RESUMO
BACKGROUND: Most caretakers of children with disabilities (CWDs) have adverse health outcomes. Approximately 31% of the caretakers have clinical depression in the world. In Sub-Saharan Africa, 42% of them face severe psychological distress. Caretakers in Africa face additional cultural challenges that undermine their coping skills, access to social support, and resilience. METHODS: This study used sequential explanatory mixed methods to examine the relationships of social support, coping skills and resilience among caretakers of CWDs in Uganda. A total of 621 caretakers were surveyed, and 43 of them participated in interviews. Hierarchical cluster analysis and binary logistic regression were conducted to determine coping patterns and predict caretakers' likelihood of using them. Hierarchical linear regression and thematic analyses then explored the relationships and perceptions of coping skills and resilience related to social support. A joint display was used to integrate results and show the convergence and expansion of quantitative and qualitative results. RESULTS: Quantitative and qualitative findings converged that caretakers who received social support used adaptive coping skills and had higher resilience. Qualitative results expanded the finding that caretakers who received formal social support perceived it as a safer mode of care than informal social support. CONCLUSIONS: The study expanded the scope of social support, coping skills, and resilience. Caretakers perceived formal social support from schools as a safe mode of care that enabled them to use adaptive coping skills and have high resilience. Therefore, enrolling children with disabilities in schools at an early age is beneficial for building the resilience of their caretakers.
Assuntos
Crianças com Deficiência , Resiliência Psicológica , Adaptação Psicológica , Criança , Humanos , Apoio Social , Inquéritos e Questionários , UgandaRESUMO
Human cytomegalovirus (CMV) is a ubiquitous pathogen that causes significant morbidity in some vulnerable populations. Individualized adoptive transfer of ex vivo expanded CMV-specific CD8+ T cells has provided proof-of-concept that immunotherapy can be highly effective, but a chimeric antigen receptor (CAR) approach would provide a feasible method for broad application. We created 8 novel CARs using anti-CMV neutralizing antibody sequences, which were transduced via lentiviral vector into primary CD8+ T cells. All CARs were expressed. Activity against CMV-infected target cells was assessed by release of cytokines (interferon-γ and tumor necrosis factor-α), upregulation of surface CD107a, proliferation, cytolysis of infected cells, and suppression of viral replication. While some CARs showed varying functional activity across these assays, 1 CAR based on antibody 21E9 was consistently superior in all measures. These results support development of a CMV-specific CAR for therapeutic use against CMV and potentially other applications harnessing CMV-driven immunotherapies.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Citomegalovirus/imunologia , Imunoterapia Adotiva , Receptores de Antígenos Quiméricos/imunologia , Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/farmacologia , Linfócitos T CD8-Positivos/metabolismo , Proliferação de Células , Células HEK293 , Humanos , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Transdução Genética , Replicação ViralRESUMO
Almost 80% of viral transcripts during early HIV-1 infection encode the Nef protein, which has been implicated in altering expression of a number of genes. In this study, we infected primary human CD4+ T cells with pseudotyped Nef-containing or Nef-deleted (Δ-nef) NL4-3 virus and used RNA-Sequencing (RNA-Seq) for transcriptomic analysis. Our results showed that the interferon response, IL-15 and JAK/STAT signaling, as well as genes involved in metabolism, apoptosis, cell cycle regulation, and ribosome biogenesis were all altered in the presence of Nef. These early Nef-mediated transcriptional alterations may play a role in priming the host cell for cellular activation and viral replication.
Assuntos
Linfócitos T CD4-Positivos/virologia , Regulação Viral da Expressão Gênica , HIV-1/fisiologia , Produtos do Gene nef do Vírus da Imunodeficiência Humana/fisiologia , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Humanos , Replicação ViralRESUMO
A 48-year-old woman was infected with a vpr-defective human immunodeficiency virus (HIV)-1 molecular clone. Seroconversion was markedly delayed, and without treatment she had durably suppressed viremia and normal T-cell levels. Neutralizing antibody and CD8+ T-cell immune responses against HIV-1 were unremarkable. Viral sequences confirmed the source but evolved defective nef, suggesting an unknown mechanistic link to vpr. There were subtle qualitative defects in T and B cells. To our knowledge, this is the only case of human infection with a characterized defective HIV-1 molecular clone, which furthermore recapitulated live-attenuated vaccination in macaque models of HIV-1 vaccine research.
