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1.
Nature ; 603(7901): 488-492, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35102311

RESUMO

The SARS-CoV-2 Omicron variant (B.1.1.529) has multiple spike protein mutations1,2 that contribute to viral escape from antibody neutralization3-6 and reduce vaccine protection from infection7,8. The extent to which other components of the adaptive response such as T cells may still target Omicron and contribute to protection from severe outcomes is unknown. Here we assessed the ability of T cells to react to Omicron spike protein in participants who were vaccinated with Ad26.CoV2.S or BNT162b2, or unvaccinated convalescent COVID-19 patients (n = 70). Between 70% and 80% of the CD4+ and CD8+ T cell response to spike was maintained across study groups. Moreover, the magnitude of Omicron cross-reactive T cells was similar for Beta (B.1.351) and Delta (B.1.617.2) variants, despite Omicron harbouring considerably more mutations. In patients who were hospitalized with Omicron infections (n = 19), there were comparable T cell responses to ancestral spike, nucleocapsid and membrane proteins to those in patients hospitalized in previous waves dominated by the ancestral, Beta or Delta variants (n = 49). Thus, despite extensive mutations and reduced susceptibility to neutralizing antibodies of Omicron, the majority of T cell responses induced by vaccination or infection cross-recognize the variant. It remains to be determined whether well-preserved T cell immunity to Omicron contributes to protection from severe COVID-19 and is linked to early clinical observations from South Africa and elsewhere9-12.


Assuntos
COVID-19/imunologia , COVID-19/virologia , Reações Cruzadas/imunologia , Imunidade Celular , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologia , Adulto , Idoso , Vacinas contra COVID-19/imunologia , Convalescença , Hospitalização , Humanos , Pessoa de Meia-Idade , SARS-CoV-2/química , SARS-CoV-2/classificação
2.
J Virol ; : e0067824, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38953380

RESUMO

SARS-CoV-2 variants of concern (VOCs) differentially trigger neutralizing and antibody-dependent cellular cytotoxic (ADCC) antibodies with variable cross-reactivity. Omicron BA.4/5 was approved for inclusion in bivalent vaccination boosters, and therefore the antigenic profile of antibodies elicited by this variant is critical to understand. Here, we investigate the ability of BA.4/5-elicited antibodies following the first documented (primary) infection (n = 13) or breakthrough infection after vaccination (n = 9) to mediate neutralization and FcγRIIIa signaling across multiple SARS-CoV-2 variants including XBB.1.5 and BQ.1. Using a pseudovirus neutralization assay and a FcγRIIIa crosslinking assay to measure ADCC potential, we show that unlike SARS-CoV-2 Omicron BA.1, BA.4/5 infection triggers highly cross-reactive functional antibodies. Cross-reactivity was observed both in the absence of prior vaccination and in breakthrough infections following vaccination. However, BQ.1 and XBB.1.5 neutralization and FcγRIIIa signaling were significantly compromised compared to other VOCs, regardless of prior vaccination status. BA.4/5 triggered FcγRIIIa signaling was significantly more resilient against VOCs (<10-fold decrease in magnitude) compared to neutralization (10- to 100-fold decrease). Overall, this study shows that BA.4/5 triggered antibodies are highly cross-reactive compared to those triggered by other variants. Although this is consistent with enhanced neutralization and FcγRIIIa signaling breadth of BA.4/5 vaccine boosters, the reduced activity against XBB.1.5 supports the need to update vaccines with XBB sublineage immunogens to provide adequate coverage of these highly antibody evasive variants. IMPORTANCE: The continued evolution of SARS-CoV-2 has resulted in a number of variants of concern. Of these, the Omicron sublineage is the most immune evasive. Within Omicron, the BA.4/5 sublineage drove the fifth wave of infection in South Africa prior to becoming the dominant variant globally. As a result this spike sequence was approved as part of a bivalent vaccine booster, and rolled out worldwide. We aimed to understand the cross-reactivity of neutralizing and Fc mediated cytotoxic functions elicited by BA.4/5 infection following infection or breakthrough infection. We find that, in contrast to BA.1 which triggered fairly strain-specific antibodies, BA.4/5 triggered antibodies that are highly cross-reactive for neutralization and antibody-dependent cellular cytotoxicity potential. Despite this cross-reactivity, these antibodies are compromised against highly resistant variants such as XBB.1.5 and BQ.1. This suggests that next-generation vaccines will require XBB sublineage immunogens in order to protect against these evasive variants.

