11.32 - Immunomodulation and the Risk for Neoplasia

Abstract

The immune system and cancer are intimately linked in a biological duel in which each attempts to eliminate the other. Cancer is a set of diseases where multiple mutations in a signaling pathway lead to uncontrolled proliferation. These mutations may arise from spontaneous or induced mechanisms and are often fixed into the genome by situations where proliferation is driven to completion before normal repair systems can remove the mutation. This forced proliferation leads to additional mutations, some of which can lead to abnormal changes in cell surface proteins. These can be recognized by the immune system as not-self and can lead to activation of the immune system. Some would-be tumors are eliminated by the immune system but in some cases the tumor develops ways to inhibit or avoid the immune system. We will discuss a brief overview of the current knowledge about the biology of cancer. This will be followed by a short- and high-level review of the immune system with emphasis on those components more directly involved in antitumor defense. Finally we will examine how infections and xenobiotics may affect the interaction between the immune system and neoplasia.