Assuntos
Vacinas contra a AIDS/imunologia , Produtos do Gene vpr/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Vacinas Atenuadas/imunologia , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Clonagem Molecular , Feminino , Humanos , Pessoa de Meia-Idade , Vacinação/métodosRESUMO
UNLABELLED: Although the use of chimeric antigen receptors (CARs) based on single-chain antibodies for gene immunotherapy of cancers is increasing due to promising recent results, the earliest CAR therapeutic trials were done for HIV-1 infection in the late 1990s. This approach utilized a CAR based on human CD4 as a binding domain and was abandoned for a lack of efficacy. The growing number of HIV-1 broadly neutralizing antibodies (BNAbs) offers the opportunity to generate novel CARs that may be more active and revisit this modality for HIV-1 immunotherapy. We used sequences from seven well-defined BNAbs varying in binding sites and generated single-chain-antibody-based CARs. These CARs included 10E8, 3BNC117, PG9, PGT126, PGT128, VRC01, and X5. Each novel CAR exhibited conformationally relevant expression on the surface of transduced cells, mediated specific proliferation and killing in response to HIV-1-infected cells, and conferred potent antiviral activity (reduction of viral replication in log10 units) to transduced CD8(+) T lymphocytes. The antiviral activity of these CARs was reproducible but varied according to the strain of virus. These findings indicated that BNAbs are excellent candidates for developing novel CARs to consider for the immunotherapeutic treatment of HIV-1. IMPORTANCE: While chimeric antigen receptors (CARs) using single-chain antibodies as binding domains are growing in popularity for gene immunotherapy of cancers, the earliest human trials of CARs were done for HIV-1 infection. However, those trials failed, and the approach was abandoned for HIV-1. The only tested CAR against HIV-1 was based on the use of CD4 as the binding domain. The growing availability of HIV-1 broadly neutralizing antibodies (BNAbs) affords the opportunity to revisit gene immunotherapy for HIV-1 using novel CARs based on single-chain antibodies. Here we construct and test a panel of seven novel CARs based on diverse BNAb types and show that all these CARs are functional against HIV-1.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Receptores de Antígenos/imunologia , Receptores de HIV/imunologia , Linfócitos T/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Células Jurkat , Homologia de Sequência de Aminoácidos , Anticorpos de Cadeia Única/imunologiaRESUMO
UNLABELLED: Cellular immunity is pivotal in HIV-1 pathogenesis but is hampered by viral sequence diversity. An approach to minimize this diversity is to focus immunity on conserved proteome sequences; therefore, we selected four relatively conserved regions (Gag amino acids 148 to 214 and 250 to 335, Env amino acids 521 to 606, and Nef amino acids 106 to 148), each created in three mosaics, to provide better coverage of M-group HIV-1 sequences. A conserved-region vaccine (CRV) delivering genes for these four regions as equal mixtures of three mosaics each (each region at a separate injection site) was compared to a whole-protein vaccine (WPV) delivering equimolar amounts of genes for whole Gag, Env, and Nef as clade B consensus sequences (separate injection sites). Three rhesus macaques were vaccinated via three DNA primes and a recombinant adenovirus type 5 boost (weeks 0, 4, 8, and 24, respectively). Although CRV inserts were about one-fifth that of WPV, the CRV generated comparable-magnitude blood CD4+ and CD8+ T lymphocyte responses against Gag, Env, and Nef. WPV responses preferentially targeted proteome areas outside the selected conserved regions in direct proportion to sequence lengths, indicating similar immunogenicities for the conserved regions and the outside regions. The CRV yielded a conserved-region targeting density that was approximately 5-fold higher than that of the WPV. A similar pattern was seen for bronchoalveolar lymphocytes, but with quadruple the magnitudes seen in blood. Overall, these findings demonstrate that the selected conserved regions are highly immunogenic and that anatomically isolated vaccinations with these regions focus immunodominance compared to the case for full-length protein vaccination. IMPORTANCE: HIV-1 sequence diversity is a major barrier limiting the capability of cellular immunity to contain infection and the ability of vaccines to match circulating viral sequences. To date, vaccines tested in humans have delivered whole proteins or genes for whole proteins, and it is unclear whether including only conserved sequences would yield sufficient cellular immunogenicity. We tested a vaccine delivering genes for four small conserved HIV-1 regions compared to a control vaccine with genes for whole Gag, Env, and Nef. Although the conserved regions ranged from 43 to 86 amino acids and comprised less than one-fifth of the whole Gag/Env/Nef sequence, the vaccines elicited equivalent total magnitudes of both CD4+ and CD8+ T lymphocyte responses. These data demonstrate the immunogenicity of these small conserved regions and the potential for a vaccine to steer immunodominance toward conserved epitopes.
