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Transfer factors are essentially small immune messenger molecules that are produced by all higher organisms. They are an ancient part of the immune system and represent "an archaic dialect in the language of cells." Transfer factors were originally described as immune molecules that are derived from blood or spleen cells that cause antigen-specific cell-mediated immunity, primarily delayed hypersensitivity and the production of lymphokines, as well as binding to the antigens themselves. They have a molecular weight of approximately 5000 Daltons and are composed entirely of amino acids. Transfer factors were discovered by Henry Sherwood Lawrence in 1954. Transfer factor has some promising findings as a target of immune research, but can only be considered an incompletely investigated field that has been essentially lost to history. A second use of the term transfer factor applies to a likely different entity 〔 derived from cow colostrum or chicken egg yolk which is marketed as an oral dietary supplement under the same name citing claims of benefit to the immune system.〔PDR http://www.pdr.net/drugpages/productlabeling.aspx?mpcode=30651060〕 ==History== In 1942, Merrill Chase discovered that cells taken from the peritoneum of Guinea pigs that had been immunized against an antigen could transfer immunity when injected into Guinea pigs that had never been exposed to the antigen; this phenomenon was the discovery of cell-mediated immunity. Subsequent research attempted to uncover how the cells imparted their effects. Henry Sherwood Lawrence, in 1955,〔 discovered that partial immunity could be transferred even when the immune cells had undergone lysis - indicating that cells did not need to be fully intact in order to produce immune effects. Dr. Lawrence went on to discover that only the factors less than 8000 Daltons were required to transfer this immunity; he termed these to be "transfer factors".〔 The history of cellular derived transfer factor as a treatment effectively ended in the early 1980s. While the research world was initially excited by the discovery of Dr Lawrence and the possibility that a small molecule could effect the immune system, the concept of small molecules having such profound biologic effect had not been proven. Despite several successes in using transfer factor to treat human disease and uncover immune effects, one then-prominent researcher was exposed for falsifying data related to his work on transfer factor and guinea pigs; effectively casting all of transfer factor science in a negative light.〔 This scandal was followed shortly thereafter by the discovery of the Interleukin-1 alpha molecule and thus attention further shifted towards research on interleukins. By 1973, it was discovered that blood products could harbor viruses such as hepatitis A, indicating that transfer factor treatments derived from human or cow blood cells had the potential to transmit these diseases. With the eventual discovery of HIV/AIDS as an additional blood-borne disease most researchers viewed a product derived from blood as an unsafe treatment since screening for hepatitis B and HIV/AIDS would not be developed until after 1985.〔http://www.bloodbook.com/trans-history.html〕 Some studies using transfer factor have been conducted after the discovery of HIV/AIDS, but almost all have been outside of the United States. Most recently, transfer factor has been harvested from sources other than blood, and administered orally, as opposed to intravenously. This use of transfer factors from sources other than blood has not been accompanied by the same concerns associated with blood-borne diseases, since no blood is involved. Transfer factor based nutritional supplements have become extremely popular throughout the world. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Transfer factor」の詳細全文を読む スポンサード リンク
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