CTLA-4: a moving target in immunotherapy

Immunomodulation in Oncolytic Measles Virotherapy

With the recognition of oncolytic virotherapy as an immunotherapy, the distinct interactions between oncolytic agents and the immune system have come into focus. The role of the immune system in oncolytic virotherapy is somewhat ambiguous: While preexisting or arising immunity directed against viral antigens may preclude efficient viral replication and spread, immunity directed against tumor antigens is considered essential for long-term treatment success. Aside from the antiviral and antitumor immune status of the patient, the specific immunological microenvironment in a given tumor adds an additional layer of complexity.In this review we focus on the case of measles virus, which has long been known for its multifaceted interplay with the immune system. The high prevalence of measles-neutralizing antibodies in the general population may pose additional challenges. The oncolytic measles virus vector platform offers manifold opportunities for tumor-targeted immunomodulation. This review provides a survey of immunomodulation in the context of measles virotherapy including strategies to suppress or circumvent antiviral immunity as well as enhance antitumor immunity that have been pursued in preclinical and clinical studies. Understanding and selective manipulation of the intricate balance between antiviral and antitumor immunity will be crucial to develop the full potential of oncolytic virotherapy.

Abatacept in rheumatoid arthritis and the risk of cancer: a world observational post-marketing study

Objectives

We aimed to investigate whether abatacept used in patients for RA was associated with an increased risk of reporting overall cancer and specific cancers, including breast, lung, lymphoma, melanoma and non-melanoma skin cancer when compared with other biologic DMARDs (bDMARDs).

Methods

We performed an observational study within VigiBase, the World Health Organization’s global database of individual case safety reports, from 2007 to 2017 to compare the cases of cancer reported in RA patients exposed to abatacept with those reported in RA patients exposed to other bDMARDs. We conducted disproportionality analyses allowing the estimation of reporting odds ratios (RORs) with 95% CIs of the exposure odds among spontaneous reporting of cancers to the exposure odds among other reported adverse effects.

Results

We identified 15 846 adverse effects reported in RA patients who received abatacept and 290 568 adverse effects reported in RA patients treated with other bDMARDs. Compared with other bDMARDs, the use of abatacept was not associated with an increased risk of reporting cancer overall [ROR 0.98 (95% CI 0.91, 1.05)]. Analyses by specific cancer sites showed a significantly increased ROR for melanoma [1.58 (95% CI 1.17, 2.08)], but not for other specific cancer sites.

Conclusion

Compared with other bDMARDs, exposure to abatacept in RA patients was only significantly associated with an increased risk of reporting melanoma. This increased risk is consistent with the properties of abatacept (CTLA-4 agonist) since it has an opposite action than ipilimumab, an antibody that blocks CTLA-4 and is approved for the treatment of malignant melanoma.

Trial registration

ClinicalTrials.gov (http://clinicaltrials.gov), NCT03980639.

Exosomal PD-L1 functions as an immunosuppressant to promote wound healing

Excessive and persistent inflammation after injury lead to chronic wounds, increased tissue damage or even aggressive carcinogenic transformation. Effective wound repair could be achieved by inhibiting overactive immune cells to the injured site. In this study, we obtained high concentration of PD-L1 in exosomes from either genetically engineered cells overexpressing PD-L1 or IFN-γ stimulated cells. We found that exosomal PD-L1 is specially bound to PD-1 on T cell surface, and suppressed T cell activation. Interestingly, exosomal PD-L1 promoted the migration of epidermal cells and dermal fibroblasts when pre-incubated with T cells. We further embedded exosomes into thermoresponsive PF-127 hydrogel, which was gelatinized at body temperature to release exosomes to the surroundings in a sustained manner. Of importance, in a mouse skin excisional wound model, exosomal PD-L1 significantly fastened wound contraction and reepithelialization when embedded in hydrogel during inflammation phase. Finally, exosomal PD-L1 inhibited cytokine production of CD8+ T cells and suppressed CD8+ T cell numbers in spleen and peripheral lymph nodes. Taken together, these data provide evidence on exosomal PD-L1 exerting immune inhibitory effects and promoting tissue repair.

Current status of therapeutic HPV vaccines

The accumulating successes of immune-based treatments for solid tumors have prompted an explosion of cancer clinical trials testing strategies to elicit tumor-specific immune effector responses, either alone, in combination with immune checkpoint blockade, or with conventional cancer treatment modalities. However, across the board, clinical responses have been achieved in only a limited subset of cancer patients, underscoring a critical need to identify mechanisms and biomarkers of response, as well as mechanisms of resistance to therapy. Cancers caused by human papillomavirus (HPV) are driven by two viral oncoproteins, E6 and E7, both of which are functionally required for cellular transformation, thereby providing non-'self', tumor-specific antigenic targets. Immune responses that are specific for either or both of these oncoproteins can be used to follow the magnitude and kinetics of immune responses to therapeutic interventions. Moreover, identifying neoantigens is not a concern in early-stage disease - since HPV cancers are driven by HPV oncoproteins, the somatic mutational load in early disease is low, particularly in comparison to non-HPV-related squamous cancers arising in the same organ site [1,2]. Cancers caused by HPV are a model clinical setting in which to test principles of immunotherapies, and to discover mechanisms of interactions between tumors and their attendant immune milieu. In this review, we will use examples of insights gained from studies of HPV disease to illustrate major themes of immune-based therapeutic strategies.

Immune Checkpoints in Circulating and Tumor-Infiltrating CD4+ T Cell Subsets in Colorectal Cancer Patients

Blockade of inhibitory immune checkpoints (ICs) is a promising therapeutic approach; however, it has shown limited success in some cancers including colorectal cancer (CRC). The tumor microenvironment (TME) is largely responsible for response to therapy, and its constituents may provide robust biomarkers for successful immunotherapeutic approaches. In this study, we performed phenotypical characterization and critical analyses of key inhibitory ICs and T regulatory cell (Treg)-related markers on CD4⁺ T cell subsets in CRC patients, and compared with normal colon tissues and peripheral blood from the same patients. We also investigated correlations between the levels of different CD4⁺ T cell subsets and the clinicopathologic features including disease stage and tumor budding. We found a significant increase in the levels of CD4⁺FoxP3⁺Helios⁺ T cells, which represent potentially highly immunosuppressive Tregs, in the CRC TME. Additionally, tumor-infiltrating CD4⁺ T cells upregulated programmed cell death protein-1 (PD-1), cytotoxic T-lymphocyte-associated protein-4 (CTLA-4), T cell immunoglobulin and mucin domain-3 (TIM-3) and lymphocyte-activation gene 3 (LAG-3). We also characterized the expression of PD-1, CTLA-4, TIM-3, and LAG-3 on different CD4⁺FoxP3^−/+Helios^−/+ T cell subsets. Interestingly, we found that CTLA-4, TIM-3, and LAG-3 were mainly co-expressed on FoxP3⁺Helios⁺ Tregs in the TME. Additionally, FoxP3^high Tregs expressed higher levels of Helios, CTLA-4 and TIM-3 than FoxP3^low T cells. These results highlight the significance of Tregs in the CRC TME and suggest that Tregs may hamper response to IC blockade in CRC patients, but effects of different IC inhibition regimes on Treg levels or activity warrants further investigations. We also found that CD4⁺CTLA-4⁺ T cells in circulation are increased in patients with advanced disease stage. This study simultaneously provides important insights into the differential levels of CD4⁺ T cell subpopulations and IC expression in CRC TME, compared to periphery and associations with clinicopathologic features, which could be used as potential biomarkers for CRC progression and response to therapy.

