The cellular receptor (CD4) of the human immunodeficiency virus is expressed on neurons and glial cells in human brain.

The expression of the CD4 antigen in normal human brain was investigated in parallel by immunohistochemical and Northern blot analyses. With anti-CD4 antibodies detecting different epitopes of the molecule, CD4+ neurons were defined in the cerebellum, thalamus, and pons. CD4+ glial cells were identified in the thalamus and pons. CD4-specific mRNA was detected in all three subareas and in the hippocampus, while other subareas were negative. The CD4+ cells were negative with anti-T cell antibodies (anti-CD2 and anti-CD8), as well as with antimonocyte antibodies (M-M 522 and M-M 42).