Whole-Genome Sequencing-Based Confirmatory Methods on RT-qPCR Results for the Detection of Foodborne Viruses in Frozen Berries

Accurate detection, identification, and subsequent confirmation of pathogens causing foodborne illness are essential for the prevention and investigation of foodborne outbreaks. This is particularly true when the causative agent is an enteric virus that has a very low infectious dose and is likely to be present at or near the limit of detection. In this study, whole-genome sequencing (WGS) was combined with either of two non-targeted pre-amplification methods (SPIA and SISPA) to investigate their utility as a confirmatory method for RT-qPCR positive results of foods contaminated with enteric viruses. Frozen berries (raspberries, strawberries, and blackberries) were chosen as the food matrix of interest due to their association with numerous outbreaks of foodborne illness. The hepatitis A virus (HAV) and human norovirus (HuNoV) were used as the contaminating agents. The non-targeted WGS strategy employed in this study could detect and confirm HuNoV and HAV at genomic copy numbers in the single digit range, and in a few cases, identified viruses present in samples that had been found negative by RT-qPCR analyses. However, some RT-qPCR-positive samples could not be confirmed using the WGS method, and in cases with very high Ct values, only a few viral reads and short sequences were recovered from the samples. WGS techniques show great potential for confirmation and identification of virally contaminated food items. The approaches described here should be further optimized for routine application to confirm the viral contamination in berries.

Use of Human Intestinal Enteroids for Recovery of Infectious Human Norovirus from Berries and Lettuce

Norovirus (NoV) is the leading cause of viral foodborne gastroenteritis globally. Currently, the gold standard for detecting NoV in clinical, food, and environmental samples is via molecular-based methods, primarily RT-PCR. Nevertheless, there is a great need for confirmatory assays that can determine the infectivity of viral particles recovered from contaminated matrices. The use of the human intestinal enteroids system (HIEs) has allowed for the expansion of norovirus replication, although it still suffers from limitations of strain preferences and the requirement of high titer stocks for infection. In this study, we wanted to explore the feasibility of using the HIEs to support the replication of NoV that had been recovered from representative food matrices that have been associated with foodborne illness. We first confirmed that HIEs can support the replication of several strains of NoV as measured by RT-qPCR. We subsequently chose two of those strains that reproducibly replicated, GII.4 and GII.6, to evaluate in a TCID50 assay and for future experiments. Infectious NoV could be recovered and quantified in the HIEs from lettuce, frozen raspberries, or frozen strawberries seeded with high titers of either of these strains. While many experimental challenges still remain to be overcome, the results of this study represent an important step toward the detection of infectious norovirus from representative produce items.

Encouraging Patients to Ask Questions: Development and Pilot Testing of a Question Prompt List for Patients Undergoing a Biopsy for Suspected Prostate Cancer

This study assessed the acceptability and feasibility of a question prompt list (QPL) to facilitate informed treatment decision-making in men with suspected localised prostate cancer, which involves values-based choices between options with similar efficacy but different side effects. The QPL was developed through iterative consultation with consumers, clinicians and researchers. Acceptability was assessed using study-specific questions regarding QPL satisfaction and usefulness and qualitative interviews. Feasibility was determined via the proportion of men given the QPL according to medical records and the completion of standardised measures of decisional outcomes. Quantitative data were analysed using descriptive and univariate statistics. Qualitative data were thematically analysed. Fifty-two men consented; 34 provided data for analysis. The QPL recipients reported moderate-high content satisfaction (70.6%) and perceived usefulness in guiding appointments when receiving biopsy results (64.7%). Two main qualitative themes also indicated the QPL acceptability: (1) the freedom to ask-acceptable timing, flexible usage and usefulness of the QPL, and (2) satisfaction with the QPL content. However, only 18.4% of eligible men received the QPL, indicating limited feasibility. The QPL is safe and acceptable, but further research is needed regarding how to facilitate the uptake of the question prompt list in clinical practice.

Doxorubicin-induced upregulation of follistatin-like 3 (FSTL3): a new therapeutic target

Introduction

Doxorubicin (DOX) is among the most used anticancer drugs with associated cardiotoxicity. Follistatin-like 3 (FSTL3), a secreted member of the follistatins family that can selectively bind to members of the TGF-β superfamily, is involved in regulation of cardiac hypertrophy and heart failure. FSTL3 is also upregulated in breast and colorectal cancer tumours, is also an unfavourable prognostic indicator for various cancers.

