Panoply™ Human CXCL13 Over-expressing Stable Cell Line

Inflammatory breast cancer (IBC) is a highly aggressive subtype of breast cancer associated with a poor prognosis. A deep understanding of the pathological and molecular basis of IBC is crucial for developing precision medicine strategies. Here, researchers analyzed IBC at both single-cell and spatial levels to investigate immune cell populations and signaling pathways, and to identify potential therapeutic targets. Single-cell RNA sequencing (scRNA-seq) revealed significantly reduced CXCL13 expression in T cells within the IBC tumor microenvironment, a finding associated with poor patient prognosis. Furthermore, immune-related gene sets were significantly downregulated and intercellular interactions were attenuated, indicating an immunosuppressive state in IBC. Spatial analysis confirmed a reduction in CD45-positive immune cells within IBC tumor tissues, highlighting the impaired immune infiltration characteristic of this aggressive cancer subtype. Crucially, overexpression of CXCL13 in tumor cells significantly promoted tumor cell death in co-culture with immune cells. CXCL13 also enhanced the efficacy of anti-PD-1 therapy in vivo. Additionally, a screen of natural products identified sanguinarine and α-mangostin as potential immunomodulatory compounds, offering promising therapeutic avenues for modulating immune responses and improving treatment outcomes in IBC.

To validate the immunomodulatory effects of CXCL13 in vitro, researchers conducted co-culture experiments using CXCL13-overexpressing 4T1 tumor cells with either T cells or macrophages (RAW264.7). As shown in Figure 1A and B, co-culture of T cells with CXCL13-overexpressing 4T1 cells resulted in a significantly higher rate of tumor cell apoptosis compared to co-culture with 4T1 cells not overexpressing CXCL13. Furthermore, ELISA analysis of the culture supernatants revealed elevated levels of TNF-α, Granzyme B, and IFN-γ (Figure 1C), indicating enhanced T-cell activation and cytotoxicity. Similarly, after 24 hours of co-culture with RAW264.7 macrophages, flow cytometry analysis showed a higher tumor cell death rate in the CXCL13-overexpression group (Figure 1D and E). Additionally, flow cytometry analysis of the macrophages revealed that CXCL13 overexpression led to an increased proportion of M1-like macrophages (CD86+) and a decreased proportion of M2-like macrophages (CD206+) (Figure 1F–H). Consistent with this, qRT-PCR analysis confirmed the upregulation of M1-associated markers, including iNOS, TNF-α, and IL-6 (Figure 1I). Further microscopic observation demonstrated enhanced macrophage phagocytosis of tumor cells in the CXCL13-overexpression group (Figure 1J and K). Collectively, these results indicate that CXCL13 remodels the tumor microenvironment by promoting T-cell-mediated cytotoxicity and macrophage M1 polarization, thereby enhancing anti-tumor immunity and promoting tumor cell death.

Figure 1. In vitro co-culture experiments. (Sun X, et al., 2025)