3.
J Virol ; 96(15): e0055822, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35867572

RESUMO

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, several variants of concern (VOCs) have arisen which are defined by multiple mutations in their spike proteins. These VOCs have shown variable escape from antibody responses and have been shown to trigger qualitatively different antibody responses during infection. By studying plasma from individuals infected with either the original D614G, Beta, or Delta variants, we showed that the Beta and Delta variants elicit antibody responses that are overall more cross-reactive than those triggered by D614G. Patterns of cross-reactivity varied, and the Beta and Delta variants did not elicit cross-reactive responses to each other. However, Beta-elicited plasma was highly cross-reactive against Delta Plus (Delta+), which differs from Delta by a single K417N mutation in the receptor binding domain, suggesting that the plasma response targets the N417 residue. To probe this further, we isolated monoclonal antibodies from a Beta-infected individual with plasma responses against Beta, Delta+, and Omicron, which all possess the N417 residue. We isolated an N417-dependent antibody, 084-7D, which showed similar neutralization breadth to the plasma. The 084-7D MAb utilized the IGHV3-23*01 germ line gene and had somatic hypermutations similar to those of previously described public antibodies which target the 417 residue. Thus, we have identified a novel antibody which targets a shared epitope found on three distinct VOCs, enabling their cross-neutralization. Understanding antibodies targeting escape mutations, such as K417N, which repeatedly emerge through convergent evolution in SARS-CoV-2 variants, may aid in the development of next-generation antibody therapeutics and vaccines. IMPORTANCE The evolution of SARS-CoV-2 has resulted in variants of concern (VOCs) with distinct spike mutations conferring various immune escape profiles. These variable mutations also influence the cross-reactivity of the antibody response mounted by individuals infected with each of these variants. This study sought to understand the antibody responses elicited by different SARS-CoV-2 variants and to define shared epitopes. We show that Beta and Delta infections resulted in antibody responses that were more cross-reactive than the original D614G variant, but they had differing patterns of cross-reactivity. We further isolated an antibody from Beta infection which targeted the N417 site, enabling cross-neutralization of Beta, Delta+, and Omicron, all of which possess this residue. The discovery of antibodies which target escape mutations common to multiple variants highlights conserved epitopes to target in future vaccines and therapeutics.


Assuntos
Anticorpos Antivirais , Reações Cruzadas , Epitopos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/virologia , Reações Cruzadas/imunologia , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Humanos , Evasão da Resposta Imune/imunologia , Testes de Neutralização , SARS-CoV-2/química , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
5.
Molecules ; 27(24)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36558190

RESUMO

There is increasing awareness of an association between the uptake of the HIV integrase inhibitor, dolutegravir, in first-line antiretroviral regimens with unusual weight gain and development of the metabolic syndrome, particularly in African women. Although seemingly unexplored, the development of systemic inflammation linked to the putative pro-inflammatory activity of dolutegravir represents a plausible pathophysiological mechanism of this unusual weight gain. This possibility was explored in the current study undertaken to investigate the effects of dolutegravir (2.5−20 µg/mL) on several pro-inflammatory activities of neutrophils isolated from the blood of healthy, adult humans. These activities included the generation of reactive oxygen species (ROS), degranulation (elastase release) and alterations in the concentrations of cytosolic Ca2+ using chemiluminescence, spectrophotometric and fluorimetric procedures, respectively. Exposure of neutrophils to dolutegravir alone resulted in the abrupt, dose-related, and significant (p < 0.0039−p < 0.0022) generation of ROS that was attenuated by the inclusion of the Ca2+-chelating agent, EGTA, or inhibitors of NADPH oxidase (diphenyleneiodonium chloride, DPI), phospholipase C (U733122), myeloperoxidase (sodium azide) and phosphoinositol-3-kinase (wortmannin). In addition, exposure to dolutegravir augmented the release of elastase by stimulus-activated neutrophils. These pro-inflammatory effects of dolutegravir on neutrophils were associated with significant, rapid, and sustained increases in the concentrations of cytosolic Ca2+ that appeared to originate from the extracellular compartment, seemingly consistent with an ionophore-like property of dolutegravir. These findings are preliminary and necessitate verification in the clinical setting of HIV infection. Nevertheless, given the complex link between inflammation and obesity, these pro-inflammatory interactions of dolutegravir with neutrophils may contribute to unexplained weight gain, possibly via the development of insulin resistance.


