Supplementary MaterialsSupplemental data jci-130-128267-s142. in several cancer versions, including intense intracranial glioblastoma. Ag-loaded monocytes induced solid CTL reactions via Ag transfer to splenic Compact disc8+ DCs in a way 3rd party of monocyte APC activity. Ag transfer required cell-cell get in touch with and the forming of connexin 43Ccontaining distance junctions between DCs and monocytes. These results demonstrate the lifestyle of a competent distance junctionCmediated Ag transfer pathway between monocytes and Compact disc8+ DCs and claim that administration of tumor AgCloaded undifferentiated monocytes may serve as a straightforward and efficacious immunotherapy for the treating human malignancies. < 0.05, **< 0.01, ***< 0.001, and ****< 0.0001. One-way ANOVA with Tukeys check (A, C, E, H); 2-method ANOVA with Bonferronis test (D and J); and unpaired 2-tailed Students test (G). Data represent mean SEM. We next determined whether monocytes loaded with a natural tumor Ag would induce similar CTL responses. Monocytes were loaded with the endogenous MHCI-restricted murine melanoma Ag, tyrosinase-related protein 2 peptide (TRP2180-188), and injected IV into mice at 106 cells/injection every other day for a total of 5 injections. Ten days after the first monocyte injection, robust TRP2-specific CD8+ T cell responses were detected in the blood (Figure 1, F and G). To evaluate the potency of monocytes relative to other leukocyte types in Z-Ile-Leu-aldehyde triggering Ag-specific CTL responses, we IV injected dose-matched (3 Z-Ile-Leu-aldehyde 106) OVA-loaded (1 mg/mL) monocytes, neutrophils, T cells, B cells, and splenocytes into mice and quantified OVA-specific CD8+ T cells 7 days later in the spleen. We found that monocytes consistently triggered at least 2-fold greater OVA-specific CD8+ T cell responses than other major blood leukocytes or splenocytes (Figure 1H). Finally, we asked whether Ag-loaded monocytes administered SQ would induce CTL responses comparable to the IV route. Seven days after injection, Z-Ile-Leu-aldehyde neither IV nor SQ OVA-monocyte administration induced significant responses in either draining or nondraining lymph nodes (LNs). In the spleen, OVA-specific CD8+ T cell responses were more than 2-fold greater after IV than after SQ OVA-monocyte administration (Figure 1, I and J). These results are consistent with previous studies showing poor migration of monocytes to the draining LNs (29C31). Taken together, these results demonstrate that monocytes loaded with protein or MHCI-restricted peptide Ag can trigger robust CTL responses, particularly after IV administration. Ag-loaded monocytes induce stronger therapeutic antitumor responses than conventional cancer vaccines. To determine whether monocyte-triggered CTL activity is sufficient to treat tumors in vivo, we examined the therapeutic antitumor activity of monocyte vaccination in several murine tumor models. Efficacy was compared to that of classic cancer vaccines. We first used a murine melanoma model. OVA-expressing B16/F10 melanoma cells (B16/F10-OVA) were injected SQ into mice and vaccine treatments started 8 days later. In this model, Rabbit Polyclonal to TUBGCP6 OVA-monocytes suppressed tumor growth to a significantly greater extent than what was seen with classic OVA/CFA immunization (Supplemental Figure 3A). In a SQ murine melanoma model using parental B16/F10 cells, monocytes loaded with TRP2180-188 peptide significantly inhibited tumor growth, whereas a classic cellular vaccine consisting of irradiated GM-CSFCsecreting B16/F10 melanoma cells (GVAX) failed to suppress tumor growth, consistent with a previous report (32) (Supplemental Figure 3B). To compare monocyte vaccination with cDC vaccination, we first used the SQ murine B16/F10-OVA melanoma model with treatments starting on day 8 after tumor inoculation. For the DC vaccine, we used an optimized vaccination protocol we have previously described involving 3 weekly SQ injections of DCs electroporated with OVA mRNA, combined with adoptive transfer of OVA-specific CD8+ (OT-I) T cells. The vaccine Z-Ile-Leu-aldehyde site was preconditioned with tetanus/diphtheria (Td) toxoid to boost migration of vaccine DCs to draining LNs (33). We found that IV injection of dosage- and frequency-matched OVA-monocytes, without adoptive lymphocyte even.

Supplementary MaterialsSupplemental data jci-130-128267-s142