OBJECTIVE

Recent studies indicate that regulatory T cells (Tregs) attenuate murine atherosclerosis. Since interleukin (IL)-2 induces Tregs proliferation, we tested the impact of L19-IL2, a fusion antibody specific to extra-domain B of fibronectin (ED-B) containing an active human IL-2 molecule, in experimental atherosclerosis.

RESULTS

L19-IL2 or appropriate controls were given intravenously to 6 month old Western diet-fed apoE(-/-) mice on day 1, 3, and 5. Human IL-2 was detected on day 7 within atherosclerotic plaques of L19-IL2-treated mice, and magnetic resonance imaging of the plaques showed a significant adventitial gadolinium enhancement on day 7 and 13, suggesting microvascular leakage as a result of the pharmacodynamic activity of L19-IL2. Treatment with L19-IL2 significantly reduced the size of pre-established atherosclerotic plaques at the thoracic aorta (Sudan III stained area) and in the aortic root area (microscopic, morphometric analysis) on day 7 as compared to controls (L19, D1.3-IL2, NaCl) as well as compared to baseline (day 0). Tregs markers Foxp3 and CTLA4 were highly increased in plaques after L19-IL2 treatment compared to controls (p<0.01), whereas the macrophage marker Mac3 was significantly reduced (p<0.03). Co-treatment with IL-2-receptor blocking antibody PC61 abrogated L19-IL2-induced plaque reduction compared with IgG control (p<0.03).

CONCLUSIONS

L19-IL2 delivers functional IL-2 to pre-established atherosclerotic plaques of WD-fed apoE(-/-) mice resulting in significant plaque size reduction mediated by local Tregs.

The immune system evolved for adequate surveillance and killing of pathogens while minimizing host damage, such as due to chronic or exaggerated inflammation and autoimmunity. This is achieved by negative regulators and checkpoints that limit the magnitude and time course of the immune response. Tumor cells often escape immune surveillance and killing. Therefore, disrupting the brakes built into the immune system should effectively boost the anticancer immune response. The success of anti-CTLA4, anti-PD-1 and anti-PD-L1 have firmly established this proof of concept. Since the response rate of anti-CTLA4, anti-PD-1 and anti-PD-L1 is still limited, there is an intense effort for the identification of new targets and development of approaches that can expand the benefits of immunotherapy to a larger patient pool. Additional T cell checkpoints are obvious targets; however, here we focus on the unusual suspects-cells that function to initiate and guide T cell activity. Innate immunity is both an obligate prerequisite for the initiation of adaptive immune responses and a requirement for the recruitment of activated T cells to the site of action. We discuss some of the molecules present in innate immune cells, including natural killer cells, dendritic cells, macrophages, myeloid-derived suppressor cells, endothelial cells and stromal cells, that can activate or enhance innate immune cell functions, and more importantly, the inhibitors or checkpoints present in these cells that restrain their functions. Boosting innate immunity, either by enhancing activator functions or, preferably, by blocking the inhibitors, may represent a new anticancer treatment modality or at least function as adjuvants to T cell checkpoint inhibitors.

T-cell-based immunotherapies are promising treatments for cancer patients. Although durable responses can be achieved in some patients, many patients fail to respond to these therapies, underscoring the need for improvement with combination therapies. From a screen of 850 bioactive compounds, we identify HSP90 inhibitors as candidates for combination with immunotherapy. We show that inhibition of HSP90 with ganetespib enhances T-cell-mediated killing of patient-derived human melanoma cells by their autologous T cells in vitro and potentiates responses to anti-CTLA4 and anti-PD1 therapy in vivo. Mechanistic studies reveal that HSP90 inhibition results in upregulation of interferon response genes, which are essential for the enhanced killing of ganetespib treated melanoma cells by T cells. Taken together, these findings provide evidence that HSP90 inhibition can potentiate T-cell-mediated anti-tumor immune responses, and rationale to explore the combination of immunotherapy and HSP90 inhibitors.Many patients fail to respond to T cell based immunotherapies. Here, the authors, through a high-throughput screening, identify HSP90 inhibitors as a class of preferred drugs for treatment combination with immunotherapy.

