Treatment of Hepatocellular Carcinoma with Neoadjuvant Nivolumab Alone Versus in Combination with a CCR2/5 Inhibitor or an Anti-IL-8 Antibody

Changes in Serum Interleukin-8 Levels Predict Response to Immune Checkpoint Inhibitors Immunotherapy in Unresectable Hepatocellular Carcinoma Patients

Background

Effective biomarkers are needed to predict the efficacy of immune checkpoint inhibitors (ICIs) therapy in hepatocellular carcinoma (HCC). We evaluated the early changes in serum interleukin-8 (IL-8) levels as a biomarker of response to ICIs in patients with unresectable HCC.

Methods

Eighty patients who received ICIs therapy alone or in combination with other treatments for unresectable HCC were included. Serum was collected at baseline and 2-4 weeks after the first dose. Serum IL-8 levels were measured using by ELISA.

Results

In the progressive disease (PD) group, serum IL-8 levels increased significantly before the second dose of ICIs therapy compared with baseline levels (P < 0.001). Early changes in serum IL-8 levels were significantly associated with the response to ICIs therapy (P < 0.001). A cutoff value of 8.1% increase over the baseline most effectively predicted the response to ICIs. Increases in serum IL-8 levels > 8.1% indicated the uselessness of ICIs immunotherapy in patients with unresectable HCC. Patients with increases in serum IL-8 levels > 8.1% had significantly shorter overall survival (OS) and progression-free survival (PFS) than those with increases in serum IL-8 levels ≤ 8.1% (P < 0.001). Increases in serum IL-8 levels > 8.1% were independent prognosticators of worse OS (P = 0.003) and PFS (P < 0.001).

Conclusion

Early changes in serum IL-8 levels, measured only 2-4 weeks after starting therapy, could predict the response to ICIs therapy, as well as OS and PFS of patients with unresectable HCC. Increases in serum IL-8 levels > 8.1% indicated the uselessness of ICIs immunotherapy and predicted worse OS and PFS.

Interferon-α induces differentiation of cancer stem cells and immunosuppression in hepatocellular carcinoma by upregulating CXCL8 secretion

Interferon-alpha (IFN-α) is widely used in the clinical treatment of patients with chronic hepatitis B and hepatocellular carcinoma (HCC). However, high levels of CXCL8 are associated with resistance to IFN-α therapy and poorer prognosis in advanced cancers. In this study, we investigated whether IFN-α could directly induce the production of CXCL8 in HCC cells and whether CXCL8 could antagonize the antitumor activity of IFN-α. We found that IFN-α not only upregulated the expression of the inducible genes CXCL9, CXCL10, CXCL11 and PD-L1, but also significantly stimulated CXCL8 secretion in HCC cells. Mechanically, IFN-α induces CXCL8 expression by activating the AKT and JNK pathways. In addition, our results demonstrate that IFN-α exposure significantly increases the differentiation of HCC stem cells, but this effect is reversed by the addition of the CXCL8 receptor CXCR1/2 inhibitor Reparixin and STAT3 inhibitor Stattic. Besides, our study reveals that the cytokine CXCL8 secreted by IFN-α-induced HCC cells inhibits T-cell function. Conversely, inhibition of CXCL8 promotes TNF-α and IFN-γ secretion by T cells. Finally, liver cancer patients who received anti-PD-1/PD-L1 immunotherapy with high CXCL8 expression had a lower immunotherapy efficacy. Overall, our findings clarify that IFN-α triggers immunosuppression and cancer stem cell differentiation in hepatocellular carcinoma by upregulating CXCL8 secretion. This discovery provides a novel approach to enhance the effectiveness of HCC treatment in the future.

Neutralizing IL-8 potentiates immune checkpoint blockade efficacy for glioma

Malignant gliomas are largely refractory to immune checkpoint blockade (ICB) therapy. To explore the underlying immune regulators, we examine the microenvironment in glioma and find that tumor-infiltrating T cells are mainly confined to the perivascular cuffs and express high levels of CCR5, CXCR3, and programmed cell death protein 1 (PD-1). Combined analysis of T cell clustering with T cell receptor (TCR) clone expansion shows that potential tumor-killing T cells are mainly categorized into pre-exhausted/exhausted and effector CD8⁺ T subsets, as well as cytotoxic CD4⁺ T subsets. Notably, a distinct subpopulation of CD4⁺ T cells exhibits innate-like features with preferential interleukin-8 (IL-8) expression. With IL-8-humanized mouse strain, we demonstrate that IL-8-producing CD4⁺ T, myeloid, and tumor cells orchestrate myeloid-derived suppressor cell infiltration and angiogenesis, which results in enhanced tumor growth but reduced ICB efficacy. Antibody-mediated IL-8 blockade or the inhibition of its receptor, CXCR1/2, unleashes anti-PD-1-mediated antitumor immunity. Our findings thus highlight IL-8 as a combinational immunotherapy target for glioma.