1 Most of these diseases are infections, caused by a variety of bacteria, viruses, and parasites that can be foodborne. 2  Other diseases are poisonings, caused by harmful toxins or chemicals that have contaminated the food, for example, poisonous mushrooms.
(cluster designation 4) symbol for a glycoprotein expressed on the surface of helper T lymphocytes and other immune cells. CD4 serves as a receptor for human immunodeficiency virus envelope glycoprotein gp120.
HIV/AIDS. The human immunodeficiency virus (HIV) weakens the body's immune defenses by destroying CD4 (T-cell) lymphocytes, a type of white blood cell. T-cells normally help guard the body against attacks by bacteria, viruses and other germs. When HIV destroys CD4 cells, the body becomes vulnerable to many different types of infections.