Rheumatoid Arthritis (RA) is a chronic, inflammatory, autoimmune disease affecting diarthrodial joints and extra-articular tissues; in the absence of an effective treatment, it is characterized by persistent symmetrical and erosive synovitis which leads to structural joint damage and lifelong disability. Several autoantibodies have been associated with RA such as rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). B cells have been shown to play a crucial role in the pathogenesis of RA by producing autoantibodies and promoting synovial inflammation through antigen presentation, T cells activation and cytokines production [1]. Although biologic agents have notably improved disease outcome and patients' quality of life, currently around 30-40% of subjects do not respond to treatment and the mechanisms leading to resistance are still not known [2]. For this reason, new prognostic biomarkers and predictors of response are needed. We and others have postulated that the development of biomarkers for patients' stratification prior therapeutic intervention may be possible through a better understanding of the different histopathological patterns present both in early and established individual RA patient and the related underlying cellular and molecular mechanisms. To date, Tumor Necrosis Factor (TNF)-α has been shown to be one of the master elements of inflammation in RA; however, even though therapies aimed at blocking this key cytokine have emerged as a major tool in the treatment of RA, a large proportion of patients (approximately 30-40%) do not achieve a meaningful clinical response assessed by either the American College of Rheumatology (ACR) or the European League Against Rheumatism (EULAR) criteria. The same limitation can be applied to the use of rituximab, a chimeric monoclonal antibody directed against CD20, which is uniquely expressed by all B-lymphocytes during the maturation process from late stage pro-B cells to memory cells. The clinical efficacy of rituximab has been proved by several clinical studies [3] but it is highly variable. Currently, NICE guidelines recommend rituximab in patients with inadequate response to a first-line biologic therapy, including at least one anti-TNFα agent independently of their pre-treatment chance to respond. In all cases, whether considering biologics used for several years in RA patients (anti-TNFα or rituximab) or relatively newer biologics in clinical use (i.e. tocilizumab, an anti-interleukin (IL) -6 receptor blocking monoclonal antibody or abatacept, a CTLA4 inhibitor fusion protein designed to target the T cell co-stimulatory signal mediated through the CD28-CD80/86 pathway), no validated biomarkers predictive of clinical response currently exist. Consequently, to date a "trial-and-error" approach is used in the prescription of biologics in RA, which has the obvious disadvantage of potentially exposing patients to drugs that they may not respond, with potential unnecessary side-effects, delaying use of an effective treatment and causing a significant economic burden to society. Therefore, identifying pre-treatment predictors of response with a customized stratification approach would be of invaluable importance in RA, also in consideration of the large number of biologics in development targeting novel pathways currently being tested in clinical trials. In this manuscript, we review existing data and provide future perspectives with regard to the role of synovial histopathology as a potential prognostic biomarker for patient stratification in RA, in particular regarding the use of specific biologic therapies.

Over 65,000 Americans are diagnosed with kidney cancer each year and nearly 13,000 die of this disease. Kidney cancer is not a single disease, it is made up of a number of different types of cancer, each with a different histology, a different clinical course, responding differently to therapy and caused by a different gene. Study of the 13 genes that are known to cause kidney cancer has led to the understanding that kidney cancer is a metabolic disease. Recent discoveries of chromatin remodeling/histone modifying genes, such as PBRM1 and SETD2, have opened up new areas of intense interest in the study of the fundamental genetic basis of kidney cancer. New approaches to immunotherapy with agents such as the CTLA4 inhibitor, ipilumumab, have opened up promising new directions for clinical trials. A number of new agents targeting of VEGF receptor signaling and the mTOR pathways as well as novel approaches targeting HIF2 will hopefully provide the foundation for the development of effective forms of therapy for this disease.

BACKGROUND

Systemic lupus erythematosus (SLE) is a common systemic autoimmune disease with a complex genetic inheritance. Genome-wide association studies (GWAS) have significantly increased the number of significant loci associated with SLE risk. To date, however, established loci account for less than 30% of the disease heritability and additional risk variants have yet to be identified. Here we performed a GWAS followed by a meta-analysis to identify new genome-wide significant loci for SLE.

