The development of a prophylactic vaccine for hepatitis C virus (HCV) remains a global health challenge. Cumulative evidence supports the importance of antibodies targeting the HCV E2 envelope ...glycoprotein to facilitate viral clearance. However, a significant challenge for a B cell-based vaccine is focusing the immune response on conserved E2 epitopes capable of eliciting neutralizing antibodies not associated with viral escape. We hypothesized that glycosylation might influence the antigenicity and immunogenicity of E2. Accordingly, we performed head-to-head molecular, antigenic, and immunogenic comparisons of soluble E2 (sE2) produced in (i) mammalian (HEK293) cells, which confer mostly complex- and high-mannose-type glycans; and (ii) insect (Sf9) cells, which impart mainly paucimannose-type glycans. Mass spectrometry demonstrated that all 11 predicted
-glycosylation sites were utilized in both HEK293- and Sf9-derived sE2, but that
-glycans in insect sE2 were on average smaller and less complex. Both proteins bound CD81 and were recognized by conformation-dependent antibodies. Mouse immunogenicity studies revealed that similar polyclonal antibody responses were generated against antigenic domains A to E of E2. Although neutralizing antibody titers showed that Sf9-derived sE2 induced moderately stronger responses than did HEK293-derived sE2 against the homologous HCV H77c isolate, the two proteins elicited comparable neutralization titers against heterologous isolates. Given that global alteration of HCV E2 glycosylation by expression in different hosts did not appreciably affect antigenicity or overall immunogenicity, a more productive approach to increasing the antibody response to neutralizing epitopes may be complete deletion, rather than just modification, of specific
-glycans proximal to these epitopes.
The development of a vaccine for hepatitis C virus (HCV) remains a global health challenge. A major challenge for vaccine development is focusing the immune response on conserved regions of the HCV envelope protein, E2, capable of eliciting neutralizing antibodies. Modification of E2 by glycosylation might influence the immunogenicity of E2. Accordingly, we performed molecular and immunogenic comparisons of E2 produced in mammalian and insect cells. Mass spectrometry demonstrated that the predicted glycosylation sites were utilized in both mammalian and insect cell E2, although the glycan types in insect cell E2 were smaller and less complex. Mouse immunogenicity studies revealed similar polyclonal antibody responses. However, insect cell E2 induced stronger neutralizing antibody responses against the homologous isolate used in the vaccine, albeit the two proteins elicited comparable neutralization titers against heterologous isolates. A more productive approach for vaccine development may be complete deletion of specific glycans in the E2 protein.
Although risk factors related to chemotherapy-induced nausea and vomiting (CINV) have been identified in previous studies, only a few studies have evaluated the risk factors associated with ...contemporary antiemetic prophylaxis, including olanzapine/aprepitant- or NEPA-containing regimens. This study aimed to identify the risk factors associated with CINV development in Chinese breast cancer patients receiving doxorubicin and cyclophosphamide chemotherapy.
Data from 304 patients enrolled in 3 previously reported prospective antiemetic studies were included. Multivariate logistic regression models were used to predict risk factors associated with CINV occurrence. Additionally, the likelihood of treatment failure in relation to the number of risk factors in individual patients was evaluated.
Multivariate analysis of the entire study group revealed that obesity status (defined as body mass index/= 25.0 kg/m2) and the use of olanzapine/aprepitant- or NEPA-containing anti-emetic regimens were associated with a high likelihood, while a history of motion sickness was associated with a lower likelihood, complete response (CR), and "no nausea" in the overall phase. A history of vomiting during pregnancy was also associated with a lower likelihood of an overall CR. Patients with an increasing number of risk factors had a higher likelihood of treatment failure and shorter time to first vomiting. Those who did not achieve CR and "no nausea" in the first cycle were less likely to achieve these parameters in the subsequent cycle of chemotherapy.
The present study confirmed previously reported risk factors for CINV in Chinese breast cancer patients receiving doxorubicin and cyclophosphamide. Further optimization of CINV control is required for patients with identifiable risk factors; olanzapine/aprepitant- or NEPA- containing prophylaxis are the preferred contemporary anti-emetics regimens for Chinese breast cancer patients undergoing doxorubicin and cyclophosphamide chemotherapy.
Habitual exercise may amplify the respiratory uptake of air pollutants in the lung, exacerbating the adverse effects of air pollution. However, it is unclear whether this can reduce the health ...benefits of habitual exercise (referred to as leisure-time exercise). Thus, the combined effects of habitual exercise and chronic exposure to ambient fine particulate matter 2.5 on cardiovascular mortality were examined among adults in Taiwan.
A total of 384,128 adults were recruited between 2001 and 2016 and followed up to May 31, 2019. Participants’ vital status was obtained by matching their unique identification numbers with records of cardiovascular death in the National Death Registry of Taiwan. A time-varying Cox regression model was used to analyze the data. Analyses were conducted in 2021.