The co-expression characteristics of LAG3 and PD-1 on the T cells of patients with breast cancer reveal a new therapeutic strategy

Many studies have shown a special interaction between LAG3 and PD-1 in T cell inhibition, while the co-expression and effect of LAG3 and PD-1 on T cells in breast cancer patients are still not very clear. Here, with strict exclusion criteria, 88 patients with breast cancer and 18 healthy controls were enrolled. The percentages of LAG3⁺PD-1⁺ T cells in their peripheral blood (PBL) and tumor infiltrating T cells (TIL) were analyzed by flow cytometry, which showed an increase in TILs but no difference in PBLs and presented differences in TILs in different molecular subtypes (P < 0.05). In triple-negative breast cancer (TNBC), the highest percentages were observed, while in ER+/PR+ breast cancer, the lowest percentages were observed; however, these percentages were not different in different clinical stages (P > 0.05). Immunohistochemical staining showed that the expression of their ligands, PD-L1, MHC class II molecular and FGL1, was inconsistent in different molecular subtypes and clinical stages. Analysis of the functions of T cells with different phenotypes showed that the proliferation and secretion capacity of LAG3⁺PD-1⁺ T cells was obviously exhausted, with more than a two-fold of decrease compared with the groups of single positive LAG3 or PD-1 (P < 0.05). Finally, in a mouse model of TNBC, the dual blockade of LAG3 and PD-1 was indicated to achieve a better anti-tumour effect than either one alone (P < 0.05), which may provide a new strategy for the immunoregulatory treatment of patients with TNBC in the future.

Targeting SHP2 as a promising strategy for cancer immunotherapy

Src homology-2-containing protein tyrosine phosphatase 2 (SHP2) is a major phosphatase involved in several cellular processes. In recent years, SHP2 has been the focus of significant attention in human diseases, particular in cancer. Several studies have shown that SHP2 plays an important role in regulating immune cell functions in tumor microenvironment. A few clinical trials conducted using SHP2 allosteric inhibitors have shown remarkable anti-tumor benefits and good safety profiles. This review focuses on the current understanding of the regulation of SHP2 and highlights the vital roles of SHP2 in T lymphocytes, macrophages and cancer cells. It also summarizes the current development of SHP2 inhibitors as a promising strategy for cancer immunotherapy.

Delivery strategies of cancer immunotherapy: recent advances and future perspectives

Immunotherapy has become an emerging strategy for the treatment of cancer. Immunotherapeutic drugs have been increasing for clinical treatment. Despite significant advances in immunotherapy, the clinical application of immunotherapy for cancer patients has some challenges associated with safety and efficacy, including autoimmune reactions, cytokine release syndrome, and vascular leak syndrome. Novel strategies, particularly improved delivery strategies, including nanoparticles, scaffolds, and hydrogels, are able to effectively target tumors and/or immune cells of interest, increase the accumulation of immunotherapies within the lesion, and reduce off-target effects. Here, we briefly describe five major types of cancer immunotherapy, including their clinical status, strengths, and weaknesses. Then, we introduce novel delivery strategies, such as nanoparticle-based delivery of immunotherapy, implantable scaffolds, injectable biomaterials for immunotherapy, and matrix-binding molecular conjugates, which can improve the efficacy and safety of immunotherapies. Also, the limitations of novel delivery strategies and challenges of clinical translation are discussed.

Antitumor effects of immunity-enhancing traditional Chinese medicine

Traditional Chinese Medicine (TCM) has been traditionally used to treat patients with cancers in China. It not only alleviates the symptoms of tumor patients and improves their quality of life, but also controls the size of tumors and prolongs the survival of tumor patients. While some herbs of TCM may exert therapeutic effects by directly targeting cancer cells or reducing side effects caused by antitumor drugs, others can control tumor growth and metastasis via enhancing antitumor immunity. In particular, TCM can exert antitumor effects by upregulating immune responses even in immunosuppressive tumor microenvironment. For instance, it reduces the number of M2-type macrophages and Treg cells in the tumor tissue. Although extensive reviews on directly killing cancer cells by TCM have been conducted, a review of anticancer activity of TCM solely based on its immunity-enhancing capacity is unusual. This review will summarize research progress of antitumor TCM that regulates the immune system, including both innate immunity, such as macrophages, dendritic cells, natural killer cells and MDSCs, and adaptive immunity, including CD4⁺/CD8⁺ T lymphocytes, regulatory T cells (Tregs) and B cells. As cancer immunotherapy has recently achieved certain success, it is expected that the clinical applications of immunity-enhancing TCM or traditional medicine for treating various cancer patients will be expanded. Further studies on the mechanisms by which TCM regulates immunity will provide new insights into how TCM controls tumor growth and metastasis, and may help improve its therapeutic effects on various cancers in clinic.

The efficacy and safety of combination of PD-1 and CTLA-4 inhibitors: a meta-analysis

Background

Recently, a series of clinical trials showed that combination of anti-programmed cell death-1 (α-PD-1) and anti-cytotoxic T-lymphocyte-associated protein 4 (α-CTLA-4) could effectively eliminate tumor. However, in comparison with widely adopted mono-immune checkpoint inhibitors, chemotherapy, and targeted therapy, the advantage of combination therapy of α-PD-1 and α-CTLA-4 in response rate and prognosis is controversial especially considering probably increased treatment related adverse event. Thus, we conducted this meta-analysis to explore the efficacy and safety of combination treatment of α-PD-1 and α-CTLA-4.

Methods

This meta-analysis involved 8 clinical trials. In most trials, the primary endpoint was objective response rate (ORR). Thus we calculated risk ratio (RR) and 95% confidence interval (CI) to compare ORR of patients undergoing different treatment strategies. Moreover, the co-primary endpoints in few trials included progression-free survival and overall survival. Hazard ratio (HR) with 95% CI were employed to weigh the influence of different treatments on prognosis of patients. Subgroup analysis was conducted in patients with high and low expression of PD-L1. Lastly, the safety of combination therapy was evaluated by comparing treatment related adverse events among various treatment groups.