Assuntos
Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/imunologia , Sequência Conservada , HIV-1/imunologia , Epitopos Imunodominantes , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Feminino , Macaca mulatta , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/administração & dosagem , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana/administração & dosagem , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene nef do Vírus da Imunodeficiência Humana/administração & dosagem , Produtos do Gene nef do Vírus da Imunodeficiência Humana/imunologiaRESUMO
Although CD8(+) cytotoxic T lymphocytes (CTLs) are protective in HIV-1 infection, the factors determining their antiviral efficiency are poorly defined. It is proposed that Gag targeting is superior because of very early Gag epitope presentation, allowing early killing of infected cells before Nef-mediated downregulation of human leukocyte antigen class I (HLA-I). To study Gag epitope presentation kinetics, three epitopes (SL977-85, KF11162-172, and TW10240-249) were genetically translocated from their endogenous location in the Rev-dependent (late) gag gene into the Rev-independent (early) nef gene with concomitant mutation of the corresponding endogenous epitopes to nonrecognized sequences. These viruses were compared to the index virus for CTL-mediated suppression of replication and the susceptibility of this antiviral activity to Nef-mediated HLA-I downregulation. SL9-specific CTLs gained activity after SL9 translocation to Nef, going from Nef sensitive to Nef insensitive, indicating that translocation accelerated infected cell recognition from after to before HLA-I downregulation. KF11-specific CTL antiviral activity was unchanged and insensitive to HLA-I downregulation before and after KF11 translocation, suggesting that already rapid recognition of infected cells was not accelerated. However, TW10-specific CTLs that were insensitive to Nef at the baseline became sensitive with reduced antiviral activity after translocation, indicating that translocation retarded epitope expression. Cytosolic peptide processing assays suggested that TW10 was inefficiently generated after translocation to Nef, compared to SL9 and KF11. As a whole, these data demonstrate that epitope presentation kinetics play an important role in CTL antiviral efficiency, that Gag epitopes are not uniformly presented early, and that the epitope context can play a major role in presentation kinetics.
Assuntos
Epitopos de Linfócito T/imunologia , HIV-1/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Linfócitos T Citotóxicos/imunologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia , Regulação para Baixo , Epitopos de Linfócito T/genética , HIV-1/genética , Antígenos de Histocompatibilidade Classe I/biossíntese , Humanos , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Recombinação Genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genéticaRESUMO
A 60 days study was conducted to evaluate the physiological response of indigenous species Labeo rohita (LR) and indigenous predator Chitala chitala (CC) in presence of an invasive species Piaractus brachypomus (PB). Two treatment groups as LR + PB (T1) and LR + PB + CC (T2) with individual control groups as T0LR, T0PB and T0CC were designed in triplicates. Fingerlings of LR, PB and CC were randomly distributed into 15 circular tanks with a stocking ratio of 1:1 and 1:1:0.3 in T1 and T2 group, respectively and 10 nos. each of LR, PB and CC in respective control groups. At first 15 min of the experiment, cortisol level was found significantly (P < 0.05) higher in all three experimental fishes in T1 and T2 groups. With the experimental duration, the level of stress hormone (cortisol), oxidative stress enzymes (superoxide dismutase, catalase, and glutathione peroxidase), tissue metabolic enzymes (lactate dehydrogenase and malate dehydrogenase), serum metabolic enzymes (transaminase enzymes) and blood glucose level were significantly (P < 0.05) increased in T1 and T2 groups for LR and CC whereas, no variation (P > 0.05) were observed for PB in both T1 and T2 groups. The total antioxidant capacity (TAC), liver glycogen, total protein, albumin and globulin were found to be significantly (P < 0.05) decreased in LR in the presence of PB and CC. The present study provides a preliminary insight into the biological interaction between native and invasive species and their physiological responses in the presence of native predator with higher trophic index. Thus, the results of the study suggest the superior traits of invasive P. brachypomus try to dominate the other two native species by negatively influencing the native fauna even with a higher trophic index (C. chitala).
