RESUMO
IL-23 is a novel cytokine composed of an IL-12 p40 and a p19 subunit. We analyzed human peripheral blood mononuclear cells (PBMC) and hematopoietic cell lines for constitutive expression of IL-23 and IL-12 subunits and expression following exposure to various stimuli, and investigated the mechanisms of their induction by LPS and SAC. IL-23 p19 and IL-12 p35 mRNAs were expressed in fresh PBMC, and expression of all IL-23 and IL-12 subunits was up-regulated by LPS and SAC. LPS-induced increase of IL-23 and IL-12 subunits expression was CD14-dependent, while CD14 was not involved in SAC-induced p19 transcription. Both LPS- and SAC-induced subunits expression required p38 MAPK pathway. PHA effected an increase of p19 mRNA in both CD4+ and CD8+ T cells, whereas p35 was minimally regulated by PHA. IFN-gamma primed monocytes for LPS stimulation of p19, p35 and p40 expression. p19 mRNA was detectable in most hematopoietic cell lines tested but p35 distribution was more restricted. A phorbol diester enhanced p19, p35 and p40 expression in EBV-positive cell lines. Our results suggest that both the subunits of IL-23 are tightly regulated; the expression pattern and regulation mode of IL-23 p19 is similar to as well as distinct from that of IL-12 p35.
Assuntos
Células-Tronco Hematopoéticas/metabolismo , Interleucina-12/biossíntese , Interleucinas/biossíntese , Leucócitos Mononucleares/metabolismo , Subunidades Proteicas/biossíntese , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Interleucina-12/genética , Subunidade p40 da Interleucina-12 , Interleucina-23 , Subunidade p19 da Interleucina-23 , Interleucinas/genética , Interleucinas/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Staphylococcus aureus/fisiologiaRESUMO
OBJECTIVE: To study the expression of gelatinases, including matrix metalloproteinase-9 (MMP-9, gelatinase B) and matrix metalloproteinase-2 (MMP-2, gelatinase A), in CD(34)(+) cells and leukemic cell lines, and explore the significance of gelatinase in migrating and homing capacity of CD(34)(+) cells, as well as the role of gelatinase in leukemia pathogenesis. METHODS: CD(34)(+) cells were isolated from umbilical cord blood and normal bone marrow by Mini MACS system. By zymogram analysis, MMP-2 and MMP-9 were detected in the serum free condition medium of CD(34)(+) cells and cell lines. RESULTS: One brilliant band with molecular weight of 92 x 10(3) was detected in condition medium of cord blood CD(34)(+) cells. No band was detected in condition medium of bone marrow CD(34)(+) cells. Brilliant bands with molecular weight of 92 x 10(3) and 72 x 10(3) were detected in the condition medium of U937, KG-1a and HL-60 cell lines, but not in that of HEL, Namalva, CEM, K562 and LCL-H cell lines. In the condition media of J6-1 and J6-2 cells only the 92 x 10(3) band was detected. CONCLUSIONS: Cord blood CD(34)(+) cells produced MMP-9, but bone marrow CD(34)(+) cells did not, partly explains the fact that cord blood CD(34)(+) cells possessed higher migrating capacity in comparison with bone marrow CD(34)(+) cells. The expression of MMP-9 and MMP-2 in leukemic cell lines varied.