Immune dysfunction in cancer patients.
Immune deficiency in cancer patients is well documented, and tumor cells have developed a variety of cellular and molecular mechanisms to avoid antitumor immune responses. These mechanisms include defective presentation of tumor antigens on the cell surface and/or an inability of the host to effectively recognize these cells and target them for destruction. Tumor-induced defects are known to occur in all major branches of the immune system. The continuous administration of vascular endothelial growth factor (VEGF), a factor produced by most solid tumors, inhibits the functional maturation of dendritic cells, significantly decreases T-cell to B-cell ratios in the peripheral lymphoid organs, and induces rapid and dramatic thymic atrophy in tumor-bearing animals. VEGF is abundantly expressed by a large percentage of solid tumors, and defective antigen presentation, T-cell defects, and premature thymic atrophy are known to occur in cancer patients and tumor-bearing animals. This review will encompass the major mechanisms responsible for tumor evasion of immune surveillance and highlight a role for VEGF as a principal contributor to tumor-associated immune deficiencies.
Ohm
Joyce E
JE
Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
Carbone
David P
DP
D017951:Antigen Presentation / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D016228:Endothelial Growth Factors / Q000502:physiology; D006801:Humans; D007107:Immune System / Q000502:physiology; D007154:Immune System Diseases / Q000276:immunology*; D008222:Lymphokines / Q000502:physiology; D009369:Neoplasms / Q000276:immunology* / Q000628:therapy; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors