Divergent preS Sequences in Virion-Associated Hepatitis B Virus Genomes and Subviral HBV Surface Antigen Particles From HBV e Antigen-Negative Patients

Background

Hepatitis B virus (HBV) surface proteins (HBsAg) coat the viral particle and form subviral particles (SVPs). Loss of HBsAg represents a functional cure and is an important treatment goal.

Methods

We analyzed the impact of the HBV genotypes A-E and pre-S mutations on SVP expression in hepatitis B virus e antigen (HBeAg)-negative chronic HBV-infected patients. A HBV genome harboring a preS1-deletion was analyzed in hepatoma cells.

Results

We observed a genotype-specific ratio of the 3 surface proteins (SHBs/MHBs/LHBs), reflecting differences in the morphology and composition of SVPs. Deletions/mutations in the preS1/preS2 domain, detected in released viral genomes, did not affect the molecular weight of MHBs and LHBs in these patients. In contrast, LHB molecular weight was altered in vitro using an HBV genome harboring a preS1-deletion derived from one of these patients.

Conclusion

Differences in composition of SVPs may result in genotype-specific immunogenicity and pathogenesis. In the patients with preS-mutations, secreted HBsAg and released viral genomes cannot be derived from the same genetic source. As viral genomes are derived from covalently closed circular DNA (cccDNA), HBsAg is presumably derived from integrated DNA. This important HBsAg source should be considered for novel antiviral strategies in HBeAg-negative chronic HBV-infected patients.

Evolutionary Pathways to Persistence of Highly Fit and Resistant Hepatitis C Virus Protease Inhibitor Escape Variants

Protease inhibitors (PIs) are important components of treatment regimens for patients with chronic hepatitis C virus (HCV) infection. However, emergence and persistence of antiviral resistance could reduce their efficacy. Thus, defining resistance determinants is highly relevant for efforts to control HCV. Here, we investigated patterns of PI resistance-associated substitutions (RASs) for the major HCV genotypes and viral determinants for persistence of key RASs. We identified protease position 156 as a RAS hotspot for genotype 1-4, but not 5 and 6, escape variants by resistance profiling using PIs grazoprevir and paritaprevir in infectious cell culture systems. However, except for genotype 3, engineered 156-RASs were not maintained. For genotypes 1 and 2, persistence of 156-RASs depended on genome-wide substitution networks, co-selected under continued PI treatment and identified by next-generation sequencing with substitution linkage and haplotype reconstruction. Persistence of A156T for genotype 1 relied on compensatory substitutions increasing replication and assembly. For genotype 2, initial selection of A156V facilitated transition to 156L, persisting without compensatory substitutions. The developed genotype 1, 2, and 3 variants with persistent 156-RASs had exceptionally high fitness and resistance to grazoprevir, paritaprevir, glecaprevir, and voxilaprevir. A156T dominated in genotype 1 glecaprevir and voxilaprevir escape variants, and pre-existing A156T facilitated genotype 1 escape from clinically relevant combination treatments with grazoprevir/elbasvir and glecaprevir/pibrentasvir. In genotype 1 infected patients with treatment failure and 156-RASs, we observed genome-wide selection of substitutions under treatment. Conclusion: Comprehensive PI resistance profiling for HCV genotypes 1-6 revealed 156-RASs as key determinants of high-level resistance across clinically relevant PIs. We obtained in vitro proof of concept for persistence of highly fit genotype 1-3 156-variants, which might pose a threat to clinically relevant combination treatments.

Direct-acting antivirals-based therapy decreases hepatic fibrosis serum biomarker microfibrillar-associated protein 4 in hepatitis C patients

Background/Aims

An estimated 80 million people worldwide are infected with viremic hepatitis C virus (HCV). Even after eradication of HCV with direct acting antivirals (DAAs), hepatic fibrosis remains a risk factor for hepatocarcinogenesis. Recently, we confirmed the applicability of microfibrillar-associated protein 4 (MFAP4) as a serum biomarker for the assessment of hepatic fibrosis. The aim of the present study was to assess the usefulness of MFAP4 as a biomarker of liver fibrosis after HCV eliminating therapy with DAAs.

Methods

MFAP4 was measured using an immunoassay in 50 hepatitis C patients at baseline (BL), the end-of-therapy (EoT), and the 12-week follow-up (FU) visit. Changes in MFAP4 from BL to FU and their association with laboratory parameters including alanine aminotransferase (ALT), aspartate aminotransferase (AST), platelets, the AST to platelet ratio index (APRI), fibrosis-4 score (FIB-4), and albumin were analyzed.

Results

MFAP4 serum levels were representative of the severity of hepatic fibrosis at BL and correlated well with laboratory parameters, especially APRI (Spearman correlation, R²=0.80). Laboratory parameters decreased significantly from BL to EoT. MFAP4 serum levels were found to decrease from BL and EoT to FU with high statistical significance (Wilcoxon p<0.001 for both).

Conclusions

Our findings indicate that viral eradication resulted in reduced MFAP4 serum levels, presumably representing a decrease in hepatic fibrogenesis or fibrosis. Hence, MFAP4 may be a useful tool for risk assessment in hepatitis C patients with advanced fibrosis after eradication of the virus.

Impact of HBV genotype and mutations on HBV DNA and qHBsAg levels in patients with HBeAg-negative chronic HBV infection

BACKGROUND

HBV DNA and quantitative (q)HBsAg levels as prognostic markers for HBV-related disease are mostly validated in Asia and their significance in Western populations is uncertain.

AIM

To analyse the impact of the HBV genotype and frequent mutations in precore (PC), basal core promoter (BCP) and preS on HBV DNA and qHBsAg levels.

METHODS

HBV DNA and qHBsAg serum levels of 465 patients with HBeAg-negative chronic HBV infection were correlated with the HBV genotype and mutations in PC, BCP and preS. For a detailed analysis of the molecular virology, genotype A2 genomes harbouring these mutations were analysed for replication efficacy and HBsAg release in cell culture.

RESULTS

While no impact of the HBV genotype on HBV DNA levels was observed, qHBsAg levels differed up to 1.4 log among the genotypes (P < 0.001), reflected by large differences regarding the 1000 IU/mL HBsAg cut-off. While PC mutations were associated with higher (P < 0.001), BCP mutations were associated with lower HBV DNA levels (P < 0.001). Higher qHBsAg levels were associated with preS and lower levels with PC mutations (P < 0.001 and P = 0.001, respectively). The cell culture experiments revealed a higher HBsAg release and shorter filaments in case of a HBV genome harbouring a preS deletion. In contrast, a perinuclear HBsAg accumulation was detected for the PC and BCP-variants, reflecting an impaired HBsAg release.

CONCLUSIONS

qHBsAg serum levels depend on the HBV genotype and together with HBV DNA levels on frequent mutations in PC, BCP and preS in HBeAg-negative patients. qHBsAg cut-offs when used as prognostic markers require genotype-dependent validation.

Macrophage-Derived Extracellular Vesicles Induce Long-Lasting Immunity Against Hepatitis C Virus Which Is Blunted by Polyunsaturated Fatty Acids

Extracellular vesicles (EVs) are increasingly recognized as important mediators of intercellular communication. In this study, we aimed to further characterize the role of macrophage-derived EVs in immune responses against hepatitis C virus (HCV) and the potential of polyunsaturated fatty acids (PUFAs) to modulate this modality of innate immunity. To this end, EVs were isolated from interferon-stimulated macrophage cultures or from serum of patients with acute or chronic hepatitis C. EVs were characterized by electron microscopy, flow cytometry, RNA-sequencing, and Western blot analysis. The effect of EVs on replication of HCV was assessed in coculture models. Functional analyses were performed to assess the impact of PUFAs on EV-mediated antiviral immunity. We found that macrophages secreted various cytokines shortly after stimulation with type I and II IFN, which orchestrated a fast but short-lasting antiviral state. This rapid innate immune answer was followed by the production of macrophage-derived EVs, which induced a late, but long-lasting inhibitory effect on HCV replication. Of note, exposure of macrophages to PUFAs, which are important regulators of immune responses, dampened EV-mediated antiviral immune responses. Finally, EVs from patients with hepatitis C exhibited long-lasting antiviral activities during IFN therapy as well. The antiviral effect of EVs from Caucasian and Japanese patients differed, which may be explained by different nutritional uptake of PUFAs. In conclusion, our data indicate that macrophage-derived EVs mediate long-lasting inhibitory effects on HCV replication, which may bridge the time until efficient adaptive immune responses are established, and which can be blunted by PUFAs.

