Inhibition of estrogen signaling in myeloid cells increases tumor immunity in melanoma
Binita Chakraborty, … , Ching-Yi Chang, Donald P. McDonnell
Binita Chakraborty, … , Ching-Yi Chang, Donald P. McDonnell
Published October 12, 2021
Citation Information: J Clin Invest. 2021;131(23):e151347. https://doi.org/10.1172/JCI151347.
View: Text | PDF
Research Article Oncology

Inhibition of estrogen signaling in myeloid cells increases tumor immunity in melanoma

Abstract

Immune checkpoint blockade (ICB) therapies have significantly prolonged patient survival across multiple tumor types, particularly in melanoma. Interestingly, sex-specific differences in response to ICB have been observed, with males receiving a greater benefit from ICB than females, although the mechanism or mechanisms underlying this difference are unknown. Mining published transcriptomic data sets, we determined that the response to ICBs is influenced by the functionality of intratumoral macrophages. This puts into context our observation that estrogens (E2) working through the estrogen receptor α (ERα) stimulated melanoma growth in murine models by skewing macrophage polarization toward an immune-suppressive state that promoted CD8+ T cell dysfunction and exhaustion and ICB resistance. This activity was not evident in mice harboring macrophage-specific depletion of ERα, confirming a direct role for estrogen signaling within myeloid cells in establishing an immunosuppressed state. Inhibition of ERα using fulvestrant, a selective estrogen receptor downregulator (SERD), decreased tumor growth, stimulated adaptive immunity, and increased the antitumor efficacy of ICBs. Further, a gene signature that determines ER activity in macrophages predicted survival in patients with melanoma treated with ICB. These results highlight the importance of E2/ER signaling as a regulator of intratumoral macrophage polarization, an activity that can be therapeutically targeted to reverse immune suppression and increase ICB efficacy.

Authors

Binita Chakraborty, Jovita Byemerwa, Jonathan Shepherd, Corinne N. Haines, Robert Baldi, Weida Gong, Wen Liu, Debarati Mukherjee, Sandeep Artham, Felicia Lim, Yeeun Bae, Olivia Brueckner, Kendall Tavares, Suzanne E. Wardell, Brent A. Hanks, Charles M. Perou, Ching-Yi Chang, Donald P. McDonnell

×

Figure 3

E2 regulates myeloid cell function in the TME.

Options: View larger image (or click on image) Download as PowerPoint
E2 regulates myeloid cell function in the TME. (A and B) uMAP plots of e...
(A and B) uMAP plots of expression profiles for tumor-infiltrating immune cells (CD45+) (n = 3 tumors/treatment, pooled together) isolated from iBP tumors. Each dot represents an individual cell (A). Percentage of CD68+ macrophages/monocytes among all sequenced cell types determined by scRNA-Seq in placebo- versus E2-treated samples (B). (C and D) Syngeneic tumor growth of B16F10 (1 × 105) and YuMM5.2 (5 × 105) cells in myeloid ERα-knockout (Esr1fl/fl LysMCre) and littermate control (Esr1fl/fl and LysMCre) mice that were ovariectomized and supplemented with either placebo or E2 pellets. Esr1fl/fl plus placebo (blue, n = 10); Esr1fl/fl plus E2 (maroon, n = 8); LysMCre plus placebo (brown, n = 7); LysMCre plus E2 (red, n = 7); Esr1fl/fl LysMCre plus placebo (black, n = 8); and Esr1fl/fl LysMCre plus E2 (purple, n = 8). (E) Tumor growth of YuMM5.2 cells (5 × 105) in CD8+ T cell–depleted C57BL6/J hosts that were ovariectomized and supplemented with placebo or E2 (n = 8 mice/treatment). (F–I) T cell proliferation was assessed after coculturing with tumor-infiltrating CD11b+ cells isolated from iBP mice treated with either placebo or E2. Shown are representative CFSE dilution plots of CD8+ (F) and CD4+(H) cells. Quantification of CFSE low/negative CD8+ (G) and CD4+ (I) populations, expressed as a percentage of CD8+ and CD4+ T cells (n = 3). Results are representative of 2 independent experiments. (J–Q) Representative flow cytometric plots and the percentage of IFN-γ+CD8+ and GZMB+CD8+ T cells (J–M) and IFN-γ+CD4+ and GZMB+CD4+ T cells (N–Q) after 72 hours of coculturing with tumor-infiltrating CD11b+ myeloid cells isolated from iBP mice treated with either placebo or E2 (n = 3/group). Data indicate the mean ± SEM. *P < 0.05 and **P < 0.01, by Student’s t test (G, I, K, M, O, and Q) and 2-way ANOVA followed by Bonferroni’s multiple-correction test (C–E). FSC-H, forward scatter height.