A network of vessels, tissues, and organs in vertebrate animals that helps the body regulate fluid balance and fight against disease. The vessels of the lymphatic system drain excess fluid (called lymph) from the tissues and return it to the circulating blood. Lymphocytes circulate throughout the lymphatic system. A network of vessels that return lymph from body tissues to blood and filter out harmful particles on the way.
HIV infects cells in the central nervous system and the immune system. HIV's main target cell is the T helper lymphocyte. These cells play a crucial role in the immune system, by coordinating the actions of other immune system cells.A large reduction in the number of T helper cells seriously weakens the immune system.he Human Immunodeficiency Virus (HIV) seems to only infect the CD4 (or T-helper) cells of the immune system. The CD4 cells are responsible for activating and directing other â¦ immune system cells.
î î î. What is the role of antigen presenting cells? Name three antigen presenting cells. Describe the role of dendritic cells, the cell surface molecules that are constitutively expressed, and the tissue distribution. Explain why dendritic cells can be targets for HIV infection. Explain why macrophages are not particularly effective as antigen ...ole of APCs is to deliver antigen to CD4+ T cells-Dendritic cells (most effecient for 1Ë) -Macrophages-B cells MHC II, B7, CD40 All.