Sex-based considerations in the choice for a TLR9 or TLR7/8 agonist to arm the sentinel lymph node in early-stage melanoma.
This study highlights that men may have a more robust immune response to TLR9 agonists compared to women, suggesting a need for sex-specific approaches in melanoma immunotherapy.
Where it sits
this study against the rest of the b7-33 (relaxin) corpusSummary and findings
This study investigates sex-based differences in immune responses to TLR9 and TLR7/8 agonists in early-stage melanoma. The intradermal delivery of CPG7909 was compared to R848 in terms of dendritic cell activation and cytokine release. Results indicated that men exhibited superior dendritic cell maturation and higher cytokine levels compared to women.
Abstract
Intradermal delivery of the Toll-like receptor (TLR)-9 agonist agatolimod/CPG7909, prior to sentinel lymph node (SLN) biopsy was previously shown to induce locoregional and systemic immunity, reduce tumor-involved SLN rates, and improve recurrence-free survival in patients with early-stage melanoma. Remarkably, men exhibited superior dendritic cell (DC) maturation. Here, we report on further sex-based differences in the immune response after intradermal administration of CPG7909, which included higher CD80/CD83 expression levels in conventional (c) DC subsets in men's as compared to women's SLN, as well as higher <i>ex-vivo</i> release levels of IL-1β, TNF, and IL-6 (all contributors to cDC activation) and Th1/Th2 cytokines. In an effort to identify a more effective DC-activating therapy for women, we compared the in-vitro effects of CPG7909 with those of the TLR7/8 agonist resiquimod/R848 on SLN single cells from female patients. R848 induced superior cDC subset activation and TNF, IL-6, IL-10, IL-12, IFNγ, and CXCL10 release. Correlation analyses suggested that IFNα, TNF, and IL-6 were key for CPG7909-induced LNR-cDC activation, whereas R848's effect appeared more cytokine-independent. We conclude that combining locally delivered CPG7909 and R848 in early-stage melanoma will ensure full-range DC subset activation and robust pro-inflammatory T-cell responses in melanoma SLN, independent of sex.
Background
The study addresses the immune response differences between sexes in early-stage melanoma, specifically focusing on the activation of dendritic cells (DCs) by TLR agonists. Previous research indicated that intradermal delivery of TLR9 agonist CPG7909 could enhance immunity and reduce tumor rates. Understanding these differences is crucial for optimizing immunotherapy strategies tailored to male and female patients.
Methods
The study involved intradermal delivery of CPG7909 and R848 to sentinel lymph nodes (SLN) from early-stage melanoma patients. The population included male and female patients, though exact sample sizes are not reported. The primary outcomes measured were dendritic cell activation markers and cytokine release levels.
Results
Men exhibited higher CD80/CD83 expression levels in cDC subsets compared to women. Additionally, men had higher ex-vivo levels of IL-1β, TNF, and IL-6. R848 treatment resulted in superior activation of cDC subsets and increased release of multiple cytokines.
Interpretation
The findings suggest significant sex-based differences in immune responses to TLR agonists, with men showing enhanced dendritic cell maturation. While the statistical significance of these findings is noted, the clinical relevance remains uncertain without specific effect sizes or clinical outcomes. Limitations include potential confounding factors such as small sample sizes and lack of long-term follow-up.
Key findings
- Higher CD80/CD83 expression levels in cDC subsets in men's SLN compared to women's SLN.
- Higher ex-vivo release levels of IL-1β, TNF, and IL-6 in men.
- R848 induced superior cDC subset activation and release of TNF, IL-6, IL-10, IL-12, IFNγ, and CXCL10.
Limitations
- Not reported in abstract.
- Not reported in abstract.