Ad blocker interference detected!
Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers
Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.
Individual differences |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |
Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)
Memory T cells are a specific type of infection-fighting T cell (also known as a T lymphocyte) that can recognize foreign invaders such as bacteria or viruses, that were encountered during a prior infection or vaccination. At a second encounter with the invader, memory T cells can reproduce to mount a faster and stronger immune response than the first time the immune system responded to the invader. This behaviour is utilized in T lymphocyte proliferation assays, which can reveal exposure to specific antigens.
Within the human cytotoxic T cell population, three distinct sub-populations have now been described:
- central memory (TCM). The TCM cells are thought to represent memory stem cells. TCM display a capacity for self-renewal due to high levels of phosphorylation of an important transcription factor known as STAT5. 
- two highly related effector memory sub-types, which strongly express genes for molecules essential to the cytotoxic function of CD8 T cells:
- effector memory (TEM)
- effector memory RA (TEMRA)
Memory T cells can be recognized by the differential expression of certain molecules.
- Central memory TCM cells express L-selectin and the chemokine receptor CCR7, they secrete IL-2, but not IFNγ or IL-4.
- Effector memory TEM cells, however, do not express L-selectin or CCR7 but produce effector cytokines like IFNγ and IL-4.
Antigen-specific memory T cells against viruses or other microbial molecules can be found in both TCM and TEM subsets. Although most information is currently based on observations in the Cytotoxic T cells (CD8-positive) subset, similar populations appear to exist for both the Helper T cells (CD4-positive) and the cytotoxic T cells.
See also Edit
- ↑ Willinger T, Freeman T, Hasegawa H, McMichael A, Callan M (2005). Molecular signatures distinguish human central memory from effector memory CD8 T cell subsets. J Immunol 175 (9): 5895-903.
- Janeway CA, Jr. et al (2005). Immunobiology., 6th ed., Garland Science.
- Cellular and Molecular Immunology (5th Ed.) Abbas AK, and Lichtman, Editor: Saunders, Philadelphia, 2003.
|This page uses Creative Commons Licensed content from Wikipedia (view authors).|