Summary Re-emergence of chikungunya virus, a mosquito-transmitted pathogen, is of serious public health concern. In the past 15 years, after decades of infrequent, sporadic outbreaks, the virus has ...caused major epidemic outbreaks in Africa, Asia, the Indian Ocean, and more recently the Caribbean and the Americas. Chikungunya virus is mainly transmitted by Aedes aegypti mosquitoes in tropical and subtropical regions, but the potential exists for further spread because of genetic adaptation of the virus to Aedes albopictus , a species that thrives in temperate regions. Chikungunya virus represents a substantial health burden to affected populations, with symptoms that include severe joint and muscle pain, rashes, and fever, as well as prolonged periods of disability in some patients. The inflammatory response coincides with raised levels of immune mediators and infiltration of immune cells into infected joints and surrounding tissues. Animal models have provided insights into disease pathology and immune responses. Although host innate and adaptive responses have a role in viral clearance and protection, they can also contribute to virus-induced immune pathology. Understanding the mechanisms of host immune responses is essential for the development of treatments and vaccines. Inhibitory compounds targeting key inflammatory pathways, as well as attenuated virus vaccines, have shown some success in animal models, including an attenuated vaccine strain based on an isolate from La Reunion incorporating an internal ribosome entry sequence that prevents the virus from infecting mosquitoes and a vaccine based on virus-like particles expressing envelope proteins. However, immune correlates of protection, as well as the safety of prophylactic and therapeutic candidates, are important to consider for their application in chikungunya infections. In this Review, we provide an update on chikungunya virus with regard to its epidemiology, molecular virology, virus-host interactions, immunological responses, animal models, and potential antiviral therapies and vaccines.
Small-cell lung cancer (SCLC), an aggressive neuroendocrine tumor with early dissemination and dismal prognosis, accounts for 15-20% of lung cancer cases and ∼200,000 deaths each year. Most cases are ...inoperable, and biopsies to investigate SCLC biology are rarely obtainable. Circulating tumor cells (CTCs), which are prevalent in SCLC, present a readily accessible 'liquid biopsy'. Here we show that CTCs from patients with either chemosensitive or chemorefractory SCLC are tumorigenic in immune-compromised mice, and the resultant CTC-derived explants (CDXs) mirror the donor patient's response to platinum and etoposide chemotherapy. Genomic analysis of isolated CTCs revealed considerable similarity to the corresponding CDX. Most marked differences were observed between CDXs from patients with different clinical outcomes. These data demonstrate that CTC molecular analysis via serial blood sampling could facilitate delivery of personalized medicine for SCLC. CDXs are readily passaged, and these unique mouse models provide tractable systems for therapy testing and understanding drug resistance mechanisms.
In most patients with small-cell lung cancer (SCLC)-a metastatic, aggressive disease-the condition is initially chemosensitive but then relapses with acquired chemoresistance. In a minority of ...patients, however, relapse occurs within 3 months of initial treatment; in these cases, disease is defined as chemorefractory. The molecular mechanisms that differentiate chemosensitive from chemorefractory disease are currently unknown. To identify genetic features that distinguish chemosensitive from chemorefractory disease, we examined copy-number aberrations (CNAs) in circulating tumor cells (CTCs) from pretreatment SCLC blood samples. After analysis of 88 CTCs isolated from 13 patients (training set), we generated a CNA-based classifier that we validated in 18 additional patients (testing set, 112 CTC samples) and in six SCLC patient-derived CTC explant tumors. The classifier correctly assigned 83.3% of the cases as chemorefractory or chemosensitive. Furthermore, a significant difference was observed in progression-free survival (PFS) (Kaplan-Meier P value = 0.0166) between patients designated as chemorefractory or chemosensitive by using the baseline CNA classifier. Notably, CTC CNA profiles obtained at relapse from five patients with initially chemosensitive disease did not switch to a chemorefractory CNA profile, which suggests that the genetic basis for initial chemoresistance differs from that underlying acquired chemoresistance.
Cytotoxic T lymphocyte antigen 4 (CTLA4), a key negative regulator of T-cell activation, is targeted by the antibody tremelimumab to release potentially useful antitumor activity.
This phase II trial ...investigated tremelimumab as a second-line treatment for patients with metastatic gastric and esophageal adenocarcinomas. Tremelimumab was given every 3 months until symptomatic disease progression. Safety, clinical efficacy, and immunologic activity were evaluated.
