Empty MHC class I molecules come out in the cold
Article Abstract:
Cytotoxic T-cells may be activated by the presentation of a specific antigen. This presentation takes place when a competent cell degrades a foreign protein into peptide fragments, which are then bound by molecules of the major histocompatibility complex (MHC). In humans, molecules of the MHC are often called HLA antigens, or human leukocyte antigen. Molecules of the MHC are then brought to the cell surface along with their peptide fragment. The 'cytotoxic' set of T-cells are only capable of recognizing an antigen when it is properly presented by a class I histocompatibility molecule. However, an unresolved question has been whether class I molecules can be expressed on the surface of cells without the presence of a peptide antigen fragment. Researchers have shown that when mouse lymphoma cells are cultured at reduced temperatures, between 19 and 33 degrees Centigrade, class I molecules not binding antigen fragments were detected on the cell surface. However, when the temperature of these cells is raised to 37 degrees, close to body temperature, the class I molecules quickly disappeared. These results suggest that the antigen fragment has a stabilizing effect on the class I molecular complex. Without this action, the complex is unstable at body temperature, and is undetected. At lower temperatures, the complex is more stable. The use of temperature to control the expression of class I molecules will likely aid in the study of these molecules and to a better understanding of their role in the immune response. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1990
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Medicine Nobel goes to pioneer of protein guidance mechanisms
Article Abstract:
Gunter Blobel of the Rockefeller University in New York, NY, has received the 1999 Nobel Prize for Physiology or Medicine. This is in recognition of his discovery that proteins are produced with in-built address labels that ensure that they reach their destinations in the cell. Many observers feel that Blobel has been a pioneer in a key area of cellular and molecular biology since the 1970s. It is reported that he plans to donate part of the prize money towards the reconstruction of the Frauenkirche cathedral in Dresden, Germany.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1999
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Plaque removers and shakers
Article Abstract:
Research on a vaccination which stopped Alzheimer's-like symptoms in mice is discussed. Scientists have found that the vaccine produced antibodies in the mice which prevented plaques associated with the disease from forming.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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