Purpose
The aim of this study was to investigate the induction of antigen-specific T cell activation and cell cycle modulation by a poly-DL-lactide/glycolide (PLGA) nanoparticle (NP)-primed CD11b+Gr-1high subset isolated from mouse bone marrow.
Methods
PLGA NPs containing the ovalbumin (OVA) antigen were prepared using the double emulsion and solvent evaporation method, and protein release rate and cell viability were determined. The Lin2¯CD11b+Gr-1highLy6clow (Gr-1high) subset was sorted from the bone marrow of C57BL/6 J mice by fluorescence-activated cell sorting (FACS) and co-cultured with OT-I CD8+ splenic T cells. Proliferation of OT-I CD8+ T cells was monitored, and cell cycles were determined by 5-bromo-2′-deoxyuridine (BrdU) labeling.
Results
Treatment of Gr-1high cells with PLGA/OVA NPs upregulated expression of the SIINFEKL-H2Kb complex in the context of MHC I. Co-cultures of OT-I CD8+ T cells with the PLGA/OVA NP-primed Gr-1high cells induced the proliferation of T cells in vitro and modulated cell division and morphology. Treatment of Gr-1high cells with PLGA/OVA NPs also induced cell apoptosis and necrosis.
Conclusion
This study demonstrated the function of PLGA/OVA NPs in the activation of OT-I CD8+ T cells and the capability of cross-presentation via the Gr-1high polymorphonuclear subset from mouse bone marrow.