Eighteen patients received tremelimumab. Most drug-related toxicity was mild; however, there was a single death due to bowel perforation that complicated colitis. Four patients had stable disease with clinical benefit; one patient achieved a partial response after eight cycles (25.4 months) and remains well on study at 32.7 months. Markers of regulatory phenotype, forkhead box protein 3 and CTLA4, doubled transiently in CD4(+)CD25(high) lymphocytes in the first month after tremelimumab before returning to baseline. In contrast, CTLA4 increased in CD4(+)CD25(low/negative) lymphocytes throughout the cycle of treatment. De novo proliferative responses to tumor-associated antigens 5T4 (8 of 18 patients) and carcinoembryonic antigen (5 of 13) were detected. Patients with a posttreatment carcinoembryonic antigen proliferative response had median survival of 17.1 months compared with 4.7 months for nonresponders (P = 0.004). Baseline interleukin-2 release after T-cell activation was higher in patients with clinical benefit and toxicity.
Despite the disappointing response rate of tremelimumab, one patient had a remarkably durable benefit for this poor-prognosis disease. In vitro evidence of enhanced proliferative responses to relevant tumor-associated antigens suggests that combining CTLA4 blockade with antigen-targeted therapy may warrant further investigation.
The primary aim of this clinical trial was to determine the feasibility of delivering first-generation CAR T cell therapy to patients with advanced, CEACAM5
+
malignancy. Secondary aims were to ...assess clinical efficacy, immune effector function and optimal dose of CAR T cells. Three cohorts of patients received increasing doses of CEACAM5
+
-specific CAR T cells after fludarabine pre-conditioning plus systemic IL2 support post T cell infusion. Patients in cohort 4 received increased intensity pre-conditioning (cyclophosphamide and fludarabine), systemic IL2 support and CAR T cells. No objective clinical responses were observed. CAR T cell engraftment in patients within cohort 4 was significantly higher. However, engraftment was short-lived with a rapid decline of systemic CAR T cells within 14 days. Patients in cohort 4 had transient, acute respiratory toxicity which, in combination with lack of prolonged CAR T cell persistence, resulted in the premature closure of the trial. Elevated levels of systemic IFNγ and IL-6 implied that the CEACAM5-specific T cells had undergone immune activation in vivo but only in patients receiving high-intensity pre-conditioning. Expression of CEACAM5 on lung epithelium may have resulted in this transient toxicity. Raised levels of serum cytokines including IL-6 in these patients implicate cytokine release as one of several potential factors exacerbating the observed respiratory toxicity. Whilst improved CAR designs and T cell production methods could improve the systemic persistence and activity, methods to control CAR T ‘on-target, off-tissue’ toxicity are required to enable a clinical impact of this approach in solid malignancies.
Circulating tumour cells (CTCs) have potential utility as minimally-invasive biomarkers to aid cancer treatment decision making. However, many current CTC technologies enrich CTCs using specific ...surface epitopes that do not necessarily reflect CTC heterogeneity. Here we evaluated the epitope-independent Parsortix system which enriches CTCs based on size and rigidity using both healthy normal volunteer blood samples spiked with tumour cells and blood samples from patients with small cell lung cancer (SCLC). Blood samples were maintained unfractionated at room temperature for up to 4 days followed by plasma removal for circulating free DNA (cfDNA) isolation and direct application of the remaining cell component to the Parsortix system. For tumour cells expressing the EpCAM cell surface marker the numbers of spiked cells retained using the Parsortix system and by EpCAM-positive selection using CellSearch® were not significantly different, whereas only the Parsortix system showed strong enrichment of cells with undetectable EpCAM expression. In a pilot clinical study we banked both enriched CTCs as well as plasma from SCLC patient blood samples. Upon retrieval of the banked Parsortix cellular samples we could detect cytokeratin positive CTCs in all 12 SCLC patients tested. Interestingly, processing parallel samples from the same patients by EpCAM enrichment using CellSearch® revealed only 83% (10/12) with cytokeratin positive CTCs indicating the Parsortix system is enriching for EpCAM negative SCLC CTCs. Our combined results indicate the Parsortix system is a valuable tool for combined cfDNA isolation and CTC enrichment that enables CTC analysis to be extended beyond dependence on surface epitopes.
Importance
This study is the first to compare the extended range of vision (ERV) intraocular lens (IOL) targeted at micro‐monovision to a monofocal targeted at binocular emmetropia.
Background
...Compares visual acuity, range of vision and spectacle independence in monofocal and ERV IOLs.
Design
Assessor‐blinded retrospective cohort study.
Participants
Eighty‐eight participants (176 eyes) with bilateral IOL implants at 5+ month postoperative review.
Methods
Regression analyses (general estimating equations and multiple linear regression) tested associations between IOL type (ZA9002 Tecnis 3‐piece or Tecnis ZCT monofocal; and Tecnis Symfony ERV IOL) and visual acuity, adjusting for key confounders including residual astigmatism.
Main Outcome Measures
Monocular and binocular visual acuity measured with and without distance refractive correction at distance (3.00 m), intermediate (1.00 and 0.63 m) and near (0.40 m) (logMAR units); near vision reading test used British ‘N’ notation; self‐reported spectacle independence.
