Antibodies Against Immune Checkpoint Molecules Restore Functions of Tumor-Infiltrating T Cells in Hepatocellular Carcinomas

BACKGROUND & AIMS

Ligand binding to inhibitory receptors on immune cells, such as programmed cell death 1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 (CTLA4), down-regulates the T-cell-mediated immune response (called immune checkpoints). Antibodies that block these receptors increase antitumor immunity in patients with melanoma, non-small-cell lung cancer, and renal cell cancer. Tumor-infiltrating CD4⁺ and CD8⁺ T cells in patients with hepatocellular carcinoma (HCC) have been found to be functionally compromised. We analyzed HCC samples from patients to determine if these inhibitory pathways prevent T-cell responses in HCCs and to find ways to restore their antitumor functions.

METHODS

We collected HCC samples from 59 patients who underwent surgical resection from November 2013 through May 2017, along with tumor-free liver tissues (control tissues) and peripheral blood samples. We isolated tumor-infiltrating lymphocytes (TIL) and intra-hepatic lymphocytes. We used flow cytometry to quantify expression of the inhibitory receptors PD-1, hepatitis A virus cellular receptor 2 (TIM3), lymphocyte activating 3 (LAG3), and CTLA4 on CD8⁺ and CD4⁺ T cells from tumor, control tissue, and blood; we studied the effects of antibodies that block these pathways in T-cell activation assays.

RESULTS

Expression of PD-1, TIM3, LAG3, and CTLA4 was significantly higher on CD8⁺ and CD4⁺ T cells isolated from HCC tissue than control tissue or blood. Dendritic cells, monocytes, and B cells in HCC tumors expressed ligands for these receptors. Expression of PD-1, TIM3, and LAG3 was higher on tumor-associated antigen (TAA)-specific CD8⁺ TIL, compared with other CD8⁺ TIL. Compared with TIL that did not express these inhibitory receptors, CD8⁺ and CD4⁺ TIL that did express these receptors had higher levels of markers of activation, but similar or decreased levels of granzyme B and effector cytokines. Antibodies against CD274 (PD-ligand1 [PD-L1]), TIM3, or LAG3 increased proliferation of CD8⁺ and CD4⁺ TIL and cytokine production in response to stimulation with polyclonal antigens or TAA. Importantly, combining antibody against PD-L1 with antibodies against TIM3, LAG3, or CTLA4 further increased TIL functions.

CONCLUSIONS

The immune checkpoint inhibitory molecules PD-1, TIM3, and LAG3 are up-regulated on TAA-specific T cells isolated from human HCC tissues, compared with T cells from tumor-free liver tissues or blood. Antibodies against PD-L1, TIM3, or LAG3 restore responses of HCC-derived T cells to tumor antigens, and combinations of the antibodies have additive effects. Strategies to block PD-L1, TIM3, and LAG3 might be developed for treatment of primary liver cancer.

The new European Society of Cardiology guidelines on myocardial revascularisation: an appraisal

The latest European Society of Cardiology (ESC) guidelines on myocardial revascularisation are reviewed. The nearly 300 recommendations make it difficult to apply them in their totality. The authors would propose 20-30 recommendations per guideline based on sound clinical evidence. Also, the scope of the current guidelines is very wide as it includes topics already incorporated in other guidelines, such as strategies for pre-intervention diagnosis and imaging as well as on secondary prevention. Some recommendations in the new guidelines are sensible and will not be disputed. In particular, the encouragement of a balanced multidisciplinary decision process (the 'heart team') is welcome. Although coronary revascularisation in unstable high risk patients is well accepted, this is less the case for the low risk patient with chest pain. This issue is controversial and a balanced discussion of the pros and cons of percutaneous coronary intervention is missing. Despite convincing evidence indicating lack of benefit of percutaneous coronary intervention for chronic total occlusion, this procedure is not discouraged. Lastly, most committee members were interventional cardiologists or cardiac surgeons. Guideline committees should be representative of the whole group of professionals as the interpretation of the evidence by specialists may be biased. There may be a role for procedure oriented guidelines but, in that case, the items at issue should remain confined to matters directly related to technical aspects of the procedure.

Comparison of six-year clinical outcome of sirolimus- and paclitaxel-eluting stents to bare-metal stents in patients with ST-segment elevation myocardial infarction: an analysis of the RESEARCH (rapamycin-eluting stent evaluated at Rotterdam cardiology hospital) and T-SEARCH (taxus stent evaluated at Rotterdam cardiology hospital) registries

BACKGROUND

Short- and long-term data showed that drug-eluting stents (DES) significantly decreased target vessel revascularization (TVR) and major adverse cardiac event (MACE) rates compared to bare-metal stents (BMS). However, conflicting long-term data remain for patients with ST-segment elevation myocardial infarction (STEMI).

OBJECTIVE

Our aim was to assess the 6-year clinical outcome of all patients undergoing primary percutaneous coronary intervention (PPCI) for a de novo lesion with exclusive use of BMS, sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES).

METHODS

Three PPCI cohorts (BMS = 80; SES = 92; PES = 162) were systematically followed for the occurrence of MACE.

RESULTS

Very late stent thrombosis was more common after the implantation of SES as compared to PES or BMS (7.6%, 0.6%, and 0.0%, respectively; p = 0.001). Kaplan-Meier estimates indicate no statistically significant difference for mortality between the three stent types at 6 years (BMS = 25%; SES = 15%; PES = 21%; Log-rank p = 0.2). After adjustment for differences in baseline characteristics, mortality, mortality/myocardial infarction (MI), and MACE rates were significantly lower for SES compared to BMS, but not for PES (aHR = 0.41, 95% CI: 0.17-0.98; aHR = 0.44, 95% CI: 0.21-0.96; aHR = 0.35, 95% CI: 0.17-0.72, respectively). No differences were observed between the three stent types for TVR rates.

CONCLUSION

Neither SES nor PES improved safety or efficacy as compared to BMS in a STEMI population at 6 years. After adjusting, the usage of SES resulted in a significant decrease in mortality, mortality/MI and MACE rates as compared to BMS, in contrast to the usage of PES. SES and PES have a similar effectiveness and safety profile, although very late stent thrombosis was more common with SES.