RESUMO
Viral mutational escape from CD8(+) cytotoxic T lymphocytes (CTLs) is typically considered to be a dichotomous process and uncommon during chronic HIV-1 infection. Ex vivo passaging of HIV-1 from persons with chronic infection, however, revealed the evolution of many fixed substitutions within and around CTL-targeted regions, with an associated increase in replicative capacity. This indicates an evolution of mutations during chronic HIV-1 infection that trade replicative fitness for incomplete evasion of CTLs, or "partial escape."
Assuntos
Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , Evasão da Resposta Imune , Mutação de Sentido Incorreto , Linfócitos T Citotóxicos/imunologia , Substituição de Aminoácidos , Doença Crônica , HIV-1/genética , HIV-1/isolamento & purificação , Humanos , Dados de Sequência Molecular , RNA Viral/genética , Análise de Sequência de DNARESUMO
Microplastic (MP) pollution in freshwater environments has drawn considerable attention over the decades due to the risk posed by MPs to the aquatic fauna and human health. In this study, the occurrence of MPs was assessed from the gastrointestinal tracts (GIT) of indigenous fishes from Bhogdoi River, a tributary of River Brahmaputra, northeast hill region, Assam, India. All the fish species (n = 180) analysed showed 100% occurrence of MPs sampled from three stations of River Bhogdoi. A total of 488 microplastic particles were recorded from GIT of fishes collected. The mean abundance of MPs was highest in Station-II (7.64 ± 2.77 numbers individual-1) with lowest in S-I (3.17 ± 0.99 numbers individual-1). The MP size of 100-500 µm, MP shape of fibre (43.33%) and fragments (35.33%), blue colour MPs (26-37%) and polymer type PA (23-30%) were most prevalent in fishes analysed from River Bhogdoi. The mean abundance of MPs was higher in herbivore fishes (8.52 ± 1.22 numbers individual-1) as compared to carnivorous and omnivorous fish species with highest abundance in Labeo rohita (12.11 ± 2.13 numbers individual-1). Fibre and fragments with size range of 100-500 µm were dominant among all the feeding habits. Blue and black colour MPs were abundant among herbivore and carnivore fishes. Fourier transform infrared spectroscopy results confirmed that polyamide and polypropylene were the most abundant MP polymer in the fishes analysed. The present study provides baseline information of MPs in River Bhogdoi, Assam, for its future monitoring and assessment of contaminants.
Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Humanos , Plásticos , Rios/química , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Peixes , Trato Gastrointestinal/química , ÍndiaRESUMO
Background: In Sub-Saharan Africa, 41 to 58% of the caregivers of children with disabilities experience psychological distress and have poor mental well-being. Cognitive behavioural therapy (CBT) has a moderate effect on improving mental well-being. However, no study has examined its effects among caregivers of children with disabilities at home and in schools. This study evaluated the effectiveness of CBT in improving mental well-being among caregivers of children with disabilities in urban Uganda. Methods: We conducted a two-arm cluster-randomized controlled trial in 11 schools across the Kampala district of Uganda. The intervention was a multi-modal CBT training program conducted for six months among 392 home and school caregivers of children with disabilities. In the first three months, caregivers received group-based CBT, and in the next three months, they received phone-based CBT. We used generalized linear mixed-effects regression to examine the differences in the mental well-being of caregivers in the control group vs those in the intervention group. Results: Home caregivers' mental well-being was significantly higher after phone-based CBT (unstandardized coefficient of the estimate (B) = 4.31, 95% CI = 1.18-6.82; P < 0.001, Cohen's D (d) = 0.27). School caregivers' mental well-being was significantly higher after group-based CBT (B = 3.98, 95% CI = 0.22-7.47; P = 0.038, d = 0.25). Conclusions: Group-based CBT improved mental well-being among school caregivers, and phone-based CBT improved mental well-being among home caregivers. Interventions targeting school caregivers of children with disabilities should employ group settings and those targeting home caregivers should utilize peer-to-peer networks to enhance the caregivers' mental well-being. Registration: The study protocol was registered with UMIN Clinical Trials Registry (UMIN-CTR). Trial ID: UMIN000040912.
Assuntos
Terapia Cognitivo-Comportamental , Crianças com Deficiência , Criança , Humanos , Cuidadores/psicologia , Uganda , Saúde Mental , Terapia Cognitivo-Comportamental/métodosRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve in humans. Spike protein mutations increase transmission and potentially evade antibodies raised against the original sequence used in current vaccines. Our evaluation of serum neutralizing activity in both persons soon after SARS-CoV-2 infection (in April 2020 or earlier) or vaccination without prior infection confirmed that common spike mutations can reduce antibody antiviral activity. However, when the persons with prior infection were subsequently vaccinated, their antibodies attained an apparent biologic ceiling of neutralizing potency against all tested variants, equivalent to the original spike sequence. These findings indicate that additional antigenic exposure further improves antibody efficacy against variants. IMPORTANCE As SARS-CoV-2 evolves to become better suited for circulating in humans, mutations have occurred in the spike protein it uses for attaching to cells it infects. Protective antibodies from prior infection or vaccination target the spike protein to interfere with its function. These mutations can reduce the efficacy of antibodies generated against the original spike sequence, raising concerns for reinfections and vaccine failures, because current vaccines contain the original sequence. In this study, we tested antibodies from people infected early in the pandemic (before spike variants started circulating) or people who were vaccinated without prior infection. We confirmed that some mutations reduce the ability of antibodies to neutralize the spike protein, whether the antibodies were from past infection or vaccination. Upon retesting the previously infected persons after vaccination, their antibodies gained the same ability to neutralize mutated spike as the original spike, suggesting that the combination of infection and vaccination drove the production of enhanced antibodies to reach a maximal level of potency. Whether this can be accomplished by vaccination alone remains to be determined, but the results suggest that booster vaccinations may help improve efficacy against spike variants through improving not only antibody quantity, but also quality.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Vacinação/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Vacinas contra COVID-19/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto JovemRESUMO
Studies of two SARS-CoV-2 mRNA vaccines suggested that they yield â¼95% protection from symptomatic infection at least short-term, but important clinical questions remain. It is unclear how vaccine-induced antibody levels quantitatively compare to the wide spectrum induced by natural SARS-CoV-2 infection. Vaccine response kinetics and magnitudes in persons with prior COVID-19 compared to virus-naiÌve persons are not well-defined. The relative stability of vaccine-induced versus infection-induced antibody levels is unclear. We addressed these issues with longitudinal assessments of vaccinees with and without prior SARS-CoV-2 infection using quantitative enzyme-linked immunosorbent assay (ELISA) of anti-RBD antibodies. SARS-CoV-2-naiÌve individuals achieved levels similar to mild natural infection after the first vaccination; a second dose generated levels approaching severe natural infection. In persons with prior COVID-19, one dose boosted levels to the high end of severe natural infection even in those who never had robust responses from infection, increasing no further after the second dose. Antiviral neutralizing assessments using a spike-pseudovirus assay revealed that virus-naiÌve vaccinees did not develop physiologic neutralizing potency until the second dose, while previously infected persons exhibited maximal neutralization after one dose. Finally, antibodies from vaccination waned similarly to natural infection, resulting in an average of â¼90% loss within 90 days. In summary, our findings suggest that two doses are important for quantity and quality of humoral immunity in SARS-CoV-2-naiÌve persons, while a single dose has maximal effects in those with past infection. Antibodies from vaccination wane with kinetics very similar to that seen after mild natural infection; booster vaccinations will likely be required.
