CD26 is a lymphocyte marker that can anchor adenosine deaminase (ADA) on the T cell surface. We found that ADA is regulated by cytokines on the cell surface during T cell activation. By means of flow cytometry, immunofluorescence, and immunoblotting techniques, we found that interleukin (IL)-2 and IL-12 up-regulate ecto-ADA and CD26 expression. In clear contrast, IL-4 led to down-regulation of ...

Adult T-cell leukemia/lymphoma (ATL), a human T-lymphotropic virus type 1 (HTLV-1)-associated disease, has a highly variable clinical course and four subtypes with therapeutic and prognostic implications. However, there are overlapping features between ATL subtypes and between ATL and nonmalignant (non-ATL) HTLV-1 infection complicating diagnosis and prognostication. To further refine the diagn...

Dipeptidylpeptidase IV/CD26 is expressed on the surface of various cell types. Through its enzymatic activity, its major function is to cleave the N-terminal dipeptide from diverse molecules including members of the chemokine family of cytokines. The N-terminus of these chemokines is important for activation of and binding to seven-transmembrane G-protein linked chemokine receptors, and early s...

The importance of ADA (adenosine deaminase) in the immune system and the role of its interaction with an ADA-binding cell membrane protein dipeptidyl peptidase IV (DPPIV), identical to the activated immune cell antigen, CD26, has attracted the interest of researchers for many years. To investigate the specific properties in the structure-function relationship of the ADA/DPPIV-CD26 complex, its ...

We studied dipeptidyl peptidase IV (DPP-IV, CD26) expression in different T helper cells and serum soluble DPP-IV/sCD26 levels in rheumatoid arthritis (RA) patients, correlated these with disease activity score (DAS), and examined how they were affected by different therapies, conventional or biological (anti-TNF, anti-CD20 and anti-IL6R or Ig-CTLA4). The percentage of CD4+CD45R0+CD26- cells wa...

By using flow cytometry with markers for CD3, CD4, CD26, and CD7, we examined the blood samples of 109 patients for abnormal T cells: 69 patients with mycosis fungoides (MF)/Sézary syndrome (SS), 31 hospitalized control subjects, and 9 patients with inflammatory skin disease. T cells were identified as quantitatively abnormal (>15% CD26- or CD7- T cells) or phenotypically abnormal (CD26- or CD7...

CD26, a 110 kDa cell surface glycoprotein, exhibits dipeptidyl peptidase IV (DPPIV; EC 3.4.14.5) enzyme activity and plays an important role in T cell co-stimulation. In the present study, the function of CD26/DPPIV in transendothelial migration was examined using beta-chemokines as chemoattractants. When soluble recombinant CD26 (sCD26/DPPIV+) was added to the transendothelial chemotaxis syste...

BACKGROUND Chronic Fatigue Syndrome (CFS) studies from our laboratory and others described decreased natural killer cell cytotoxicity (NKCC) and elevated proportion of lymphocytes expressing the activation marker, dipeptidyl peptidase IV (DPPIV) also known as CD26. However, neither these assays nor other laboratory tests are widely accepted for the diagnosis or prognosis of CFS. This study soug...

Note In 1979, a large molecular weight complex composed of adenosine deaminase (ADA) were reported to be found as an adenosine deaminase-binding protein (ADBP), also known as adenosine deaminase complexing protein-2 (ADCP2). In 1993, this adenosine deaminase-binding protein is determined to be identical to CD26, a T-cell activation molecule and a 110-kD glycoprotein that is present also on epit...

BACKGROUNDS CD26, a multifunctional T cell surface glycoprotein, is a type II transmembrane protein containing only six amino acid residues in its cytoplasmic region. In addition to its membrane form, CD26 exists in plasma in a soluble form (sCD26), which is thought to be the extracellular domain of the molecule cleaved from the cell surface. Recent studies indicated CD26 have an important role...