Recommended if funds allow White blood cells are the main
players of human immunity in defense against infection. Defects
in CD4 T white blood cells, for example, can lead to the
devastating infections observed in AIDS patients and patients
with a genetic immunodeficiency syndrome (“bubble boy”
syndrome). A normal immune system can recognize and attack
pathogens but not “self”. This is achieved by rigorous selection
and “education” during development of T or B white blood cells
and by regulatory T cells that suppress occasional “run-away”
white blood cells. Glitches in these processes can also lead to
equally devastating problems as seen in many autoimmune diseases
like type I diabetes, multiple sclerosis and rheumatoid
arthritis. Thus, the availability of T cells or regulatory cells
could lead to therapies for many human diseases. A major
limitation in using T cells in therapy is the lack of available
primary T cells generated in the laboratory. Attempts thus far
to generate T cell precursors in a tissue cul