Results
There was no significant difference between ERV and monofocal groups in uncorrected binocular visual acuity at distance (P = 0.595). Binocular uncorrected visual acuity at intermediate (0.63 m: monofocal 0.24, ERV 0.09, P < 0.001) and near (0.40 m: monofocal 0.42, ERV 0.18, P < 0.001) were significantly better in the ERV group. Binocular uncorrected near vision: all the ERV group read N8 or better, compared to 36% in the monofocal group (P < 0.001); 93% of the ERV group reported spectacle independence at near compared to 33% in the monofocal group (P < 0.001).
Conclusions and Relevance
The ERV IOL, targeted to achieve micro‐monovision, demonstrated superior range of visual acuity and spectacle independence compared to the monofocal targeted to achieve emmetropia.
Abstract Conversion of conventional T cells into T regulatory cells (Tregs) has been proposed as a potential mechanism for Treg expansion in cancer. However, this evidence is supported by in vitro or ...mouse model studies with no data from in vivo or human studies to support its role in enriching peripheral and tumor-infiltrating Tregs. Recent work has shown that induced FoxP3+ Tregs (iTregs) do not express Helios; an Ikaros family transcription factor. We analyzed peripheral blood samples from untreated renal cell carcinoma (RCC) patients and following interleukin (IL)-2 treatment for the expression of FoxP3 and Helios. Our work shows that expanded peripheral FoxP3+ Tregs in untreated RCC patients co-express Helios. Interestingly, IL-2 administration results in expansion of FoxP3+ Helios+ natural Tregs (nTregs) significantly more than FoxP3+ Helios− iTregs. Our work shows that the increased FoxP3+ Treg subpopulation in RCC patients co-express Helios, indicating that they could be derived from natural but not induced Tregs.
Abstract Cytotoxic T Lymphocyte Antigen 4 (CTLA4) blockade has shown antitumor activity against common cancers. However, the exact mechanism of immune mediation by anti-CTLA4 remains to be ...elucidated. Further understanding of how CTLA4 blockade with tremelimumab mediates immune responses may allow a more effective selection of responsive patients. Our results show that tremelimumab enhanced the proliferative response of T effector cells (Teff) upon TCR stimulation, and abrogated Treg suppressive ability. In the presence of tremelimumab, frequencies of IL-2-secreting CD4+ T cells and IFN-γ-secreting CD4+ and CD8+ T cells were increased in response to polyclonal activation and tumor antigens. Importantly, Treg frequency was not reduced in the presence of tremelimumab, and expanded Tregs in cancer patients treated with tremelimumab expressed FoxP3 with no IL-2 release, confirming them as bona fide Tregs. Taken together, this data indicates that tremelimumab induces immune responses mainly by direct activation of Teff rather than by affecting Tregs.
The CellSearch® semiautomated CTC enrichment and staining system has been established as the ‘gold standard’ for CTC enumeration with CellSearch® CTC counts recognized by the FDA as prognostic for a ...number of cancers. We and others have gone on to show that molecular analysis of CellSearch® CTCs isolated shortly after CellSearch® enrichment provides another valuable layer of information that has potential clinical utility including predicting response to treatment. Although CellSearch® CTCs can be readily isolated after enrichment, the process of analysing a single CellSearch® patient sample, which may contain many CTCs, is both time‐consuming and costly. Here, we describe a simple process that will allow storage of all CellSearch®‐enriched cells in glycerol at −20 °C for up to 2 years without any measurable loss in the ability to retrieve single cells or in the genome integrity of the isolated cells. To establish the suitability of long‐term glycerol storage for single‐cell molecular analysis, we isolated individual CellSearch®‐enriched cells by DEPArray™ either shortly after CellSearch® enrichment or following storage of matched enriched cells in glycerol at −20 °C. All isolated cells were subjected to whole‐genome amplification (WGA), and the efficacy of single‐cell WGA was evaluated by multiplex PCR to generate a Genome Integrity Index (GII). The GII results from 409 single cells obtained from both ‘spike‐in’ controls and clinical samples showed no statistical difference between values obtained pre‐ and postglycerol storage and that there is no further loss in integrity when DEPArray™‐isolated cells are then stored at −80 °C for up to 2 years. In summary, we have established simple yet effective ‘stop‐off’ points along the CTC workflow enabling CTC banking and facilitating selection of suitable samples for intensive analysis once patient outcomes are known.
Here, we describe a simple process for the storage of CellSearch®‐enriched cells for up to 2 years without any measurable loss in the ability to retrieve single cells, or in the genome integrity of the isolated cells. This workflow enables CTC banking and facilitates the retrospective selection of samples for intensive analysis once patient outcomes are known.
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