Immune checkpoints: Cytotoxic T-lymphocyte antigen 4 and programmed cell death protein 1 in breast cancer surgery

Differential Response of MDA-MB-231 and MCF-7 Breast Cancer Cells to In Vitro Inhibition with CTLA-4 and PD-1 through Cancer-Immune Cells Modified Interactions

Drugs targeting immune checkpoint molecules have been found effective in melanoma, lung cancer, and other malignancies treatment. Recent studies on breast cancer demonstrated the significance of inhibitory anti-CTLA-4 and anti-PD-1 in the regulation of disease progression. However, seemingly the same types of breast cancer do not always respond unambiguously to immunotherapy. Thus, here we set out to analyze the in vitro effects of inhibiting CTLA-4 and PD-1 on interactions between co-cultured lymphocytes and two selected breast adenocarcinoma cell lines. Breast cancer cells were co-cultured with lymphocytes to evaluate the effects of CTLA-4 and PD-1 inhibition. Proliferation, cell cycle, and viability assessment were measured in cancer cells. IFN-gamma, IL-10, perforin, granzyme B production, and CTLA-4 and PD-1 expression were analyzed in lymphocytes. We found that administration of anti-CTLA-4 improved the anti-cancer activity of T cells with reduced proliferation and viability of MDA-MB-231. Lack of response was observed in the context of MCF-7. In addition, differential expression of checkpoint proteins was found between studied cancer cells lines. Inhibition of molecules was followed by IL-10 and IFN-gamma decrease in lymphocytes co-cultured with MDA-MB-231, not demonstrated in reference to MCF-7. Furthermore, CTLA-4 blockage was associated with reduction of CTLA-4+ and PD-1+ lymphocytes in MDA-MB-231, with a significant increase in MCF-7, reduced by anti-PD-1. Altogether, our study revealed that anti-CTLA-4 and anti-PD-1 treatment can improve lymphocytes effects on breast cancer cells. Favorable effects seemed to be related to breast cancer cells features as differential responses were reported. Novel blocking antibodies strategies should be tested for more effective cancer inhibition.

The effect of apis Dorsata honey as a complementary therapy to interleukin-6 (IL-6) levels and T lymphocytes of post-chemotherapy breast cancer patients

BACKGROUND

The overproduction of interleukin-6 (IL-6) in breast cancer cases can aggravate metastases. In comparison, the production of T lymphocytes plays a role in suppressing the development of tumor cells. Honey as a complementary therapy is expected to reduce the overproduction of IL-6 and facilitate the production of T lymphocytes in breast cancer cases.

OBJECTIVE

This study aims to determine the effect of Dorsata honey (DH) as a complementary therapy to IL-6 levels and T lymphocytes of post-chemotherapy in breast cancer.

METHODS

This study was a quasi-experimental approach that employed a pretest-posttest group control design. As many as 30 post-chemotherapy breast cancer patients at the Central Hospital in Eastern Indonesia were randomly selected into a control group of 15 participants. Additionally, an intervention group of 15 participants was given DH orally three times a day at a dose of 15 ml. The blood sample was taken two times, day 0 of the chemotherapy and day 16 (post-chemotherapy). The level of IL-6 was measured by ELISA, while the data were analyzed by Wilcoxon, independent T-test, and Mann-Whitney test.

RESULTS

The results showed that DH did not significantly affect IL-6 levels (p = 0.17). However, there was an increase in T lymphocyte levels with statistically significant differences (p = 0.01) in intervention groups. There was no difference in Il-6 and T lymphocyte levels between the intervention and control groups (p > 0.05).

CONCLUSIONS

Il-6 levels tend to be constant in the intervention group. However, there is a significant increase in the T lymphocyte levels which can indirectly increase the immune system and inhibit tumor cell growth in patients with breast cancer.

Identification of CTLA-4 associated with tumor microenvironment and competing interactions in triple negative breast cancer by co-expression network analysis

Background: The study of CTLA-4 inhibitors has been one of the hot spots in the field of tumor immunotherapy. As the most immunogenic subtype of breast cancer, Triple negative breast cancer (TNBC) has a great potential in the treatment strategy. The aim of this study was to explore the relevant genes and pathways of CTLA-4 in TNBC and to explore the prognostic value, so as to provide a theoretical basis for clinical studies.

Materials and methods: We used the data from The Cancer Genome Atlas (TCGA) to analyze the expression of CTLA-4 in different types of breast cancer, and analyzed the TNBC data of CTLA-4 related co-expression genes by WGCNA and enrichment analysis. LncRNA-miRNA-CTLA-4 network was constructed to explore the immune infiltration and immune checkpoint associated with CTLA-4. The effect of CTLA-4 on clinical outcomes in TNBC patients was also evaluated. Finally, we used data from GEO database to verify the differences of CTLA-4 in different molecular types of breast cancer and related prognostic results.

