The expression of CTLA-4 in hepatic alveolar echinococcosis patients and blocking CTLA-4 to reverse T cell exhaustion in Echinococcus multilocularis-infected mice

Alveolar echinococcosis (AE) is a zoonotic parasitic disease caused by the infection of Echinococcus multilocularis (E. multilocularis) larvae. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) produces inhibitory signals and induces T cell exhaustion, thereby inhibiting the parasiticidal efficacy of the liver immune system. Therefore, the purpose of this study is to explore how T-cell exhaustion contributes to AE and whether blocking CTLA-4 could reverse T cell exhaustion. Here we discovered that the expression of CTLA-4 was increased in the infiltrating margin around the lesion of the liver from AE patients by using western blot and immunohistochemistry assay. Multiple fluorescence immunohistochemistry identified that CTLA-4 and CD4/CD8 molecules were co-localized. For in vitro experiments, it was found that the sustained stimulation of E. multilocularis antigen could induce T cell exhaustion, blocking CTLA-4-reversed T cell exhaustion. For in vivo experiments, the expression of CTLA-4 was increased in the liver of E. multilocularis-infected mice, and the CTLA-4 and CD4/CD8 molecules were co-localized. Flow cytometry analysis demonstrated that the percentages of both CD4+ T cells and CD8+ T cells in the liver and peripheral blood were significantly increased and induced T exhaustion. When the mice were treated with anti-CTLA-4 antibodies, the number and weight of the lesions decreased significantly. Meanwhile, the flow cytometry results suggested that blocking CTLA-4 could effectively reverse T cell exhaustion and reactivate immune function. Our work reveals that blocking CTLA-4 could effectively reverse the T cell exhaustion caused by E. multilocularis and could be used as a novel target for the treatment of AE.

Drug therapy for myocarditis induced by immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs), including cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death 1 (PD-1), and its ligand 1 (PD-L1), have improved the survival in multiple types of cancers; however, ICIs may cause cardiovascular toxicity. Although rare, ICI-mediated cardiotoxicity is an extremely serious complication with a relatively high mortality. In this review, we discuss the underlying mechanism and clinical manifestations of cardiovascular toxicity induced by ICIs. According to previous studies, multiple signaling pathways are involved in myocarditis induced by ICIs. Further, we summarize the clinical trials of drugs for the treatment of ICI-associated myocarditis. Although these drugs have shown the beneficial effects of alleviating cardiac function and reducing mortality rates, their efficacy is not optimal. Finally, we discuss the therapeutic potential of some novel compounds as well as the underlying mechanisms of their action.

Comprehensive Analysis of 29,464 Cancer Cases and 35,858 Controls to Investigate the Effect of the Cytotoxic T-Lymphocyte Antigen 4 Gene rs231775 A/G Polymorphism on Cancer Risk

In our previous studies, we found that the rs231775 polymorphism of cytotoxic T-lymphocyte antigen 4 (CTLA-4) is associated with risks of different cancer types; however, the association remains controversial and ambiguous, so we conducted an in-depth meta-analysis to verify the association. A complete search of the PubMed, Google Scholar, Embase, Chinese databases, and Web of Science was conducted without regard to language limitations, covering all publications since November 20, 2021. The search criteria for cancer susceptibility associated with the polymorphism in the CTLA-4 gene rs231775 resulted in 87 case-control studies with 29,464 cases and 35,858 controls. The association strength was analyzed using odds ratios and 95% confidence intervals. Overall, we found that the CTLA-4 rs231775 polymorphism may reduce cancer risk. A stratified cancer type analysis showed that CTLA-4 rs231775 polymorphism was a risk factor for colorectal cancer and thyroid cancer; on the other hand, it was a protective factor for breast cancer, liver cancer, cervical cancer, bone cancer, head and neck, and pancreatic cancer. We also classified cancer into five systems and observed an increased association with digestive tract cancer, decreased associations with orthopedic tumors, tumors of the urinary system, and gynecological tumors. In the subgroup based on race, decreased relationships were observed in both Asians and Caucasians. The same decreased association was also shown in the analysis of the source of control analysis. Our present study indicates that the CTLA-4 rs231775 polymorphism contributes to cancer development and aggression.

