Yin-Yang of the Adaptive Immune System
Raul M. Torres (NJC, UCD)

Immunofluorescent histology
We study the migration of white blood cells in the body and are able to differentially label these cells with different fluorescent colored tags (antibodies). This photo represents a thin (6 micron) histological section of a mouse spleen and shows the two major white blood cell types of the adaptive immune system: T lymphocytes in green and B lymphocytes in red (the blue cells are another kind of B lymphocyte). These two cell types are always found in the spleen but normally segregate into distinct juxtaposed regions of random shapes. On one particular evening at the microscope I came across this almost perfect circle in which one half were T lymphocytes and the other half B lymphocytes. The symmetry was not only almost physically perfect but suggested a yin-yang between these two cell types and was appropriate to the major different, but complimentary, roles these cells play in adaptive immunity.