title: Decreased dipeptidyl peptidase IV enzyme activity of plasma soluble CD26 and its inverse correlation with HIV-1 RNA in HIV-1 infected individuals.
abstract: Human plasma contains soluble CD26/dipeptidyl peptidase IV (sCD26/DPPIV) although its physiological significance remains unclear. To determine whether the plasma sCD26 levels have clinical relevance in HIV-1 infected individuals, the concentration and DPPIV enzyme activity of plasma sCD26 were measured. While there is no significant difference between the plasma levels of sCD26 in 90 HIV-1 infected individuals and in 79 uninfected controls, specific DPPIV enzyme activity of sCD26 was significantly decreased HIV-1 infected individuals (P < 0.0001). Specific DPPIV enzyme activity was correlated with the levels of CD4+ T cells (r = 0.247; P < 0.02), CD8+ T cells (r = 0.236; P < 0.03), and adenosine deaminase (r = 0.227; P < 0.05) and had an inverse correlation with HIV-1 RNA (Spearman's r = 0.474; P = 0.0012). Furthermore, recombinant sCD26 enhanced the in vitro PPD-induced response of lymphocytes from HIV-1 infected individuals with decreased specific DPPIV enzyme activity. These results suggest that the specific DPPIV enzyme activity of plasma sCD26 may contribute to the immunopathogenesis of HIV infection.
authors.affiliation: Department of Clinical Immunology, University of Tokyo, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Hosono
authors.forename: T
authors.initials: T
authors.lastname: Homma
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Munakata
authors.forename: Y
authors.initials: Y
authors.lastname: Nojima
authors.forename: A
authors.initials: A
authors.lastname: Iwamoto
authors.forename: C
authors.initials: C
authors.lastname: Morimoto
mesh_terms: D000243:Adenosine Deaminase / Q000097:blood; D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D018819:Dipeptidyl Peptidase 4 / Q000097:blood*; D005260:Female; D015658:HIV Infections / Q000201:enzymology* / Q000276:immunology* / Q000821:virology; D015497:HIV-1; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008297:Male; D012367:RNA, Viral / Q000097:blood*; D012995:Solubility; D014373:Tuberculin / Q000276:immunology
chemical_list: D012367:RNA, Viral; D014373:Tuberculin; D018819:Dipeptidyl Peptidase 4; D000243:Adenosine Deaminase