Assuntos
COVID-19 , Vacinas Virais , Humanos , Vacinas contra COVID-19 , COVID-19/prevenção & controle , Formação de Anticorpos , SARS-CoV-2 , Anticorpos Antivirais , Anticorpos Neutralizantes , VacinaçãoRESUMO
CD8+ T cell responses restricted by MHC-E, a nonclassical MHC molecule, have been associated with protection in an SIV/rhesus macaque model. The biological relevance of HLA-E-restricted CD8+ T cell responses in HIV infection, however, remains unknown. In this study, CD8+ T cells responding to HIV-1 Gag peptides presented by HLA-E were analyzed. Using in vitro assays, we observed HLA-E-restricted T cell responses to what we believe to be a newly identified subdominant Gag-KL9 as well as a well-described immunodominant Gag-KF11 epitope in T cell lines derived from chronically HIV-infected patients and also primed from healthy donors. Blocking of the HLA-E/KF11 binding by the B7 signal peptide resulted in decreased CD8+ T cell responses. KF11 presented via HLA-E in HIV-infected cells was recognized by antigen-specific CD8+ T cells. Importantly, bulk CD8+ T cells obtained from HIV-infected individuals recognized infected cells via HLA-E presentation. Ex vivo analyses at the epitope level showed a higher responder frequency of HLA-E-restricted responses to KF11 compared with KL9. Taken together, our findings of HLA-E-restricted HIV-specific immune responses offer intriguing and possibly paradigm-shifting insights into factors that contribute to the immunodominance of CD8+ T cell responses in HIV infection.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Infecções por HIV/imunologia , HIV-1/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Sequência de Aminoácidos , Apresentação de Antígeno , Linhagem Celular , Infecções por HIV/genética , Infecções por HIV/virologia , Soronegatividade para HIV/imunologia , HIV-1/genética , Antígenos HLA-B/imunologia , Humanos , Epitopos Imunodominantes , Técnicas In Vitro , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia , Antígenos HLA-ERESUMO
CD8+ class I-restricted cytotoxic T lymphocytes (CTLs) usually incompletely suppress HIV-1 in vivo, and while analogous partial suppression induces antiretroviral drug-resistance mutations, epitope escape mutations are inconsistently observed. However, escape mutation depends on the net balance of selective pressure and mutational fitness costs, which are poorly understood and difficult to study in vivo. Here we used a controlled in vitro system to evaluate the ability of HIV-1 to escape from CTL clones, finding that virus replicating under selective pressure rapidly can develop phenotypic resistance associated with genotypic changes. Escape varied between clones recognizing the same Gag epitope or different Gag and RT epitopes, indicating the influence of the T cell receptor on pressure and fitness costs. Gag and RT escape mutations were monoclonal intra-epitope substitutions, indicating limitation by fitness constraints in structural proteins. In contrast, escape from Nef-specific CTL was more rapid and consistent, marked by a polyclonal mixture of epitope point mutations and upstream frameshifts. We conclude that incomplete viral suppression by CTL can result in rapid emergence of immune escape, but the likelihood is strongly determined by factors influencing the fitness costs of the particular epitope targeted and the ability of responding CTL to recognize specific epitope variants.