Assuntos
Infecções por HIV , Inibidores de Integrase de HIV , Adulto , Humanos , Feminino , Espécies Reativas de Oxigênio/metabolismo , Infecções por HIV/tratamento farmacológico , Infecções por HIV/metabolismo , Neutrófilos , Compostos Heterocíclicos com 3 Anéis/farmacologia , Compostos Heterocíclicos com 3 Anéis/metabolismo , Inibidores de Integrase de HIV/farmacologia , Inibidores de Integrase de HIV/uso terapêutico , Elastase Pancreática/metabolismo , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo
6.
J Infect Dis ; 224(4): 673-678, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-33373447

RESUMO

This multicountry prospective study investigated whether persistent systemic inflammation, measured by 8 plasma biomarkers, in HIV-1-infected Africans during suppressive antiretroviral therapy (ART) (viral load <50 copies/mL), was associated with CD4+ T-cell recovery and viral rebound (>1000 copies/mL) during long-term treatment. On-ART sCD14 and C-reactive protein concentrations were inversely associated with subsequent CD4+ T-cell counts. Risk of viral rebound was increased for participants with higher on-ART CXCL10 concentrations and reduced for those with a greater sCD163 decline during the first year of ART. Persistent systemic inflammation predicted CD4+ T-cell recovery and viral rebound, warranting further mechanistic research in relation to clinical outcomes.


Assuntos
Fármacos Anti-HIV , Linfócitos T CD4-Positivos , Infecções por HIV , Soropositividade para HIV , Fármacos Anti-HIV/uso terapêutico , Biomarcadores , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/tratamento farmacológico , Soropositividade para HIV/tratamento farmacológico , HIV-1 , Humanos , Inflamação/tratamento farmacológico , Estudos Prospectivos , Carga Viral
7.
J Infect Dis ; 220(6): 1029-1033, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31086991

RESUMO

We evaluated immune biomarker profiles in human immunodeficiency virus (HIV)-infected adults (n = 398) from 5 African countries. Although all biomarkers decreased after antiretroviral therapy (ART) initiation, levels of C-X-C chemokine ligand 10 (CXCL10), lipopolysaccharide-binding protein, C-reactive protein, soluble CD163, and soluble scavenger receptor CD14 were significantly higher during ART than in an HIV-uninfected reference group (n = 90), indicating persistent monocyte/macrophage activation, inflammation, and microbial translocation. Before ART initiation, high HIV viral load was associated with elevated CXCL10 and tuberculosis coinfection was associated with elevated soluble CD14. High pre-ART levels of each biomarker strongly predicted residual immune activation during ART. Chemokine (C-C motif) ligand 2, lipopolysaccharide-binding protein, C-reactive protein, and interleukin 6 were differentially expressed between countries. Further research is needed on the clinical implications of residual immune dysregulation.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Antígenos CD/sangue , Antígenos de Diferenciação Mielomonocítica/sangue , Proteína C-Reativa/análise , Proteínas de Transporte/sangue , Quimiocina CCL2/sangue , Quimiocina CXCL10/sangue , Infecções por HIV/tratamento farmacológico , HIV-1/imunologia , Interleucina-6/sangue , Receptores de Lipopolissacarídeos/sangue , Glicoproteínas de Membrana/sangue , Receptores de Superfície Celular/sangue , Proteínas de Fase Aguda , Adulto , África Subsaariana , Biomarcadores/sangue , Contagem de Linfócito CD4 , Estudos de Coortes , Coinfecção/tratamento farmacológico , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , Humanos , Inflamação/sangue , Inflamação/imunologia , Masculino , Tuberculose/tratamento farmacológico , Carga Viral/efeitos dos fármacos
9.
BMC Med Ethics ; 20(1): 9, 2019 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-30678664

RESUMO

BACKGROUND: Consent processes for clinical trials involving HIV prevention research have generated considerable debate globally over the past three decades. HIV cure/eradication research is scientifically more complex and consequently, consent processes for clinical trials in this field are likely to pose a significant challenge. Given that research efforts are now moving toward HIV eradication, stakeholder engagement to inform appropriate ethics oversight of such research is timely. This study sought to establish the perspectives of a wide range of stakeholders in HIV treatment and research to inform consent processes for cure research. METHODS: In total, 68 South African stakeholders participated in two qualitative research modalities. In-depth interviews (IDIs) were conducted with a purposive sample of 42 individuals - audiotaped with consent. Twenty-six stakeholders participated in three focus group discussions (FGDs). Thematic analysis of transcribed IDIs and FGDs was conducted. RESULTS: The majority of respondents indicated that there could be unique challenges in HIV cure research requiring special attention. In particular, given the complexity of cure science, translation of concepts into lay language would be critical for potential participants to adequately appreciate risks and benefits in early phase research with experimental interventions. Furthermore, to aid understanding of risks and benefits against a background of desperation for a cure, specially trained facilitators would be required to assist with a psychological assessment prior to consent to avoid curative misconceptions. Long-term participant engagement to assess durability of a cure would mean that the consent process would be prolonged, necessitating annual re-consent. Building trust to maintain such long-term relationships would be critical to retain study participants. CONCLUSION: Unique consent requirements for cure research in South Africa would include significant efforts to maximise understanding of trial procedures, risks and the need for long-term follow-up. However, the psychological dimension of cure must not be underestimated. Beyond an understanding of cure science, the emotional impact of HIV cure advances the discourse from cure to healing. Consequently, the consent process for cure research would need to be enhanced to include psychological support and counselling. This has several important implications for research ethics review requirements for consent in HIV cure research.


