38 research outputs found
Acceptability and Preliminary Efficacy of a Web- and Telephone-Based Personalised Exercise Intervention for Individuals with Metastatic Prostate Cancer: The ExerciseGuide Pilot Randomised Controlled Trial.
Preliminary research has shown the effectiveness of supervised exercise-based interventions in alleviating sequela resulting from metastatic prostate cancer. However, many individuals encounter barriers that limit the uptake of face-to-face exercise. Technology-enabled interventions offer a distance-based alternative. This pilot study aimed to explore the acceptability, safety and preliminary efficacy of a web-based exercise intervention (ExerciseGuide) in individuals with metastatic prostate cancer. Forty participants (70.2 ± 8.5 years) with metastatic prostate cancer were randomised into the 8-week intervention (N = 20) or a wait-list control (N = 20). The intervention arm had access to a computer-tailored website, personalised exercise prescription and remote supervision. ExerciseGuide was deemed acceptable with a score ≥20 on the client satisfaction questionnaire; however, the usability score was just below the pre-specified score of ≥68 on the software usability scale. There were no serious adverse events reported. Moderate-to-vigorous physical activity levels between baseline and follow-ups were significantly higher (10.0 min per day; 95% CI = (1.3-18.6); p = 0.01) in the intervention group compared to wait-list control. There were also greater improvements in step count (1332; 95% CI = (159-2505); p = 0.02) and identified motivation (0.4, 95% CI = (0.0, 0.7); p = 0.04). Our findings provide preliminary evidence that ExerciseGuide is acceptable, safe and efficacious among individuals with metastatic prostate cancer
Vaccine protection against simian immunodeficiency virus in monkeys using recombinant gamma-2 herpesvirus
Recombinant strains of replication-competent rhesus monkey rhadinovirus (RRV) were constructed in which strong promoter/enhancer elements were used to drive expression of simian immunodeficiency virus (SIV) Env or Gag or a Rev-Tat-Nef fusion protein. Cultured rhesus monkey fibroblasts infected with each recombinant strain were shown to express the expected protein. Three RRV-negative and two RRV-positive rhesus monkeys were inoculated intravenously with a mixture of these three recombinant RRVs. Expression of SIV Gag was readily detected in lymph node biopsy specimens taken at 3 weeks postimmunization. Impressive anti-SIV cellular immune responses were elicited on the basis of major histocompatibility complex (MHC) tetramer staining and gamma interferon enzyme-linked immunospot (ELISPOT) assays. Responses were much greater in magnitude in the monkeys that were initially RRV negative but were still readily detected in the two monkeys that were naturally infected with RRV at the time of immunization. By 3 weeks postimmunization, responses measured by MHC tetramer staining in the two Mamu-A*01(+) RRV-negative monkeys reached 9.3% and 13.1% of all CD8(+) T cells in peripheral blood to the Gag CM9 epitope and 2.3% and 7.3% of all CD8(+) T cells in peripheral blood to the Tat SL8 epitope. Virus-specific CD8(+) T cell responses persisted at high levels up to the time of challenge at 18 weeks postimmunization, and responding cells maintained an effector memory phenotype. Despite the ability of the RRVenv recombinant to express high levels of Env in cultured cells, and despite the appearance of strong anti-RRV antibody responses in immunized monkeys, anti-Env antibody responses were below our ability to detect them. Immunized monkeys, together with three unimmunized controls, were challenged intravenously with 10 monkey infectious doses of SIVmac239. All five immunized monkeys and all three controls became infected with SIV, but peak viral loads were 1.2 to 3.0 log(10) units lower and chronic-phase viral loads were 1.0 to 3.0 log(10) units lower in immunized animals than the geometric mean of unimmunized controls. These differences were statistically significant. Anti-Env antibody responses following challenge indicated an anamnestic response in the vaccinated monkeys. These findings further demonstrate the potential of recombinant herpesviruses as preventive vaccines for AIDS. We hypothesize that this live, replication-competent, persistent herpesvirus vector could match, or come close to matching, live attenuated strains of SIV in the degree of protection if the difficulty with elicitation of anti-Env antibody responses can be overcome
Multiplex RT-PCR Amplification of HIV Genes to Create a Completely Autologous DC-Based Immunotherapy for the Treatment of HIV Infection