METHODS

We genotyped a cohort of 907 patients with SLE (cases) and 1524 healthy controls from Spain and performed imputation using the 1000 Genomes reference data. We tested for association using logistic regression with correction for the principal components of variation. Meta-analysis of the association results was subsequently performed on 7,110,321 variants using genetic data from a large cohort of 4036 patients with SLE and 6959 controls of Northern European ancestry. Genetic association was also tested at the pathway level after removing the effect of known risk loci using PASCAL software.

RESULTS

We identified five new loci associated with SLE at the genome-wide level of significance (p < 5 × 10- 8): GRB2, SMYD3, ST8SIA4, LAT2 and ARHGAP27. Pathway analysis revealed several biological processes significantly associated with SLE risk: B cell receptor signaling (p = 5.28 × 10- 6), CTLA4 co-stimulation during T cell activation (p = 3.06 × 10- 5), interleukin-4 signaling (p = 3.97 × 10- 5) and cell surface interactions at the vascular wall (p = 4.63 × 10- 5).

CONCLUSIONS

Our results identify five novel loci for SLE susceptibility, and biologic pathways associated via multiple low-effect-size loci.

OBJECTIVE

Rates of malignant melanoma are continuing to increase, and until recently effective treatments were lacking. However, since 2011 three immunotherapeutic agents, known as checkpoint inhibitors, have been approved. This review aims to establish whether these three drugs - ipilimumab, nivolumab, and pembrolizumab - offer greater efficacy and tolerability compared to control interventions (placebo, immunotherapy, or chemotherapy) in patients with stage III or IV unresectable cutaneous melanoma.

METHODS

A search on four major medical and scientific databases yielded 7,553 records, of which seven met the inclusion criteria, with a total study population of 3,628. Only prospective Phase II or III randomized controlled trials on checkpoint inhibitors for patients with unresectable cutaneous melanoma that reported data on survival (overall or progression-free), tumor response, or adverse events were included. Three meta-analyses were carried out.

RESULTS

The hazard ratio for progression or death was 0.54 (95% confidence interval [CI]: 0.44-0.67), and the odds ratio for best overall response rate was 4.48 (95% CI: 2.77-7.24), both in favor of checkpoint inhibitors. However, control treatments were associated with an insignificantly lower rate of discontinuation of treatment due to adverse effects or treatment-related adverse events (odds ratio =1.63 [95% CI: 0.55-4.88]).

CONCLUSIONS

This study finds that checkpoint inhibitors are more effective than control interventions, both in terms of survival and tumor response, and yet no less tolerable. PD1 therapies (nivolumab and pembrolizumab) appear to offer greater efficacy than CTLA4 therapy (ipilimumab). The combination of nivolumab and ipilimumab was, however, the most effective, but significantly less tolerable than monotherapy. The lack of published clinical data does, however, limit this study. Further research is needed in two areas in particular: 1) to determine the optimal use of checkpoint inhibitors, specifically in terms of combination therapy, and 2) to identify reliable biomarkers to predictive responders and guide treatment assignment.

OBJECTIVE

Primary biliary cirrhosis (PBC) is an organ-specific autoimmune disease of still unidentified genetic etiology that is characterized by chronic inflammation of the liver. Since cytotoxic T-lymphocyte antigen 4 (CTLA4) polymorphisms have recently been linked with PBC susceptibility in studies on Caucasians, we investigated the genetic association between CTLA4 polymorphisms and PBC in a Japanese population.

METHODS

Five single nucleotide polymorphisms (SNPs) in the CTLA4 gene (rs733618, rs5742909, rs231775, rs3087243, and rs231725) were genotyped in 308 patients with PBC and 268 healthy controls using a TaqMan assay.