Purpose

We aim to determine the dual role of FSTL3 in prevention of DOX-induced cardiotoxicity and synergistic anti-cancer effects.

Methods

Human cardiomyocytes (HCMs) were treated with DOX at 1uM (EC50) for 72 hours. Cell viability was assessed via CellTiter-Glo®. Secreted FSTL3 levels, as measured by ELISA (R&D systems). FSTL3 and TGF-β mRNA levels were measured by qPCR. Co-treatment of DOX with human anti-FSTL3 antibodies (Aviva Systems Biology) at 10ug/mL were introduced for 72hrs treatment.

Results

Secreted FSTL3 levels were significantly increased in DOX-treated HCMs at 72hrs compared to control (n=5, p<0.001). Consistently, FSTL3 and TGF-β mRNA levels, in collected HCMs were significantly increased in DOX-treated cells. Co-treatment of DOX with human anti-FSTL3 antibodies at 10ug/mL significantly improved HCM viability compared to IgG control group. Conversely, anti-FSTL3 antibodies provided synergistic anti-cancer effects with DOX: MCF-7 breast cancer cells were significantly reduced when co-treated with DOX and anti-FSTL3 antibody vs. IgG controls.

Conclusion

We show, for the first time, that: 1) FSTL3 is secreted directly from HCMs; 2) FSTL3 levels (both circulating and mRNA) is markedly elevated with DOX treatment; 3) neutralisation of FSTL3 in DOX-treated HCMs, restored HCM viability; and 4) exhibit synergistic anti-cancer effects with DOX. Taken together, FSTL3 is a potential target for dual anti-cancer and cardioprotective effects.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Heart Foundation of Australia Future Leader FellowshipsNSW Ministry of Health EMC FellowshipNSW Ministry of Health Translational Research Grant

Follistatin-like 3 (FSTL3) levels are increased in acute heart failure patients

Introduction

Follistatin-like 3 (FSTL3) is a secreted protein that has been suggested to play an important role in modulating cardiac remodeling and hypertrophy. In this study, we aim to determine whether: 1) FSTL3 is incrementally elevated in patients with HF vs those with other cardiovascular disease (CVD); and 2) increased FSTL3 is associated with 2 or more hospital admissions due to major adverse CV events (MACE) within 1 year.

Methods and results

We measured circulating levels of FSTL3 using commercially available ELISA (R&D systems) in a total of n=696 patients. FSTL3 levels were compared between: 1) healthy-aging volunteers with no prior major CVD (n=267, age 67±6 years) and 2) patients admitted to cardiology unit for various CVD (n=429, age 66±14 years); among those (n=178, age 68±13 years) had HF. Patients with HF had 2-fold higher FSTL3 levels vs healthy age-matched controls vs those with other CVD (p<0.001). Occurrences of MACE were recorded up to 1 year for patients admitted to cardiology unit. On univariate analyses, patient with 2 or more MACE within 1 year (n=91, 27%) had significant elevated FSTL3 levels (P=0.003), is associated with older age (P<0.005). On multivariate analysis, high FSTL3 levels (P=0.034) is an independent predictor of 2 or more MACE admissions within 1 year after adjusting for age, clinical comorbidities and medications.

Conclusions

FSTL3 is incrementally increased in patients with HF and is associated with poorer prognosis. Elevated FSTL3 levels is associated with increased risks of cardiac hospital readmissions for patients with multiple CV morbidities.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NSW Ministry of Health EMC Fellowship (Australia)

Low conflict and high satisfaction: Decisional outcomes after attending a combined clinic to choose between robotic prostatectomy and radiotherapy for prostate cancer

BACKGROUND

Decisional conflict and post-treatment decisional regret have been documented in men with localised prostate cancer (LPC). However, there is limited evidence regarding decisional outcomes associated with the choice between robotic-assisted radical prostatectomy (RARP) and radiotherapy, when both treatment options are available in the public health system. There is increasing support for multidisciplinary approaches to guide men with LPC in their decision-making process. This study assessed decisional outcomes in men deciding between RARP or radiotherapy treatment before and after attending a LPC combined clinic (CC).

