Immune Responses To Antigen-Bearing Dendritic Cells in Patients With Malignancy

Cancer cells make proteins called antigens that act as markers for the tumor cells. These antigens cannot cause the cancer itself. Special white blood cells, called T cells or T lymphocytes, recognize and respond to antigens. In many diseases, these and other cells in the immune system help your body get rid of the disease. However, T cells are normally resting, and they need other proteins on the diseased cell surface to begin working. Unfortunately, cancer cells do not usually make all the other proteins that T cells need to work. Therefore, T cells do not normally work against the cancer cells. We think this is one of the reasons that cancers grow and are not rejected by the body in the first place. Another white blood cell, called a dendritic cell, does have most if not all of the special proteins needed to make T cells work to destroy cancer cells. However, dendritic cells do not normally have the cancer proteins on their surface. The challenge then is to combine the cancer markers (antigens) with these dendritic cells to make a vaccine. We think that the body's T cells might then react against the tumor and help destroy it. This study will see if putting tumor antigens made in a lab onto dendritic cells will make T cells work against tumor cells. We want to answer this question by injecting you with dendritic cells loaded with the antigens. Then we will check for a response based on lab studies and your own clinical course. We will compare your response against melanoma with your response against a common antigen, to which almost everyone has already been exposed. Flu, for example, is a common antigen to which most people have been exposed. We also need to test your response to an antigen that your body has not likely seen before. For example, we plan to use KLH (keyhole limpet hemocyanin), which is a pigment or color protein made from a sea creature known as a keyhole limpet. Each of these, the flu and KLH antigens, which should be harmless to you, will be used along with the dendritic cell-tumor vaccine. This will help us find out if the vaccine is working, based on the lab studies we will check before and after the vaccinations.