RESULTS

One CTLA4 gene SNP (rs231725) was significantly associated with susceptibility to anti-mitochondrial antibody (AMA)-positive PBC, but clinical significance disappeared after correction for multiple testing. Moreover, CTLA4 gene SNPs did not influence AMA development or disease progression to orthotopic liver transplantation in our Japanese cohort. In haplotype analyses, one haplotype [haplotype 1 (CGGA)] at rs5742909, rs231775, rs3087243, and rs231725, was significantly associated with susceptibility to both AMA-positive PBC and overall PBC.

CONCLUSIONS

This study showed that CTLA4 gene polymorphisms had a modest, but significant association with susceptibility to PBC in the Japanese population. The connection between genetic variants and the function of the CTLA4 gene remains to be addressed in future investigations.

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system white matter characterized by inflammation, demyelination and axonal damage. The cytotoxic T lymphocyte antigen-4 (CTLA-4) protein plays a key role in the down-regulation of T cell activation. We analysed the CTLA4 +49A/G and CT60 polymorphisms in a cohort of 120 MS trio families recruited from the Flanders region in Belgium. Both polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (RFLP). The +49 G-allele was significantly more transmitted to affected probands (P = 0.005). No transmission distortion was observed for the CT60 polymorphism. Haplotype analysis revealed significant overtransmission of the +49 A/G*G-CT60*G haplotype (P = 0.0025), and undertransmission of the +49 A/G*A-CT60*G haplotype (P = 0.015). The CTLA4 gene has been the focus of intense investigation in MS. Of 15 recently published papers, only six reported significant associations of various CTLA4 polymorphisms with MS, with the remainder being negative. Ours is the first report investigating the CT60 polymorphism in MS. Our data highlight a need for further scrutiny of the CTLA4 gene in MS.

Studies in the past have clearly established that CTLA4 is a susceptible gene for Graves' disease (GD). However, association studies between CTLA4 and the risk of developing Graves' ophthalmopathy (GO) in GD patients have shown conflicting results. In this study, associations of five CTLA4 single nucleotide polymorphisms (-1722A/G, -1661A/G, -318C/T, +49G/A, CT60) with GD risk and GO susceptibility in GD patients were investigated in a Chinese population. Our results showed that either +49A/G or CT60 polymorphism was associated with GD susceptibility in the Chinese population. Significant differences in the distribution of the genotypes or alleles evaluated between GD patients with and without clinically evident GO were only found for -318C/T polymorphism (P = 0.03). Multiple logistic regressions revealed that the -318T allele was negatively associated with GO under both additive and dominant genetic models (adjusted OR = 0.56, 95%CI 0.35-0.89, P = 0.014; adjusted OR = 0.51, 95%CI 0.30-0.84, P = 0.009, respectively). Stratification analysis according to gender demonstrated different scenarios concerning the role of the -318T allele in GO risk: a significant protective role for GO was only confirmed in male but not in female GD patients. Haplotype analyses showed that only the haplotypes containing the -318T allele played a protective role in GO. In conclusion, results from this study suggested that the -318T allele might play a protective role in GO susceptibility for GD patients at least in the Chinese population. However, extended analyses with larger sample size should be carried out in patients from different ethnic origins to further verify this association.

Human papillomavirus (HPV) virus-like particle (VLP) vaccines were recently licensed. Although neutralizing Ab titers are thought to be the main effectors of protection against infection, early predictors of long-term efficacy are not yet defined and a comprehensive understanding of innate and adaptive immune responses to vaccination is still lacking. Here, microarrays were used to compare the gene expression signature in HPV-16 L1 VLP-stimulated PBMCs from 17 vaccine and 4 placebo recipients before vaccination and 1 mo after receiving the second immunization. Vaccination with a monovalent HPV-16 L1 VLP vaccine was associated with modulation of genes involved in the inflammatory/defense response, cytokine, IFN, and cell cycle pathways in VLP-stimulated PBMCs. Additionally, there was up-regulation of probesets associated with cytotoxic (GZMB, TNFSF10) and regulatory (INDO, CTLA4) activities. The strongest correlations with neutralizing Ab titers were found for cyclin D2 (CCND2) and galectin (LGALS2). Twenty-two differentially expressed probesets were selected for confirmation by RT-PCR in an independent sample set. Agreement with microarray data was seen for more than two-thirds of these probesets. Up-regulation of immune/defense response genes by HPV-16 L1 VLP, in particular, IFN-induced genes, was observed in PBMCs collected before vaccination, with many of these genes being further induced following vaccination. In conclusion, we identified important innate and adaptive response-related genes induced by vaccination with HPV-16 L1 VLP. Further studies are needed to identify gene expression signatures of immunogenicity and long-term protection with potential utility in prediction of long-term HPV vaccination outcomes in clinical trials.

