CD4 (T4) or CD4+ CellsJAMA 1. White blood cells killed or disabled during HIV infection. These cells normally orchestrate the
immune response, signaling other cells in the immune system to perform their special functions. Also
known as T helper cells.
2. HIV's preferred targets are cells that have a docking molecule called cluster designation 4 (CD4) on
their surfaces. Cells with this molecule are known as CD4-positive (or CD4+) cells. Destruction of CD4+
lymphocytes is the major cause of the immunodeficiency observed in AIDS, and decreasing CD4+
lymphocyte levels appear to be the best indicator of morbidity in these patients. Although CD4 counts fall,
the total T-cell level remains fairly constant through the course of HIV disease, owing to a concomitant
increase in the CD8+ cells. The ratio of CD4+ to CD8+ cells is therefore an important measure
of disease progression. See also CD NOmenclature; CD8 (T8) Cells; Immunodeficiency.
CD4 Cell (CD4 Lymphocyte, T-helper Cell, T4 Cell):SFAF
a type of
white blood cell that carries the CD4 cell surface marker and helps the
body fight infection. CD4 cells engulf and process invaders (e.g., viruses)
and display pieces for recognition by disease-fighting cells (e.g., cytotoxic
T-lymphocytes). CD4 cells release cytokines that coordinate a broad range
of immune system activities including killer cell activation and antibody
production. HIV invades CD4 cells, typically resulting in their dysfunction
to find source(s) of the term definition cited above (see superscript).
If the term you are looking for is not included in this glossary/dictionary, search