Assuntos
HIV-1/genética , HIV-1/imunologia , Mutação , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Linhagem Celular , Epitopos , Produtos do Gene gag/imunologia , Produtos do Gene nef/imunologia , Transcriptase Reversa do HIV/imunologia , Humanos , Dados de Sequência Molecular , Produtos do Gene nef do Vírus da Imunodeficiência HumanaRESUMO
Proper dietary practices should be developed during the student years that will continue into the future. This study aimed to identify the eating habits and dietary practices among King Faisal University (KFU) students, explore the barriers to adherence to healthy eating, associate the understanding of healthy diets with students' characteristics, and determine the association between body mass index (BMI) and awareness of the concept of healthy diets, academic discipline, and enrollment in a nutrition course. In this cross-sectional study, students were selected randomly and a questionnaire was distributed using an electronic platform through KFU email. Out of 564 students, nearly half (45.7%) reported eating snacks as their main food, and some (38.3%) reported eating with their family twice daily. The students rarely reported eating with friends (73%) or eating dates (48.8%). Furthermore, many reported that they were not consuming a balanced diet (42.6%). Some students (46.3%) reported taking breakfast daily, and 49.1% reported eating meals regularly. There was low consumption of vegetables (29.3%) and fruits (26.2%) among the students. The barriers to adherence to healthy eating were the availability of fast food (73.2%), high cost of healthy food (72.7%), limited time (59%), and laziness (57.1%). Statistically significant data indicated that the students with a normal BMI were more aware of the concept of healthy diets, studied medical and applied sciences, and were enrolled in KFU nutrition courses.
Assuntos
Dieta Saudável , Universidades , Estudos Transversais , Dieta , Comportamento Alimentar , Feminino , Humanos , Masculino , EstudantesRESUMO
HIV-1-induced cytopathicity of thymocytes is a major cause of reduced peripheral T cells and rapid disease progression observed in HIV-1-infected infants. Understanding the virulence factors responsible for thymocyte depletion has paramount importance in addressing the pathogenesis of disease progression in children. In this study, thymocyte depletion was analyzed following infection with two primary CXCR4-tropic HIV-1 pediatric isolates (PI), PI-2 and PI-2.1, which were serially derived from an in utero-infected infant. Although highly similar to each other, PI-2 showed markedly decreased thymocyte depletion in vitro compared with PI-2.1. Further analysis showed a novel deletion in the Nef protein (NefΔK7S) of PI-2, which was absent in PI-2.1. This deletion inhibited Nef-mediated major histocompatibility complex class I (MHC-I) downregulation in infected thymocytes in vitro and in vivo; in contrast, the mutated Nef continued to downregulate CD4 surface expression in vitro. These results suggest that HIV-1 Nef contributes to thymic damage in infants through selective functions.
Assuntos
Infecções por HIV/genética , Antígenos de Histocompatibilidade Classe I/genética , Timócitos/virologia , Produtos do Gene nef do Vírus da Imunodeficiência Humana/genética , Animais , Células Cultivadas , Pré-Escolar , Efeito Citopatogênico Viral , Regulação para Baixo , Deleção de Genes , Infecções por HIV/virologia , HIV-1/genética , Humanos , Recém-Nascido , Camundongos , Camundongos SCID , Mutação , Timócitos/patologiaRESUMO
Vaccination for human immunodeficiency virus type 1 (HIV-1) remains an elusive goal. Whether an unsuccessful vaccine might not only fail to provoke detectable immune responses but also could actually interfere with subsequent natural immunity upon HIV-1 infection is unknown. We performed detailed assessment of an HIV-1 gag DNA vaccine recipient (subject 00015) who was previously uninfected but sustained HIV-1 infection before completing a vaccination trial and another contemporaneously acutely infected individual (subject 00016) with the same strain of HIV-1. Subject 00015 received the vaccine at weeks 0, 4, and 8 and was found to have been acutely HIV-1 infected around the time of the third vaccination. Subject 00016 was a previously HIV-1-seronegative sexual contact who had symptoms of acute HIV-1 infection approximately 2 weeks earlier than subject 00015 and demonstrated subsequent seroconversion. Both individuals reached an unusually low level of chronic viremia (<1,000 copies/ml) without treatment. Subject 00015 had no detectable HIV-1-specific cytotoxic T-lymphocyte (CTL) responses until a borderline response was noted at the time of the third vaccination. The magnitude and breadth of Gag-specific CTL responses in subject 00015 were similar to those of subject 00016 during early chronic infection. Viral sequences from gag, pol, and nef confirmed the common source of HIV-1 between these individuals. The diversity and divergence of sequences in subjects 00015 and 00016 were similar, indicating similar immune pressure on these proteins (including Gag). As a whole, the data suggested that while the gag DNA vaccine did not prime detectable early CTL responses in subject 00015, vaccination did not appreciably impair his ability to contain viremia at levels similar to those in subject 00016.