Evaluation of the association between single-nucleotide polymorphisms (SNPs) and disease outcomes is widely used to identify genetic risk factors for complex diseases. Although this analysis paradigm has made significant progress in many genetic studies, many challenges remain, such as the requirement of a large sample size to achieve adequate power. Here we use rheumatoid arthritis (RA) as an example and explore a new analysis strategy: pathway-based analysis to search for related genes and SNPs contributing to the disease.We first propose the application of measure of explained variation to quantify the predictive ability of a given SNP. We then use gene set enrichment analysis to evaluate enrichment of specific pathways, where pathways, are considered enriched if they consist of genes that are associated with the phenotype of interest above and beyond is expected by chance. The results are also compared with score tests for association analysis by adjusting for population stratification.Our study identified some significantly enriched pathways, such as "cell adhesion molecules," which are known to play a key role in RA. Our results showed that pathway-based analysis may identify other biologically interesting loci (e.g., rs1018361) related to RA: the gene (CTLA4) closest to this marker has previously been shown to be associated with RA and the gene is in the significant pathways we identified, even though the marker has not reached genome-wide significance in univariate single-marker analysis.

T cells play an important role in initiating autoimmune responses and maintaining synovial inflammation in rheumatoid arthritis. Although, anti-type II collagen antibody-induced arthritis (CAIA) is generally believed to be a T cell- and B cell-independent model, the detailed pathogenesis of CAIA remains unclear. In the present study, to elucidate the contribution of T cells to the pathogenesis of CAIA, we evaluated the effects of CTLA4 Ig and cyclosporin (CsA). Arthritis was induced in mice by intravenous injection of anti-type II collagen antibody followed by intraperitoneal injection of lipopolysaccharide. CTLA4 Ig was intraperitoneally administered and CsA was subcutaneously administered; then the severity of arthritis was evaluated by scoring the edema and erythema of paws and by measuring hind paw thickness. Paw samples were collected 12 days after the antibody injection, and the mRNA expression levels were analyzed by real-time quantitative polymerase chain reaction. Administration of CTLA4 Ig ameliorated the increases in arthritic score and paw thickness in the later phase, but not in the early phase of arthritis. CsA suppressed the increases in arthritic score and paw thickness in both the early and later phases of arthritis. CTLA4 Ig and CsA suppressed mRNA up-regulation of T-cell markers, CD3 and CD25, and immune response-related mediators, IFN-gamma and IL-12. They also suppressed the up-regulation of macrophage marker, F4/80, and proinflammatory cytokines, TNF-alpha, IL-1beta and IL-6. The results provide direct evidence that arthritis in this model is T-cell activation dependent.

T cells are required for continuous parathyroid hormone (cPTH) treatment to induce bone loss as they sensitize stromal cells to PTH through CD40 ligand (CD40L), a surface molecule of activated T cells. Since CD40L expression is a feature of activated T cells, we investigated whether antigen (Ag)-mediated T cell activation is required for PTH to exert its catabolic activity. We report that inhibition of Ag presentation through silencing of either class I or class II MHC-T cell receptor (TCR) interaction prevents the cortical bone loss induced by in vivo cPTH treatment. We also show that the bone loss and the stimulation of bone resorption induced by cPTH treatment are prevented by CTLA4-Ig, an inhibitor of T cell costimulation approved for the treatment of rheumatoid arthritis. Since inhibition of antigen-driven T cell activation by blockade of either TCR signaling or T cell costimulation is sufficient to silence the catabolic activity of cPTH, antigen-presenting cells and T lymphocyte interactions therefore play a critical role in the mechanism of action of PTH.

