Immunology

The immune system: basis of so much health and disease: 8. antigens and MHC

Antigens (immunogens) are substances, usually proteins, that can be recognized by the body as foreign and can elicit an antibody response. Antigens are usually exogenous but may be endogenous...

The immune system: basis of so much health and disease: 7. antibodies

Antibodies are produced by activated B-lymphocytes (plasma cells) and react specifically with the antigen that stimulated their production; they make up approximately 20% of the plasma proteins....

The immune system: basis of so much health and disease: 6. cytokines

Cytokines are produced by many cell populations, but the predominant producers are helper T-cells (Th) and macrophages. Some cytokines (eg type 1 interferons [IFN] and tumour necrosis factor [TNF])...

The immune system: basis of so much health and disease: 5. complement

Numbering of each component of the classical pathway of complement is from C1–C9. The sequence in which complement components are activated is C1, C4, C2, C3 and C5–C9 (since C4 was identified before,...

The immune system: basis of so much health and disease: 4. immunocytes

Antigen presenting cells are a heterogeneous group of immune cells that mediate the cellular immune response by processing and presenting antigens for recognition by T-cells. APCs are either:.

The immune system: basis of so much health and disease: 3. adaptive immunity

The main cells that mediate adaptive immunity are white blood cells (leukocytes) termed immunocytes – mainly lymphocytes:.

The immune system: basis of so much health and disease: 2. innate immunity

Innate defences include basic mechanisms resisting infections; predominantly including:.

The immune system: basis of so much health and disease: 1. overview of immunity and the immune system

The main primary organs of the immune system are lymphoid – the thymus and bone marrow (Figure 2) and secondary tissues such as spleen, tonsils, lymph vessels, lymph nodes, adenoids, skin and liver...