METHODS

Quantitative longitudinal data were collected from 52 men who attended a LPC CC, where they saw both a urologist and radiation oncologist. Patients completed questionnaires assessing involvement in decision-making, decisional conflict, satisfaction and regret before and after the CC, three months, six months and 12 months post-treatment. Urologists and radiation oncologists also reported their perceptions regarding patients' suitability for, openness to, perceived preferences and appropriateness for each treatment. Data was analysed using paired/independent samples t-tests and McNemar's tests.

RESULTS

Most participants (n = 37, 71%) opted for RARP over radiotherapy (n = 14, 27%); one participant deferred treatment (2%). Urologists and radiation oncologists reported low agreement (κ = 0.26) regarding the most appropriate treatment for each patient. Participants reported a desire for high levels of control over their decision-making process (77.5% patient-led, 22.5% shared) and high levels of decisional satisfaction (M = 4.4, SD = 0.47) after the CC. Decisional conflict levels were significantly reduced (baseline: M = 29.3, SD = 16.9, post-CC: M = 16.3, SD = 11.5; t = 5.37, P < 0.001) after the CC. Mean decisional regret scores were 'mild' at three-months (M = 16.0, SD = 17.5), six-months (M = 18.8, SD = 18.7) and 12-months (M = 18.2, SD = 15.1) post-treatment completion.

CONCLUSION

This is the first Australian study to assess decisional outcomes when patients are offered the choice between RARP and radiotherapy in the public health system. A CC seems to support decision-making in men with LPC and positively impact some decisional outcomes. However, larger-scale controlled studies are needed to confirm these findings.

Variation in Health Care Access and Quality Among US States and High-Income Countries With Universal Health Insurance Coverage

IMPORTANCE

Based on mortality estimates for 32 causes of death that are amenable to health care, the US health care system did not perform as well as other high-income countries, scoring 88.7 out of 100 on the 2016 age-standardized Healthcare Access and Quality (HAQ) index.

OBJECTIVE

To compare US age-specific HAQ scores with those of high-income countries with universal health insurance coverage and compare scores among US states with varying insurance coverage.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used 2016 Global Burden of Diseases, Injuries, and Risk Factor study results for cause-specific mortality with adjustments for behavioral and environmental risks to estimate the age-specific HAQ indices. The US national age-specific HAQ scores were compared with high-income peers (Canada, western Europe, high-income Asia Pacific countries, and Australasia) in 1990, 2000, 2010, and 2016, and the 2016 scores among US states were also analyzed. The Public Use Microdata Sample of the American Community Survey was used to estimate insurance coverage and the median income per person by age and state. Age-specific HAQ scores for each state in 2010 and 2016 were regressed based on models with age fixed effects and age interaction with insurance coverage, median income, and year. Data were analyzed from April to July 2018 and July to September 2020.

MAIN OUTCOMES AND MEASURES

The age-specific HAQ indices were the outcome measures.

RESULTS

In 1990, US age-specific HAQ scores were similar to peers but increased less from 1990 to 2016 than peer locations for ages 15 years or older. For example, for ages 50 to 54 years, US scores increased from 77.1 to 82.1 while high-income Asia Pacific scores increased from 71.6 to 88.2. In 2016, several states had scores comparable with peers, with large differences in performance across states. For ages 15 years or older, the age-specific HAQ scores were 85 or greater for all ages in 3 states (Connecticut, Massachusetts, and Minnesota) and 75 or less for at least 1 age category in 6 states. In regression analysis estimates with state-fixed effects, insurance coverage coefficients for ages 20 to 24 years were 0.059 (99% CI, 0.006-0.111); 45 to 49 years, 0.088 (99% CI, 0.009-0.167); and 50 to 54 years, 0.101 (99% CI, 0.013-0.189). A 10% increase in insurance coverage was associated with point increases in HAQ scores among the ages of 20 to 24 years (0.59 [99% CI, 0.06-1.11]), 45 to 49 years (0.88 [99% CI, 0.09-1.67]), and 50 to 54 years (1.01 [99% CI, 0.13-1.89]).

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, the US age-specific HAQ scores for ages 15 to 64 years were low relative to high-income peer locations with universal health insurance coverage. Among US states, insurance coverage was associated with higher HAQ scores for some ages. Further research with causal models and additional explanations is warranted.

