HPV16 E6 and E7 expressing cancer cells suppress the antitumor immune response by upregulating KLF2-mediated IL-23 expression in macrophages
Menée à l'aide de modèles murins, cette étude met en évidence un mécanisme par lequel les cellules cancéreuses exprimant les protéines E6 et E7 du papillomavirus humain de type16 suppriment la réponse immunitaire antitumorale en favorisant, via l'augmentation de l'expression du facteur KLF2 dans les macrophages associés à la tumeur, la production d'interleukine IL-23 par les macrophages M2
Background : Human papillomavirus type 16 (HPV16) positive cancers have a tumor environment that induces antigen-presenting cells to increase IL-23 expression. Unclear is if HPV16 E6/E7 oncoproteins expressed in these cancers play a role in upregulating interleukin (IL)-23 in the tumor microenvironment (TME), and how this cytokine impacts the antitumor cytotoxic T-cell response in HPV16+ cancer.
Methods : CD8 T-cells targeting HPV16+ cancer cells were isolated from C57BL/6 mice bearing HPV16+ C3.43 tumors that were therapeutically vaccinated against HPV16 E6/E7 and incubated with IL-23. These T-cells were then co-incubated with HPV16+ target cells in a cytotoxicity assay to assess their cytolytic capacity. Additionally, carboxyfluorescein succinimidyl ester (CFSE) labeled T-cells were used to track the effect of IL-23 on their proliferation. The effect of IL-23 neutralization on vaccine-induced antitumor immunity during tumor progression was studied in vivo to assess its potential as either a standalone treatment or combined with a vaccine targeting HPV16 E6/E7. HPV16
−
tumors were engineered to express E6/E7 to find out if these oncoproteins upregulate IL-23. To understand how HPV oncoproteins in the TME affect transcriptional regulation of IL-23 producing cells, we used single-cell Assay for Transposase-Accessible Chromatin (ATAC)+RNA sequencing.
Results : Inside macrophages residing in the HPV+ TME, transcription factor enrichment and linkage analysis identified KLF2 as a potential regulator of Il23a. Overexpression of KLF2 in macrophages upregulates IL-23 production. CD8 T-cells that recognize HPV16+ cells incubated with IL-23 are inhibited in both their killing and proliferative capacities. IL-23 neutralization increased the presence of HPV-specific cytotoxic CD8 T-cells inside the HPV16+TME in an IL-17 independent manner. Combination of IL-23 neutralization followed by HPV16 E6/E7 vaccination increases survival by amplifying the anti-tumor immune response.
Conclusion : This study finds that the presence of HPV oncoproteins in tumor cells increases KLF2 expression in tumor-associated macrophages in vivo. It also shows that KLF2 upregulates IL-23 production in M2 macrophages, resulting in increased IL-23 levels in the TME. In addition, it is shown that elevated levels of IL-23 suppress the antitumor immune response and that IL-23 neutralization synergizes with therapeutic vaccination against HPV oncoproteins.
Journal for ImmunoTherapy of Cancer , article en libre accès, 2025