C D26, the T cell activation molecule, is a 110-kD gly-coprotein that is also present on epithelial cells of various tissues, including the liver, kidney, and intestine. CD26 possesses a known dipeptidyl peptidase (DPP)IV activity in its extracellular domain (1). A paper by Wesley et al. in this issue indicates a possible role for CD26/DPPIV in suppressing malignant transformation of melanocyte...

C D26, the T cell activation molecule, is a 110-kD gly-coprotein that is also present on epithelial cells of various tissues, including the liver, kidney, and intestine. CD26 possesses a known dipeptidyl peptidase (DPP)IV activity in its extracellular domain (1). A paper by Wesley et al. in this issue indicates a possible role for CD26/DPPIV in suppressing malignant transformation of melanocyte...

Adenosine deaminase (ADA) is responsible for the deamination of immunosuppressive adenosine to inosine. In human T lymphocytes, ADA is associated with dipeptidyl peptidase IV (CD26). ADA expression and activity were evaluated in regulatory T cells (Treg) and CD4(+) T effector cells (Teff) of patients with head and neck squamous cell cancer (HNSCC). CD4(+)CD39(+) and CD4(+)CD39(neg) T cells were...

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...

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...

The present study evaluated the presence and clinical relevance of a cluster of differentiation (CD)26+/CD326- subset of circulating tumor cells (CTCs) in pre- and post-operative blood samples of colorectal cancer patients, who had undergone curative or palliative intervention, in order to find a novel prognostic factor for patient management and follow-up. In total, 80 colorectal cancer patien...

Patients who have undergone allogeneic bone marrow transplantation (allo-BMT) are susceptible to a variety of opportunistic infectious complications in the months to years after engraftment. Impaired in vitro T-cell functions have been documented in these patients, and these T-cell dysfunctions contribute to the prolonged immune deficiency after allo-BMT. In the present study, we examined the e...

Sir, Tumour necrosis factor α (TNF-α) is a proven adequate target for treatment of psoriasis. The chimeric TNF-α antibody infliximab binds to the transmembrane receptors and induces a neutralizing effect on soluble TNF by reversed signalling, ultimately causing a reduction in lesional T cells and, indirectly, increased programmed cell death of keratinocytes (1). CD26/dipeptidylpeptidase IV (DPP...

Aminopeptidase N (APN)/CD13 is a transmembrane ectopeptidase expressed on a wide variety of cells. However, the precise function of APN/CD13 in tumor cells and the relationship of APN/CD13 to thyroid cancer remain unclear. In our study, we quantified the expression of APN/CD13 and additionally dipeptidyl peptidase IV (DPIV)/CD26 in thyroid carcinoma cell lines and in tissues of patients with th...

Dipeptidyl peptidase IV (DPPIV, CD26), a protease-cleaving N-terminal X-Pro dipeptide from selected proteins including some chemokines, is expressed both as a soluble form in plasma and on the cell surface of various immune and nonimmune cell types. To gain insights into the pathophysiological role of CD26 in arthritis, we explored DPPIV/CD26 expression during murine antigen-induced arthritis (...