Abbott, C.A.

De Meester, Ingrid

Gorrell, M.D.

Gysbers, V.

K\ue4hne, T.

Knott, H.M.

McCaughan, G.W.

Riekhoff, A.G.M.

Slaitini, L.

Yu, D.M.T.

Abstract: Human CD26 has dipeptidyl peptidase-4 (DPP IV) enzyme activity and binds to adenosine deaminase (ADA). CD26 is costimulatory for lymphocytes and has a circulating soluble form (sCD26). DPP IV enzyme inhibition is a new successful type 2 diabetes therapy. We examined whether the ADA binding and catalytic functions of sCD26 contribute to its effects on T-cell proliferation. Wildtype soluble recombinant human CD26 (srhCD26), an enzyme inactive mutant (srhCD26E-) and an ADA non-binding mutant (srhCD26A-) were co-incubated in in vitro T-cell proliferation assays with peripheral blood mononuclear cells (PBMC) stimulated with phytohaemagglutinin (PHA), muromonab-CD3 or Herpes simplex virus antigen (HSV Ag). Both srhCD26 and srhCD26E- enhanced PHA-induced T-cell proliferation dose-dependently in all six subjects tested. srhCD26 and srhCD26A- had no overall effect on anti-CD3-stimulated PBMC proliferation in four of five subjects. srhCD26, srhCD26E- and srhCD26A- enhanced HSV Ag induced PBMC proliferation in low responders to HSV Ag, but had no effect or inhibited proliferation in HSV-high responders. Thus, effects of soluble human CD26 on human T-cell proliferation are mechanistically independent of both the enzyme activity and the ADA-binding capability of sCD26

Institutional Repository Universiteit Antwerpen

Soluble CD26\u200a/\u200adipeptidyl peptidase IV enhances human lymphocyte proliferation **in vitro** independent of dipeptidyl peptidase enzyme activity and adenosine deaminase binding

Soluble CD26&#8202;/&#8202;dipeptidyl peptidase IV enhances human lymphocyte proliferation **in vitro** independent of dipeptidyl peptidase enzyme activity and adenosine deaminase binding

Soluble CD26 / dipeptidyl peptidase IV enhances human lymphocyte proliferation in vitro independent of dipeptidyl peptidase enzyme activity and adenosine deaminase binding

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Institutional Repository Universiteit Antwerpen

Soluble CD26&#8202;/&#8202;dipeptidyl peptidase IV enhances human lymphocyte proliferation **in vitro** independent of dipeptidyl peptidase enzyme activity and adenosine deaminase binding

Abstract

Similar works

Full text

Available Versions

Institutional Repository Universiteit Antwerpen

Soluble CD26 / dipeptidyl peptidase IV enhances human lymphocyte proliferation in vitro independent of dipeptidyl peptidase enzyme activity and adenosine deaminase binding