Reduced motion and improved rectal dosimetry through endorectal immobilization for prostate stereotactic body radiotherapy

OBJECTIVE

PROMETHEUS (ACTRN12615000223538) is a multicentre clinical trial investigating the feasibility of 19 Gy in 2 fractions of stereotactic body radiotherapy (SBRT) as a boost technique for prostate cancer. The objective of this substudy was to evaluate intrafraction motion using cine MRI and assess the dosimetric impact of using a rectal displacement device (RDD).

METHODS

The initial 10 patients recruited underwent planning CT and MRI, with and without a RDD. Cine MRI images were captured using an interleaved T2 HASTE sequence in sagittal and axial planes with a temporal resolution of 5.2 s acquired over 4.3 min. Points of interest (POIs) were defined and a validated tracking algorithm measured displacement of these points over the 4.3 min in the anteroposterior, superior-inferior and left-right directions. Plans were generated with and without a RDD to examine the impact on dosimetry.

RESULTS

There was an overall trend for increasing displacement in all directions as time progressed when no RDD was in situ . points of interest remained comparatively stable with the RDD. In the sagittal plane, the RDD resulted in statistically significant improvement in the range of anteroposterior displacement for the rectal wall, anterior prostate, prostate apex and base. Dosimetrically, the use of a RDD significantly reduced rectal V16, V14 and D_max, as well as the percentage of posterior rectal wall receiving 8.5 Gy.

CONCLUSION

The RDD used in stereotactic prostate radiotherapy leads to reduced intrafraction motion of the prostate and rectum, with increasing improvement with time. It also results in significant improvement in rectal wall dosimetry.

ADVANCES IN KNOWLEDGE

It was found that the rectal displacement device improved prostate stabilization significantly, improved rectum stabilization and dosimetry significantly. The rectal displacement device did not improve target volume dosimetry.

Long-term outcomes in 1121 Australian prostate cancer patients treated with definitive radiotherapy

INTRODUCTION

Optimal definitive treatment of prostate cancer is controversial, especially in high-risk patients. We report the largest prospective cohort of Australian patients treated with radiotherapy for localised prostate cancer.

METHODS

One thousand, one hundred and twenty-one patients with prostate cancer were prospectively registered and treated to a dose of 70-74 Gy. Patients were classified as low, intermediate or high risk based on PSA, clinical staging and Gleason score. Intermediate-risk patients were treated with 0-6 months of hormonal therapy (ADT) and high-risk patients were offered neoadjuvant and adjuvant ADT. Overall survival (OS) and biochemical relapse-free survival (bNED) were calculated using the Kaplan-Meier method.

RESULTS

Median follow-up was 92 months. Eight-year OS and bNED were 78.4% and 68.1% respectively in the entire cohort. OS for the low, intermediate and high-risk groups was 84.5%, 78.4% and 68% respectively. For these risk groups, bNED was 80.3%, 65.7% and 53.7% respectively. In the intermediate and high-risk group, OS and bNED decreased with increasing number of risk factors.

CONCLUSION

Definitive radiotherapy is an effective treatment for prostate cancer, including in high-risk cases.

BCL11A enhancer haplotypes and fetal hemoglobin in sickle cell anemia

BACKGROUND

Fetal hemoglobin (HbF) levels in sickle cell anemia patients vary. We genotyped polymorphisms in the erythroid-specific enhancer of BCL11A to see if they might account for the very high HbF associated with the Arab-Indian (AI) haplotype and Benin haplotype of sickle cell anemia.

METHODS AND RESULTS

Six BCL112A enhancer SNPs and their haplotypes were studied in Saudi Arabs from the Eastern Province and Indian patients with AI haplotype (HbF ~20%), African Americans (HbF ~7%), and Saudi Arabs from the Southwestern Province (HbF ~12%). Four SNPs (rs1427407, rs6706648, rs6738440, and rs7606173) and their haplotypes were consistently associated with HbF levels. The distributions of haplotypes differ in the 3 cohorts but not their genetic effects: the haplotype TCAG was associated with the lowest HbF level and the haplotype GTAC was associated with the highest HbF level and differences in HbF levels between carriers of these haplotypes in all cohorts were approximately 6%.

CONCLUSIONS

Common HbF BCL11A enhancer haplotypes in patients with African origin and AI sickle cell anemia have similar effects on HbF but they do not explain their differences in HbF.