Interferon-free treatment choice according to baseline RASs leads to high SVR rates in HCV genotype 1 infected patients

AIM

Different combinations of direct antiviral agents (DAA) lead to high SVR rates in HCV genotype 1 infected patients. However, presence of baseline resistance-associated substitutions (RASs) represents a major risk factor for treatment failure. It is unknown whether choice of treatment based on RASs has the potential to decrease virologic failure rates.

METHODS

Population-based sequencing of NS3 and NS5A genes was performed in HCV genotype 1 infected patients at a German university hospital. Treatment was individually selected based on resistance analyses.

RESULTS

In total, 319 patients (50% treatment-experienced and 30% with cirrhosis) were included. With the treatment choice based on the baseline NS3 and NS5A resistance profile SVR rates between 96 and 100% were observed in all subgroups, including treatment-experienced patients with cirrhosis and HCV genotype 1a infected cirrhotic patients.

CONCLUSIONS

The choice of treatment based on the RASs status at baseline may be beneficial for optimizing treatment efficacy in patients with HCV genotype 1 infection and risk factors for treatment failure.

Patterns of Resistance-Associated Substitutions in Patients With Chronic HCV Infection Following Treatment With Direct-Acting Antivirals

BACKGROUND & AIMS

Little is known about substitutions that mediate resistance of hepatitis C virus (HCV) to direct-acting antivirals (DAAs), due to the small number of patients with treatment failure in approval studies. It is important to identify resistance patterns to select effective salvage treatments.

METHODS

We performed a comprehensive analysis for resistance-associated substitutions (RASs) in HCV genes (nonstructural protein [NS]3, NS5A, NS5B) targeted by DAAs. We compared NS3, NS5A, and NS5B sequences from 626 patients in Europe with DAA failure with sequences from 2322 DAA-naïve patients, infected with HCV genotypes 1 to 4. We considered RASs to be relevant if they were associated with DAA failure in patients or conferred a greater than twofold change in susceptibility compared with a reference strain in in vitro replicon assays. Data were collected on pretreatment status, DAA regimen, the treatment initiation date and duration, and virologic response. Patients who received at least 4 weeks of antiviral treatment were included in the analysis.

RESULTS

RASs in NS3 associated with simeprevir or paritaprevir failure include R155K and D168E/V. In addition, several RASs were specifically associated with failure of simeprevir (Q80K/R in patients with genotype 1a or 4) or paritaprevir (Y56H in combination with D168V in patients with genotype 1b). Y93H in NS5A was the RAS most frequently associated with failure of daclatasvir, ledipasvir, or ombitasvir in patients with genotype 1b infection, and L31M was associated with failure of daclatasvir or ledipasvir, but not ombitasvir. RASs in NS5A were heterogeneous among patients with HCV genotype 1a or genotype 4 infections. In patients with HCV genotype 3, Y93H was associated with resistance to daclatasvir, but no RASs were associated with ledipasvir failure, pointing to a limited efficacy of ledipasvir in patients with genotype 3. Among patients failed by sofosbuvir-containing regimens, L159F was enriched in patients with genotype 1b (together with C316N) or genotype 3 infection, whereas the RAS S282T was rarely observed.