Immune-Checkpoint Inhibitors in B-Cell Lymphoma

Simple Summary

Immune-based treatment strategies, which include immune checkpoint inhibition, have recently become a new frontier for the treatment of B-cell-derived lymphoma. Whereas checkpoint inhibition has given oncologists and patients hope in specific lymphoma subtypes like Hodgkin lymphoma, other entities do not benefit from such promising agents. Understanding the factors that determine the efficacy and safety of checkpoint inhibition in different lymphoma subtypes can lead to improved therapeutic strategies, including combinations with various chemotherapies, biologics and/or different immunologic agents with manageable safety profiles.

Abstract

For years, immunotherapy has been considered a viable and attractive treatment option for patients with cancer. Among the immunotherapy arsenal, the targeting of intratumoral immune cells by immune-checkpoint inhibitory agents has recently revolutionised the treatment of several subtypes of tumours. These approaches, aimed at restoring an effective antitumour immunity, rapidly reached the market thanks to the simultaneous identification of inhibitory signals that dampen an effective antitumor response in a large variety of neoplastic cells and the clinical development of monoclonal antibodies targeting checkpoint receptors. Leading therapies in solid tumours are mainly focused on the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1) pathways. These approaches have found a promising testing ground in both Hodgkin lymphoma and non-Hodgkin lymphoma, mainly because, in these diseases, the malignant cells interact with the immune system and commonly provide signals that regulate immune function. Although several trials have already demonstrated evidence of therapeutic activity with some checkpoint inhibitors in lymphoma, many of the immunologic lessons learned from solid tumours may not directly translate to lymphoid malignancies. In this sense, the mechanisms of effective antitumor responses are different between the different lymphoma subtypes, while the reasons for this substantial difference remain partially unknown. This review will discuss the current advances of immune-checkpoint blockade therapies in B-cell lymphoma and build a projection of how the field may evolve in the near future. In particular, we will analyse the current strategies being evaluated both preclinically and clinically, with the aim of fostering the use of immune-checkpoint inhibitors in lymphoma, including combination approaches with chemotherapeutics, biological agents and/or different immunologic therapies.

Drug resistance in cancer immunotherapy: new strategies to improve checkpoint inhibitor therapies

Recent advances in pharmacological immune modulation against tumor cells has dramatically changed the paradigm of cancer treatment. Checkpoint inhibitor therapy is a form of cancer immunotherapy already in clinical setting but also under active basic and clinical investigation. Nevertheless, some patients are primary unresponsive or develop ulterior resistance to these family of drugs. This review aims to update the basic molecular mechanism of resistance as well as the current strategies for checkpoint inhibitor selection in order to propose new approaches to individualize the use of these novel therapies.

What did we learn from CTLA-4 insufficiency on the human immune system?

Cytotoxic-T-lymphocyte-antigen-4 (CTLA-4) is a negative immune regulator constitutively expressed on regulatory T (Treg) cells and upregulated on activated T cells. CTLA-4 inhibits T cell activation by various suppressive functions including competition with CD28, regulation of the inhibitory function of Treg cells, such as transendocytosis, and the control of adhesion and motility. Intrinsic CTLA-4 signaling has been controversially discussed, but so far no distinct signaling pathway has been identified. The CTLA-4-mediated Treg suppression plays an important role in the maintenance of peripheral tolerance and the prevention of autoimmune diseases. Human CTLA-4 insufficiency is caused by heterozygous germline mutations in CTLA4 and characterized by a complex immune dysregulation syndrome. Clinical studies on CTLA4 mutation carriers showed a reduced penetrance and variable expressivity, suggesting modifying factor(s). One hundred and forty-eight CTLA4 mutation carriers have been reported; patients showed hypogammaglobulinemia, recurrent infectious diseases, various autoimmune diseases, and lymphocytic infiltration into multiple organs. The CTLA-4 expression level in Treg cells was reduced, while the frequency of Treg cells was increased in CTLA-4-insufficient patients. The transendocytosis assay is a specific functional test for the assessment of newly identified CTLA4 gene variants. Immunoglobulin substitution, corticosteroids, immunosuppressive therapy, and targeted therapy such as with CTLA-4 fusion proteins and mechanistic target of rapamycin (mTOR) inhibitors were applied; patients with life-threatening, treatment-resistant symptoms underwent hematopoietic stem cell transplantation. The fact that in humans CTLA-4 insufficiency causes severe disease taught us that the amount of CTLA-4 molecules present in/on T cells matters for immune homeostasis. However, whether the pathology-causing activated T lymphocytes in CTLA-4-insufficient patients are antigen-specific is an unsolved question. CTLA-4, in addition, has a role in autoimmune diseases and cancer. Anti-CTLA-4 drugs are employed as checkpoint inhibitors to target various forms of cancer. Thus, clinical research on human CTLA-4 insufficiency might provide us a deeper understanding of the mechanism(s) of the CTLA-4 molecule and immune dysregulation disorders.

