Investigation On Exosomes Carrying TSA Derived From Healthy Human White Buffy Coat with Positive HLA-A2 and PolyI:C On Subcellular Antitumor Vaccination.

Use human leukocyte antigen –A2 (HLA-A2) positive human dendritic cell (DC) derived DEX to support NY-ESO-1 antigen and polyI:C to increase the proliferation of specific cytotoxic T lymphocyte (CTL) in transgenic mice, and increase its anti-tumor effect.

Mature dendritic cells derived from peripheral blood mononuclear cells (PBMC) are isolated from the blood from healthy adults with positive HLA-2A. By centrifugation and membrane ultrafiltration, EXO is extracted from the supernatant of DC secretions. Transgenic C57 mice were immunized by human derived tumor testis antigen NY-ESO-1/EXO with or without polyI:C. Mice were sacrificed four weeks after immunization, and spleen cells were isolated and underwent function test. The experiments include: antigen specific CTL proliferation efficiency was tested by dimerization experiment; the antitumor effect for K562 cells and melanoma were tested under different ratio between effecter cells and target cells (0:1, 10:1, 50:1 and 100:1).

Dimerization experiment indicated that the effect of DEX/TSA+PolyI:C was (1.98±0.79)%. The effect of DEX/TSA was (1.61±0.58)%. The antitumor effect for the ratio of 0:1, 10:1, 50:1 and 100:1 by DEX/TSA:PolyI:C were (11.14±1.36%) A (14.17±0.62%) A (15.71±2.48%) A (24.31±2.91%) for K562 cells; The antitumor effect for DEX/TSA group (12.23±2.25%)A(13.10±1.57%)A(15.27±2.93%)A(19.87±2.72%)for K562 cells; With ratio 10:1 and 100:1, the antitumor effect of DEX/TSA +PolyI:C is better than DEX/TSA group (P<0.05). Whereas, with increased ratio between effecter cells and target cells, there is no significant improvement on antitumor effect for control cells.

It is promising to combine DEX/TSA derived from healthy human blood with positive HLA-A2 and PolyI:C as a new subcellular antitumor vaccination.

No relevant conflicts of interest to declare.