CONCLUSIONS

We compared RASs in NS3, NS5A, and NS5B among patients failed by DAA therapy. Theses varied with the HCV genotype and subtype, and the different drug classes. These findings might be used to select salvage therapies.

Persistence of HCV in Acutely-Infected Patients Depletes C24-Ceramide and Upregulates Sphingosine and Sphinganine Serum Levels

Hepatitis C virus (HCV) substantially affects lipid metabolism, and remodeling of sphingolipids appears to be essential for HCV persistence in vitro. The aim of the current study is the evaluation of serum sphingolipid variations during acute HCV infection. We enrolled prospectively 60 consecutive patients with acute HCV infection, most of them already infected with human immunodeficiency virus (HIV), and serum was collected at the time of diagnosis and longitudinally over a six-month period until initiation of antiviral therapy or confirmed spontaneous clearance. Quantification of serum sphingolipids was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Spontaneous clearance was observed in 11 out of 60 patients (18.3%), a sustained viral response (SVR) in 43 out of 45 patients (95.5%) receiving an antiviral treatment after follow-up, whereas persistence of HCV occurred in six out of 60 patients (10%). C24-ceramide (C24-Cer)-levels increased at follow-up in patients with spontaneous HCV eradication (p < 0.01), as compared to baseline. Sphingosine and sphinganine values were significantly upregulated in patients unable to clear HCV over time compared to patients with spontaneous clearance of HCV infection on follow-up (p = 0.013 and 0.006, respectively). In summary, the persistence of HCV after acute infection induces a downregulation of C24Cer and a simultaneous elevation of serum sphingosine and sphinganine concentrations.

Interferon lambda 4 genotypes and resistance-associated variants in patients infected with hepatitis C virus genotypes 1 and 3

Single-nucleotide polymorphisms (SNPs) in the interferon lambda 4 (IFNL4) gene are predictors for treatment success in patients with hepatitis C virus (HCV) infection. For direct-acting antiviral combinations only weak association with IFNL4 SNPs was observed. Little is known about potential selections of resistance-associated variants (RAVs) by the IFNL4 genotype. This study analyzed the prevalence of RAVs to currently approved direct-acting antivirals in a large European population in correlation to SNPs in IFNL4. Samples of 633 patients chronically infected with HCV genotypes 1a (n = 259), 1b (n = 323), and 3 (n = 51) were genotyped for rs12979860 (formerly known as IL28B) and rs368234815. RAVs in NS3, NS5A, and NS5B were detected by population-based sequencing. In addition, IFNL4 SNPs and NS5A RAVs were analyzed including deep sequencing (n = 109) in an independent replication cohort of HCV genotype 1-infected patients (n = 201). No significant correlation was found between IFNL4 SNPs and rare and common RAVs within NS3 and NS5B. In contrast, the NS5A RAV Y93H was detected frequently in HCV genotype 1b (14%) and significantly associated with the beneficial IFNL4 SNPs (P < 0.001 and P = 0.002, respectively). Moreover, the presence of Y93H in HCV genotype 1b patients was significantly associated with the second site variant T83M (P < 0.001). Independent factors significantly associated with the presence of Y93H were IFNL4 genotype and high baseline viral load.

CONCLUSION

The NS5A RAV Y93H is significantly associated with the presence of beneficial IFNL4 SNPs and a high baseline viral load in HCV genotype 1-infected patients, which may explain a lack of correlation or even an inverse correlation of treatment response with IFNL4 genotype in some NS5A inhibitor containing IFN-free regimens.

