Auto or Self Antigens
Antigens present in one's own cells.
Altered by the action of bacteria, viruses, chemicals, or drugs as a non-self.
Altered cell (Auto Ag) - elicits the production of Antibody.
Autoimmunity (misnomer, alternative = auto allergy)
Immune response of auto Ab against self Ag.
Humoral or cell-mediated immune response against the constituents of the body's own tissues.
There are more than 80 different kinds of diseases caused by autoimmunity.
Causes of Autoimmune Diseases
Sequestered or Hidden antigens
Ag in the secluded places - are not accessible to the immune system.
Altered or Modified Antigens – by physical (irradiation), chemical (drugs), or microbial agents (intracellular viruses).
Cessation of Tolerance
It may result when tolerance to the self-Ag is abrogated.
A foreign Ag which resembles self a 2nd Ag.
Many species share organ-specific Ags.
Loss of Immunoregulation
Loss of Self tolerance - caused by overactivity or lowered activity of T and B-cells.