Temperature and density dependent induction of a cytopathic effect following infection with non-cytopathic HAV strains

Hepatitis A virus infection and growth in cultured cells is protracted, cell-type restricted, and generally not accompanied by the appearance of a cytopathic effect, with the exception of some culture-adapted strains. We demonstrate that the non-cytopathic HAV strain HM175/clone 1 can be induced to exhibit a cytopathic phenotype in both persistently or acutely infected cells under co-dependent conditions of lower incubation temperature (<34°C) and reduced cell density in both monkey (FRhK-4) and human (A549) cells. This phenotype is not virus-strain restricted, as it was also observed in cells infected with HAV strains, HAS-15 and LSH/S. Cytopathic effect was accompanied by rRNA cleavage, indicating activation of the RNase L pathway, viral negative strand synthesis, caspase-3 activation, and apoptosis. The results indicate that a cytopathic phenotype may be present in some HAV strains that can be induced under appropriate conditions, suggesting the potential for development of a plaque assay for this virus.

Highly nonlinear solitary wave propagation in Y-shaped granular crystals with variable branch angles

We study the propagation of highly nonlinear waves in a branched (Y-shaped) granular crystal composed of chains of spherical particles of different materials, arranged at variable branch angles. We experimentally test the dynamic behavior of a solitary pulse, or of a train of solitary waves, crossing the Y-junction interface, and splitting between the two branches. We describe the dependence of the split pulses' speed and amplitude on the branch angles. Analytic predictions based on the quasiparticle model and numerical simulations based on Hertzian interactions between the particles are found to be in excellent agreement with the experimental data.

Highly nonlinear pulse splitting and recombination in a two-dimensional granular network

The propagation of highly nonlinear signals in a branched two-dimensional granular system was investigated experimentally and numerically for a system composed of chains of spherical beads of different materials. The system studied consists of a double Y-shaped guide in which high- and low-modulus/mass chains of spheres are arranged in various geometries. We observed the transformation of a single or a train of solitary pulses crossing the interface between branches. We report fast splitting of the initial pulse, rapid chaotization of the signal and impulse redirection and bending. Pulse and energy trapping was also observed in the branches. Numerical analysis based on Hertzian interaction between the particles and the side walls of the guide was found in agreement with the experimental data, except for nonsymmetric arrangements of particles excited by a large mass striker.

Endogenous estrogen regulation of inflammatory arthritis and cytokine expression in male mice, predominantly via estrogen receptor alpha

OBJECTIVE

A number of experimental observations have associated elevated estrogen levels with amelioration of inflammation. The involvement of estrogen and estrogen receptor (ER) isotypes in the regulation of inflammation in males is not well understood. In this study, we used specific ERalpha and ERbeta agonists in male mice deficient in estrogen because of a deletion of aromatase (aromatase-knockout [ArKO] mice) to investigate ER isotype utilization in estrogen regulation of inflammation.

METHODS

Lipopolysaccharide (LPS)-induced cytokine expression and antigen-induced arthritis (AIA) were investigated in male ArKO and WT littermate mice, as well as in response to selective agonists of ERalpha (16alpha-LE2) and ERbeta (8beta-VE2). The therapeutic effect of selective ER agonists was also examined in mice with collagen-induced arthritis (CIA).

RESULTS

Estrogen deficiency in ArKO mice was associated with significant increases in LPS-induced serum interleukin-6 (IL-6), tumor necrosis factor, monocyte chemotactic protein 1, and interferon-gamma levels, which were significantly abrogated by administration of 16alpha-LE2, but not 8beta-VE2. In contrast, both 16alpha-LE2 and 8beta-VE2 significantly increased LPS-induced IL-10 levels. Estrogen deficiency was also associated with significant exacerbation of AIA and antigen-specific T cell proliferation, which was reversed by administration of either 16alpha-LE2 or 8beta-VE2. ArKO mice showed increased antigen-specific T cell proliferation in response to immunization with type II collagen (CII). Administration of 16alpha-LE2, but not 8beta-VE2, significantly reduced the severity of CIA, which was associated with inhibition of anti-CII-specific IgG.

CONCLUSION

These data indicate that endogenous estrogen plays an essential inhibitory role in inflammation in male mice and that ERalpha is the dominant receptor that mediates these effects.

