U.C.L.A. Rheumatology Pathophysiology of Disease Course Lecture,
Second Year Medical School 1997

Figure 2. The HLA molecules that one inherits determines in part the susceptibility to autoimmune disease. Both class I and class II HLA molecules have an intracellular, transmembrane, and extracellular portion.
       When organisms enter the body they are metabolized to small peptides and combine in antigen presenting cells to the extracellular portion of HLA molecules. The HLA-antigen complex is then displayed on the surface of the cell where is made available to interact with T cells.
       This is the first cell-cell interaction following antigen exposure and it is crucial to the nature of the ongoing immune response, i.e. what type of immune defense will be mounted. The type of HLA molecules inherited by an individual dictates in part how foreign antigens are handled by the body. The role that HLA molecules play in autoimmunity is unknown but under intense study. 420 x 355 pixels 27kbs