BACKGROUND: Effective therapy for HIV-infected individuals remains an unmet medical need. Promising clinical trials with dendritic cell (DC)-based immunotherapy consisting of autologous DC loaded with autologous virus have been reported, however, these approaches depend on large numbers of HIV virions to generate sufficient doses for even limited treatment regimens. METHODOLOGY/PRINCIPAL FINDINGS: The present study describes a novel approach for RT-PCR amplification of HIV antigens. Previously, RT-PCR amplification of autologous viral sequences has been confounded by the high mutation rate of the virus which results in unreliable primer-template binding. To resolve this problem we developed a multiplex RT-PCR strategy that allows reliable strain-independent amplification of highly polymorphic target antigens from any patient and requires neither viral sequence data nor custom-designed PCR primers for each individual. We demonstrate the application of our RT-PCR process to amplify translationally-competent RNA encoding regions of Gag, Vpr, Rev and Nef. The products amplified using this method represent a complex mixture of autologous antigens encoded by viral quasispecies. We further demonstrate that DCs electroporated with in vitro-transcribed HIV RNAs are capable of stimulating poly-antigen-specific CD8+ T cell responses in vitro. CONCLUSION/SIGNIFICANCE: This study describes a strategy to overcome patient to patient viral diversity enabling strain-independent RT-PCR amplification of RNAs encoding sequence divergent quasispecies of Gag, Vpr, Rev and Nef from small volumes of infectious plasma. The approach allows creation of a completely autologous therapy that does not require advance knowledge of the HIV genomic sequences, does not have yield limitations and has no intact virus in the final product. The simultaneous use of autologous viral antigens and DCs may provoke broad patient-specific immune responses that could potentially induce effective control of viral loads in the absence of conventional antiretroviral drug therapy
Trivalent live attenuated influenza-simian immunodeficiency virus vaccines: efficacy and evolution of cytotoxic T lymphocyte escape in macaques.
There is an urgent need for a human immunodeficiency virus (HIV) vaccine that induces robust mucosal immunity. CD8+ cytotoxic T lymphocytes (CTLs) apply substantial antiviral pressure, but CTLs to individual epitopes select for immune escape variants in both HIV in humans and SIV in macaques. Inducing multiple simian immunodeficiency virus (SIV)-specific CTLs may assist in controlling viremia. We vaccinated 10 Mane-A1*08401+ female pigtail macaques with recombinant influenza viruses expressing three Mane-A1*08401-restricted SIV-specific CTL epitopes and subsequently challenged the animals, along with five controls, intravaginally with SIVmac251. Seroconversion to the influenza virus vector resulted and small, but detectable, SIV-specific CTL responses were induced. There was a boost in CTL responses after challenge but no protection from high-level viremia or CD4 depletion was observed. All three CTL epitopes underwent a coordinated pattern of immune escape during early SIV infection. CTL escape was more rapid in the vaccinees than in the controls at the more dominant CTL epitopes. Although CTL escape can incur a "fitness" cost to the virus, a putative compensatory mutation 20 amino acids upstream from an immunodominant Gag CTL epitope also evolved soon after the primary CTL escape mutation. We conclude that vaccines based only on CTL epitopes will likely be undermined by rapid evolution of both CTL escape and compensatory mutations. More potent and possibly broader immune responses may be required to protect pigtail macaques from SIV. <br /
Effects of Single Nucleotide Polymorphisms on Human N-Acetyltransferase 2 Structure and Dynamics by Molecular Dynamics Simulation
BACKGROUND: Arylamine N-acetyltransferase 2 (NAT2) is an important catalytic enzyme that metabolizes the carcinogenic arylamines, hydrazine drugs and chemicals. This enzyme is highly polymorphic in different human populations. Several polymorphisms of NAT2, including the single amino acid substitutions R64Q, I114T, D122N, L137F, Q145P, R197Q, and G286E, are classified as slow acetylators, whereas the wild-type NAT2 is classified as a fast acetylator. The slow acetylators are often associated with drug toxicity and efficacy as well as cancer susceptibility. The biological functions of these 7 mutations have previously been characterized, but the structural basis behind the reduced catalytic activity and reduced protein level is not clear. METHODOLOGY/PRINCIPAL FINDINGS: We performed multiple molecular dynamics simulations of these mutants as well as NAT2 to investigate the structural and dynamical effects throughout the protein structure, specifically the catalytic triad, cofactor binding site, and the substrate binding pocket. None of these mutations induced unfolding; instead, their effects were confined to the inter-domain, domain 3 and 17-residue insert region, where the flexibility was significantly reduced relative to the wild-type. Structural effects of these mutations propagate through space and cause a change in catalytic triad conformation, cofactor binding site, substrate binding pocket size/shape and electrostatic potential. CONCLUSIONS/SIGNIFICANCE: Our results showed that the dynamical properties of all the mutant structures, especially in inter-domain, domain 3 and 17-residue insert region were affected in the same manner. Similarly, the electrostatic potential of all the mutants were altered and also the functionally important regions such as catalytic triad, cofactor binding site, and substrate binding pocket adopted different orientation and/or conformation relative to the wild-type that may affect the functions of the mutants. Overall, our study may provide the structural basis for reduced catalytic activity and protein level, as was experimentally observed for these polymorphisms
Immunization with Single-Cycle SIV Significantly Reduces Viral Loads After an Intravenous Challenge with SIVmac239
