Biology subjects

Ramos, R. N.

Publications and source records attributed to Ramos, R. N..

3 recordsLinked to original sources

bioRxiv2026

Single-cell proteomics maps circulating monocyte dynamics in advanced head and neck squamous cell carcinoma

It remains unclear whether metastatic progression in head and neck squamous cell carcinoma (HNSCC) is accompanied by functional remodeling of circulating immune cells at the proteome level. To address this question, we applied single-cell proteomics (SCP) to cryopreserved peripheral blood mononuclear cells (PBMCs) from three patients with HNSCC representing distinct stages of metastatic progression and two healthy donors. Proteomic analysis of 619 individual PBMCs resolved major immune cell populations, with up to 1,638 proteins quantified per cell. Trajectory inference, clustering, and differential abundance analyses revealed proteomic remodeling associated with disease progression, with the most pronounced changes occurring within a monocyte cluster composed exclusively of cells from patients with nodal metastasis. This population showed increased abundance of interferon-related proteins, HLA molecules, and myeloid immunoregulatory signatures, consistent with an activated, interferon-associated monocyte state. In parallel, lymphocytes showed reduced coordinated abundance of proteins associated with activation, cytotoxicity, and degranulation, consistent with altered cytotoxic effector programs across disease stages. Overall, these findings reveal distinct proteomic states in circulating monocytes and lymphocytes associated with HNSCC progression and identify selective remodeling of the monocyte compartment in nodal metastatic disease.

cancer biology↗

bioRxiv2026

CAR-Engineered Human Hematopoietic Stem Cell Macrophages Control Solid Tumors

Chimeric antigen receptor (CAR) T-cells have represented a groundbreaking advance in the control of hematological cancers. However, their efficacy in controlling solid tumors has been rather limited, highlighting the importance of new cell-based therapies strategies to curb the progression of solid cancers. Here, we generated functional macrophages from human umbilical cord blood derived CD34+ hematopoietic stem cells (HSCs) engineered to express CARs. Approximately 50% of the CAR-MacCD34 population expressed anti-HER2 CARs and maintained high viability throughout differentiation. Mass spectrometry (MS) and multiparametric flow cytometry analysis revealed upregulation of proteins associated with phagocytosis, matrix remodeling, and degradation, indicating enhanced tumor infiltration potential. In vitro, CAR-MacCD34 exhibited a significantly higher capacity to phagocytose HER2-positive tumor cells compared to untransduced MacCD34 cells. Additionally, CAR-MacCD34 cells that phagocytosed cancer cells showed increased nuclear translocation of NF-kB, suggesting CAR-mediated intracellular signaling. To assess functionality in a more physiologically relevant context, we used tumor spheroids embedded in a dense 3D collagen matrix. Confocal microscopy and live imaging revealed that CAR-MacCD34 cells exhibited superior infiltration of dense tumor spheroids compared to untransduced MacCD34 cells. Notably, we observed multiple instances of tumor cell phagocytosis by CAR-MacCD34 cells in this 3D model. In addition, we employed in vivo zebrafish larvae models of HER2-positive tumors. We noted that CAR-MacCD34 cells persisted for over 8 days post-injection and demonstrated significantly greater efficacy in controlling tumor growth compared to untransduced MacCD34 cells. Our findings introduce a novel CAR-macrophage therapeutic approach with promising clinical potential, leveraging a renewable and accessible cellular source. Optimizing CAR-MacCD34 functionality in combination with existing therapies may lead to durable and effective anti-tumor responses for patients with solid tumors.

immunology↗

bioRxiv2021

Tissue-resident FOLR2+ macrophages associate with tumor-infiltrating CD8+ T cells and with increased survival of breast cancer patients.

Macrophage infiltration is a hallmark of solid cancers and overall macrophage infiltration is correlated with lower patient survival and resistance to therapy. However, tumor-associated macrophages are phenotypically and functionally heterogeneous. Specific tumor-associated macrophage subsets might be endowed with antagonistic role on cancer progression and on the development of anti-tumor immunity. For instance, monocyte-derived TREM2+ tumor-associated macrophages have pro-tumorigenic and immunosuppressive functions. Here, we identify a discrete population of FOLR2+ tumor-associated macrophages positively correlating with patient survival in breast cancer. FOLR2+ macrophages are evolutionarily conserved across species and populate human and murine healthy mammary gland. Moreover, FOLR2+ macrophages co-localize with lymphoid aggregates containing CD8+ T cells in breast cancer and across ten other types of cancers. This study highlights antagonistic roles for tumor-associated macrophage subsets and paves the way for subset-specific therapeutic interventions in macrophages-based cancer therapies.

immunology↗