Chemokine expression in CLL and normal lymph node tissue.

Formalin-fixed, paraffin-embedded material was stained by a triple-layer technique involving antichemokine antibody, a biotinylated second layer, and ExtrAvidin-alkaline phosphatase as a third layer. H indicates HEV; S, sinus. Note that HEVs contain weak staining for both CCL21 and CLL19. Some stromal cells, including peri-HEV fibroblasts, showed particularly marked staining for SLC. Control staining with the relevant nonspecific antibodies was completely negative. In the top panels (n = 5); bottom, (n = 4).