Cardiac Complications in Immune Checkpoint Inhibition Therapy

Immune checkpoint inhibitors (ICIs) have changed the treatment landscape of advanced cancers. Unfortunately, these agents can induce a wide spectrum of immune-related adverse events (irAEs) through activation of immune responses in non-target organs, including the heart. As the clinical use of ICI therapy increases rapidly, management of irAEs is becoming extremely important. The most commonly presented cardiac irAE is myocarditis. Histopathologically, T-cell (with a predominance of CD8⁺ cells) and macrophage infiltration in the myocardium is typically observed in ICI-associated myocarditis. Other presentations of cardiac irAEs include congestive heart failure, Takotsubo cardiomyopathy, pericardial disease, arrhythmias, and conduction disease. Although cardiac irAEs are relatively rare, they can be life-threatening. Hence, cardiologists and oncologists should be vigilant for these presentations.

Association of cytotoxic T-lymphocyte antigen 4 rs231775 gene polymorphism with colorectal cancer risk

Aim of the Study

Results on the relationship between cytotoxic T-lymphocyte antigen 4 (CTLA4) +49A/G (rs231775) gene polymorphism and colorectal cancer risk are still debated. This meta-analysis was performed to assess the association between CTLA4 +49A/G and colorectal cancer risk.

Materials and Methods

The relevant studies were searched from PubMed, Cochrane Library, and China Biological Medicine Database-disc, and eligible investigations were included and synthesized using meta-analysis method.

Results

Eleven studies were recruited into this meta-analysis for the association of CTLA4 A/G gene polymorphism and colorectal cancer risk, consisting of 1802 colorectal cancer patients and 2939 controls. G allele was a risk factor for the colorectal cancer risk, and AA genotype might be a protective factor against colorectal cancer risk in overall populations (G allele: Odds ratio [OR] = 1.19, 95% confidence interval [CI]: 1.03-1.38, P = 0.02; AA genotype: OR = 0.63, 95% CI: 0.47-0.84, P = 0.002). However, the GG genotype was not associated with colorectal cancer risk in overall populations.

Conclusion

The association between CTLA4 G allele/AA genotype and colorectal cancer risk was found in this meta-analysis.

Immune checkpoint inhibitor-related myocarditis

Immune checkpoint inhibitors have demonstrated significant clinical benefit in many cancers. The clinical benefit afforded by these treatments can be accompanied by a unique and distinct spectrum of adverse events. Recently, several fatal cases of immune checkpoint inhibitor-related myocarditis were reported. Although its frequency is comparatively lower than that of other immune-related adverse events, myocarditis can lead to circulatory collapse and lethal ventricular arrhythmia. Immune checkpoints, cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1), play important roles in establishing peripheral tolerance to the heart. Evidence from studies using genetically engineered mouse models suggests that CTLA-4 signaling terminates proliferation and promotes anergy during the primary response to cardiac self-peptide recognition. PD-1 signaling restrains autoreactive T cells that enter the peripheral tissues and recognize cardiac-peptide, maintaining them in an anergic state. Patients affected by immune checkpoint inhibitor-related myocarditis often experience rapid onset of profound hemodynamic compromise progressing to cardiogenic shock. Early diagnosis is mandatory to address specific therapy and correct the timing of circulatory support. However, the diagnosis of myocarditis is challenging due to the heterogeneity of clinical presentations. Owing to its early onset, nonspecific symptomatology and fulminant progression, especially when these drugs are used in combination, oncologists should be vigilant for immune checkpoint inhibitor-related myocarditis. With many questions yet to be answered, from basic immune biology to clinical management, future research should aim to optimize the use of these drugs by identifying predictive biomarkers of either a response to therapy or the risks of myocarditis development.