Results: CTLA-4 was significantly higher in TNBC than in Luminal subtype and Her-2 + subtype (P=0.019 and P<0.001, separately), and was significantly higher in ER and PR negative samples than in ER and PR positive samples (P<0.001). CTLA-4 related genes mainly enriched in biological process of leukocyte differentiation, regulation of leukocyte activation and T cell activation. Hsa-mir-92a was found to be a survival significance marker associated with CTLA-4 and lncRNA-miRNA-CTLA-4 network was constructed. The results of immune infiltration analysis showed that CTLA-4 was mainly related with T cell (r=0.74). For immune checkpoints analysis, CTLA-4 was mainly related to PDCD1(r=0.72) and CD28(r=0.64). In TNBC, high expression of CTLA-4 is related to good survival (P=0.0061). Results consistent with previous analysis were obtained in the GEO database, the expression of CTLA-4 in TNBC was significantly higher than that in non-TNBC (p<0.001), CTLA-4 was associated with favorable survival of TNBC (p<0.001).

Conclusion: Among all types of breast cancer, the expression of CTLA-4 was the highest in TNBC.CTLA-4 in TNBC can be regulated by hsa-mir-92a to form ceRNA networks and influence the prognosis of TNBC patients through the leukocyte differentiation, regulation of leukocyte activation and T cell activation pathway.

Synergistic antitumor effect of anti-PD-L1 combined with oxaliplatin on a mouse tumor model

Oxaliplatin (OXP) can change tumor microenvironment from immune-suppressive toward the immune-favorable condition. Almost all of the antitumor agents cannot totally cure cancer as monotherapy. So the current focus of cancer research became combining therapy using different treatment regimen, especially chemotherapy with checkpoint blockers. In this study, we assessed the activity of combining regimen using anti-PD-L1 with OXP in CT26 tumor-bearing BALB/c mice. We further analyzed the immune cell phenotypes in tumor site, lymph nodes, and spleen by flow cytometry analysis. Our study showed that combination therapy with OXP and anti-PD-L1 significantly increased survival in vivo and inhibited tumor growth of tumor-bearing mice. Inconsistent with better antitumor activity, our combination therapy led to an increase in tumor-infiltrating activated CD8+ T cells. In draining lymph nodes and spleen, regulatory T cells decreased significantly. Mice receiving either anti-PD-L1 or OXP alone had a larger tumor and lower survival rate in comparison with combination therapy receiving group. The time and order of administration of each component of the combination therapy affected antitumor response.

Changes in plasma EBV-DNA and immune status in patients with nasopharyngeal carcinoma after treatment with intensity-modulated radiotherapy

BACKGROUND

Previous studies reported the early diagnostic values of plasma Epstein-Barr virus (EBV)-DNA. The present study aimed to assess the relationship between the concentration of plasma EBV-DNA and the number of CD8⁺PD-1⁺(programmed cell death-1,PD-1) and regulatory T (Treg) cells in patients with nasopharyngeal carcinoma (NPC) who were treated with intensity-modulated radiotherapy (IMRT).

METHODS

This study included 37 patients treated with IMRT. Peripheral blood samples were collected two times for each patient, before radiation therapy and 1 week after the treatment. Further, the numbers of CD4⁺, Treg, CD8⁺, and CD8⁺PD1⁺ cells were determined by flow cytometry.

RESULTS

The changes after IMRT were determined by comparing the numbers of neutrophils, lymphocytes, CD4⁺, Treg, CD8⁺, CD8⁺PD1⁺ cells, and the concentration of plasma EBV-DNA between pretreatment and post-treatment groups. IMRT could reduce the expression level of PD-1 and the number of Treg cells. The concentration of plasma EBV-DNA and the expression level of CD8⁺PD-1⁺ were closely associated with the occurrence and development of NPC. Thus, EBV-DNA can be used as an important marker for early diagnosis, and IMRT can strongly reduce the copies of EBV-DNA.

CONCLUSIONS

This study showed that IMRT could reverse T-cell exhaustion and reduce the copies of EBV-DNA. In clinical practice, plasma EBV-DNA is a sensitive biomarker for diagnosis, prognosis, and evaluation of clinical efficacy.

