Today’s wake-up word is histocompatibility. Also known as tissue compatibility, histocompatibility is the property of having the same, or sufficiently similar, alleles of a set of genes called human leukocyte antigens (HLA), or major histocompatibility complex (MHC) so that a cell is accepted among the biological community.
Each of us expresses unique HLA proteins on the surface of our cells. This communicates to the immune system whether the cell is part of the self or “other”. If it is detected as “other” it is marked as an invading organism. Immune cells called T cells, when working properly, can recognize foreign HLA molecules. This recognition triggers an immune response aimed at destroying foreign (or sick) cells.
Histocompatibility testing is important when considering the probability of success in organ, tissue, or stem cell transplants. The donor’s HLA alleles and the recipient’s has to be similar enough so it doesn’t trigger the immune system of the host body to reject the transplant.
The process map of this biological subsystem is similar to the way we express social behaviors such as the development of culture and the use of story maps to establish in-group affinity or out-group antagonism. It illustrates how we use a currency of familiarity to establish friends from foes. How we nourish and protect self-similar architectures to maintain coherence over time. It begs the question: Is what we experience as us already established by the story told through the structural architectures of nature on which our coherence depends? Maybe.
MHC class I assembly and presentation