Generation of dendritic cells using viral lysate of tumor cells in vitro.

Abstract

e15202 Background: The purpose of the study was to investigate the effect of a new unclassified rotavirus on the effectiveness of maturation of dendritic cells (DC) and their activation of lymphocytes in vitro. Methods: Strain No.100 of the RVK virus was isolated by S.A. Kolpakov and characterized as rotavirus. U87MG cell lysate (glioblastoma) was obtained by incubation with 108 RVK particles in the DMEM medium with L-glutamine for 72 hours; a cytopathic effect was observed. Immature DCs were cultured for 7 days in the presence of IL-4 and GM-CSF. For antigen loading of DCs, we used the following options for 48 h: a) U87MG lysate obtained by repeated freeze-thaw cycles (TL); b) U87MG lysate obtained by co-cultivation with RVK (VTL); c) RVK. To assess the DC ability to activate autologous lymphocytes, they were co-cultured for 5 days in a 3:1 ratio. Results: The use of VTL culture for DC loading caused an increase in the expression of mature DC (mDC) markers compared to TL: the number of CD83+/CD86+ cells increased by more than 2 times, CD83+/CD80+ by 1.2 times, CD83+HLA-DR - by 5.5 times. With VTL, expression of markers of immature DCs (CD1a, CD14) was minimal. The use of RVK as an antigen induced the generation of DCs from monocytes, but their maturation was much less pronounced: a significant increase in the membrane expression of CD86, but not CD83, was determined. These DCs demonstrated a higher expression of markers of immature DCs, compared to stimulation with cell lysates (both TL and VTL): CD1a and CD14; CD80+/CD86+ level was the highest among all options. Analysis of the DC effect on co-cultivated lymphocytes showed that DCs loaded with RVK, both alone and as part of VTL, stimulated predominantly the NKT subpopulation. The same samples contained more T lymphocytes, activated CD4+ and CD8+ compared to samples stimulated by TL. However, the samples co-cultivated with VTL contained the maximal amount of CD4+/CD25+/CD127dim phenotypically corresponding to Tregs. Conclusions: The antigen loading of immature DCs with RVK alone causes their activation, but not maturation, which is not realized in typical terms of the DC generation from blood monocytes. The presence of RVK, including in VTL, has a stimulating effect on NKT lymphocytes suggesting the possible generation of specific highly active cytotoxic lymphocytes.