Results

Our results showed that ORR was significantly higher in patients receiving α-PD-1 plus α-CTLA-4 compared with α-PD-1 (RR 1.31, 95% CI 1.16–1.48) or α-CTLA-4 monotherapy (RR 2.11, 95% CI 1.84–2.43), chemotherapy and targeted therapy (RR 1.41, 95% CI 1.26–1.58). α-PD-1 plus α-CTLA-4 treated patients had a great advantage on monotherapy, chemotherapy and targeted therapy treated patients in PFS. Notably, no significant alteration in total adverse event rate was observed in α-PD-1 plus α-CTLA-4 treated patients. Results of subgroup analysis showed that combination therapy could enhance anti-tumor response in comparison with other treatments, especially for low PD-L1 expression patients undergoing nivolumab treatment (ORR: RR 1.35, 95% CI 1.11–1.65).

Conclusion

Combination treatment of α-PD-1 and α-CTLA-4 is a feasible strategy with enhanced efficacy and acceptable adverse event. Moreover, for some low PD-L1 expression patients, α-CTLA-4 might decrease the risk of resistance to α-PD-1 and demonstrate the synergistic anti-tumor effect.

Higher frequency of the CTLA-4+ LAG-3+ T-cell subset in patients with newly diagnosed acute myeloid leukemia

AIM

Immune suppression based on alternative regulation of immune checkpoint proteins, for example, programmed cell death receptor-1 (PD-1) and cytotoxic T lymphocyte-associated molecule-4 (CTLA-4), which results in T-cell exhaustion, contributes to cancer development and progression. In this study, we sought to characterize the distribution of CTLA-4 and T-cell lymphocyte activation gene-3 (LAG-3) expression on exhausted T cells in different T-cell subsets from patients with acute myeloid leukemia (AML).

METHODS

The coexpression of CTLA-4 and LAG-3 on exhausted CD244⁺ and CD57⁺ T cells from the CD3⁺ , CD4⁺ , and CD8⁺ T-cell subsets in peripheral blood from 12 patients with newly diagnosed AML was analyzed by multicolor flow cytometry assay.

RESULTS

A significantly higher percentage of CTLA-4⁺ CD3⁺ , CD4⁺ and CD8⁺ T cells was found in patients with AML. In addition, higher numbers of both CTLA-4⁺ CD244+ and CTLA-4⁺ CD57⁺ CD3⁺ T cells were detected. Interestingly, the increased CTLA-4⁺ CD244⁺ T cells were predominantly CD4⁺ T cells. In contrast, the increased CTLA-4⁺ CD57⁺ T cells primarily consisted of the CD8⁺ T-cell subset. A high proportion of LAG-3⁺ T cells was found in only a few cases with AML; however, a significantly higher proportion of coexpression of CTLA-4 and LAG-3 in the CD3⁺ and CD8⁺ T-cell subsets was detected.

CONCLUSION

We for the first time observed higher CTLA-4⁺ CD244⁺ CD4⁺ , CTLA-4⁺ CD57⁺ CD8⁺ , CTLA-4⁺ LAG-3⁺ CD3⁺ and CTLA-4⁺ LAG-3⁺ CD8⁺ T cells in patients with AML, whereas the upregulated expression of LAG-3 on T cells was only found in a subset of the cases. These data may provide further information by complementing the heterogeneity of immune checkpoints expression in AML.

Immunopathogenesis of Immune Checkpoint Inhibitor-Related Adverse Events: Roles of the Intestinal Microbiome and Th17 Cells

The advent of novel, innovative, and effective anti-cancer immunotherapies has engendered an era of renewed optimism among cancer specialists and their patients. Foremost among these successful immunotherapies are monoclonal antibodies (MAbs) which target immune checkpoint inhibitor (ICI) molecules, most prominently cytotoxic T-lymphocyte-associated protein (CTLA-4) and programmed cell death protein-1 (PD-1) and its major ligand, PD-L1. These immunotherapeutic agents are, however, often associated with the occurrence of immune-mediated toxicities known as immune-related adverse events (IRAEs). The incidence of severe toxicities increases substantially when these agents are used together, particularly with CTLA-4 in combination with PD-1 or PD-L1 antagonists. Accordingly, dissociating the beneficial anti-tumor therapeutic activity of these agents from the emergence of IRAEs represents a significant challenge to attaining the optimum efficacy of ICI-targeted immunotherapy of cancer. This situation is compounded by an increasing awareness, possibly unsurprising, that both the beneficial and harmful effects of ICI-targeted therapies appear to result from an over-reactive immune system. Nevertheless, this challenge may not be insurmountable. This contention is based on acquisition of recent insights into the role of the gut microbiome and its products as determinants of the efficacy of ICI-targeted immunotherapy, as well as an increasing realization of the enigmatic involvement of Th17 cells in both anti-tumor activity and the pathogenesis of some types of IRAEs. Evidence linking the beneficial and harmful activities of ICI-targeted immunotherapy, recent mechanistic insights focusing on the gut microbiome and Th17 cells, as well as strategies to attenuate IRAEs in the setting of retention of therapeutic activity, therefore represent the major thrusts of this review.

Prospects for combining immune checkpoint blockade with PARP inhibition

The immunogenicity of a cancer cell is derived from accumulated somatic mutations. However, on the contrary to increased immunogenicity, anti-cancer immune response tends to be feeble. This impaired anti-cancer immunity could be attributed to multiple factors including loss of immunodominant epitopes, downregulation of major histocompatibility complex, and immunosuppressive microenvironment, as well as aberrant negative co-stimulatory signals. Immune checkpoint inhibitors block negative co-stimulatory signals such as programmed cell death-1 and cytotoxic T-lymphocyte-associated protein 4, ultimately reactivating anti-cancer immunity. Immune checkpoint inhibitors elicit potent anti-cancer effect and have been approved for multiple cancers. Nevertheless, there still are significant potential improvements for the applications of checkpoint inhibitor, especially considering frequent resistance. Recent studies demonstrated that additional PARP inhibition could alleviate resistance and enhance efficacy of immune checkpoint blockade therapy via promoting cross-presentation and modifying immune microenvironment. We proposed that PARP inhibitors could enhance the priming and tumor-killing activities of T cell, boost the whole cancer-immunity cycle, and thereby improve the response to immune checkpoint blockade. In this review, we focused the latest understanding of the effect of PARP inhibitors on anti-cancer immunity and PARP inhibitors combining immune checkpoint blockade therapy. Moreover, we summarized the preclinical and clinical evidence and discussed the feasibility of this combination therapy in future clinical practice.

