Using circulating molecular biomarkers to screen for cancer and other debilitating disorders in a high-throughput and low-cost fashion is becoming increasingly attractive in medicine. One major limitation of investigating protein biomarkers in body fluids is that only one-fourth of the entire proteome can be routinely detected in these fluids. In contrast, Human Leukocyte Antigen (HLA) presents peptides from the entire proteome on the cell surface. While peptide-HLA complexes are predominantly membrane-bound, a fraction of HLA molecules is released into body fluids which is referred to as soluble HLAs (sHLAs). Recent developments in mass spectrometry (MS)-based proteomics have enabled the acquisition of ever smaller input amounts and therefore enabling valuable information to be extracted out of the peptidome of these circulating sHLA.
In this poster we will describe the findings of the method optimization to unravel the potential of sHLA as a source of circular biomarkers using low input volume of plasma.