Cardiovascular death risks were inversely associated with habitual exercise and positively associated with chronic exposure to particulate matter 2.5. The beneficial effects of habitual exercise on cardiovascular mortality were not modified by chronic exposure to particulate matter 2.5. Inactive participants with high particulate matter 2.5 exposure exhibited a 123% higher risk of cardiovascular death than high-exercise-group participants exposed to low levels of particulate matter 2.5 (95% CI=89, 163).
High level of habitual exercise combined with low exposure level of ambient particulate matter 2.5 is associated with the lowest risk of cardiovascular death. A higher level of habitual exercise is associated with a lower risk of cardiovascular death at all levels of particulate matter 2.5 exposure studied. The results indicate that habitual exercise is a safe health promotion strategy even for people residing in relatively polluted regions.
To study the dynamic changes in plasma Epstein-Barr virus (pEBV) DNA after radiotherapy in nasopharyngeal cancer (NPC).
We conducted a randomized controlled trial of adjuvant chemotherapy versus ...observation in patients with NPC who had detectable pEBV DNA at 6 weeks post-radiotherapy. Randomized patients had a second pEBV DNA checked at 6 months post-randomization. The primary endpoint was progression-free survival (PFS).
We prospectively enrolled 789 patients. Baseline post-radiotherapy pEBV DNA was undetectable in 573 (72.6%) patients, and detectable in 216 (27.4%) patients, of whom 104 (13.2%) patients were eligible for randomization to adjuvant chemotherapy (
= 52) versus observation (
= 52). The first post-radiotherapy pEBV DNA had a sensitivity of 0.48, specificity of 0.81, area under receiver-operator characteristics curve (AUC) of 0.65, false positive (FP) rate of 13.8%, and false negative (FN) rate of 14.4% for disease progression. The second post-radiotherapy pEBV DNA had improved sensitivity of 0.81, specificity of 0.75, AUC of 0.78, FP rate of 14.3%, and FN rate of 8.1%. Patients with complete clearance of post-radiotherapy pEBV DNA (51%) had survival superior to that of patients without post-radiotherapy pEBV DNA clearance (5-year PFS, 85.5% vs. 23.3%; HR, 9.6;
< 0.0001), comparable with patients with initially undetectable post-radiotherapy pEBV DNA (5-year PFS, 77.1%), irrespective of adjuvant chemotherapy or observation.
Patients with NPC with detectable post-radiotherapy pEBV DNA who experienced subsequent pEBV DNA clearance had superior survival comparable with patients with initially undetectable post-radiotherapy pEBV DNA. Post-radiotherapy pEBV DNA clearance may serve as an early surrogate endpoint for long-term survival in NPC.
Direct‐acting antivirals (DAAs) have led to a high cure rate in treated patients with chronic hepatitis C virus (HCV) infection, but this still leaves a large number of treatment failures secondary ...to the emergence of resistance‐associated variants (RAVs). To increase the barrier to resistance, a complementary strategy is to use neutralizing human monoclonal antibodies (HMAbs) to prevent acute infection. However, earlier efforts with the selected antibodies led to RAVs in animal and clinical studies. Therefore, we identified an HMAb that is less likely to elicit RAVs for affinity maturation to increase potency and, more important, breadth of protection. Selected matured antibodies show improved affinity and neutralization against a panel of diverse HCV isolates. Structural and modeling studies reveal that the affinity‐matured HMAb mediates virus neutralization, in part, by inducing conformational change to the targeted epitope, and that the maturated light chain is responsible for the improved affinity and breadth of protection. A matured HMAb protected humanized mice when challenged with an infectious HCV human serum inoculum for a prolonged period. However, a single mouse experienced breakthrough infection after 63 days when the serum HMAb concentration dropped by several logs; sequence analysis revealed no viral escape mutation. Conclusion: The findings suggest that a single broadly neutralizing antibody can prevent acute HCV infection without inducing RAVs and may complement DAAs to reduce the emergence of RAVs. (Hepatology 2016;64:1922‐1933).
