The Immunomodulation of Macrophages by tumor cells (2016)
Undergraduates: Charlotte Story, Eric Ubil
Faculty Advisor: Shelton Earp
Department: Biology
Macrophages are immune cells that can either activate or suppress the human immune system, depending on the needs of the body. Macrophages cycle, in a regulated fashion, through these two major states. When the body is under attack, the M1 state prevails. An M1 macrophage promotes immune response and inhibits tumor progression. The M2 macrophage promotes creation of new blood vessels and suppresses the immune system: this M2 stage can promote cancer growth. Ideally, an M1-stage macrophage would recognize a tumor cell, activate the immune system, and the immune system would work to destroy the tumor. However, cancerous tumors have a mechanism for neutralizing the M1 macrophage response, and have even been shown to hijack the macrophage machinery in order to promote their own growth. Thus tumor cells can reset the immune-activating response in macrophages.
Previous studies demonstrate that Pros1, a protein secreted by the tumor, plays a role in inhibiting macrophage immune response. Interferon-¿¿ and Lipopolysaccharide are used to turn on M1 macrophage genes IL-1 and IL-6, which are immune-activating genes. Media were harvested from plates of melanoma cell line B16F10. This media was hypothesized to contain a secreted molecule that suppressed the activation of M1 macrophages genes, based on previous results. Adding Pros1 in a bead vector further decreased macrophage M1 activation. Adding the membrane phospholipid phosphatidylserine also decreased macrophage M1 activation.