Molecular evolution of peptides by yeast surface display technology

Genetically encoded peptides possess unique properties, such as a small molecular weight and ease of synthesis and modification, that make them suitable to a large variety of applications. However, despite these favorable qualities, naturally occurring peptides are often limited by intrinsic weak binding affinities, poor selectivity and low stability that ultimately restrain their final use. To overcome these limitations, a large variety of in vitro display methodologies have been developed over the past few decades to evolve genetically encoded peptide molecules with superior properties. Phage display, mRNA display, ribosome display, bacteria display, and yeast display are among the most commonly used methods to engineer peptides. While most of these in vitro methodologies have already been described in detail elsewhere, this review describes solely the yeast surface display technology and its valuable use for the evolution of a wide range of peptide formats.

Dendritic cells in cancer immunology and immunotherapy

Dendritic cells (DCs) are a diverse group of specialized antigen-presenting cells with key roles in the initiation and regulation of innate and adaptive immune responses. As such, there is currently much interest in modulating DC function to improve cancer immunotherapy. Many strategies have been developed to target DCs in cancer, such as the administration of antigens with immunomodulators that mobilize and activate endogenous DCs, as well as the generation of DC-based vaccines. A better understanding of the diversity and functions of DC subsets and of how these are shaped by the tumour microenvironment could lead to improved therapies for cancer. Here we will outline how different DC subsets influence immunity and tolerance in cancer settings and discuss the implications for both established cancer treatments and novel immunotherapy strategies.

Immune checkpoint inhibitors: a new era for esophageal cancer

Introduction: The poor prognosis for patients with esophageal cancer (EC) requires evolving current treatment regimens. Immune checkpoint inhibitors show clinical efficacy and a great safety profile in multiple tumors. And the monoclonal antibodies that target programmed death receptor-1/programmed death receptor ligand-1 or the cytotoxic T lymphocyte antigen-4 pathway has shown potential curable effect of EC. Areas covered: This review article covers the prognostic significance of immune checkpoint expression, the accumulating current clinical studies of checkpoint inhibitors in esophageal cancer patients, and future directions. Expert opinion: Many clinical studies have reported favorable survival results with manageable toxicity of anti-programmed death receptor-1/programmed death receptor ligand-1 and anti-cytotoxic T lymphocyte antigen-4 treatment. More results are expected from future clinical studies. It is believed that combining chemoradiotherapy and immune checkpoint inhibitors can induce safe and efficient anti-tumor immune responses and can be a promising therapeutic strategy.

Genetic and Environmental Interaction in Type 1 Diabetes: a Relationship Between Genetic Risk Alleles and Molecular Traits of Enterovirus Infection?

PURPOSE OF REVIEW

We provide an overview of the current knowledge regarding the natural history of human type 1 diabetes (T1D) and the documented associations between virus infections (in particular the enteroviruses) and disease development. We review studies that examine whether T1D-specific risk alleles in genes involved in the function of the immune system can alter susceptibility to virus infections or affect the magnitude of the host antiviral response. We also highlight where the major gaps in our knowledge exist and consider possible implications that new insights gained from the discussed gene-environment interaction studies may bring.

RECENT FINDINGS

A commonality between several of the studied T1D risk variants studied is their role in modulating the host immune response to viral infection. Generally, little support exists indicating that the risk variants increase susceptibility to infection and moreover, they usually appear to predispose the immune system towards a hyper-reactive state, decrease the risk of infection, and/or favor the establishment of viral persistence. In conclusion, although the current number of studies is limited, this type of research can provide important insights into the mechanisms that are central to disease pathogenesis and further describe how genetic and environmental factors jointly influence the risk of T1D development. The latter may provide genetic markers that could be used for patient stratification and for the selection of method(s) for disease prevention.

Role of CTLA4 A49G polymorphism in systemic lupus erythematosus and its geographical distribution

CTLA-4 (cytotoxic T-lymphocyte-associated protein-4) or CD152 is an inhibitory receptor expressed constitutively on CD4+ CD25+ T regulatory lymphocytes and transiently on activated CD4+ and CD8+ T lymphocytes. Its inhibitory function promotes long-lived anergy in immune cells and prevents autoimmunity. Therefore, it plays a crucial role in T cell-mediated autoimmunity, and thus in susceptibility to autoimmune diseases, including systemic lupus erythematosus (SLE). It is encoded by CTLA4 gene in humans. AtoG polymorphism at position +49 of CTLA4 gene is the only polymorphism which changes amino acid sequence from alanine to threonine in the leader sequence, which may affect the function of CTLA-4. Association of CTLA4 polymorphisms with SLE has been investigated in several reports in different ethnic populations from different countries, which have shown highly inconsistent findings. In this review, we have compiled previous studies which have reported the association of CTLA4 A49G polymorphism in SLE and its geographical distribution.

Chronic Implant-Related Bone Infections-Can Immune Modulation be a Therapeutic Strategy?

Chronic implant-related bone infections are a major problem in orthopedic and trauma-related surgery with severe consequences for the affected patients. As antibiotic resistance increases in general and because most antibiotics have poor effectiveness against biofilm-embedded bacteria in particular, there is a need for alternative and innovative treatment approaches. Recently, the immune system has moved into focus as the key player in infection defense and bone homeostasis, and the targeted modulation of the host response is becoming an emerging field of interest. The aim of this review was to summarize the current knowledge of impaired endogenous defense mechanisms that are unable to prevent chronicity of bone infections associated with a prosthetic or osteosynthetic device. The presence of foreign material adversely affects the immune system by generating a local immune-compromised environment where spontaneous clearance of planktonic bacteria does not take place. Furthermore, the surface structure of the implant facilitates the transition of bacteria from the planktonic to the biofilm stage. Biofilm formation on the implant surface is closely linked to the development of a chronic infection, and a misled adaption of the immune system makes it impossible to effectively eliminate biofilm infections. The interaction between the immune system and bone cells, especially osteoclasts, is extensively studied in the field of osteoimmunology and this crosstalk further aggravates the course of bone infection by shifting bone homeostasis in favor of bone resorption. T cells play a major role in various chronic diseases and in this review a special focus was therefore set on what is known about an ineffective T cell response. Myeloid-derived suppressor cells (MDSCs), anti-inflammatory macrophages, regulatory T cells (T_regs) as well as osteoclasts all suppress immune defense mechanisms and negatively regulate T cell-mediated immunity. Thus, these cells are considered to be potential targets for immune therapy. The success of immune checkpoint inhibition in cancer treatment encourages the transfer of such immunological approaches into treatment strategies of other chronic diseases. Here, we discuss whether immune modulation can be a therapeutic tool for the treatment of chronic implant-related bone infections.