Association between rs3087243 and rs231775 polymorphism within the cytotoxic T-lymphocyte antigen 4 gene and Graves' disease: a case/control study combined with meta-analyses

We conducted a case/control study to assess the impact of SNP rs3087243 and rs231775 within the CTLA4 gene, on the susceptibility to Graves' disease (GD) in a Chinese Han dataset (271 cases and 298 controls). The frequency of G allele for rs3087243 and rs231775 was observed to be significantly higher in subjects with GD than in control subjects (p = 0.005 and p = 0.000, respectively). After logistic regression analysis, a significant association was detected between SNP rs3087243 and GD in the additive and recessive models. Similarly, association for the SNP rs231775 could also be detected in the additive model, dominant model and recessive model. A meta-analysis, including 27 published datasets along with the current dataset, was performed to further confirm the association. Consistent with our case/control results, rs3087243 and rs231775 showed a significant association with GD in all genetic models. Of note, ethnic stratification revealed that these two SNPs were associated with susceptibility to GD in populations of both Asian and European descent. In conclusion, our data support that the rs3087243 and rs231775 polymorphisms within the CTLA4 gene confer genetic susceptibility to GD.

CTLA-4 expressed by FOXP3+ regulatory T cells prevents inflammatory tissue attack and not T-cell priming in arthritis

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) -mediated regulation of already tolerized autoreactive T cells is critical for understanding autoimmune responses. Although defects in CTLA-4 contribute to abnormal FOXP3⁺ regulatory T (Treg) cell function in rheumatoid arthritis, its role in autoreactive T cells remains elusive. We studied immunity towards the dominant collagen type II (CII) T-cell epitope in collagen-induced arthritis both in the heterologous setting and in the autologous setting where CII is mutated at position E266D in mouse cartilage. CTLA-4 regulated all stages of arthritis, including the chronic phase, and affected the priming of autologous but not heterologous CII-reactive T cells. CTLA-4 expression by both conventional T (Tconv) cells and Treg cells was required but while Tconv cell expression was needed to control the priming of naive autoreactive T cells, CTLA-4 on Treg cells prevented the inflammatory tissue attack. This identifies a cell-type-specific time window when CTLA-4-mediated tolerance is most powerful, which has important implications for clinical therapy with immune modulatory drugs.

Association between the cytotoxic T-lymphocyte antigen 4-318C/T polymorphism and malignant tumor risk

The cytotoxic T-lymphocyte antigen 4 (CTLA-4) polymorphic loci -318 cytosine/thymine (-318C/T) has been previously implicated in malignant tumor susceptibility. However, there were no precise conclusions about the correlation, the results from published studies were inconclusive. The aim of the current meta-analysis was to investigate the associations between CTLA-4 -318C/T polymorphisms and risk of malignant tumors in Asian population. We conducted a search in PubMed, Embase, the Chinese Journals Full-Text Database, Chinese Biomedical Database, and the Wanfang database. All studies were published up to September 30, 2015. Two reviewers analysed the data independently. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association. In total, 20 case-controlled studies with 3,539 cases and 4,690 controls were included in the final meta-analysis. The overall estimation demonstrated a significant association between CTLA-4 -318C/T polymorphism and malignant tumor risk in the Asian populations (TT+TC vs. CC: OR, 1.28; 95% CI, 1.07-1.53. TT vs. TC+CC: OR, 1.43; 95% CI, 1.03-1.99; TT vs. CC: OR, 1.51; 95% CI, 1.09-2.10. TC vs. CC: OR, 1.26; 95% CI, 1.06-1.50. T vs. C: OR, 1.25, 95% CI, 1.05-1.47). In the subgroup analysis by countries, we found that the dominant model (TT+TC vs. CC) revealed an increased risk of developing malignant tumors in the Chinese study population (OR, 1.41; 95% CI, 1.13-1.76), but no association was demonstrated in the other countries. The current meta-analysis suggests that CTLA-4 -318C/T polymorphism is significantly associated with the risk of malignance tumors in Asian populations, especially in those from China. Further studies for additional Asian countries are required to further evaluate the association.