Assuntos
Pesquisa Biomédica/ética , Ensaios Clínicos como Assunto/ética , Erradicação de Doenças , Ética em Pesquisa , Infecções por HIV/prevenção & controle , Consentimento Livre e Esclarecido/ética , Pesquisadores/ética , Sujeitos da Pesquisa/psicologia , Atenção à Saúde , Infecções por HIV/psicologia , Humanos , Consentimento Livre e Esclarecido/psicologia , Seleção de Pacientes/ética , Pesquisa Qualitativa , África do Sul
10.
Mediators Inflamm ; 2018: 8357109, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30622435

RESUMO

Like HIV infection, smoking, which is common among HIV-infected persons, is associated with chronic, systemic inflammation. However, the possible augmentative effects of HIV infection and smoking and other types of tobacco usage on indices of systemic inflammation and the impact of combination antiretroviral therapy (cART) thereon remain largely unexplored and represent the focus of the current study. Of the total number of HIV-infected persons recruited to the study (n = 199), 100 were categorised as pre-cART and 99 as virally suppressed (HIV viral load < 40 copies/mL). According to serum cotinine levels, 144 and 55 participants were categorised as nonusers and users of tobacco, respectively. In addition to cytokines (IL-6, IL-8, and TNF-α) and chemokines (IP-10, MIG, IL-8, MCP-1, and RANTES), other biomarkers of systemic inflammation included C-reactive protein (CRP), ß2-microglobulin, and those of neutrophil activation [ICAM-1, L-selectin, matrix metalloproteinase-9 (MMP-9)], microbial translocation (soluble CD14, LPS-binding protein), and oxidative stress (cyclophilin A, surfactant D). These were measured using multiplex bead array, ELISA, and immunonephelometric procedures. Viral suppression was associated with significant decreases in the levels of most of the biomarkers tested (P < 0.0037-0.0008), with the exceptions of CRP, cyclophilin A, and MMP-9. With respect to tobacco usage, irrespective of cART status, circulating levels of ß2-microglobulin, cyclophilin A, and RANTES were significantly elevated (P < 0.042-0.012) in users vs nonusers. Additional analysis of the groups of tobacco users and nonusers according to cART status revealed high levels of RANTES in pre-cART/tobacco users relative to the three other subgroups (P < 0.004-0.0001), while more modest increases in cyclophilin A and MMP-9 (P < 0.019-0.027) were observed in comparison with the cART/tobacco user subgroup. Notwithstanding the efficacy of cART in attenuating HIV-associated, chronic systemic inflammation, the current study has identified RANTES as being significantly and seemingly selectively increased in those with active HIV infection who use tobacco, a mechanism which may underpin augmentative proinflammatory activity.


Assuntos
Terapia Antirretroviral de Alta Atividade/métodos , Biomarcadores/metabolismo , Infecções por HIV/metabolismo , Nicotiana , Fármacos Anti-HIV/uso terapêutico , Antirretrovirais/uso terapêutico , Proteína C-Reativa/metabolismo , Infecções por HIV/tratamento farmacológico , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo
11.
Mediators Inflamm ; 2016: 9026573, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27019552

RESUMO

Little is known about immune activation profiles of children infected with HIV-1 subtype C. The current study compared levels of selected circulating biomarkers of immune activation in HIV-1 subtype C-infected untreated mothers and their children with those of healthy controls. Multiplex bead array, ELISA, and immunonephelometric procedures were used to measure soluble CD14 (sCD14), beta-2 microglobulin (ß2M), CRP, MIG, IP-10, and transforming growth factor beta 1 (TGF-ß1). Levels of all 6 biomarkers were significantly elevated in the HIV-infected mothers and, with the exception of MIG, in their children (P < 0.01-P < 0.0001). The effects of antiretroviral therapy (ART) and maternal smoking on these biomarkers were also assessed. With the exception of TGF-ß1, which was unchanged in the children 12 months after therapy, initiation of ART was accompanied by decreases in the other biomarkers. Regression analysis revealed that although most biomarkers were apparently unaffected by smoking, exposure of children to maternal smoking was associated with a significant increase in IP-10. These findings demonstrate that biomarkers of immune activation are elevated in HIV-infected children pre-ART and decline, with the exception of TGF-ß1, after therapy. Although preliminary, elevation of IP-10 in smoke-exposed infants is consistent with a higher level of immune activation in this group.


