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.
The structure of the HIV gp120 envelope glycoprotein allows direct visualization of two overlapping sets of machinery. One, involved in entry, binds to both CD4 and a chemokine receptor and transmits a signal to gp41 to initiate membrane fusion.