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

Immune checkpoints refer to a plethora of inhibitory pathways built into the immune system, and recent studies have emphasized the role of these checkpoints in carcinogenesis. The aim of the present study was to evaluate two major immune checkpoints, the cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1), in the serum of 35 patients with stage I and II breast cancer. Serum concentrations of CTLA-4 and PD-1 were measured at three time points: i) Preoperatively; ii) during anesthesia following the harvesting of sentinel nodes (SNs); and iii) 24 h postoperatively. Control samples were obtained from 25 healthy, age-matched females. Assessment of CTLA-4 and PD-1 expression levels was conducted using flow cytometry. A statistically significant difference in PD-1 expression was identified between breast cancer patients preoperatively and healthy controls (26.31±11.87 vs. 12.72±8.15; P<0.0001). In addition, a statistically significant association was found between CTLA-4 and PD-1 levels prior to surgery (P=0.0084). In addition, CTLA-4 expression was associated with age (P=0.0453), with elevated levels of CTLA-4 detected in older breast cancer patients. Higher PD-1 expression levels were observed in T2 tumors compared with T1 tumors prior to surgery and intraoperatively; however, the differences were not statistically significant. Furthermore, a decrease in PD-1 levels was observed subsequent to harvesting SNs with metastasis, but not in SN-negative patients (P=0.05). A negative correlation was also observed between PD-1 expression and progesterone receptor (PR) status following surgery (P=0.024). These results provided a basis for further investigation of immune checkpoints in breast cancer. Breast cancer patients exhibit an altered profile of immune checkpoint markers, with higher concentrations of PD-1 observed in larger, PR-negative tumors.

Immuno-regulatory antibodies for the treatment of cancer

INTRODUCTION

After years of limited success, progress of anti-cancer immuno-therapeutics has been considerable over the past decade. Key to this progress has been the application of new biological insights around the importance and nature of immune checkpoints that are able to reverse down-regulation of anti-tumor immunity.

AREAS COVERED

An overview of the preclinical and recent clinical trial data on key immuno-regulatory agents currently in development, including antibody targeting of cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed death receptor 1 (PD-1) on T-lymphocytes and its principal ligand (PD-L1) on tumor cells as well as immune agonists (e.g., anti-CD40).

EXPERT OPINION

Durable long-term responses in some patients with advanced melanoma, initially with ipilimumab (anti-CTLA-4) and more recently antibodies targeting either PD-1 or PD-L1 in patients with melanoma and renal cancer, non-small-cell lung, bladder and head and neck cancers with less toxicity, have provided real optimism that immunotherapeutic approaches can improve outcomes in a wide range of cancer. The manageable tolerability of PD-1-pathway blockers and their unique mechanism of action are encouraging combination approaches. Current efforts focus on registration trials of single agents plus combinations in many different tumor types and treatment settings and identifying and developing predictive biomarkers of immunological response.

Immunologic checkpoints in cancer therapy: focus on the programmed death-1 (PD-1) receptor pathway

T-lymphocytes have the potential to recognize cancer antigens as foreign and therefore eliminate them. However, immune checkpoints such as cytotoxic T-lymphocyte-associated antigen (CTLA)-4 and programmed cell death (PD)-1 receptor and its ligands (PD-L1, PD-L2) suppress the activity of T-lymphocytes. Advances in the understanding of immunology and its role in cancer have led to the development of immune checkpoint inhibitors that block CTLA-4 and PD-1 and result in durable responses in patients with a wide range of cancers. PD-1 and PD-L1 inhibitors are currently in many stages of clinical investigation, and the anti-PD-1 antibody, pembrolizumab, was recently approved by the US Food and Drug Administration. Many questions remain to be answered, such as the optimal administration schedule, biomarkers that associate with benefit, and potential for use of PD-1 agents in combination approaches. Nonetheless, immunotherapy with PD-1 blocking antibodies is now becoming an integral part in the management of cancer.