Consideration of Viral Resistance for Optimization of Direct Antiviral Therapy of Hepatitis C Virus Genotype 1-Infected Patients

Different highly effective interferon-free treatment options for chronic hepatitis C virus (HCV) infection are currently available. Pre-existence of resistance associated variants (RAVs) to direct antiviral agents (DAAs) reduces sustained virologic response (SVR) rates by 3-53% in hepatitis C virus (HCV) genotype 1 infected patients depending on different predictors and the DAA regimen used. Frequencies of single and combined resistance to NS3, NS5A and NS5B inhibitors and consequences for the applicability of different treatment regimens are unknown. Parallel population based sequencing of HCV NS3, NS5A and NS5B genes in 312 treatment-naïve Caucasian HCV genotype 1 infected patients showed the presence of major resistant variants in 20.5% (NS3), 11.9% (NS5A), and 22.1% (NS5B) with important differences for HCV subtypes. In NS3, Q80K was observed in 34.7% and 2.1% of subtype 1a and 1b patients, respectively while other RAVs to second generation protease inhibitors were detected rarely (1.4%). Within NS5A RAVs were observed in 7.1% of subtype 1a and 17.6% in subtype 1b infected patients. RAVs to non-nucleoside NS5B inhibitors were observed in 3.5% and 44.4% of subtype 1a and 1b patients, respectively. Considering all three DAA targets all subtype 1a and 98.6% of subtype 1b infected patients were wildtype for at least one interferon free DAA regimen currently available. In conclusion, baseline resistance testing allows the selection of at least one RAVs-free treatment option for nearly all patients enabling a potentially cost- and efficacy-optimized treatment of chronic hepatitis C.

Evolution and function of the HCV NS3 protease in patients with acute hepatitis C and HIV coinfection

Little is known about the importance of the hepatitis C virus (HCV) NS3 protease in acute hepatitis C. In this prospective study, 82 consecutive patients with acute hepatitis C and human immunodeficiency virus (HIV) coinfection were enrolled. Individuals were infected with highly related HCV strains and the baseline NS3 quasispecies diversity and complexity was higher compared to a chronic hepatitis C control group (P<0.0001). Both parameters were comparable in patients with spontaneous clearance (n=6) versus treatment-induced SVR (n=5) or development of chronic hepatitis C (n=9). Longitudinal NS3 quasispecies kinetics showed a trend to a decreasing diversity and complexity (P<0.05) within 4 weeks in patients with spontaneous clearance compared to the other groups. The innate immune signalling protein CARDIF was cleaved to a similar extent independent of the outcome. Together with a more pronounced viral load decline (P<0.05), an early decreasing NS3 quasispecies evolution indicates spontaneous clearance of acute hepatitis C.

Variations in serum sphingolipid levels associate with liver fibrosis progression and poor treatment outcome in hepatitis C virus but not hepatitis B virus infection

Ablation of very-long-chain ceramides (Cers) with consecutive elevations in sphinganine levels has been shown to cause a severe hepatopathy in a knockout mouse model. We have recently shown that serum sphingolipids (SLs) are deregulated in patients with chronic liver disease. However, their role as possible biomarkers in liver fibrosis remains to date unexplored. We assessed, using liquid chromatography/tandem mass spectrometry, serum concentrations of various SL metabolites in 406 patients with chronic viral hepatitis, 203 infected with genotype 1 hepatitis C virus (HCV) and 203 with hepatitis B virus (HBV), respectively. We observed significant variations of serum SLs, with sphingosine and sphinganine being, both in univariate (P<0.05) as well as in multivariate analysis, significantly associated to severity of liver fibrosis in HCV-infected patients (odds ratio [OR]: 1.111; confidence interval [CI]: 1.028-1.202; P=0.007 and OR, 0.634; CI, 0.435-0.925; P=0.018, respectively). Serum SLs correlated significantly with serum triglyceride and cholesterol levels as well as with insulin resistance, defined by the homeostatic model assessment index, in HCV patients. Sustained viral response rates in HCV patients were independently predicted by serum C24Cer (OR, 0.998; CI, 0.997-0.999; P=0.001), its unsaturated derivative C24:1Cer (OR, 1.001; CI, 1.000-1.002; P=0.059), and C18:1Cer (OR, 0.973; CI, 0.947-0.999; P=0.048), together with ferritin (OR, 1.006; CI, 1.003-1.010; P<0.001), alkaline phosphatase (OR, 1.020; CI, 1.001-1.039; P=0.032), and interleukin-28B genotype (OR, 9.483; CI, 3.139-28.643; P<0.001).