Assuntos
Biomarcadores/sangue , Infecções por HIV/sangue , Adulto , Terapia Antirretroviral de Alta Atividade , Proteína C-Reativa/metabolismo , Quimiocina CXCL10/sangue , Quimiocina CXCL9/sangue , Criança , Pré-Escolar , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Lactente , Masculino , Mães , Fator de Crescimento Transformador beta1/sangue , Adulto Jovem
12.
BMC Med Ethics ; 17(1): 26, 2016 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-27137204

RESUMO

BACKGROUND: The ethical concerns associated with HIV prevention and treatment research have been widely explored in South Africa over the past 3 decades. However, HIV cure research is relatively new to the region and significant ethical and social challenges are anticipated. There has been no published empirical enquiry in Africa into key informant perspectives on HIV cure research. Consequently, this study was conducted to gain preliminary data from South African HIV clinicians, researchers and activists. METHODS: In-depth interviews were conducted on a purposive sample of fourteen key informants in South Africa. Audiotaped interviews were transcribed verbatim with concurrent thematic analysis. The perspectives of HIV clinicians, researchers and activists were captured. Analyst triangulation occurred as the data were analysed by three authors independently. RESULTS: The rapid evolution of HIV cure research agendas was prominent with participants expressing some concern that the global North was driving the cure agenda. Participants described a symbiotic relationship between cure, treatment and prevention research necessitating collaboration. Assessing and managing knowledge and expectations around HIV cure research emerged as a central theme related to challenges to constructing 'cure' - how patients understand the idea of cure is important in explaining the complexity of cure research especially in the South African context where understanding of science is often challenging. Managing expectations and avoiding curative misconception will have implications for consent processes. Unique strategies in cure research could include treatment interruption, which has the potential to create therapeutic and ethical conflict and will be perceived as a significant risk. Ethical challenges in cure research will impact on informed consent and community engagement. CONCLUSIONS: It was encouraging to note the desire for synergy amongst researchers and clinicians working in the fields of prevention, treatment and cure. Translation of complex HIV cure science into lay language is critical. Moving forward, RECs must be adequately constituted with scientific expertise and community representation when reviewing cure protocols. It is hoped that knowledge and resource sharing in the context of collaboration between research scientists working in cure and those working in treatment and prevention will accelerate progress towards cure.


Assuntos
Atitude , Pesquisa Biomédica/ética , Ética em Pesquisa , Infecções por HIV , Defesa do Paciente , Médicos , Pesquisadores , Erradicação de Doenças , Feminino , Infecções por HIV/prevenção & controle , Infecções por HIV/terapia , Humanos , Masculino , Sujeitos da Pesquisa , África do Sul
13.
Eur Respir J ; 46(6): 1781-95, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26250491

RESUMO

HIV-infected persons not only have higher rates of smoking than the general population, but are also unusually vulnerable to the associated adverse health effects, both infective and noninfective in origin. Indeed, in the setting of well-organised care and availability of highly active antiretroviral therapy, HIV-infected smokers lose more life-years to smoking than to HIV infection per se, presenting a major challenge to healthcare providers. Not surprisingly, the respiratory system is particularly susceptible to the damaging interactive chronic inflammatory and immunosuppressive effects of HIV and smoking, intensifying the risk of the development of opportunistic infections, as well as lung cancer and obstructive lung disorders. The impact of smoking on the immunopathogenesis and frequencies of these respiratory conditions in the setting of HIV infection, as well as on the efficacy of antiretroviral therapy, represent the primary focus of this review.


Assuntos
Infecções por HIV/imunologia , Imunidade nas Mucosas/imunologia , Hospedeiro Imunocomprometido/imunologia , Pneumopatias/imunologia , Pulmão/imunologia , Fumar/imunologia , Terapia Antirretroviral de Alta Atividade , Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/tratamento farmacológico , Humanos , Inflamação/imunologia , Neoplasias Pulmonares/imunologia , Monócitos/imunologia , Neutrófilos/imunologia , Doença Pulmonar Obstrutiva Crônica/imunologia
14.
BMC Infect Dis ; 15: 430, 2015 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-26475133