Immunologic checkpoints in cancer therapy: focus on the programmed death-1 (PD-1) receptor pathway

T-lymphocytes have the potential to recognize cancer antigens as foreign and therefore eliminate them. However, immune checkpoints such as cytotoxic T-lymphocyte-associated antigen (CTLA)-4 and programmed cell death (PD)-1 receptor and its ligands (PD-L1, PD-L2) suppress the activity of T-lymphocytes. Advances in the understanding of immunology and its role in cancer have led to the development of immune checkpoint inhibitors that block CTLA-4 and PD-1 and result in durable responses in patients with a wide range of cancers. PD-1 and PD-L1 inhibitors are currently in many stages of clinical investigation, and the anti-PD-1 antibody, pembrolizumab, was recently approved by the US Food and Drug Administration. Many questions remain to be answered, such as the optimal administration schedule, biomarkers that associate with benefit, and potential for use of PD-1 agents in combination approaches. Nonetheless, immunotherapy with PD-1 blocking antibodies is now becoming an integral part in the management of cancer.

Controversies in the management of advanced melanoma: "gray" areas amid the "black and blue"

OBJECTIVE

To examine the current controversies and discuss consensus recommendations regarding treatment sequencing and the role of BRAF inhibitor at disease progression.

DATA SOURCE

An English-language literature search of MEDLINE/PubMed (1966-May 2014), using the keywords advanced melanoma, ipilimumab, cytotoxic T-lymphocyte antigen 4, dabrafenib, vemurafenib, BRAF inhibitor, trametinib, MEK inhibitor, and treatment sequencing was conducted. Data were also obtained from package inserts, meeting abstracts, and clinical registries.

STUDY SELECTION AND DATA EXTRACTION

All relevant published articles and abstracts on ipilimumab, vemurafenib, dabrafenib, and trametinib were reviewed. Clinical trial registries and meeting abstracts were used for ongoing studies.

DATA SYNTHESIS

The availability of new agents has made therapy selection more complex. Immunotherapy supporters reason that immunotherapy offers the best chance for long-term benefit and does not compromise the antitumor activity of subsequent BRAF inhibitors. Targeted therapy advocates rely on the high probability and rapid onset of response to BRAF inhibitors. Currently, there is insufficient evidence regarding the role of BRAF inhibitor at disease progression.

CONCLUSIONS

Therapy should be individualized based on patient- and disease-specific factors. Immunotherapy represents the best option for durable remission; however, targeted therapy is more appropriate for patients who are symptomatic or have rapidly growing tumors. The novel therapies have also demonstrated meaningful intracranial activity; thus, the presence of brain metastases should be taken into consideration in selecting therapy. Limited data exist about the continuation of BRAF inhibitors after therapeutic failure. Active research is ongoing to define the best option for patients with BRAF inhibitor refractory disease.

The CTLA4 +49 A/G (rs231775) polymorphism influences susceptibility to SLE in South Indian Tamils

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with complex etiology. Loss of immune tolerance and synthesis of autoantibodies against nuclear antigens contributes to the disease. Genetic aberrations disrupting the functions of immune regulatory receptors may facilitate the development of autoimmune diseases. Cytotoxic T-lymphocyte antigen 4 (CTLA4) is an inhibitory receptor for T cells and this study was carried out to analyze the influence of CTLA4 +49A/G (rs231775) polymorphism on susceptibility to SLE in ethnic Tamils. Three hundred SLE patients and 460 age and sex similar, ethnicity-matched controls were screened for the +49 A/G polymorphism by real time polymerase chain reaction (PCR). The wild allele (A) frequency in controls and cases was 63% and 47%, respectively. The presence of heterozygous (AG) and homozygous mutant (GG) genotype was associated with a significant risk to develop SLE (P = 0.0001, OR-2.29, 95% confidence interval (CI), 1.6-3.3) and (P = 0.0001, OR-4.3, 95% CI, 2.8-6.99). The frequency of mutant allele (G) in patients was also significantly associated with SLE (P = 0.0001, OR-1.9, 95% CI, 1.5-2.4). However, this polymorphism did not influence the clinical or serological phenotypes in our study. Therefore the CTLA4 +49 A/G polymorphism is a potential genetic risk factor for lupus susceptibility in South Indian Tamils, but does not appear to influence either the clinical or serological phenotype.