Genome-wide association studies and meta-analysis indicate that several genes/loci are consistently associated with rheumatoid arthritis (RA) in European and Asian populations. To evaluate the transferability status of these findings to an ethnically diverse north Indian population, we performed a replication analysis. We investigated the association of 47 single-nucleotide polymorphisms (SNPs) at 43 of these genes/loci with RA in a north Indian cohort comprising 983 RA cases and 1007 age and gender matched controls. Genotyping was done using Infinium human 660w-quad. Association analysis by chi-square test implemented in plink was carried out in two steps. Firstly, association of the index or surrogate SNP (r2>0.8, calculated from reference GIH Hap-Map population) was tested. In the second step, evidence for allelic/locus heterogeneity at aforementioned genes/loci was assessed for by testing additional flanking SNPs in linkage equilibrium with index/surrogate marker.Of the 44 European specific index SNPs, neither index nor surrogate SNPs were present for nine SNPs in the genotyping array. Of the remaining 35, associations were replicated at seven genes namely PTPN22 (rs1217407, p = 3×10(-3)); IL2-21 (rs13119723, p = 0.008); HLA-DRB1 (rs660895, p = 2.56×10(-5); rs6457617, p = 1.6×10(-09); rs13192471, p = 6.7×10(-16)); TNFA1P3 (rs9321637, p = 0.03); CCL21 (rs13293020, p = 0.01); IL2RA (rs2104286, p = 1.9×10(-4)) and ZEB1 (rs2793108, p = 0.006). Of the three Asian specific loci tested, rs2977227 in PADI4 showed modest association (p<0.02). Further, of the 140 SNPs (in LE with index/surrogate variant) tested, association was observed at 11 additional genes: PTPRC, AFF3, CD28, CTLA4, PXK, ANKRD55, TAGAP, CCR6, BLK, CD40 and IL2RB. This study indicates limited replication of European and Asian index SNPs and apparent allelic heterogeneity in RA etiology among north Indians warranting independent GWAS in this population. However, replicated associations of HLA-DRB1, PTPN22 (which confer ∼50% of the heritable risk to RA) and IL2RA suggest that cross-ethnicity fine mapping of such loci is apposite for identification of causal variants.

The CD154-CD40 pathway is one of the critical costimulatory pathways that are required for full activation of T cells during alloimmune responses. Blockade of this pathway with anti-CD154 antibodies has been reported to prolong allograft survival in experimental transplantation models and to induce tolerance in some instances. However, anti-CD154 monotherapy cannot induce tolerance in "stringent" models such as skin and islet transplantation and is not sufficient to prevent chronic graft vasculopathy in vascularized organ transplantation. Therefore, combined therapies of anti-CD154 antibodies plus donor-specific transfusion, bone marrow infusion, or B7 blockade by CTLA4-Ig have been tried, and synergistic effects for tolerance induction have been reported. Furthermore, the efficacy of CD154 blockade in primate models has been confirmed for islet and kidney transplantation. The mechanisms of CD154 blockade in vivo include CTLA4-dependent anergy or regulation, T-cell apoptosis, and induction of regulatory cells. Finally, anti-CD154 antibody therapy has been reported to result in unexpected thromboembolic complications in both primates and humans, although the etiology of these conditions remains unclear. In addition, not all antibodies cause this side effect. Clinical trials with humanized anti-CD154 monoclonal antibodies are underway in severe autoimmune diseases, but its development in transplantation is unclear at this time.

BACKGROUND

Transplantation of human islets has been successful clinically. Since human islets are scarce, we are studying microencapsulated porcine islet xenografts in nonobese diabetic (NOD) mice. We have evaluated the cellular immune response in NOD mice with and without dual costimulatory blockade.

METHODS

Alginate-poly-L-lysine-encapsulated adult porcine islets were transplanted i.p. in untreated diabetic NODs and NODs treated with CTLA4-Ig to block CD28/B7 and with anti-CD154 mAb to inhibit CD40/CD40-ligand interactions. Groups of mice were sacrificed on subsequent days; microcapsules were evaluated by histology; peritoneal cells were analyzed by FACS; and peritoneal cytokines were quantified by ELISA. Controls included immunoincompetent NOD-Scids and diabetic NODs given sham surgery or empty microcapsules.