RESUMO

BACKGROUND: Intestinal macrophages are key regulators of inflammatory responses to the gut microbiome and play a central role in maintaining tissue homeostasis and epithelial integrity. However, little is known about the role of these cells in HIV infection, a disease fuelled by intestinal inflammation, a loss of epithelial barrier function and increased microbial translocation (MT). METHODS: Phenotypic and functional characterization of intestinal macrophages was performed for 23 African AIDS patients with chronic diarrhea and/or weight loss and 11 HIV-negative Africans with and without inflammatory bowel disease (IBD). AIDS patients were treated with cotrimoxazole for the prevention of opportunistic infections (OIs). Macrophage phenotype was assessed by flow cytometry and immuno-histochemistry (IHC); production of proinflammatory mediators by IHC and Qiagen PCR Arrays; in vitro secretion of cytokines by the Bio-Plex Suspension Array System. Statistical analyses were performed using Spearman's correlation and Wilcoxon matched-pair tests. Results between groups were analyzed using the Kruskal-Wallis with Dunn's post-test and the Mann-Whitney U tests. RESULTS: None of the study participants had evidence of enteric co-infections as assessed by stool analysis and histology. Compared to healthy HIV-negative controls, the colon of AIDS patients was highly inflamed with increased infiltration of inflammatory cells and increased mRNA expression of proinflammatory cytokine (tumour necrosis factor (TNF)-α, interleukin (IL)-1ß, IFN-γ, and IL-18), chemokines (chemokine (C-C motif) ligand (CCL)2 and chemokine (C-X-C) motif ligand (CXCL)10) and transcription factors (TNF receptor-associated factor (TRAF)6 and T-box (TXB)21). IHC revealed significant co-localization of TNF-α and IL-1ß with CD68(+) cells. As in IBD, HIV was associated with a marked increase in macrophages expressing innate response receptors including CD14, the co-receptor for lipopolysaccharide (LPS). The frequency of CD14(+) macrophages correlated positively with plasma LPS, a marker of MT. Total unfractionated mucosal mononuclear cells (MMC) isolated from the colon of AIDS patients, but not MMC depleted of CD14(+) cells, secreted increased levels of proinflammatory cytokines ex vivo in response to LPS. CONCLUSIONS: Intestinal macrophages, in the absence of overt OIs, play an important role in driving persistent inflammation in HIV patients with late-stage disease and diarrhea. These results suggest intensified treatment strategies that target inflammatory processes in intestinal macrophages may be highly beneficial in restoring the epithelial barrier and limiting MT in HIV-infected patients.


Assuntos
Síndrome da Imunodeficiência Adquirida/patologia , Colo/imunologia , Citocinas/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Macrófagos/imunologia , Síndrome da Imunodeficiência Adquirida/imunologia , Adulto , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Quimiocinas/genética , Quimiocinas/metabolismo , Coinfecção/patologia , Colo/microbiologia , Colo/patologia , Citocinas/genética , Feminino , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Inflamação , Doenças Inflamatórias Intestinais/patologia , Lipopolissacarídeos/toxicidade , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Mucosa/metabolismo , RNA Mensageiro/metabolismo , Células Th1/imunologia , Células Th1/metabolismo , Fator de Necrose Tumoral alfa
15.
Mediators Inflamm ; 2014: 198413, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24808634

RESUMO

Few studies have examined immune activation profiles in patients with advanced HIV-1 subtype C infection or assessed their potential to predict responsiveness to HAART. BioPlex, ELISA, and nephelometric procedures were used to measure plasma levels of inflammatory biomarkers in HIV-1 subtype C-infected patients sampled before and after 6 months of successful HAART (n = 20); in patients failing HAART (n = 30); and in uninfected controls (n = 8). Prior to HAART, CXCL9, CXCL10, ß 2M, sTNF-R1, TGF- ß 1, IFN- γ , IL-6, TNF, and sCD14 were significantly elevated in HIV-1-infected patients compared to controls (P < 0.01). All of these markers, with the exception of sTNF-R1, were also elevated in patients failing HAART (P < 0.05). The persistently elevated levels of CXCL9, CXCL10, and ß 2M in patients failing therapy in the setting of a marked reduction in these markers in patients on successful HAART suggest that they may be useful not only to monitor immune activation during HAART, but also to distinguish between good and poor responders. In the case of sCD14 and TGF- ß 1, the levels of these biomarkers remained persistently elevated despite HAART-induced virological suppression, a finding that is consistent with ongoing monocyte-macrophage activation, underscoring a potential role for adjuvant anti-inflammatory therapy.


Assuntos
Biomarcadores/sangue , Infecções por HIV/sangue , HIV-1/efeitos dos fármacos , Adulto , Terapia Antirretroviral de Alta Atividade , Quimiocina CXCL10/sangue , Quimiocina CXCL9/sangue , Feminino , HIV-1/patogenicidade , Humanos , Interferon gama/sangue , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , Fator de Crescimento Transformador beta1/sangue , Adulto Jovem
16.
BMC Health Serv Res ; 14: 116, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24606875

