Anti-PD-1 immunotherapy with adjuvant ablative fractional laser displays increased tumour clearance of squamous cell carcinoma, a murine study.

PD-1 checkpoint inhibitors are used as systemic immunotherapy for locally advanced and metastatic cutaneous squamous cell carcinoma (SCC); however, improved treatment efficacy is urgently needed. In this study, we aimed to investigate the effect of combining systemic anti-PD-1 treatment with adjuvant ablative fractional laser (AFL) in a spontaneous SCC mouse model. Tumours induced by ultraviolet radiation in the strain C3.Cg-Hrhr /TifBomTac were divided into four groups: anti-PD-1-antibody+AFL (n = 33), AFL alone (n = 22) anti-PD-1-antibody alone (n = 31) and untreated controls (n = 46). AFL was given at Day 0 (100 mJ/mb, 5% density), while anti-PD-1-antibody (ip, 200 µg) at Days 0, 2, 4, 6 and 8. Response to treatment was evaluated by tumour growth, survival time and by dividing response to treatment into complete responders (clinically cleared tumours), partial responders (reduced tumour growth rate compared to untreated controls) and non-responders (no decrease in tumour growth rate compared to untreated controls). The strongest tumour response was observed following the combination of systemic anti-PD-1 treatment combined with laser exposure, resulting in the highest percentage of complete responders (24%) compared with untreated controls (0%, p < 0.01), AFL monotherapy (13%, p > 0.05) and anti-PD-1-antibody monotherapy (3%, p > 0.05). Moreover, all three treatment interventions demonstrated significantly reduced tumour growth rates compared with untreated controls (p < 0.01), and the mice had significantly longer survival times (p < 0.01). In conclusion, the combination treatment revealed an improved treatment effect that significantly enhanced the complete tumour clearance not observed with the monotherapies, indicating a possible additive effect of anti-PD-1 with adjuvant AFL in treatment of SCC.

Ablative fractional CO2 laser treatment promotes wound healing phenotype in skin macrophages.

OBJECTIVES: Ablative fractional laser (AFL) treatment is a well-established method for reducing signs of skin photoaging. However, the biological mechanisms underlying AFL-induced healing responses and skin rejuvenation remain largely unknown. It is known that macrophages play an important role in orchestrating healing, normalization, and remodeling processes in skin. Macrophage phenotypes are characterized by inflammatory markers, including arginase-1 (Arg1), major histocompatibility class II molecules (MHC II), and CD206. This study aims to explore AFL's effect on macrophage phenotype by evaluating changes in inflammatory markers and the potential concurrent accumulation of Arg1 in the skin. METHODS: Mice (n = 9) received a single AFL treatment on the left side of the back skin (100 mJ/microbeam, 5% density) while the right side of the back remained untreated as control. Treated and untreated skin from each mouse were collected Day 5 posttreatment for flow cytometry and histology analysis. Flow cytometry evaluated the immune infiltration of macrophages and the expression of macrophage inflammatory markers (Arg1, MHC II, and CD206). In addition, Arg1 presence in the skin was evaluated through antibody staining of histology samples and quantification was performed using QuPath image analysis software. RESULTS: Following AFL, the number of macrophages increased 11-fold (p = 0.0053). Phenotype analysis of AFL-treated skin revealed an increase in the percentage of macrophages positive for Arg1 (p < 0.0001) and a decrease in the percentage of macrophages positive for MHC II (p < 0.0001) compared to untreated skin. No significant differences were observed in percentage of CD206-positive macrophages (p = 0.8952). Visualization of AFL-treated skin demonstrated a distinct pattern of Arg1 accumulation that correlated with the microscopic treatment zones (MTZ). Quantification of the percentage of Arg1-positive area in epidermis and dermis showed a significant increase from 3.5% ± 1.2% to 5.2% ± 1.7 (p = 0.0232) and an increase from 2.2% ± 1.2% to 9.6% ± 3.3 (p < 0.0001) in whole skin samples. CONCLUSION: AFL treatment polarizes macrophages toward a wound healing phenotype and induces Arg1 accumulation in the MTZ. We propose that the polarized wound healing macrophages are a major source for the increased Arg1 levels observed in the skin following treatment.

Cell surface-tethered IL-12 repolarizes the tumor immune microenvironment to enhance the efficacy of adoptive T cell therapy.

Immune-activating cytokines such as interleukin-12 (IL-12) hold strong potential for cancer immunotherapy but have been limited by high systemic toxicities. We describe here an approach to safely harness cytokine biology for adoptive cell therapy through uniform and dose-controlled tethering onto the surface of the adoptively transferred cells. Tumor-specific T cells tethered with IL-12 showed superior antitumor efficacy across multiple cell therapy models compared to conventional systemic IL-12 coadministration. Mechanistically, the IL-12-tethered T cells supported a strong safety profile by driving interferon-γ production and adoptively transferred T cell activity preferentially in the tumor. Immune profiling revealed that the tethered IL-12 reshaped the suppressive tumor immune microenvironment, including triggering a pronounced repolarization of monocytic myeloid-derived suppressor cells into activated, inflammatory effector cells that further supported antitumor activity. This tethering approach thus holds strong promise for harnessing and directing potent immunomodulatory cytokines for cell therapies while limiting systemic toxicities.

Anti-PD-1 Therapy with Adjuvant Ablative Fractional Laser Improves Anti-Tumor Response in Basal Cell Carcinomas.

The efficacy of anti-programmedcelldeath1therapy (aPD-1), which was recently approved for basal cell carcinoma (BCC) treatment, can be enhanced by adjuvant ablative fractional laser (AFL) in syngeneic murine tumor models. In this explorative study, we aimed to assess locally applied AFL as an adjuvant to systemic aPD-1 treatment in a clinically relevant autochthonous BCC model. BCC tumors (n = 72) were induced in Ptch1+/-K14-CreER2p53fl/fl-mice (n = 34), and the mice subsequently received aPD-1 alone, AFL alone, aPD-1+AFL, or no treatment. The outcome measures included mouse survival time, tumor clearance, tumor growth rates, and tumor immune infiltration. Both aPD-1 and AFL alone significantly increased survival time relative to untreated controls (31 d and 34.5 d, respectively vs. 14 d, p = 0.0348-0.0392). Complementing aPD-1 with AFL further promoted survival (60 d, p = 0.0198 vs. aPD-1) and improved tumor clearance and growth rates. The BCCs were poorly immune infiltrated, but aPD-1 with adjuvant AFL and AFL alone induced substantial immune cell infiltration in the tumors. Similar to AFL alone, combined aPD-1 and AFL increased neutrophil counts (4-fold, p = 0.0242), the proportion of MHCII-positive neutrophils (p = 0.0121), and concordantly, CD4+ and CD8+ T-cell infiltration (p = 0.0061-0.0242). These descriptive results suggest that the anti-tumor response that is generated by aPD-1 with adjuvant AFL is potentially promoted by increased neutrophil and T-cell engraftment in tumors. In conclusion, local AFL shows substantial promise as an adjuvant to systemic aPD-1 therapy in a clinically relevant preclinical BCC model.