CONCLUSION

Our study demonstrates a tight interaction between variations in serum SL levels and progression of liver fibrosis as well as responsiveness to antiviral therapy. Particularly, sphingosine, sphinganine, and C24Cer appear as promising novel biomarkers in chronic HCV infection and should be further evaluated within the noninvasive prediction of liver fibrosis.

[Bone tumours in lizards and snakes. A rare clinical finding]

OBJECTIVE

This article presents the pathological findings of 13 bone and cartilage tumours in lizards (n=8) and snakes (n=5) within the clinical context.

MATERIAL AND METHODS

Within a 12-year period (2001-2013), 13 cases of bone tumours in reptiles were diagnosed from 358 submitted tumour specimens. Pathological examination was performed on eight excisions, two biopsies, two amputates and four carcasses. Macroscopically, the samples displayed a light-coloured surface when cut and had a generally solid consistency. For the histological examination, representative specimens were decalcified when necessary, embedded in paraffin and stained using haematoxylin and eosin. Diagnosis was made based on the World Health Organisation classification for veterinary and human medicine.

RESULTS

Benign proliferations of the bone (ossifying fibroma [n=2], fibrous dysplasia [n=1]) as well as malignant cartilage (chondrosarcoma [n=2]) and bone tumours (fibroblastic osteosarcoma [n=2], small cell osteosarcoma [n=1]) were found on the head (n=5) and limbs (n=3) of various lizard species. In snakes only malignant cartilage neoplasms (chondrosarcoma [n=2], dedifferentiated chondrosarcoma [n=3]) of the spine were diagnosed. The histological appearance of the malignant tumours ranged from low to highly malignant differentiated aggregations of tumour cells, that produced varying amounts of osteoid or a hyaline matrix. Curative therapy was achieved in one ossifying fibroma by complete surgical removal and in two chondrosarcomas through amputation. No metastasis was observed in any of the four necropsies.

CONCLUSION AND CLINICAL RELEVANCE

Primary neoplasias of the bone are rare tumours in reptiles. Considering the information on therapeutic procedures and clinical course, the therapy of choice in lizards is complete surgical removal whereas in snakes reductive surgery may prolong the survival time.

A heterogeneous hierarchy of co-regulatory receptors regulates exhaustion of HCV-specific CD8 T cells in patients with chronic hepatitis C

BACKGROUND & AIMS

The functionality of virus-specific T cells is regulated by a sophisticated network of an expanding repertoire of co-regulatory receptors, which could be harnessed for immunotherapeutic applications. However, targeting particular pathways during persistent virus infections has resulted in variable outcomes. The extent to which T cell exhaustion can be reversed, by targeting multiple co-regulatory pathways, still remains not fully investigated.

METHODS

We analysed the phenotype and in vitro functionality of HCV-specific CD8(+) T cells expressing PD-1, CTLA-4, TIM-3 or 2B4 either alone or in various combinations and compared expression levels to those of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) specific T cells in peripheral blood mononuclear cells (PBMCs) from the same cohort of patients with chronic hepatitis C (CHC) infection.

RESULTS

Blockade and/or crosslinking of distinct co-regulatory pathways in exhausted HCV-specific CD8(+) T cells resulted in rather diverse and individualized T cell responses, irrespective of the type and number of receptors targeted. Overall, in vitro manipulations of these pathways yielded three response possibilities: (i) total non-response (ii) good single blockade response and (iii) good dual/multiple blockade response, with each comprising approximately one-third of the patients tested. The diversity of the in vitro responsiveness of HCV-specific T cells was reflected by an enormous ex vivo phenotypic heterogeneity. Despite this broad heterogeneity, HCV-specific CD8(+) T cells differed from EBV- and CMV-specific T cells in particular by TIM-3 expression, which also correlated with liver disease activity and viral load.