In situ evaluation of residual breast tumor and tumor grade using medical hyperspectral imaging (MHSI)

10677

Background: MHSI is a camera-based technique providing spectral data regarding tissue chemistry for each pixel in an image. Over 30% of women suffer local recurrence after resection. Intraoperative assessment of residual tumor & tumor grade would optimize care. Methods: We studied 42 S-D rats w/ breast tumors induced by gavage of DMBA & 15 controls. Tumors were exposed & resected, intentionally leaving ∼1mm residual tumor pieces. Gross examination, histo-pathology & MHSI (total 335) were performed for tumors, tumor beds after partial and total resection & control sites. A visible light MHSI system (HyperMed,Waltham, MA) w/ 40μm resolution & algorithms based on spectral features of the surgical field were developed and implemented for this study. Gross observation at surgery represents truth, as small tumor pieces were left intentionally by the surgeon and recorded. Samples from tumor beds were collected and histopathologically analyzed. When seen, gross tumor was removed from tumor bed by the pathologist. Results: MHSI performed well at identifying tumor. The kappa statistic(κ) for gross vs MHSI (84%) is significantly higher than κ for gross vs histopathology (76%) where for the κ the estimated asymptotic standard error is 3%. MHSI associates more strongly with gross than histopathology does. 81 tissue samples were separated into histologic grade: 0 = normal, 1 = benign tumor, 2 = intraductal Ca, 3 = papillary & cribiform Ca, 4 = papillary & cribiform Ca with invasion &/or comedo Ca. The imaging team (blinded) assigned tumor grade to each MHSI image. Statistical analysis defined 3 histologic groups: 9 normal (grade 0) tissue, 18 benign & intraductal tumors (grades 1–2), 54 advanced tumors (papillary, cribiform with invasion/comedo Ca, grades 3–4). Both histopathology & MHSI identified all 9 normal samples. Of 18 samples in group 2 (benign/intraductal by histopathology), 17 were qualified as benign/intraductal by MHSI (94% sens) & 1 as advanced. Of 54 samples with adv tumors by histopathology, MHSI identified 48 (89% sens) as advanced & 6 as intraductal. Conclusions: MHSI may provide convenient intraoperative, near real-time images with useful data about residual tumor & tumor grade. Human trials are planned.

[Table: see text]

Apoptosis induced by a cytopathic hepatitis A virus is dependent on caspase activation following ribosomal RNA degradation but occurs in the absence of 2'-5' oligoadenylate synthetase

We have presented previously evidence that the cytopathogenic 18f strain of hepatitis A virus (HAV) induced degradation of ribosomal RNA (rRNA) in infected cells [Arch. Virol. 148 (2003) 1275–1300]. In contrast, the non-cytopathogenic parent virus HM175 clone 1 had no effect on rRNA integrity. We present here data showing that rRNA degradation is followed by apoptosis accompanied by characteristic DNA laddering in the cytoplasm of 18f infected cells. The DNA laddering coincided with the detection of caspase 3 and PARP-1 cleavage and was dependent upon activation of the caspase pathway, since treatment with Z-VAD-FMK, a pan-caspase inhibitor, inhibited both events. RNase L mRNA was present in both virus-infected and uninfected cells. Messenger RNA for the interferon inducible enzyme 2′–5′ oligoadenylate synthetase (2′–5′ OAS), which polymerizes ATP into 2′–5′ oligo adenylate (2–5A, the activator of RNase L) in the presence of double-stranded RNA, was not detected following virus infection. 2′–5′ OAS mRNA was induced by treatment of the cells with interferon-β (IFN-β). IFN-β mRNA was marginally induced following infection. However, phosphorylated STAT 1, a key regulator of interferon-stimulated gene transcription was not detected in virus infected cells. STAT 1 phosphorylation in response to IFN treatment was lower in virus-infected cells, compared to uninfected cells treated with interferon, suggesting that 18f virus infection interferes with interferon signaling. The results suggest that 18f infection causes the induction of a 2–5A independent RNase L like activity.