Strains of simian immunodeficiency virus (SIV) that are limited to a single cycle of infection were evaluated for the ability to elicit protective immunity against wild-type SIVmac239 infection of rhesus macaques by two different vaccine regimens. Six animals were inoculated at 8-week intervals with 6 identical doses consisting of a mixture of three different envelope variants of single-cycle SIV (scSIV). Six additional animals were primed with a mixture of cytoplasmic domain-truncated envelope variants of scSIV and boosted with two doses of vesicular stomatitis virus glycoprotein (VSV G) trans-complemented scSIV. While both regimens elicited detectable virus-specific T cell responses, SIV-specific T cell frequencies were more than 10-fold higher after boosting with VSV G trans-complemented scSIV (VSV G scSIV). Broad T cell recognition of multiple viral antigens and Gag-specific CD4+ T cell responses were also observed after boosting with VSV G scSIV. With the exception of a single animal in the repeated immunization group, all of the animals became infected following an intravenous challenge with SIVmac239. However, significantly lower viral loads and higher memory CD4+ T cell counts were observed in both immunized groups relative to an unvaccinated control group. Indeed, both scSIV immunization regimens resulted in containment of SIVmac239 replication after challenge that was as good as, if not better than, what has been achieved by other non-persisting vaccine vectors that have been evaluated in this challenge model. Nevertheless, the extent of protection afforded by scSIV was not as good as typically conferred by persistent infection with live, attenuated SIV. These observations have potentially important implications to the design of an effective AIDS vaccine, since they suggest that ongoing stimulation of virus-specific immune responses may be essential to achieving the degree of protection afforded by live, attenuated SIV
Generation and characterization of a defective HIV-1 Virus as an immunogen for a therapeutic vaccine
BACKGROUND: The generation of new immunogens able to elicit strong specific immune responses remains a major challenge in the attempts to obtain a prophylactic or therapeutic vaccine against HIV/AIDS. We designed and constructed a defective recombinant virus based on the HIV-1 genome generating infective but non-replicative virions able to elicit broad and strong cellular immune responses in HIV-1 seropositive individuals. RESULTS: Viral particles were generated through transient transfection in producer cells (293-T) of a full length HIV-1 DNA carrying a deletion of 892 base pairs (bp) in the pol gene encompassing the sequence that codes for the reverse transcriptase (NL4-3/ΔRT clone). The viral particles generated were able to enter target cells, but due to the absence of reverse transcriptase no replication was detected. The immunogenic capacity of these particles was assessed by ELISPOT to determine γ-interferon production in a cohort of 69 chronic asymptomatic HIV-1 seropositive individuals. Surprisingly, defective particles produced from NL4-3/ΔRT triggered stronger cellular responses than wild-type HIV-1 viruses inactivated with Aldrithiol-2 (AT-2) and in a larger proportion of individuals (55% versus 23% seropositive individuals tested). Electron microscopy showed that NL4-3/ΔRT virions display immature morphology. Interestingly, wild-type viruses treated with Amprenavir (APV) to induce defective core maturation also induced stronger responses than the same viral particles generated in the absence of protease inhibitors. CONCLUSIONS: We propose that immature HIV-1 virions generated from NL4-3/ΔRT viral clones may represent new prototypes of immunogens with a safer profile and stronger capacity to induce cellular immune responses than wild-type inactivated viral particles.This study was supported by grants FIS PI050265, FIS PI040503, FIS PI070291, FIS Intrasalud 080752, FIS PS09/01297, FIS PI10/02984, SAF2006-26667-E, FIT 09-010-205-9, FIPSE 36780/08, Fundación Mútua Madrileña, TRA-094, EC10-153, ISCIII-RETIC RD06/0006, HIVACAT–HIV Development Program in Catalonia, FIPSE 36630/07, UE Program Health 2009 CHAARM. Spanish Health Institute Carlos III (ISCIII) and the Health Department of the Catalan Government (Generalitat de Catalunya). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S
Evaluating a web- and telephone-based personalised exercise intervention for individuals living with metastatic prostate cancer (ExerciseGuide): protocol for a pilot randomised controlled trial
Introduction: Preliminary research has shown the effectiveness of supervised exercise-based interventions in alleviating sequela resulting from metastatic prostate cancer. Despite this, many individuals do not engage in sufficient exercise to gain the benefits. There are many barriers, which limit the uptake of face-to-face exercise in this population including lack of suitable facilities, remoteness, and access to experts, significant fatigue, urinary incontinence and motivation. Technology-enabled interventions offer a distance-based alternative. This protocol describes a pilot two-armed randomised controlled study that will investigate the feasibility and preliminary efficacy of an online exercise and behavioural change tool (ExerciseGuide) amongst individuals with metastatic prostate cancer.
