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.
Macrophages and dendritic cells on the surface of mucous membranes bind virus and shuttle it into the lymph nodes, which contain high concentrations of helper T cells (CD4+ T cells). Once HIV has entered the body, the immune system initiates anti-HIV antibody and cytotoxic T cell production. However, it can take one to six months for an individual exposed to HIV to produce measurable quantities of antibody. The immune response is weakened as memory T cells (CD4 + CCR5 +) are destroyed.