The alveolar immune cell landscape is dysregulated in checkpoint inhibitor pneumonitis

BACKGROUND

Checkpoint inhibitor pneumonitis (CIP) is a highly morbid complication of immune checkpoint immunotherapy (ICI), one which precludes the continuation of ICI. Yet, the mechanistic underpinnings of CIP are unknown.

METHODS

To better understand the mechanism of lung injury in CIP, we prospectively collected bronchoalveolar lavage (BAL) samples in ICI-treated patients with (n=12) and without CIP (n=6), prior to initiation of first-line therapy for CIP (high dose corticosteroids. We analyzed BAL immune cell populations using a combination of traditional multicolor flow cytometry gating, unsupervised clustering analysis and BAL supernatant cytokine measurements.

RESULTS

We found increased BAL lymphocytosis, predominantly CD4+ T cells, in CIP. Specifically, we observed increased numbers of BAL central memory T-cells (Tcm), evidence of Type I polarization, and decreased expression of CTLA-4 and PD-1 in BAL Tregs, suggesting both activation of pro-inflammatory subsets and an attenuated suppressive phenotype. CIP BAL myeloid immune populations displayed enhanced expression of IL-1β and decreased expression of counter-regulatory IL-1RA. We observed increased levels of T cell chemoattractants in the BAL supernatant, consistent with our pro-inflammatory, lymphocytic cellular landscape.

CONCLUSION

We observe several immune cell subpopulations that are dysregulated in CIP, which may represent possible targets that could lead to therapeutics for this morbid immune related adverse event.

Phosphoinositide 3-kinase δ is a regulatory T-cell target in cancer immunotherapy

Tumour infiltration by regulatory T (Treg) cells contributes to suppression of the anti-tumour immune response, which limits the efficacy of immune-mediated cancer therapies. The phosphoinositide 3-kinase (PI3K) pathway has key roles in mediating the function of many immune cell subsets, including Treg cells. Treg function is context-dependent and depends on input from different cell surface receptors, many of which can activate the PI3K pathway. In this review, we explore how PI3Kδ contributes to signalling through several major immune cell receptors, including the T-cell receptor and co-stimulatory receptors such as CD28 and ICOS, but is antagonized by the immune checkpoint receptors CTLA-4 and PD-1. Understanding how PI3Kδ inhibition affects Treg signalling events will help to inform how best to use PI3Kδ inhibitors in clinical cancer treatment.

Immune checkpoints in the tumor microenvironment

Interactions between immune checkpoints (ICs) and their ligands negatively regulate T cell activation pathways involved in physiological immune responses against specific antigens. ICs and their ligands are frequently upregulated in the tumor microenvironment (TME) of various malignancies, and they represent significant barriers for induction of effective anti-tumor immune responses. Several IC inhibitors (ICIs) have been developed, with some currently in clinical trials and others have been approved for the treatment of different cancers. However, tumor cells are able to counteract the activity of ICIs and can commission additional inhibitory pathways via expression of other ICs/ligands within the TME. This review discusses the expression of various ICs/ligands in the TME and their impact on tumor immune evasion. Additionally, we discuss various regulatory mechanisms, including genetic and epigenetic, and other modulatory factors including hypoxia and the presence of immunosuppressive populations in the TME, which result in upregulation of ICs in various cancers. Moreover, we discuss the prognostic significance of ICs and their ligands, and the potential strategies to enhance treatment responses to ICIs. This review aims to advance our current knowledge on the role of ICs in the TME and the clinical benefits of targeting them.

Potential immune escape mechanisms underlying the distinct clinical outcome of immune checkpoint blockades in small cell lung cancer

Small cell lung cancer (SCLC) is one of the deadliest cancer types in the world. Despite the high response rate to frontline platinum-containing doublets, relapse is inevitable for the majority of patients and the prognosis is poor. Topotecan, which has limited efficacy, has remained the standard second-line therapy for approximately three decades. Although SCLC has a high mutation burden, the clinical efficacy of immune checkpoint blockades (ICBs) in SCLC is far less pronounced than that in non-small cell lung cancer (NSCLC). Only atezolizumab in combination with chemotherapy improved overall survival over chemotherapy alone in the phase III CheckMate 133 trial and has recently received FDA approval as first-line therapy. Most studies concerning ICBs in SCLC are limited to early-phase studies and found that ICBs were not superior to traditional chemotherapy. Why is there such a large difference between SCLC and NSCLC? In this review, comparative analyses of previous studies indicate that SCLC is even more immunodeficient than NSCLC and the potential immune escape mechanisms in SCLC may involve the low expression of PD-L1 and the downregulation of major histocompability complex (MHC) molecules and regulatory chemokines. In consideration of these immune dysfunctions, we speculate that chemotherapy and radiotherapy prior to immunotherapy, the combination of ICBs with antiangiogenic treatment, and selecting tumor mutation burden in combination with PD-L1 expression as biomarkers could be promising strategies to improve the clinical efficacy of immunotherapy for SCLC.

Anti-CTLA-4 monoclonal antibody improves efficacy of the glyceraldehyde-3-phosphate dehydrogenase protein vaccine against Schistosoma japonicum in mice

Schistosomiasis is a devastating disease caused by Schistosoma infection. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has emerged as a candidate vaccine component against Schistosoma japonicum, but only confers partial protection. Cytotoxic T lymphocyte antigen-4 (CTLA-4) regulates T cell activation and shows negative effects on vaccine-induced immune protection; however, its potential influence on the protective effects of a GAPDH vaccine against S. japonicum and the underlying mechanism remain unclear. In this study, we established a mouse model of S. japonicum infection, and the mice were randomly divided into uninfected, infected control, anti-CTLA-4 monoclonal antibody (anti-CTLA-4 mAb), GAPDH, and GAPDH combined with anti-CTLA-4 mAb groups to compare the protective effects against infection and the consequent tissue damage. The worm reduction rate in the GAPDH-treated infected mice was 26.58%, which increased to 54.61% when combined with anti-CTLA-4 mAb. The frequency of regulatory T cells (Tregs) was significantly higher in the anti-CTLA-4 mAb group and was lower in the GAPDH group. However, both anti-CTLA-4 mAb and GAPDH elevated the levels of the cytokines IFN-γ, IL-2, IL-4, and IL-5 in the spleens of infected mice, and their combination further enhanced cytokine production. The diameter of egg granuloma in the anti-CTLA-4 mAb group and combined treatment group increased significantly compared to that of the other groups. These results suggest that anti-CTLA-4 mAb can be used as an adjuvant to enhance the immune protection of the GAPDH vaccine via inducing the Th1 immune response, although this comes at the cost of enhanced body injury.