Rilpivirine and etravirine are second generation non-nucleoside reverse transcriptase inhibitors approved recently by the United States Food and Drug Administration for the treatment of human ...immunodeficiency virus-1 infection. Pregnane X receptor (PXR) is a member of the superfamily of nuclear receptors that regulate the expression of various genes controlling diverse biological functions. The present study investigated the effects of rilpivirine and etravirine on the activity of human PXR (hPXR), including the mode of activation, and compared them to those of efavirenz, nevirapine, and delavirdine, which are first generation non-nucleoside reverse transcriptase inhibitors. In transiently transfected HepG2 cells, rilpivirine, etravirine, and efavirenz, but not nevirapine or delavirdine, activated human, mouse, and rat PXR. Results from mechanistic studies indicated that rilpivirine, etravirine, and efavirenz, but not nevirapine or delavirdine, bound to the ligand-binding domain of hPXR, as assessed by a transactivation assay and by a competitive ligand-binding assay using time-resolved fluorescence resonance energy transfer; triggered nuclear translocation of a green fluorescence protein-tagged hPXR, as visualized by confocal imaging; and recruited steroid receptor coactivator-1 (SRC-1), SRC-2, and SRC-3 to hPXR, as demonstrated by mammalian two-hybrid assays. Rilpivirine, etravirine, and efavirenz, but not nevirapine or delavirdine, increased hPXR target gene (CYP3A4) expression in primary cultures of human hepatocytes. In summary, select non-nucleoside reverse transcriptase inhibitors activated human and rodent PXR. Rilpivirine, etravirine, and efavirenz, but not nevirapine or delavirdine, were identified as agonists of hPXR, as assessed in mechanistic experiments, and inducers of CYP3A4, as determined in primary cultures of human hepatocytes.
This post-hoc analysis retrospectively assessed data from two recent studies of antiemetic regimens for chemotherapy-induced nausea and vomiting (CINV). The primary objective was to compare ...olanzapine-based versus netupitant/palonosetron (NEPA)-based regimens in terms of controlling CINV during cycle 1 of doxorubicin/cyclophosphamide (AC) chemotherapy; secondary objectives were to assess quality of life (QOL) and emesis outcomes over four cycles of AC.
This study included 120 Chinese patients with early-stage breast cancer who were receiving AC; 60 patients received the olanzapine-based antiemetic regimen, whereas 60 patients received the NEPA-based antiemetic regimen. The olanzapine-based regimen comprised aprepitant, ondansetron, dexamethasone, and olanzapine; the NEPA-based regimen comprised NEPA and dexamethasone. Patient outcomes were compared in terms of emesis control and QOL.
During cycle 1 of AC, the olanzapine group exhibited a higher rate of 'no use of rescue therapy' in the acute phase (olanzapine vs NEPA: 96.7% vs 85.0%, P=0.0225). No parameters differed between groups in the delayed phase. The olanzapine group had significantly higher rates of 'no use of rescue therapy' (91.7% vs 76.7%, P=0.0244) and 'no significant nausea' (91.7% vs 78.3%, P=0.0408) in the overall phase. There were no differences in QOL between groups. Multiple cycle assessment revealed that the NEPA group had higher rates of total control in the acute phase (cycles 2 and 4) and the overall phase (cycles 3 and 4).
These results do not conclusively support the superiority of either regimen for patients with breast cancer who are receiving AC.
Chemotherapy-induced nausea and vomiting (CINV) are distressing symptoms. This randomized study evaluated the antiemetic efficacies of standard antiemetic regimen with/without olanzapine.
Eligible ...patients were chemotherapy-naive Chinese breast cancer patients who were planned for (neo)adjuvant doxorubicin/cyclophosphamide. Antiemetic regimen for all studied population included aprepitant, ondansetron and dexamethasone; patients were randomized to Olanzapine (with olanzapine) or Standard arms (without olanzapine). Patients filled in self-reported diaries and completed visual analogue scales for nausea, as well as Functional Living Index-Emesis questionnaires. Blood profiles including fasting glucose and lipids were monitored.
120 patients were randomized. In Cycle 1 doxorubicin/cyclophosphamide, the Olanzapine arm had significantly higher rates of “Complete Response” than the Standard arm: 65.0% vs 38.3% in the overall period (p = 0.0035), 70.0% vs 51.7% in the acute period (p = 0.0397) and 92.9% vs 74.2% in the delayed period (p = 0.0254). Olanzapine arm also had significantly higher rates of “No significant nausea” and “No nausea” during all 3 time-frames and better QOL. Similar findings were also revealed throughout multiple cycles. Pre-study abnormalities in glucose and lipids occurred in 39.7% and 34.2% of the studied population respectively; there were no differences in these parameters between the two arms at end-of-study assessment.
The addition of olanzapine to standard aprepitant-based antiemetic regimen provides clinically meaningful improvement in controlling CINV. This was associated with a positive impact on QOL and tolerable toxicity profiles among Chinese breast cancer patients receiving doxorubicin/cyclophosphamide chemotherapy. Further studies on metabolic profiles of breast cancer patients are warranted.
•Olanzapine is reported to reduce nausea and vomiting after highly emetogenic chemotherapy.•Reported studies are limited by heterogeneous populations receiving diverse cytotoxic regimes.•This study enrolled Chinese breast cancer patients undergoing doxorubicin/cyclophosphamide.•Adding olanzapine to aprepitant/ondansetron/dexamethasone is superior in controlling nausea and vomiting.•Baseline investigations shows a surprisingly high rate of glucose and lipids abnormalities.
PDF