RESUMO

BACKGROUND: Antiretroviral drug resistance is becoming increasingly common with the expansion of human immunodeficiency virus (HIV) treatment programmes in high prevalence settings. Genotypic resistance testing could have benefit in guiding individual-level treatment decisions but successful models for delivering resistance testing in low- and middle-income countries have not been reported. METHODS: An HIV Treatment Failure Clinic model was implemented within a large primary health care HIV treatment programme in northern KwaZulu-Natal, South Africa. Genotypic resistance testing was offered to adults (≥16 years) with virological failure on first-line antiretroviral therapy (one viral load >1000 copies/ml after at least 12 months on a standard first-line regimen). A genotypic resistance test report was generated with treatment recommendations from a specialist HIV clinician and sent to medical officers at the clinics who were responsible for patient management. A quantitative process evaluation was conducted to determine how the model was implemented and to provide feedback regarding barriers and challenges to delivery. RESULTS: A total of 508 specimens were submitted for genotyping between 8 April 2011 and 31 January 2013; in 438 cases (86.2%) a complete genotype report with recommendations from the specialist clinician was sent to the medical officer. The median turnaround time from specimen collection to receipt of final report was 18 days (interquartile range (IQR) 13-29). In 114 (26.0%) cases the recommended treatment differed from what would be given in the absence of drug resistance testing. In the majority of cases (n = 315, 71.9%), the subsequent treatment prescribed was in line with the recommendations of the report. CONCLUSIONS: Genotypic resistance testing was successfully implemented in this large primary health care HIV programme and the system functioned well enough for the results to influence clinical management decisions in real time. Further research will explore the impact and cost-effectiveness of different implementation models in different settings.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Testes de Sensibilidade Microbiana , Adulto , Fármacos Anti-HIV/administração & dosagem , Farmacorresistência Viral , Feminino , Genótipo , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Humanos , Masculino , Testes de Sensibilidade Microbiana/métodos , Atenção Primária à Saúde/organização & administração , Serviços de Saúde Rural/organização & administração , África do Sul/epidemiologia , Falha de Tratamento
17.
BMC Med Ethics ; 15: 25, 2014 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-24666413

RESUMO

BACKGROUND: Misconduct in research tarnishes the reputation, credibility and integrity of research institutions. Studies on research or scientific misconduct are still novel in developing countries. In this study, we report on the attitudes, perceptions and factors related to the work environment thought to be associated with research misconduct in a group of researchers in Nigeria - a developing country. METHOD: A survey of researchers attending a scientific conference was done using an adapted Scientific Misconduct Questionnaire-Revised (SMQ-R). Initial descriptive analysis of individual items using frequencies and proportions for all quantitative data was performed. Thereafter, Likert scale responses were transformed into dichotomous responses. Fisher exact test was performed for associations as appropriate. A two-tailed p-value of less than 0.05 was accepted as significant. RESULT: Half of the respondents (50.4%) were aware of a colleague who had committed misconduct, defined as "non-adherence to rules, regulations, guidelines, and commonly accepted professional codes or norms". Over 88% of the researchers were concerned about the perceived amount of misconduct prevalent in their institution and 96.2% believed that one or more forms of scientific misconduct had occurred in their workplace. More than half (52.7%) rated the severity of penalties for scientific misconduct in their work environment as low. Furthermore¸ the majority (56.1%) were of the view that the chance of getting caught for scientific misconduct in their work environment was low. CONCLUSION: Researchers in Nigeria perceive that scientific misconduct is commonplace in their institutions, but are however worried about the negative effects of scientific misconduct on the credibility of scientific research. We recommend that researchers be empowered with the knowledge and virtues necessary for self-regulation that advance research integrity. Research institutions should however also step into their role of fostering a responsible research ethic and discouraging misconduct.


Assuntos
Academias e Institutos , Pesquisa Biomédica/ética , Pesquisadores/ética , Má Conduta Científica/ética , Academias e Institutos/ética , Academias e Institutos/normas , Atitude do Pessoal de Saúde , Ética em Pesquisa , Feminino , Humanos , Masculino , Nigéria , Pesquisadores/psicologia , Inquéritos e Questionários
18.
BMC Med Ethics ; 15: 4, 2014 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-24447822

RESUMO

BACKGROUND: The use of biological samples in research raises a number of ethical issues in relation to consent, storage, export, benefit sharing and re-use of samples. Participant perspectives have been explored in North America and Europe, with only a few studies reported in Africa. The amount of research being conducted in Africa is growing exponentially with volumes of biological samples being exported from the African continent. In order to investigate the perspectives of African research participants, we conducted a study at research sites in the Western Cape and Gauteng, South Africa. METHODS: Data were collected using a semi-structured questionnaire that captured both quantitative and qualitative information at 6 research sites in South Africa. Interviews were conducted in English and Afrikaans. Data were analysed both quantitatively and qualitatively. RESULTS: Our study indicates that while the majority of participants were supportive of providing samples for research, serious concerns were voiced about future use, benefit sharing and export of samples. While researchers view the provision of biosamples as a donation, participants believe that they still have ownership rights and are therefore in favour of benefit sharing. Almost half of the participants expressed a desire to be re-contacted for consent for future use of their samples. Interesting opinions were expressed with respect to export of samples. CONCLUSIONS: Eliciting participant perspectives is an important part of community engagement in research involving biological sample collection, export, storage and future use. A tiered consent process appears to be more acceptable to participants in this study. Eliciting opinions of researchers and research ethics committee (REC) members would contribute multiple perspectives. Further research is required to interrogate the concept of ownership and the consent process in research involving biological samples.