Preexisting Autoimmune Disease: Implications for Immune Checkpoint Inhibitor Therapy in Solid Tumors

The use of immune checkpoint inhibitors (ICIs) is rapidly expanding to the treatment of many cancer types, both in the metastatic setting and as an adjuvant to other therapies. Clinical trials using ICIs have largely excluded patients with preexisting autoimmune diseases due to concerns for increased toxicity. However, emerging evidence shows that ICIs may be considered in some patients with autoimmunity. This review discusses the commonalities between clinical autoimmune diseases and ICI-induced immunotherapy-related adverse events, and summarizes the existing case series that describes patients with solid tumors who have a preexisting autoimmune disease. This review also discusses which patients with autoimmunity could be considered reasonable candidates for ICI therapy.

IFN-γ: A cytokine at the right time, is in the right place

Interferon gamma has long been studied as a critical mediator of tumor immunity. In recent years, the complexity of cellular interactions that take place in the tumor microenvironment has become better appreciated in the context of immunotherapy. While checkpoint inhibitors have dramatically improved remission rates in cancer treatment, IFN-γ and related effectors continue to be identified as strong predictors of treatment success. In this review, we provide an overview of the multiple immunosuppressive barriers that IFN-γ has to overcome to eliminate tumors, and potential avenues for modulating the immune response in favor of tumor rejection.

Nanomaterial-Based Modulation of Tumor Microenvironments for Enhancing Chemo/Immunotherapy

The tumor microenvironment (TME) has drawn considerable research attention as an alternative target for nanomedicine-based cancer therapy. Various nanomaterials that carry active substances have been designed to alter the features or composition of the TME and thereby improve the delivery and efficacy of anticancer chemotherapeutics. These alterations include disruption of the extracellular matrix and tumor vascular systems to promote perfusion or modulate hypoxia. Nanomaterials have also been used to modulate the immunological microenvironment of tumors. In this context, nanomaterials have been shown to alter populations of cancer-associated fibroblasts, tumor-associated macrophages, regulatory T cells, and myeloid-derived suppressor cells. Despite considerable progress, nanomaterial-based TME modulation must overcome several limitations before this strategy can be translated to clinical trials, including issues related to limited tumor tissue penetration, tumor heterogeneity, and immune toxicity. In this review, we summarize recent progress and challenges of nanomaterials used to modulate the TME to enhance the efficacy of anticancer chemotherapy and immunotherapy.

Effect of Cytotoxic T-Lymphocyte Antigen-4 on the Efficacy of the Fatty Acid-Binding Protein Vaccine Against Schistosoma japonicum

The present study evaluated the impact of blocking cytotoxic T-lymphocyte antigen-4 (CTLA-4) activity on the protective effect elicited by the fatty acid binding protein (FABP) vaccine against Schistosoma japonicum infection. Mice were randomly divided into uninfected, infected control, anti-CTLA-4 monoclonal antibody (anti-CTLA-4 mAb), FABP, and combination (anti-CTLA-4 mAb and FABP) groups. An assessment of the S. japonicum worm and egg burden in the infected mice revealed that the worm reduction-rate induced by FABP administration was increased from 26.58 to 54.61% by co-administration of the monoclonal anti-CTLA antibody (anti-CTLA-4 mAb). Furthermore, the regulatory T cell (Treg) percentage was significantly increased in mice after administration of the anti-CTLA-4 mAb, but not the FABP vaccine, and elevated levels of the cytokines interferon (IFN)-γ, interleukin (IL)-2, IL-4, and IL-5 were observed in infected mice that were administered the anti-CTLA-4 mAb. Notably, the diameter of egg granulomas in the anti-CTLA-4 mAb and combination groups was significantly increased compared to that observed in the infected control group. Together, these results suggest that co-administering the FABP vaccine and anti-CTLA-4 treatment may have synergistically increased the immunoprotective effect of the FABP vaccine by promoting T-helper 1-type immune responses, while incurring increased tissue damage.

Identification of susceptibility SNPs in CTLA-4 and PTPN22 for scleritis in Han Chinese

The aim of this study was to determine the association between 13 single nucleotide polymorphisms (SNPs) in the cytotoxic T lymphocyte-associated antigen-4 (CTLA4) and protein tyrosine phosphatase non-receptor type 22 (PTPN22) genes with scleritis in a Chinese Han population. We recruited 432 scleritis patients and 710 healthy controls. Four tag SNPs of CTLA4 and nine tag SNPs of PTPN22 were selected using Haploview. Genotyping was performed with the Sequenom MassArray® iPLEX GOLD Assay. Genotype and allele frequency differences were analyzed by χ² test and Bonferroni correction. Haplotype analysis was performed to further evaluate the association of these two genes with scleritis. In this study, CTLA4/rs3087243 G allele frequency and GG genotype frequency were significantly increased in scleritis patients compared to healthy controls [corrected P-value (Pc) = 0·02, odds ratio (OR) = 1·475, 95% confidence interval (CI) = 1·175-1·851; Pc = 0·04, OR = 1·546, 95% CI = 1·190-2·008, respectively]. None of the tested SNPs in the PTPN22 gene showed an association with scleritis. Haplotype analysis revealed a lower frequency of a CTLA4 TCAA haplotype (order of SNPs: rs733618, rs5742909, rs231775, rs3087243) (Pc = 4·26 × 10^-3 , OR = 0·618, 95% CI = 0·540-0·858) and a higher frequency of a PTPN22 TTATACGCG haplotype (order of SNPs: rs3789604, rs150426536, rs1746853, rs1217403, rs1217406, rs3789609, rs1217414, rs3789612, rs2488457) (Pc = 2·83 × 10^-4 , OR = 1·457, 95% CI = 1·210-1·754) in scleritis patients when compared to healthy controls. In conclusion, our findings indicate that CTLA4 and PTPN22 might confer genetic susceptibility to scleritis in a Chinese Han population.

Immunotherapy of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second most common cause of cancer-related death in the United States by 2030. So far surgery remains the only curative option for pancreatic cancer, but fewer than 20% of patients have surgically resectable disease. Furthermore, pancreatic cancer exhibits a remarkable resistance to established therapeutic options, including chemotherapy, radiotherapy, and targeted therapy, because pancreatic cancer exhibits numerous mechanisms of resistance like genetic and epigenetic alterations and a complex and dense tumor microenvironment. The tumor microenvironment is populated with different types of immune cells that play a critical role in therapy resistance, tumor progression, and carcinogenesis. Cancer immunotherapy has now been recognized as the fourth pillar of cancer care and a number of preclinical and clinical studies have been conducted for pancreatic cancer. Targeting and modulating the tumor immune microenvironment could not only switch the immune system toward anti-cancer, but also may improve sensitivity toward established chemotherapy. In this review, we discuss both preclinical and clinical studies on pancreatic cancer immunotherapy with natural killer cells, dendritic cells, and chimeric antigen receptor T cells. Furthermore, we summarize strategies for reprogramming the tumor immune microenvironment by targeting macrophages and stromal cell factors in pancreatic cancer. The development of systemic therapies is essential for improving the outcomes of pancreatic cancer patients, and cancer immunotherapy would improve effectiveness of other established therapeutic options, which might together improve the prognosis of pancreatic tumors.