CONCLUSIONS

HCV-specific CD8(+) T cell functionality, upon co-regulatory receptor manipulations, was characterized by an individual pattern of responses in patients with CHC, suggesting that treatment approaches, targeting these receptors, should consider inter-individual differences and be personalized.

The late positive potential, emotion and apathy in Parkinson's disease

Parkinson's disease is associated with emotional changes including depression, apathy, and anxiety. The current study investigated emotional processing in non-demented individuals with Parkinson disease (PD) using an electrophysiological measure, the centro-parietal late positive potential (LPP). Non-demented patients with Parkinson's disease (n=17) and healthy control participants (n=16) viewed pleasant, neutral, and unpleasant pictures while EEG was recorded from a 64-channel geodesic net. The Parkinson patients did not differ from controls in terms of early electrophysiological components that index perceptual processing (occipital P100, N150, P250). Parkinson patients, however, showed reduced LPP amplitude specifically when viewing unpleasant, compared to pleasant, pictures as well as when compared to controls, consistent with previous studies suggesting a specific difference in aversive processing between PD patients and healthy controls. Importantly, LPP amplitude during unpleasant picture viewing was most attenuated for patients reporting high apathy. The data suggest that apathy in PD may be related to a deficit in defensive activation, and may be indexed cortically using event-related potentials.

Emotion and ocular responses in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disease that affects motor, cognitive, and emotional functioning. Previous studies reported reduced skin conductance responses in PD patients, compared to healthy older adults when viewing emotionally arousing pictures. Attenuated skin conductance changes in PD may reflect peripheral autonomic dysfunction (e.g., reduced nerve endings at the sweat gland) or, alternatively, a more central emotional deficit. The aim of the current study was to investigate a second measure of sympathetic arousal-change in pupil dilation. Eye movements, a motor-based correlate of emotional processing, were also assessed. Results indicated that pupil dilation was significantly greater when viewing emotional, compared to neutral pictures for both PD patients and controls. On the other hand, PD patients made fewer fixations with shorter scan paths, particularly when viewing pleasant pictures. These results suggest that PD patients show normal sympathetic arousal to affective stimuli (indexed by pupil diameter), but differences in motor correlates of emotion (eye movements).

Dual function of the NK cell receptor 2B4 (CD244) in the regulation of HCV-specific CD8+ T cells

The outcome of viral infections is dependent on the function of CD8+ T cells which are tightly regulated by costimulatory molecules. The NK cell receptor 2B4 (CD244) is a transmembrane protein belonging to the Ig superfamily which can also be expressed by CD8+ T cells. The aim of this study was to analyze the role of 2B4 as an additional costimulatory receptor regulating CD8+ T cell function and in particular to investigate its implication for exhaustion of hepatitis C virus (HCV)-specific CD8+ T cells during persistent infection. We demonstrate that (i) 2B4 is expressed on virus-specific CD8+ T cells during acute and chronic hepatitis C, (ii) that 2B4 cross-linking can lead to both inhibition and activation of HCV-specific CD8+ T cell function, depending on expression levels of 2B4 and the intracellular adaptor molecule SAP and (iii) that 2B4 stimulation may counteract enhanced proliferation of HCV-specific CD8+ T cells induced by PD1 blockade. We suggest that 2B4 is another important molecule within the network of costimulatory/inhibitory receptors regulating CD8+ T cell function in acute and chronic hepatitis C and that 2B4 expression levels could also be a marker of CD8+ T cell dysfunction. Understanding in more detail how 2B4 exerts its differential effects could have implications for the development of novel immunotherapies of HCV infection aiming to achieve immune control.

