Skin immunity
Skin immunity is a property of skin that allows it to resist infections from pathogens. In addition to providing a passive physical barrier against infection, the skin also contains elements of the innate and adaptive immune systems which allows it to actively fight infections. Hence the skin provides defense in depth against infection.
The skin acts as a barrier, a kind of sheath, made of several layers of cells and their related glands. The skin is a dynamic organ that contains different cells which contains elements of the innate and the adaptive immune systems which are activated when the tissue is under attack by invading pathogens. Shortly after infection, the immune adaptive response is induced by
Afferent and efferent phases of the immune system of the skin
Some humoral and cellular components of the skin pass through the vessel lymph to get to the circulation. This circulation net has a big importance, it's the way of direct communication between the specific site of the skin and the lymph cells found inside the lymph node and the systematic tissues. The epidermis antigens are connected with some cells of the skin. Among them there are the APC, antigen presenting cells (
Antigenic presentation from the Langerhans cells to the lymphocytes
The Langerhans cells, once they are activated, rapidly migrate to the lymph nodes where they will accumulate in the paracortex and show the antigen of the skin to the lymph nodes via efferent lymph vessels. The Langerhans cells induce a vast proliferation of the naïve lymphocytes T and they participate in the immunoestimulation phase of the immune response, converting the lymphocytes in T helper cells. Recently, it has been shown that Langerhans cells can express an antigenic peptide associated to
Microbiota and skin immunity
Skin microbiota plays an important role in tissue homeostasis and local immunity.[4][5][6][7] Skin microbial communities are highly diverse and can be remodeled over time or in response to environment challenges.[8][9][10]
From around 2005 on, the scientific community has thoroughly developed the concept of human microbiome
T cells and microbiota in skin immunity
Recent studies have demonstrated that specific components of the microbiota, as well as their metabolites, selectively promote the activation and the expansion of different
The majority bacteria tested increased the number of skin T cells. Interactions between T cells and specific microbiota components may represent evolutionary outcome by which the skin immune system and the microbiota provide heterologous protection against invasive pathogens and calibrate barrier immunity through the use of chemical signals. This shows that the skin immune system is a highly dynamic environment that can be rapidly and specifically remodeled by certain commensals.[18]
Finally, studying microbiota interactions and skin T cells can help to detect the cause of various diseases and possible cures for these. The increasing development of tools for personalized medicine will undoubtedly help to this goal, because each person has a different microbiota.
References
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- ^ a b Laura E Castrillón Rivera; Alejandro Palma Ramos; Carmen Padilla Desgarennes (2008). "La función inmunológica de la piel". Dermatología Rev Mex. 52 (5): 211–24.
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Further reading
- Salmon JK, Armstrong CA, Ansel JC (February 1994). "The skin as an immune organ". West. J. Med. 160 (2): 146–52. PMID 8160465.