Pathology caused by the cellmediated immune response

The mere expression of a cell-mediated immune response involves some degree of inflammation, lymphocyte infiltration, macrophage accumulation and activation and can therefore by itself cause pathological changes. This type of response predominates in the pathogenesis of tuberculosis, with mononuclear cell infiltration, degeneration of parasitised macrophages, and the formation of giant cells as central features. In chronic mycobacterial infection, the continuous release of microbial antigens...

Classification of autoimmune disease

In the 1950s, Witebsky established the criteria for determining the aetiology of human diseases which were thought to be autoimmune. Witebsky's postulates were modelled on those of Koch and required the presence of autoantibody or a cell-mediated immune response to a self-antigen, which having been identified, could induce a similar disease in an experimental host mediated by the same immunological mechanism. Since these criteria were established, our knowledge of immunology has increased by...

The lectin pathway

The third complement activation pathway is the lectin pathway Figure 3.5 . Lectins are carbohydrate-binding proteins, which are able to bind to a wide range of microorganisms. There are two major types found in serum the ficollins consisting of a fibrinogen- and a collagen-like domain and the mannose-binding lectin MBL . Both of these lectins can activate complement. Like the classical pathway, which involves the activation of the serine proteases C1r and C1s, the lectin pathway is activated by...

Which of the following statements concerning autoimmunity is Correct

a Autoimmunity is vital to the development of a normal immune response. b T cells only recognise and respond to antigen when it is processed and presented in association with foreign MHC gene products. c Autoimmune disease arises as a result of the development of self-tolerance. d Autoimmunity may develop as a result of exposure in adult life to an antigen which was hidden from the immune system in the early stages ofdevelopment. e Self-tolerance develops within the first 6 months of life.