William A. Knaus, MD

William A. Knaus, MD

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Biomarkers identified by data-mining and statistics

The Knaus translational research team utilizes tools of cell biology, molecular biology, and immunology in a concerted effort with complex data mining and advanced statistics to understand the relationship between a patient's health history and biomarkers identified through an examination of their neoplastic clinical isolates.  The major focus of this research is on the gene and protein expression of key activated lymphocyte populations (CD4+ T cells, CD8+ T cells, and dendritic cells) that have been isolated from patients with Stage III and Stage IV metastatic melanoma.  In a collaborative effort with the Human Immune Therapy Center (Mullins et al., 2004), a novel association between T cell expression of the surface marker CXCR3 (a molecule that directs T cells to exit circulation at sites of inflammation or tumor growth) and significantly enhanced survival was demonstrated in patients with advanced disease.  Ongoing collaborative studies will assess vaccine strategies that specifically induce T cell expression of CXCR3, which may ultimately improve prognosis.

A second, and ongoing, research focus of the team is a systematic analysis of gene expression from isolated lymphocyte subpopulations of long-term survivor and rapid-progressor melanoma patients using oligo microarrays.  Because microarrays provide a snap-shot of all of the genes that are expressed at the moment of RNA isolation, a significant task for the team has been methodological development: obtaining pure lymphocyte subpopulations, isolating total RNA from small amounts of tissue, and amplifying that RNA for gene chip hybridization.  In collaboration with the Flow Cytometry Core Facility, live cells are sorted using BL-2 containment from snap-frozen patient tissue in order to obtain homogeneous samples that are as close to the real microenvironment found in the patient as possible.  The patterns of gene expression obtained from these groups (UVA BRF Gene Chip Core) should provide a more global immunological understanding as to why some patients with advanced melanoma survive for extended periods while others succumb quickly.

CXC Chemokine receptor 3 Expression by Activated CD8+ T Cells is Associated with Survival in Melanoma Patients with Stage III Disease. Cancer Research. 64,7697-7701, November 1, 2004.