Infection with the hepatitis C Virus (HCV) is a world-wide health burden, the infection becomes persistent in the majority of cases. In chronic patients HCV-specific immune responses are weak, HCV-specific CD8+ T cells were shown to be functionally exhausted and to be negatively controlled by costimulatory molecules like PD-1. Here, we show that the costimulatory molecule 2B4 (CD244) is also involved in the regulation of HCV-specific CD8+ T cell responses and that 2B4 expression is selectively upregulated on virus-specific CD8+ T cells in persistent infections. Proliferation of HCV-specific CD8+ T cells from chronic patients increased by 2B4 cross-linking only if the ex vivo 2B4 expression was low, while we could observe no effect on samples with high 2B4 expression levels. Of note, expression of the intracellular 2B4 adaptor molecule SAP, which leads to an activation of the cell, decreased with higher 2B4 expression levels. Finally, we were able to show that 2B4 cross-linking can counter-act enhanced proliferation of HCV-specific CD8+ T cells seen upon PD-1 blockade. Thus, our study provides new insights into the regulation of CD8+ T cell responses demonstrating an implication of the costimulatory molecule 2B4.

Abstract P5-14-04: Patterns of Locoregional Failure in Women with Invasive Breast Cancer Treated with Mastectomy and Tissue Expander/Implant Reconstruction

BACKGROUND: Breast reconstruction with a tissue expander/implant (TE/I) following mastectomy for invasive breast cancer poses unique challenges in detecting local recurrence and in the technical delivery of post-mastectomy radiotherapy (PMRT). For women identified as having high risk disease, PMRT lowers the risk of locoregional failure (LRF) and enhances long-term survival. The aim of this study was to evaluate the patterns of LRF in women who underwent mastectomy and implant reconstruction, with or without adjuvant PMRT.

METHODS: We performed a retrospective review of all patients undergoing mastectomy with TE/I reconstruction for non-metastatic invasive breast cancer from 2001-2006 at the Cleveland Clinic, after approval from the institutional review board. The presence and location of locoregional recurrence was noted. Kaplan-Meier curves were generated to estimate locoregional recurrence free survival (LRFS) and overall survival (OS) rates.

RESULTS: The study population consisted of 326 patients: 121 (37%) with pathologic stage I disease, 128 (39%) with stage II, 46 (14%) with stage III, and 31 (10%) who underwent neoadjuvant systemic therapy prior to mastectomy. The median number of lymph nodes dissected was 10 and the median follow-up was 5.5 years. The OS for all patients at 5 years was 92.4%. By stage, 5-year OS was 95.9% for stage I, 94.4% for stage II,87.2% for stage III, and 79.6% for those undergoing pre-operative systemic therapy. The LRFS at 5 years for all patients was 91.3%. The 5-year LRFS was 95.4% for stage I, 93.6% for stage II, 79.4% for stage III, and 87.4% for those who underwent pre-operative systemic therapy. 8% of all patients had a LRF. By lymph node status, node-negative patients (N0) had a LRF rate of 4.8% (9/189), those with 1-3 nodes positive (N1) had a LRF rate of 5.0% (4/80), those with 4-9 nodes positive (N2) had a LRF rate of 17.5% (7/40), and those with 10 or more nodes positive (N3) had a LRF rate of 50% (6/12).

The most common sites of LRF were cutaneous chest wall (8/26) and axilla (8/26), followed by the supraclavicular/cervical nodes (5/26) and chest wall with muscle involvement (3/26). The remaining 2/26 failed at a combination of the above sites.

21.2% of the total population (69/326) underwent PMRT to the chest wall and regional nodes. By nodal status, including those who received neoadjuvant systemic therapy, 7.4% of women with zero nodes positive underwent radiation, followed by 18.8% with 1-3 nodes positive, and 76.9% with 4 or more nodes positive.

CONCLUSIONS: The crude rate of LRF in this large institutional series is similar to what has been previously reported in the literature. In our population, LRF in the superficial chest wall occurred at the same rate as the axillary nodes, which was followed in frequency by the supraclavicular/cervical nodes. Nearly 1/4 of women with 4 or more positive axillary nodes underwent no adjuvant radiation therapy following mastectomy, despite being a population of women known to derive benefit from PMRT. Further investigation is required to determine whether the presence of a TE/I reconstruction alters decision-making for adjuvant local therapy and/or impacts the technical delivery of PMRT.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-14-04.