Methods: Sixty-six participants with histologically diagnosed metastatic prostate cancer will be randomised into either the 8-week intervention or a wait-list control. The intervention arm will have access to a tailored website, remote supervision, and tele-coaching sessions to enhance support and adherence. Algorithms will individually prescribe resistance and aerobic exercise based upon factors such as metastasis location, pain, fatigue, confidence and current exercise levels. Behavioural change strategies and education on exercise benefits, safety and lifestyle are also tailored through the website. The primary outcome will be intervention feasibility (safety, usability, acceptability, and adherence). Secondary exploratory outcomes include changes in physical activity, quality of life, sleep, and physical function. Outcomes will be measured at baseline and week 9.
Discussion: The study aims to determine the potential feasibility of an online remotely monitored exercise intervention developed for individuals with metastatic prostate cancer. If feasible, this pilot intervention will inform the design and implementation of further distance-based interventions
Evaluating a web-based computer-tailored physical activity intervention for those living with and beyond lung cancer (ExerciseGuide UK): protocol for a single group feasibility and acceptability study
Background: Lung cancer is the leading cause of cancer-related death globally. Physical activity and exercise provide unequivocal benefits to those living with and beyond lung cancer. However, few of those living with and beyond cancer meet the national physical activity guidelines. Various barriers exist for this population’s engagement in physical activity and exercise, such as the lack of knowledge and lack of tailored information, little access to exercise specialists, fatigue, and mobility challenges. Digitally delivered programmes have the potential to address several of these barriers, with techniques like “computer-tailoring” available to enable the delivery of tailored content at a time and place that is convenient. However, evaluation of such programmes is needed prior to implementation. This protocol describes a single group study that will examine the feasibility and acceptability of an online tool (ExerciseGuide UK) that provides those living with and beyond lung cancer web-based computer-tailored physical activity prescription and modules underpinned by behaviour change theories. Methods: Thirty-five individuals diagnosed with lung cancer, or cancer affecting the lung (e.g. pleural mesothelioma), will be recruited into a single-intervention arm. The platform will provide tailored resources and a personalised physical activity programme using IF-THEN algorithms. Exercise prescription will be tailored on factors such as self-reported specific pain location, exercise history, and current physical fitness. In addition, modules grounded in behaviour change will supplement the physical activity programme and will focus on topics such as exercise benefits, safety, goal setting, and tracking. The primary outcome will be assessed using pre-established criteria on feasibility and mixed-methods approach for acceptability. Secondary outcomes will explore changes in the physical activity, quality of life, anxiety, and depression. Discussion: This manuscript describes the protocol for a study examining the feasibility and acceptability of a web-based computer-tailored physical activity intervention for those living with and beyond lung cancer. The publication of this protocol aims to increase the transparency of the methods, report pre-determined criteria, and aid replication of the study and associated materials. If feasible and acceptable, this intervention will inform future studies of digital-based interventions. Trail registration: ClinicalTrails.gov, NCT05121259. Registered on November 16, 2021
Examining the priorities, needs and preferences of men with metastatic prostate cancer in designing a personalised eHealth exercise intervention
Background: Few individuals with metastatic prostate cancer have access to prostate cancer-specific exercise support, despite demonstrated benefits. eHealth tools, such as websites, may be viable options for increasing access. To be effective and acceptable, future eHealth websites need to consider end-users’ perspectives, capacity and needs. We aim to provide insight into these factors by exploring daily priorities, activities and health literacy of individuals with metastatic prostate cancer and their perspectives towards exercise and exercise-based web-based eHealth interventions. Methods: Semi-structured interviews explored participant’s experiences and understanding of their disease, exercise levels, advice received from health care providers, as well as acceptability of and suggested content for an eHealth tool. A thematic analysis was undertaken. Results: Interviews were conducted with eighteen Australians (55–83 years; M = 71.5, SD = 8.9) living with metastatic prostate cancer. Needing to perform daily responsibilities was a key priority. Participants had limited understanding of the benefits of prostate cancer-specific exercise, and less than half discussed exercise with their health team. Fourteen men felt they could report metastases location, but only four could provide detailed information, which has clinical implications for exercise prescription. A potential web-based intervention was considered acceptable by seventeen men for reasons such as affordability, accessibility and convenience. User-friendly design and practitioner support were important. Conclusions: Results identified key aspects useful for person-centred design of exercise programs. Participants were positive towards the proposed web-based tool and expressed the need for individualised, user-friendly and reliable information with support from a professional embedded. Lastly, not all participants could accurately report metastasis locations