Cell-mediated immunity

Cell-mediated immunity is an immune response that does not involve antibodies, but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.

Historically, the immune system was separated into two branches: humoral immunity, for which the protective function of immunization could be found in the humor (cell-free bodily fluid or serum) and cellular immunity, for which the protective function of immunization was associated with cells. CD4 cells or helper T cells provide protection against different pathogens. Cytotoxic T cells cause death by apoptosis without using cytokines; therefore in cell-mediated immunity cytokines are not always present.

The innate immune system and the adaptive immune system each comprise both humoral and cell-mediated components.

Cellular immunity protects the body by:

T-cell mediated immunity or T-cell immunity : activating antigen-specific cytotoxic T cells that are able to induce apoptosis in body cells displaying epitopes of foreign antigen on their surface, such as virus-infected cells, cells with intracellular bacteria, and cancer cells displaying tumor antigens;
activating macrophages and natural killer cells, enabling them to destroy pathogens; and
stimulating cells to secrete a variety of cytokines that influence the function of other cells involved in adaptive immune responses and innate immune responses.

Cell-mediated immunity is directed primarily at microbes that survive in phagocytes and microbes that infect non-phagocytic cells. It is most effective in removing virus-infected cells, but also participates in defending against fungi, protozoans, cancers, and intracellular bacteria. It also plays a major role in transplant rejection.

References

Cell-mediated immunity (Encyclopædia Britannica)
Chapter 8:T Cell-Mediated Immunity Immunobiology: The Immune System in Health and Disease. 5th edition.

Antigens	Antigen Superantigen Allergen Hapten Epitope Linear Conformational Mimotope Antigen presentation/Professional APCs: Dendritic cell Macrophage B cell Immunogen

Antibodies	Antibody Monoclonal antibodies Polyclonal antibodies Autoantibody Microantibody Polyclonal B cell response Allotype Isotype Idiotype Immune complex Paratope

Immunity vs. tolerance	action: Immunity Autoimmunity Alloimmunity Allergy Hypersensitivity Inflammation Cross-reactivity inaction: Tolerance Central Peripheral Clonal anergy Clonal deletion Tolerance in pregnancy Immunodeficiency

Immunogenetics	Affinity maturation (Somatic hypermutation Clonal selection) V(D)J recombination Junctional diversity Immunoglobulin class switching MHC/HLA

Lymphocytes

Substances

Hypersensitivity and autoimmune diseases (279.5–6)

Type I/allergy/atopy
(IgE)

Foreign	Atopic eczema Allergic urticaria Allergic rhinitis (Hay fever) Allergic asthma Anaphylaxis Food allergy common allergies include: Milk Egg Peanut Tree nut Seafood Soy Wheat Penicillin allergy

Autoimmune	Eosinophilic esophagitis

Type II/ADCC

- IgM
- IgG

Foreign

Hemolytic disease of the newborn

Autoimmune

Cytotoxic	Autoimmune hemolytic anemia Immune thrombocytopenic purpura Bullous pemphigoid Pemphigus vulgaris Rheumatic fever Goodpasture's syndrome Guillain–Barré syndrome

"Type V"/receptor	Graves' disease Myasthenia gravis Pernicious anemia

Type III
(Immune complex)

Foreign	Henoch–Schönlein purpura Hypersensitivity vasculitis Reactive arthritis Farmer's lung Post-streptococcal glomerulonephritis Serum sickness Arthus reaction

Autoimmune	Systemic lupus erythematosus Subacute bacterial endocarditis Rheumatoid arthritis

Type IV/cell-mediated
(T cells)

Foreign	Allergic contact dermatitis Mantoux test

Autoimmune	Diabetes mellitus type 1 Hashimoto's thyroiditis Multiple sclerosis Coeliac disease Giant-cell arteritis Postorgasmic illness syndrome Reactive arthritis

GVHD	Transfusion-associated graft versus host disease

Unknown/
multiple

Foreign	Hypersensitivity pneumonitis Allergic bronchopulmonary aspergillosis Transplant rejection Latex allergy (I+IV)

Autoimmune	Sjögren's syndrome Autoimmune hepatitis Autoimmune polyendocrine syndrome APS1 APS2 Autoimmune adrenalitis Systemic autoimmune disease

This article is issued from Wikipedia - version of the 11/26/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.

Cell-mediated immunity

References

Further reading