CXCR3 is induced early on the pathway of CD4+ T cell differentiation and bridges central and peripheral functions

Chemokine receptors on T cells are frequently categorized as functioning either in immune system homeostasis within lymphoid organs, or in peripheral inflammation. CXCR3 is in the latter category and is reported to be expressed selectively on Th1 cells. We found that CXCR3 was expressed in vivo on newly activated tonsillar CD4(+) T cells. Using CD4(+) T cells from cord blood, we found that CXCR3 was induced by cellular activation in vitro independently of the cytokine milieu, although on resting cells, expression was maintained preferentially on those that had been activated in type 1 conditions. In inflamed tonsils, CXCR3(+)CD4(+) T cells were localized around and within germinal centers. The inference that CXCR3 has a role in germinal center reactions was supported by the finding that the CXCR3 ligand CXC chemokine ligand 9 was expressed in a pattern demarcating a subset of germinal centers both in tonsil and in lymph nodes from an HIV-infected individual. We next investigated the role of CXCR3 on peripheral effector/memory CD4(+) T cells by comparing its pattern of expression with that of CCR5, another Th1-cell associated chemokine receptor. Analysis of cells directly from peripheral blood and after activation in vitro suggested that CXCR3 expression preceded that of CCR5, supporting a model of sequential induction of chemokine receptors during CD4(+) T cell differentiation. Taken together, our data show that CXCR3 can be expressed at all stages of CD4(+) T cell activation and differentiation, bridging central function in lymphoid organs and effector function in peripheral tissues.

The cytopathic 18f strain of Hepatitis A virus induces RNA degradation in FrhK4 cells

The mechanism responsible for the induction of apoptosis by the rapidly replicating HM175/18f strain of Hepatitis A virus (HAV) was investigated. Full length HAV RNA and viral capsid protein VP1 were detected in 18f infected cells at earlier times post-infection than in HM175/clone 1 infected cells. Analysis of total cellular RNA from HM175/18f infected FrhK4 cells by denaturing agarose gel electrophoresis and Northern blot hybridization revealed extensive degradation of both the 28S and 18S ribosomal RNA (rRNA) molecules. Similar degradation was observed when these cells were infected with Human coxsackievirus B1, a fast replicating enterovirus. In contrast, the parental strain of 18f, HM175/clone 1 did not induce RNA degradation. Inhibition of RNA degradation correlated with inhibition of virus replication. The pattern of rRNA degradation resembled degradation of rRNAs by RNase L, an enzyme activated in interferon-treated cells following infection with certain viruses. Ribosomal RNA degradation was accompanied by the reduction in the levels of several cellular RNAs including those for beta-actin and glyceraldehyde-3-phosphate dehydrogenase, while the levels of c-myc and c-jun were higher. Interferon mRNAs could not be detected in either infected or mock-infected control cells, and STAT1, a key regulator of interferon action was not phosphorylated following virus infection. These results reveal a heretofore-undescribed pathway that involves the regulation of RNA degradation and apoptosis following HAV/18f replication in FrhK4 cells.

A polymerase chain reaction-based method for the detection of hepatitis A virus in produce and shellfish

Outbreaks of gastroenteritis that are suspected to be of viral origin are on the rise. Thus, there is a need for regulatory agencies entrusted with food safety to develop adequate techniques for the detection of viruses in foods. We have established a general procedure for the detection of hepatitis A virus (HAV) in shellfish that, with minor modifications, is also applicable to fresh produce such as cilantro. Total RNA was isolated from shellfish or cilantro, followed by isolation of poly(A)-containing RNA. Because HAV genomic RNA contains a poly(A) tail, the isolation of poly(A)-containing RNA also enriches HAV genomic RNA. Reverse transcription was used to convert the RNA to cDNA, and then amplification was carried out by polymerase chain reaction (PCR). Reamplification with internal primers was used to improve the quality and the quantity of amplified DNA, allowing for post-PCR analysis such as sequence identification of the viral strain. With this procedure, multiple samples could be analyzed in four working days by a single trained individual. The nominal sensitivity of detection of the procedure was 0.15 TCID50 (50% tissue culture infective dose) per 0.62 g of tissue with a test virus. The direct RNA isolation protocol avoided pitfalls associated with whole-virus purification procedures by replacing virus precipitation steps involving polyethylene glycol and Procipitate with phenol extraction. The method is straightforward and reliable. We successfully used this procedure to detect naturally occurring HAV in clams involved in a gastroenteritis outbreak, as well as in cilantro artificially contaminated with a test virus.