CD4, CCR5, and CXCR4 expression.

Nonsorted (A-F) and CD4⁺/CD117⁺ sorted (G-I) freshly isolated cells from patients with asthma were stained pink with antichymase (A-C,H) or antitryptase (D-F,I) IgG. In some instances, the resulting cells were then stained brown with anti-CD4 (A,D), anti-CCR5 (B,E), or anti-CXCR4 (C,F) IgG. As assessed by this double-immunohistochemical procedure, most of the tryptase⁺/chymase⁺ cells in the blood of these patients expressed CD4, CCR5, and CXCR4. The sorted cells depicted in panels H and I are shown at a lower magnification than the cells in panels A through F to better evaluate the efficiency of the purification procedure. As noted in the nonfixed cells in panel G, CD4 is expressed on the surface of the MCs/basophils. The apparent intracellular location of CD4 in panels A and D could be a consequence of the fixation step used in this immunohistochemistry procedure.