IMDQ- and OVA-loaded
nanogels provide both prophylactic and therapeutic
immunity toward a surface neoantigen-expressing tumor model. (A) MC38
cancer cells were genetically engineered to stably express OVA on
their surface. (B) ImageStream analysis of wild-type MC38 cells (top),
MC38 cells expressing only EGFP (middle) and MC38mOVA (EGFP+, bottom) stained for surface OVA by OVA-specific antibodies. Image
panels (left to right) show brightfield (BF, magnification 40×),
EGFP expression (green), surface OVA expression (Alexa Fluor 647,
red), and overlay image (EGFP/surface OVA). (C) CD8+ T
cell-mediated killing of MC38mOVA and control target cells (MC38 and
peptide-pulsed MC38 (1 μM, 45 min at 37 °C)) after incubation
with OT-I T cells at the indicated ratios (specific target lysis was
calculated as described in the Supporting Information). (D) Prophylactic immunization schedule and challenge with MC38mOVA
tumor cells. (E) Results of the individual tumors after prophylactic
immunization with the corresponding nanogel samples or PBS (n = 10). (F) End point tumor volume showing reduced tumor
growth for NP(IMDQ+OVA)- and NP(IMDQ)+sOVA-immunized mice compared
to PBS group; however, no significant difference between NP(IMDQ+OVA)
and NP(IMDQ)+sOVA could be found. (G) Therapeutic schedule for the
treatment of mice challenged with MC38mOVA tumor cells (n = 10). (H) Results of the individual tumors after therapeutic treatment
with the corresponding nanogel samples or PBS. (I) End point tumor
volume showing reduced tumor growth for NP(IMDQ+OVA) and NP(IMDQ)+sOVA-treated
mice compared to PBS group. A more significant difference between
NP(IMDQ+OVA) and NP(IMDQ)+sOVA could be found compared to the prophylactic
treatment.