Processing by CD26/dipeptidyl‐peptidase IV reduces the chemotactic and anti‐HIV‐1 activity of stromal‐cell‐derived factor‐1α

摘要

>The chemokine stromal-cell-derived factor-1α (SDF-1α) chemoattracts lymphocytes and CD34+ haematopoietic progenitors and is the ligand for CXCR4 (CXC chemokine receptor 4), the main co-receptor for T-tropic HIV-1 strains. SDF-1α was NH₂-terminally cleaved to SDF-1α(3-68) by dipeptidyl-peptidase IV (CD26/DPP IV), which is present in blood in soluble and membrane-bound form. SDF-1α(3-68) lost both lymphocyte chemotactic and CXCR4-signaling properties. However, SDF-1α(3-68) still desensitized the SDF-1α(1-68)-induced Ca2+ response. In contrast to CD26/DPP IV-processed RANTES(3-68), SDF-1α(3-68) had diminished potency to inhibit HIV-1 infection. Thus, CD26/DPP IV impairs the inflammatory and haematopoietic potency of chemokines but plays a dual role in AIDS.