53 Nephrectomy Remodels Peripheral Myeloid Cell States in Renal Cell Carcinoma

Abstract

Abstract Background Renal cell carcinoma (RCC) is a highly immunogenic cancer characterized by abundant CD8+ T cell infiltration, yet most patients do not achieve durable responses to immunotherapy. Notably, surgical removal of the primary tumor, even in metastatic disease, may enhance response to immunotherapy, an effect not observed with targeted therapies. This clinical observation suggests that the primary tumor in RCC imposes a systemic immunosuppressive state that can be reversed by primary tumor removal. However, the mechanisms by which RCC exerts this systemic immune suppression remain elusive. Interestingly, emerging evidence across tumor types suggests that primary tumors can perturb peripheral immunity by expanding suppressive myeloid populations, impairing antigen-presenting cell differentiation and function, and thereby dampening T cell responses. However, whether these mechanisms operate in RCC are unknown. Methods We profiled paired pre- and post-nephrectomy (2-45 weeks) PBMCs from 16 patients with RCC by single-cell RNA/CITE-seq (BioLegend TotalSeq-C Universal Cocktail) using weighted nearest-neighbor clustering to integrate RNA and protein modalities. Most patients present with localized disease (n = 13) and clear cell histology (n = 13). Myeloid subpopulations were subclustered and annotated. Differential gene expression was assessed using paired pseudobulk DESeq2 (FDR < 0.05, log2FC > 1). Cell type proportions were compared using centered log-ratio transformation, and pathway enrichment was assessed by GSEA. Results We identified 7 myeloid subpopulations, including two classical monocyte subtypes (C Mono.1-2; CD14), three non-classical monocyte subtypes (NC Mono.1-3; FCGR3A), a CD14+ IFN-stimulated subset (CD14+ IFN-stim; ISG15, MX1, STAT1), and conventional dendritic cells (cDC; CD1C, XCR1). Notably, the CD14+ IFN-stimulated population was significantly enriched pre-nephrectomy and largely resolved following tumor removal (p = 0.008), suggesting that this state depends on tumor-associated signals. At the broad level, total classical monocyte proportions increased significantly post-nephrectomy (p = 0.013), with non-classical monocytes showing a similar trend (p = 0.096), reflecting a global expansion of the monocyte compartment following tumor removal. cDC proportions also expanded significantly post-nephrectomy (p < 0.001), consistent with prior reports of increased antigen-presenting cell abundance following tumor removal. Monocyte subtypes showed striking temporal specificity, with distinct transcriptional states enriched pre- or post-nephrectomy, suggesting the tumor drives the systemic emergence of transcriptionally distinct monocyte states. C Mono.1, the dominant pre-surgical classical subtype, was characterized by androgen response and glycolysis pathway enrichment, consistent with a metabolically active tumor-conditioned state. C Mono.2, which emerged post-nephrectomy, exhibited a distinct inflammatory transcriptional program marked by TNFα signaling via NF-κB (NES = 2.07), allograft rejection (NES = 1.81), and inflammatory response (NES = 1.76). In concordance with C Mono.1, NC Mono.1 carried a pre-surgical glycolytic and tumor-conditioned signature, while NC Mono.2 expanded post-surgically with interferon alpha (NES = 2.19), interferon gamma (NES = 1.90), and TNFα signaling via NF-κB (NES = 1.92), mirroring the inflammatory transcriptional program observed in C Mono.2 and suggesting coordinated reprogramming across monocyte subsets following tumor removal. Conclusions Nephrectomy drives coordinated reprogramming of peripheral myeloid subsets in RCC, shifting both classical and non-classical monocytes from tumor-conditioned metabolic states toward a distinct inflammatory transcriptional program marked by interferon and TNFα/NF-κB signaling, which is sustained for weeks to months following tumor removal. The temporal specificity of these myeloid states implicates peripheral monocyte reprogramming as a key immunological outcome of nephrectomy, with implications for IO priming in the metastatic setting.53 Figure