Ipilimumab in non-small cell lung cancer and small-cell lung cancer: new knowledge on a new therapeutic strategy

INTRODUCTION

Despite recent advances with new chemotherapeutic agents and target therapies, the prognosis of NSCLC remains poor. Recent results from clinical trials of immunotherapeutic agents, especially with immune checkpoint inhibitors, make this approach very exciting in NSCLC. Ipilimumab is a monoclonal antibody directed against cytotoxic T-lymphocyte antigen 4 that is able to stimulate the antitumour immune response by promoting T-cell activation.

AREAS COVERED

We have reviewed the literature and have described the most important results obtained with ipilimumab in NSCLC in recent trials with a specific focus on its peculiar toxicity profile and pattern of response. Trials ongoing with ipilimumab are also reported.

EXPERT OPINION

The results from clinical trials with ipilimumab are promising. Some important issues in the near future will be to identify prognostic and predictive biomarkers to select patients who could benefit from this drug. Further studies are warranted to understand how to combine ipilimumab with other anticancer strategies.

Low gene expression levels of activating receptors of natural killer cells (NKG2E and CD94) in patients with fulminant type 1 diabetes

Fulminant type 1 diabetes is an independent subtype of type 1 diabetes characterized by extremely rapid onset and absence of islet-related autoantibodies. However, detailed pathophysiology of this subtype is poorly understood. In this study, a comprehensive approach was applied to understand the pathogenesis of fulminant type 1 diabetes. We determined the genes that were differentially expressed in fulminant type 1 diabetes compared with type 1A diabetes and healthy control, using gene expression microarray in peripheral blood cells. Using volcano plot analysis, we found reduced expression of killer cell lectin-like receptor subfamily C, member 3 (KLRC3) which encodes NKG2E, a natural killer (NK) cell activating receptor, in fulminant type 1 diabetes, compared with healthy controls. This difference was confirmed by real-time RT-PCR among NK-enriched cells. The expression of KLRD1 (CD94), which forms heterodimer with NKG2E (KLRC3), was also reduced in NK-enriched cells in fulminant type 1 diabetes. Furthermore, flow cytometry showed significantly lower proportion of NK cells among peripheral blood mononuclear cells (PBMCs) in fulminant type 1 diabetes than in healthy controls. In patients with fulminant type 1 diabetes, the relative proportion of NK cells correlated significantly with the time period between onset of fever to the appearance of hyperglycemic-related symptoms. We conclude the presence of reduced NK activating receptor gene expression and low proportion of NK cells in fulminant type 1 diabetes.

Targeting autophagy as a potential therapeutic approach for melanoma therapy

Melanoma, occurring as a rapidly progressive skin cancer, is resistant to current chemo- and radiotherapy, especially after metastases to distant organs has taken place. Most chemotherapeutic drugs exert their cytotoxic effect by inducing apoptosis, which, however, is often deficient in cancer cells. Thus, it is appropriate to attempt the targeting of alternative pathways, which regulate cellular viability. Recent studies of autophagy, a well-conserved cellular catabolic process, promise to improve the therapeutic outcome in melanoma patients. Although a dual role for autophagy in cancer therapy has been reported, both protecting against and promoting cell death, the potential for using autophagy in cancer therapy seems to be promising. Here, we review the recent literature on the role of autophagy in melanoma with respect to the expression of autophagic markers, the involvement of autophagy in chemo- and immunotherapy, as well as the role of autophagy in hypoxia and altered metabolic pathways employed for melanoma therapy.