Immunotherapy Associated Pulmonary Toxicity: Biology Behind Clinical and Radiological Features

The broader use of immune checkpoint blockade in clinical routine challenges clinicians in the diagnosis and management of side effects which are caused by inflammation generated by the activation of the immune response. Nearly all organs can be affected by immune-related toxicities. However, the most frequently reported are: fatigue, rash, pruritus, diarrhea, nausea/vomiting, arthralgia, decreased appetite and abdominal pain. Although these adverse events are usually mild, reversible and not frequent, an early diagnosis is crucial. Immune-related pulmonary toxicity was most frequently observed in trials of lung cancer and of melanoma patients treated with the combination of the anti-cytotoxic T lymphocyte antigen (CTLA)-4 and the anti-programmed cell death-1 (PD-1) antibodies. The most frequent immune-related adverse event in the lung is represented by pneumonitis due to the development of infiltrates in the interstitium and in the alveoli. Clinical symptoms and radiological patterns are the key elements to be considered for an early diagnosis, rendering the differential diagnosis crucial. Diagnosis of immune-related pneumonitis may imply the temporary or definitive suspension of immunotherapy, along with the start of immuno-suppressive treatments. The aim of this work is to summarize the biological bases, clinical and radiological findings of lung toxicity under immune checkpoint blockade, underlining the importance of multidisciplinary teams for an optimal early diagnosis of this side effect, with the aim to reach an improved patient care.

CD103+ tumor-infiltrating lymphocytes predict favorable prognosis in patients with esophageal squamous cell carcinoma

As an indispensable factor in preventing the recirculation of tissue lymphocytes to the lymphatic and blood systems, the integrin CD103 has enabled the characterization of lymphocyte populations in non-lymphoid tissues and organs. However, the expression, distribution, and clinical significance of CD103⁺ tumor-infiltrating lymphocytes (TILs) in esophageal squamous cell carcinoma (ESCC) remain unclear. In the present study, we included tumor and adjacent non-tumor tissue specimens from 198 patients with ESCC who had undergone surgical resection. Immunohistochemistry and immunofluorescence were used to detect CD103⁺ TIL distribution, as well as the co-expression of CD103 and T cell markers and functional molecules. Kaplan-Meier analysis and the Cox proportional hazards model were used to estimate the prognostic value of CD103⁺ TILs. The results showed that CD103⁺ TILs were predominantly located in adjacent non-tumor tissues compared with tumor tissues (P < 0.0001). Immunofluorescence double staining revealed that CD8⁺ T cells, but not CD4⁺ T cells, comprised the majority of CD103-expressing cells. Most of these CD103-expressing cells co-expressed CTLA-4 and granzyme B rather than the exhaustion marker PD-1. High density of intratumoral CD103⁺ TIL is associated with longer overall survival (OS) and disease-free survival (DFS) in both the internal (OS, P = 0.0004 and DFS, P = 0.0002) and external (OS, P = 0.038 and DFS, P = 0.12) cohorts. Multivariate Cox analysis showed the density of CD103⁺ TILs was an independent positive prognostic factor for OS (hazards ratio [HR] = 0.406; P = 0.0003 in the internal cohort; HR = 0.328, P = 0.01, in the external cohort) and DFS (HR = 0.385; P = 0.0002 in the internal cohort; HR = 0.270, P = 0.003, in the external cohort). Our findings indicate that CD103⁺ TILs might play an important role in the tumor microenvironment, and intratumoral CD103⁺ TILs could serve as a promising prognostic marker in ESCC.

Biomaterials for vaccine-based cancer immunotherapy

The development of therapeutic cancer vaccines as a means to generate immune reactivity against tumors has been explored since the early discovery of tumor-specific antigens by Georg Klein in the 1960s. However, challenges including weak immunogenicity, systemic toxicity, and off-target effects of cancer vaccines remain as barriers to their broad clinical translation. Advances in the design and implementation of biomaterials are now enabling enhanced efficacy and reduced toxicity of cancer vaccines by controlling the presentation and release of vaccine components to immune cells and their microenvironment. Here, we discuss the rational design and clinical status of several classes of cancer vaccines (including DNA, mRNA, peptide/protein, and cell-based vaccines) along with novel biomaterial-based delivery technologies that improve their safety and efficacy. Further, strategies for designing new platforms for personalized cancer vaccines are also considered.

Cancer research in the era of immunogenomics

The most meaningful advancement in cancer treatment in recent years has been the emergence of immunotherapy. Checkpoint inhibitor blockade and adoptive T cell therapy have shown remarkable clinical effects in a wide range of tumour types. Despite these advances, many tumours do not respond to these treatments, which raises the need to further investigate how patients can benefit from immunotherapy. This effort can now take advantage of the recent technological progress in single-cell, high-throughput sequencing and computational efforts. In this review, we will discuss advances in different immunotherapies and the principles of cancer immunogenomics, with an emphasis on the detection of cancer neoantigens with human leucocyte antigen peptidomics, and how these principles can be further used for more efficient clinical output.

Antigen-loaded dendritic cells triggers a specific cytotoxic T lymphocytes immune response against hepatocellular carcinoma: in vitro study

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the common malignancies, characterized by poor response to conventional therapeutic options. Immunotherapy with dendritic cells (DCs)-vaccines is one of the most successful strategies used for the treatment of HCC. However, the methods applied in the preparation of antigen-loaded DCs are important factors for optimization of DCs vaccines.

PURPOSE

The present study was conducted to investigate the effect of HCC-whole tumor cell lysate prepared using rapid repetitive freeze-thaw cycles on the immunogenicity of DCs and evaluate the ability of whole tumor cell lysate-pulsed DCs vaccine to induce a specific cytotoxic T lymphocytes (CTLs) response against HepG2 cell line.

METHODS

Immature DCs generated from peripheral blood monocytes were randomized into two groups: control DCs and whole tumor cell lysate-pulsed DCs. Phenotypic analysis of the DCs' cell maturation marker CD83 and co-stimulatory molecule CD86 was performed. HCC-specific cytotoxic activity of CD8⁺ CTLs was measured in vitro.

RESULTS

Loading of DCs with necrotic whole cell lysate resulted in non-significant changes in DCs' expression of CD83, but a significant increase in expression of CD86. In addition, CD8⁺ CTLs stimulated with whole tumor cell lysate-pulsed DCs showed a high cytotoxic activity that specifically attack HepG2 cells.

