Glioma-associated hyaluronan induces apoptosis in dendritic cells via inducible nitric oxide synthase: implications for the use of dendritic cells for therapy of gliomas.

摘要: As a means of enhancing immunity to gliomas, we investigated local delivery rat, bone marrow-derived dendritic cells (DCs) into rat 9L gliosarcoma tumors and induced undergo apoptosis by gamma knife radiosurgery. Contrary other tumors, DCs had no therapeutic effect on even when tumor was via radiosurgery, which leads efficient "loading" the with antigen. To determine whether antigen-presenting cells, such as DCs, were viable in carried out multiparametric staining using phycoerythrin-conjugated OX6 (MHC class II) or OX62 (DC specific) FITC-labeled Val-Ala-Asp-fluoromethyl ketone (FITC-VAD-FMK; activated caspases). It determined that undergoing these tumors. We therefore sought glioma cell surface receptors components extracellular matrix gliomas influenced DC viability. Hyaluronan (HA) is major component has been found support migration metastasis. However, its influence immune system, particularly receptor CD44 not well documented. Using reverse transcription-PCR, Northern blot, Western blot analyses, HA stimulated production inducible nitric oxide synthase (iNOS) DCs. NO HA-stimulated then verified biochemically. dependent size HA; intermediate fragments greatest capacity induce DC, whereas completely digested oligosaccharides failed NO. Furthermore, N-monomethyl-L-arginine, an inhibitor iNOS, blocked HA-induced Because induction results macrophages treated examined for terminal deoxynucleotidyl transferase (TdT)-mediated dUTP biotin nick-end labeling assays. demonstrated because it entirely inhibited N-monomethyl-L-arginine. flow cytometric analyses FITC-VAD-FMK, specific caspases, also could be titrated. Coincubation indicated fluorescent FITC-VAD-FMK. Specificity this reaction CD44-HA interactions pretreatment anti-CD44 hyaluronidase, These data indicate expressed may contribute their immunosuppressive effects promoting among professional iNOS after interactions.