RESULTS

Within 20 days, encapsulated porcine islets induced accumulation of large numbers of macrophages, eosinophils, and significant numbers of CD4 and CD8 T cells at the graft site, and all grafts were rejected. During rejection, IFNgamma, IL-12 and IL-5 were significantly elevated over sham-operated controls, whereas IL-2, TNFalpha, IL-4, IL-6, IL-10, IL-1beta and TGFbeta were unchanged. Treatment with CTLA4-Ig and anti-CD154 prevented graft destruction in all animals during the 26 days of the experiment, dramatically inhibited recruitment of host inflammatory cells, and inhibited peritoneal IFNgamma and IL-5 concentrations while delaying IL-12 production.

CONCLUSIONS

When two different pathways of T cell costimulation were blocked, T cell-dependent inflammatory responses were inhibited, and survival of encapsulated islet xenografts was significantly prolonged. These findings suggest synergy between encapsulation of donor islets and simultaneous blockade of two host costimulatory pathways in prolonging xenoislet transplant survival.

The presented comprehensive review of current knowledge about genetic factors predisposing to Graves' disease (GD) put emphasis on functional significance of observed associations. In particular, we discuss recent efforts aimed at refining diseases associations found within the HLA complex and implicating HLA class I as well as HLA-DPB1 loci. We summarize data regarding non-HLA genes such as PTPN22, CTLA4, CD40, TSHR and TG which have been extensively studied in respect to their role in GD. We review recent findings implicating variants of FCRL3 (gene for FC receptor-like-3 protein), SCGB3A2 (gene for secretory uteroglobin-related protein 1- UGRP1) as well as other unverified possible candidate genes for GD selected through their documented association with type 1 diabetes mellitus: Tenr-IL2-IL21, CAPSL (encoding calcyphosine-like protein), IFIH1(gene for interferon-induced helicase C domain 1), AFF3, CD226 and PTPN2. We also review reports on association of skewed X chromosome inactivation and fetal microchimerism with GD. Finally we discuss issues of genotype-phenotype correlations in GD.

Systemic Lupus Erythematosus (SLE) is one of the most relevant world-wide autoimmune disorders. The formation of autoantibodies and the deposition of antibody-containing immune complexes in blood vessels throughout the body is the main pathogenic mechanism of SLE leading to heterogeneous clinical manifestations and target tissue damage. The complexity of etiology and pathogenesis in SLE, enclosing genetic and environmental factors, apparently is one of the greatest challenges for both researchers and clinicians. Strong indications for a genetic background in SLE come from studies in families as well as in monozygotic and dizygotic twins, discovering several SLE-associated loci and genes (e.g. IRF5, PTPN22, CTLA4, STAT4 and BANK1). As SLE has a complex genetic background, none of these genes is likely to be entirely responsible for triggering autoimmune response in SLE even if they disclosure a potentially novel molecular mechanisms in the pathogenesis' disease. The clinical manifestations and disease severity varies greatly among patients, thus several studies try to associate clinical heterogeneity and prognosis with specific genetic polymorphisms in SLE associated genes. The continue effort to describe new predisposing or modulating genes in SLE is justified by the limited knowledge about the pathogenesis, assorted clinical manifestation and the possible prevention strategies. In this review we describe newly discovered, as well as the most studied genes associated to SLE susceptibility, and relate them to clinical manifestations of the disease.