CD45RA-Foxp3(high) activated/effector regulatory T cells in the CCR7 + CD45RA-CD27 + CD28+central memory subset are decreased in peripheral blood from patients with rheumatoid arthritis

Human CD4+ T cells can be classified as either naïve, central memory (TCM), or effector memory (TEM) cells. To identify the CD4+ T cell subsets most important in the pathogenesis of rheumatoid arthritis (RA), we phenotypically defined human CD4+ T cells as functionally distinct subsets, and analyzed the distribution and characteristics of each subset in the peripheral blood. We classified CD4+ T cells into six novel subsets based on the expression of CD45RA, CCR7, CD27, and CD28. The CCR7 + CD45RA-CD27 + CD28+ TCM subset comprised a significantly smaller proportion of CD4+ T cells in RA patients compared to healthy controls. The frequency of TNF-α-producing cells in the CCR7-CD45RA-CD27 + CD28+ TEM subset was significantly increased in RA. Furthermore, within the CCR7 + CD45RA-CD27 + CD28+ TCM subset, which was decreased in periperal blood from RA, the proportions of total Foxp3+ Treg cells and CD45RA-Foxp3(high) activated/effector Treg cells were significantly lower in RA patients. Our findings suggest that the increased proportion of TNF-α-producing cells and the decreased proportion of CD45RA-Foxp3(high) activated/effector Treg cells in particular subsets may have critical roles in the pathogenesis of RA.

Pharmacotherapy of metastatic melanoma: emerging trends and opportunities for a cure

Metastatic melanoma is one of the most deadly forms of cancer and is poorly responsive to standard chemotherapeutics, such as Dacarbazine and Paclitaxel. Recently, the advent of Vemurafenib and Ipilimumab has broadened the spectrum of therapeutic options for advanced melanoma patients but the occurrence of resistance and of high-grade toxicities call for better and more effective treatments. This review focuses on approved and experimental therapies for metastatic melanoma. The mechanism of action and the reported efficacy data for small molecule drugs and biologics are discussed, outlining directions for future pharmaceutical research in this field.

Therapeutic gene modified cell based cancer vaccines

History of cancer immunotherapy lasts for more than 120 years. In 1891 William B. Coley injected bacteria into inoperable cancer (bone sarcoma) and observed tumor shrinkage. He is recognized as the "'"Father of Immunotherapy"'". Cancer immunotherapy is based on the ability of the immune system to recognize cancer cells and to affect their growth and expansion. Beside the fact that, tumor cells are genetically distinct from their normal counterparts, and should be recognized and eliminated by immune system, the tumor associated antigens (TAAs) are often poorly immunogenic due to immunoediting. This process allows tumor to evolve during continuous interactions with the host immune system, and eventually escape from immune surveillance. Furthermore, tumor microenvironment consists of immunosuppressive cells that release immunosuppressive factors including IL-6, IL-10, IDO, TGFβ or VEGF. Interactions between cancer and stroma cells create network of immunosuppressive pathways, while activation of immune defense is inhibited. A key to successful immunotherapy is to overcome the local immunosuppression within tumor microenvironment and activate mechanisms that lead to tumor eradication. There are two clinical approaches of immunotherapy: active and passive. Active immunotherapy involves stimulation of immune response to tumor associated antigens (TAAs), either non-specifically via immunomodulating agents or specifically employing cancer vaccines. This review presents the progress and breakthroughs in design, development and clinical application of selected cell-based tumor vaccines achieved due to the generation and development of gene transfer technologies.

Ipilimumab for advanced melanoma: a pharmacologic perspective

Ipilimumab, a fully human anti-CTLA-4 antibody, has been approved for the treatment of unresectable or metastatic melanoma based on its survival benefit demonstrated in randomized phase III studies. The current approved dosing schedule of ipilimumab is 3 mg/kg as a 90-min intravenous infusion every 3 weeks for a total of 4 doses. The immune-mediated mechanism of action of ipilimumab can result in tumor response patterns that may differ from those observed with conventional chemotherapy; therefore, revised response criteria to fully capture the spectrum of responses have been developed and are being prospectively validated. The safety profile of ipilimumab also reflects its mechanism of action and is characterized by immune-related adverse events. Although most of these events are mild, tolerable and reversible, high-grade immune-related adverse events have been observed in 15% of patients and can be potentially life-threatening if not managed appropriately. Guidelines for the management of these events emphasize thorough patient education, vigilant monitoring and prompt intervention with corticosteroids when appropriate. Ongoing research, including evaluation of ipilimumab in the adjuvant setting, investigation of its use in combination with other agents and assessment of alternative doses, will help optimize and expand the use of this innovative treatment.