Combination immunotherapy with interleukin-2 surface-modified tumor cell vaccine and programmed death receptor-1 blockade against renal cell carcinoma

Immunotherapy may be an effective way to prevent postoperative recurrence of renal cell carcinoma. Streptavidin‐interleukin‐2 (SA‐IL‐2) surface‐modified tumor cell vaccine developed through our protein‐anchor technology could induce specific antitumor T‐cell responses, but this immunotherapy cannot completely eradicate the tumor. These effector T cells highly expressed programmed death receptor‐1 (PD‐1), and the expression of programmed death ligand‐1 (PD‐L1) in the tumor environment also was upregulated after SA‐IL‐2‐modified vaccine therapy. PD‐1/PD‐L1 interaction promotes tumor immune evasion. Adding PD‐1 blockade to SA‐IL‐2‐modified vaccine therapy increased the number of CD4⁺, CD8⁺ and CD8⁺interferon‐γ⁺ but not CD4⁺Foxp3⁺ T cells. PD‐1 blockade could rescue the activity of tumor‐specific T lymphocytes induced by the SA‐IL‐2‐modified vaccine. Combination therapy delayed tumor growth and protected mice against a second Renca cells but not melanoma cells challenge. Taken together, PD‐1 blockade could reverse immune evasion in the treatment with SA‐IL‐2‐modified vaccine, and eventually induce a stronger specific antitumor immune response against renal cell carcinoma.

Breast cancer genomics and immuno-oncological markers to guide immune therapies

There is an increasing awareness of the importance of tumor - immune cell interactions to the evolution and therapy responses of breast cancer (BC). Not surprisingly, numerous studies are currently assessing the clinical value of immune modulation for BC patients. However, till now durable clinical responses are only rarely observed. It is important to realize that BC is a heterogeneous disease comprising several histological and molecular subtypes, which cannot be expected to be equally immunogenic and therefore not equally sensitive to single immune therapies. Here we review the characteristics of infiltrating leukocytes in healthy and malignant breast tissue, the prognostic and predictive values of immune cell subsets across different BC subtypes and the various existing immune evasive mechanisms. Furthermore, we describe the presence of certain groups of antigens as putative targets for treatment, evaluate the outcomes of current clinical immunotherapy trials, and finally, we propose a strategy to better implement immuno-oncological markers to guide future immune therapies in BC.

PD-1/PD-L1 blockade enhances the efficacy of SA-GM-CSF surface-modified tumor vaccine in prostate cancer

Program death receptor-1 (PD-1)/program death ligand 1 (PD-L1) signaling plays an important role in tumor adaptive immune resistance. The streptavidin-granulocyte-macrophage colony stimulating factor (SA-GM-CSF) surface-modified tumor cells vaccine developed through our novel protein-anchor technology could significantly promote the activation of dendritic cells. Although GM-CSF vaccine could significantly increase the number of tumor-specific CD8⁺T-cells, the majority of these CD8⁺T-cells expressed PD-1. Moreover, GM-CSF vaccine up-regulated the PD-L1 expression of tumor cells, resulting in immune resistance. Adding PD-1/PD-L1 blockade to GM-CSF vaccine therapy could significantly increase the population of CD4⁺ T, CD8⁺ T and CD8⁺ IFN-γ⁺ T but not CD4⁺ Foxp3⁺ T-cells and induced the highest production of IFN-γ. PD-1/PD-L1 blockade could effectively rescue the tumor-specific T lymphocytes generated by the GM-CSF vaccine, resulting in consistent tumor rejection. Taken together, PD-1/PD-L1 blockade combined with SA-GM-CSF-modified vaccine could effectively induce a strong specific antitumor immune response against prostate cancer.

Association of cytotoxic T-lymphocyte antigen 4 +49A/G gene polymorphism with acute rejection risk in renal transplantation

The conclusions on the association between cytotoxic T-lymphocyte antigen 4 (CTLA4) +49A/G gene polymorphism and acute rejection risk in renal transplantation are still debated. This meta-analysis was performed to update the association between CTLA4 +49A/G and acute rejection risk in renal transplantation. The association investigations were identified from PubMed and Cochrane Library, and eligible studies were included and synthesized using meta-analysis method. Fourteen reports were included into this meta-analysis for the association of CTLA4 A/G gene polymorphism and acute rejection risk in renal transplantation, consisting of 962 acute rejection patients and 2084 non-acute rejection controls. The association between CTLA4 G allele/GG genotype and acute rejection risk in renal transplantation was found in this meta-analysis (G allele: OR=1.21, 95% CI: 1.03-1.44, P=.02; GG genotype: OR=1.37, 95% CI: 1.10-1.69, P=.004). However, the AA genotype was not associated with acute rejection risk in renal transplantation. In conclusion, CTLA4 G allele/GG genotype is associated with the acute rejection risk in renal transplantation.