We previously showed that agonistic antibodies to CD40 could substitute for CD4 T-cell help and prevent reactivation of murine gammaherpesvirus 68 (MHV-68) in the lungs of major histocompatibility complex (MHC) class II(-/-) (CII(-/-)) mice, which are CD4 T cell deficient. Although CD8 T cells were required for this effect, no change in their activity was detected in vitro. A key question was whether anti-CD40 treatment (or CD4 T-cell help) changed the function of CD8 T cells or another cell type in vivo. To address this question, in the present study, we showed that adoptive transfer of CD8 T cells from virus-infected wild-type mice or anti-CD40-treated CII(-/-) mice caused a significant reduction in lung viral titers, in contrast to those from control CII(-/-) mice. Anti-CD40 treatment also greatly prolonged survival of infected CII(-/-) mice. This confirms that costimulatory signals cause a change in CD8 T cells enabling them to maintain effective long-term control of MHV-68. We investigated the nature of this change and found that expression of the inhibitory receptor PD-1 was significantly increased on CD8 T cells in the lungs of MHV-68-infected CII(-/-), CD40(-/-), or CD80/86(-/-) mice, compared with that in wild-type or CD28/CTLA4(-/-) mice, correlating with the level of viral reactivation. Furthermore, blocking PD-1-PD-L1 interactions significantly reduced viral reactivation in CD4 T-cell-deficient mice. In contrast, the absence of another inhibitory receptor, NKG2A, had no effect. These data suggest that CD4 T-cell help programs a change in CD8 T-cell function mediated by altered PD-1 expression, which enables effective long-term control of MHV-68.

Metastatic melanoma has a poor prognosis and until recently systemic therapy was ineffective. Advances in the understanding of tumour biology and immune regulation have led to the development of targeted agents that have changed clinical practice, with further improvements expected with new compounds and combinations. The first major advance was the development of selective mitogen-activated protein (MAP) kinase inhibitors (BRAF and MEK inhibitors) and immune checkpoint blockade with a CTLA4 antibody (ipilimumab). These drugs proved vastly superior to conventional chemotherapy, however response, resistance and toxicity were limitations. The second major advance is the development of other immune checkpoint blocking agents, including PD-1 and PD-L1 antibodies, and the use of BRAF and MEK inhibitors in combination, with a higher proportion of durable responses coupled with less toxicity. In an effort to improve outcomes for patients with melanoma further, trials are underway examining the combination of MAPK inhibitors, immunotherapies and other pathway inhibitors and adjuvant studies of many of these agents have commenced.

Immune checkpoint inhibitors have recently become a cornerstone for the treatment of different advanced cancers. These drugs, represented mainly by monoclonal antibodies anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4), anti-programmed cell death protein-1 (PD-1) and anti-PD-1 ligand molecules (PD-L1 and L2), have the ability to reactivate the immune system against tumor cells, but can also trigger a myriad of autoimmune side effects, termed immune-related adverse events (irAEs). In particular, there are a number of endocrine-related irAEs. Current data from clinical trials show increased incidence of hypophysitis with CTLA4 inhibition and thyroid dysfunction with PD-(L)1 blockade. In addition, a few cases of type 1 diabetes mellitus and primary adrenal insufficiency have been reported. We discuss the incidence, clinical manifestations, diagnosis and management of immune-related endocrinopathies in this highly complex context of oncological patients in need of immunotherapies.

Cytotoxic lymphocyte antigen-4 (CTLA-4) plays an important role in regulating T cell activation, and may help to limit T cell response under conditions of inflammation. Genetic variability in CTLA-4 has been implicated in the development of several autoimmune diseases. Some studies have described associations between CTLA-4 polymorphisms and systemic lupus erythematosus (SLE), but findings have been inconsistent. We examined polymorphisms in the CTLA-4 gene promoter region (-1722T/C, -1661 A/G, -318C/T) and exon I (+49G/A) with respect to SLE in a population-based case-control study in the southeastern US. Genotypes from 230 recently diagnosed cases and 276 controls were examined separately for African-Americans and whites. We observed no overall associations between SLE and the four CTLA-4 polymorphisms examined. Subgroup analyses revealed effect modification by age for the presence of the -1661G allele, yielding a significant positive association with SLE in younger (<35 years) African-Americans (OR = 3.3). CTLA-4 genotypes also interacted with HLA-DR2 and GM allotype to contribute to risk of SLE. These findings suggest allelic variation in this region of CTLA4 is not a major independent risk factor for SLE, but may contribute to risk of disease in younger African-Americans or in the presence of certain immunogenetic markers.