Assuntos
Pesquisa Biomédica/ética , Revelação/ética , Consentimento Livre e Esclarecido/ética , Propriedade/ética , Sujeitos da Pesquisa , Manejo de Espécimes/ética , Bancos de Tecidos/ética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Atitude , Comitês de Ética em Pesquisa , Ética em Pesquisa , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Qualitativa , Sujeitos da Pesquisa/psicologia , África do Sul , Inquéritos e Questionários
19.
J Infect Dis ; 208(7): 1113-22, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23749968

RESUMO

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) infection is associated with a massive depletion of intestinal CD4(+) T cells that is only partially reversed by combination antiretroviral therapy (cART). Here, we assessed the ability of nucleoside reverse-transcriptase inhibitor/nonnucleoside reverse-transcriptase inhibitor treatment to restore the CD4(+) T-cell populations in the intestine of South African patients with AIDS. METHODS: Thirty-eight patients with advanced HIV-1 infection who had chronic diarrhea (duration, >4 weeks) and/or unintentional weight loss (>10% decrease from baseline) of uncertain etiology were enrolled. Blood specimens were collected monthly, and gastrointestinal tract biopsy specimens were collected before cART initiation (from the duodenum, jejunum, ileum, and colon), 3 months after cART initiation (from the duodenum), and 6 months after cART initiation (from the duodenum and colon). CD4(+), CD8(+), and CD38(+)CD8(+) T cells were quantified by flow cytometry and immunohistochemistry analyses, and the HIV-1 RNA load was determined by the Nuclisens assay. RESULTS: CD4(+) T-cell and HIV-1 RNA levels were significantly lower, whereas CD8(+) T-cell levels, including activated CD38(+)CD8(+) T cell levels, were higher in the duodenum and jejunum, compared with the colon. After 6 months of cART, a significant but incomplete recovery of CD4(+) T cells was detected in the colon and peripheral blood but not in the duodenum. Failed restoration of the CD4(+) T-cell count in the duodenum was associated with nonspecific enteritis and CD8(+) T-cell activation. CONCLUSIONS: Strategies that target inflammation and immune activation in the small intestine may be required to expedite CD4(+) T-cell recovery and improve therapeutic outcomes.


Assuntos
Antirretrovirais/uso terapêutico , Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Mucosa Intestinal/imunologia , Intestino Grosso/imunologia , Intestino Delgado/imunologia , Adulto , Terapia Antirretroviral de Alta Atividade/métodos , Biópsia , Linfócitos T CD8-Positivos/imunologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , África do Sul , Resultado do Tratamento , Adulto Jovem
20.
Viruses ; 16(2)2024 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-38400088

RESUMO

HIV-exposed, uninfected (HEU) children present with suboptimal growth and a greater susceptibility to infection in early life when compared to HIV-unexposed, uninfected (HUU) children. The reasons for these findings are poorly understood. We used a metabolomics approach to investigate the metabolic differences between pregnant women living with HIV (PWLWH) and their HEU infants compared to the uninfected and unexposed controls. Untargeted metabolomic profiling was performed using 1H-NMR spectroscopy on maternal plasma at 28 weeks' gestation and infant plasma at birth, 6/10 weeks, and 6 months. PWLWH were older but, apart from a larger 28 week mid-upper-arm circumference, anthropometrically similar to the controls. At all the time points, HEU infants had a significantly reduced growth compared to HUU infants. PWLWH had lower plasma 3-hydroxybutyric acid, acetoacetic acid, and acetic acid levels. In infants at birth, threonine and myo-inositol levels were lower in the HEU group while formic acid levels were higher. At 6/10 weeks, betaine and tyrosine levels were lower in the HEU group. Finally, at six months, 3-hydroxyisobutyric acid levels were lower while glycine levels were higher in the HEU infants. The NMR analysis has provided preliminary information indicating differences between HEU and HUU infants' plasma metabolites involved in energy utilization, growth, and protection from infection.


Assuntos
Infecções por HIV , Lactente , Recém-Nascido , Criança , Humanos , Feminino , Gravidez , Infecções por HIV/prevenção & controle , Mães , Betaína , Metabolômica
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