CONCLUSION

Our findings indicated that pulsation of DCs with whole tumor cell lysate prepared by repetitive freeze-thaw cycles could efficiently enhance the ability of DCs to induce proliferation and clonal expansion of CD8⁺ CTLs. Data herein, also indicated that whole tumor cell lysate-pulsed DCs triggers a specific CD8⁺ CTLs against HCC tumor cells.

Combination of immune checkpoint blockade with DNA cancer vaccine induces potent antitumor immunity against P815 mastocytoma

DNA vaccination against cancer has become a promising strategy for inducing a specific and long-lasting antitumor immunity. However, DNA vaccines fail to generate potent immune responses when used as a single therapy. To enhance their activity into the tumor, a DNA vaccine against murine P815 mastocytoma was combined with antibodies directed against the immune checkpoints CTLA4 and PD1. The combination of these two strategies delayed tumor growth and enhanced specific antitumor immune cell infiltration in comparison to the corresponding single therapies. The combination also promoted IFNg, IL12 and granzyme B production in the tumor microenvironment and decreased the formation of liver metastasis in a very early phase of tumor development, enabling 90% survival. These results underline the complementarity of DNA vaccination and immune checkpoint blockers in inducing a potent immune response, by exploiting the generation of antigen-specific T cells by the vaccine and the ability of immune checkpoint blockers to enhance T cell activity and infiltration in the tumor. These findings suggest how and why a rational combination therapy can overcome the limits of DNA vaccination but could also allow responses to immune checkpoint blockers in a larger proportion of subjects.

Not All Immune Checkpoints Are Created Equal

Antibodies that block T cell inhibition via the immune checkpoints CTLA-4 and PD-1 have revolutionized cancer therapy during the last 15 years. T cells express additional inhibitory surface receptors that are considered to have potential as targets in cancer immunotherapy. Antibodies against LAG-3 and TIM-3 are currently clinically tested to evaluate their effectiveness in patients suffering from advanced solid tumors or hematologic malignancies. In addition, blockade of the inhibitory BTLA receptors on human T cells may have potential to unleash T cells to effectively combat cancer cells. Much research on these immune checkpoints has focused on mouse models. The analysis of animals that lack individual inhibitory receptors has shed some light on the role of these molecules in regulating T cells, but also immune responses in general. There are current intensive efforts to gauge the efficacy of antibodies targeting these molecules called immune checkpoint inhibitors alone or in different combinations in preclinical models of cancer. Differences between mouse and human immunology warrant studies on human immune cells to appreciate the potential of individual pathways in enhancing T cell responses. Results from clinical studies are not only highlighting the great benefit of immune checkpoint inhibitors for treating cancer but also yield precious information on their role in regulating T cells and other cells of the immune system. However, despite the clinical relevance of CTLA-4 and PD-1 and the high potential of the emerging immune checkpoints, there are still substantial gaps in our understanding of the biology of these molecules, which might prevent the full realization of their therapeutic potential. This review addresses PD-1, CTLA-4, BTLA, LAG-3, and TIM-3, which are considered major inhibitory immune checkpoints expressed on T cells. It provides summaries of our current conception of the role of these molecules in regulating T cell responses, and discussions about major ambiguities and gaps in our knowledge. We emphasize that each of these molecules harbors unique properties that set it apart from the others. Their distinct functional profiles should be taken into account in therapeutic strategies that aim to exploit these pathways to enhance immune responses to combat cancer.

The role of proteomics in the age of immunotherapies

The antigenic landscape of the adaptive immune response is determined by the peptides presented by immune cells. In recent years, a number of immune-based cancer therapies have been shown to induce remarkable clinical responses through the activation of the patient's immune system. As a result, there is a need to identify immune biomarkers capable of predicting clinical response. Recent advances in proteomics have led to considerable developments in the more comprehensive profiling of the immune response. "Immunoproteomics" utilises a rapidly increasing collection of technologies in order to identify and quantify antigenic peptides or proteins. This includes gel-based, array-based, mass spectrometry (MS), DNA-based, or computer-based (in silico) approaches. Immunoproteomics is yielding an understanding of disease and disease progression, vaccine candidates, and biomarkers to a depth not before understood. This review gives an overview of the emerging role of proteomics in improving personalisation of immunotherapy treatment.

Emergence of immunotherapy as a novel way to treat hepatocellular carcinoma

Tumor immunity proceeds through multiple processes, which consist of antigen presentation by antigen presenting cells (APCs) to educate effector cells and destruction by the effector cytotoxic cells. However, tumor immunity is frequently repressed at tumor sites. Malignantly transformed cells rarely survive the attack by the immune system, but cells that do survive change their phenotypes to reduce their immunogenicity. The resultant cells evade the attack by the immune system and form clinically discernible tumors. Tumor microenvironments simultaneously contain a wide variety of immune suppressive molecules and cells to dampen tumor immunity. Moreover, the liver microenvironment exhibits immune tolerance to reduce aberrant immune responses to massively-exposed antigens via the portal vein, and immune dysfunction is frequently associated with liver cirrhosis, which is widespread in hepatocellular carcinoma (HCC) patients. Immune therapy aims to reduce tumor burden, but it is also expected to prevent non-cancerous liver lesions from progressing to HCC, because HCC develops or recurs from non-cancerous liver lesions with chronic inflammatory states and/or cirrhosis and these lesions cannot be cured and/or eradicated by local and/or systemic therapies. Nevertheless, cancer immune therapy should augment specific tumor immunity by using two distinct measures: enhancing the effector cell functions such as antigen presentation capacity of APCs and tumor cell killing capacity of cytotoxic cells, and reactivating the immune system in immune-suppressive tumor microenvironments. Here, we will summarize the current status and discuss the future perspective on immune therapy for HCC.

Gut microbiome modulates efficacy of immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) therapy is a novel strategy for cancer treatments in recent years. However, it was observed that most patients treated with ICIs could not get benefit from the therapy, which led to the limitation of clinical application. Motivated by potent and durable efficacy of ICIs, oncologists endeavor to explore the mechanisms of resistance to ICIs and increase the drug sensitivity. It is known that heterogeneity of gut microbiome in populations may result in different outcomes of therapy. In xenograft model, bacteria in gut have been proved as a crucial factor regulating immunotherapy efficacy. And the similar phenomenon was obtained in patients. In this review, we summarized relevant advancements about gut microbiome and ICIs. Furthermore, we focused on modulatory function of gut microbiome in ICIs therapy and possible antitumor mechanism of specific commensals in ICIs treatment. We propose that gut microbiome is an important predictive factor, and manipulation of gut microbiome is feasible to elevate response rate in ICIs therapy.