Assuntos
Vacinas contra a AIDS/administração & dosagem , Produtos do Gene gag/imunologia , Infecções por HIV/prevenção & controle , HIV-1/imunologia , Adulto , Ensaio de Imunoadsorção Enzimática , Produtos do Gene gag/genética , Genes Virais , Humanos , Masculino , Filogenia , Linfócitos T Citotóxicos/imunologiaRESUMO
The present study suggests the formation of polyvinyl alcohol (PVA)-Azadirachta indica (neem)-chitosan blend nanofibrous mat (PNCNM) by bi-layered technique under optimum processing conditions. The antibacterial activity against Staphylococcus aureus (S. aureus) bacteria, morphology, bonding behavior, thermal stability, tensile behavior and moisture management properties of the developed sample had been investigated. The scanning electron microscopy (SEM) images revealed the homogeneous and smooth fibers produced having average diameter of 213.52nm (nm) with the minimum and maximum diameter of 152nm and 298nm respectively. Besides, it showed 91% porosity which is indicative of porous structure. The presence of PVA, neem constituents and chitosan was established by Fourier Transform Infrared Spectroscopy (FTIR) indicating the formation of hydrogen bonding among them. The addition of neem extracts led to enhanced thermal stability and moisture management properties. In addition, the developed mat showed a tensile strength of 18.78N corresponding to the elongation value of 4.98mm. Besides, the incorporation of neem extract into the nanofiber mat exhibited a significant synergistic antibacterial activity against bacterial cells through the formation of inhibition zone. Thus, the newly developed nanofibrous mat could turn out to be a suitable material for the wound dressing purpose.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Azadirachta/química , Quitosana/química , Nanofibras/química , Extratos Vegetais/química , Álcool de Polivinil/química , Testes de Sensibilidade Microbiana , Folhas de Planta/química , Porosidade , Staphylococcus aureus/efeitos dos fármacos , Resistência à TraçãoRESUMO
BACKGROUND: Several studies were carried out to study the prevalence of overweight and obesity among Saudi children, but those assessed the association between eating habits, socio-demographic differentials and obesity in these children are scarce. OBJECTIVES: To assess the magnitude of obesity and overweight among male primary schoolchildren and to find the possible association between obesity/overweight with dietary habits and socio-demographic differentials among them. STUDY DESIGN AND METHODS: A cross-sectional descriptive study including 1,139 Saudi male enrolled in the fifth and sixth grades in public primary schools in Al Hassa, KSA, through a multistage random sampling technique, submitted to interview using Youth and Adolescent Food Frequency Questionnaire, gathering data regarding dietary intake, some dietary habits, followed by anthropometric measurements with calculation of body mass index, the interpretation of which was based on using Cole's tables for standard definition of overweight and obesity. Socio-demographics data were collected through parental questionnaire form. Data analysis was carried out using SPSS 12 (SPSS Inc. Chicago, IL, USA), univariate as well as multivariate analyses were conducted. RESULTS: The age ranged from 10 to 14 years. The prevalence of overweight among the included subjects was 14.2% while obesity was 9.7%, more in urban, older age students, mothers of obese and overweight were less educated, more working. Missing and or infrequent intake of breakfast at home, frequent consumption of fast foods, low servings of fruits, vegetables, milk and dairy product per day, with frequent consumption of sweets/candy and carbonated drinks were all predictors of obesity and overweight among the included male schoolchildren. CONCLUSION: The prevalence of childhood obesity is escalating and approaching figures reported in the developed countries. Less healthy dietary habits and poor food choices may be responsible for this high prevalence.