis)	No disclosure on file
Anita Sil (UCSF)	No disclosure on file
Michael R. Wilson, MD, FAAN (University of California San Francisco)	Dr. Wilson has received personal compensation in the range of $10,000-$49,999 for serving as an officer or member of the Board of Directors for Delve Bio. Dr. Wilson has stock in Delve Bio. The institution of Dr. Wilson has received research support from Genentech / Roche. The institution of Dr. Wilson has received research support from NIH. The institution of Dr. Wilson has received research support from UCSF Weill Institute for Neurosciences. The institution of Dr. Wilson has received research support from Novartis. The institution of Dr. Wilson has received research support from National Multiple Sclerosis Society. The institution of Dr. Wilson has received research support from Fanconi Anemia Research Foundation. The institution of Dr. Wilson has received research support from Department of Defense. Dr. Wilson has received intellectual property interests from a discovery or technology relating to health care. Dr. Wilson has received intellectual property interests from a discovery or technology relating to health care. Dr. Wilson has received personal compensation in the range of $10,000-$49,999 for serving as a Expert Witness with US Dept of Justice.