To determine the protective potential of the humoral immune response against HIV-1 in vivo we evaluated the potency of three neutralizing antibodies (2G12, 2F5 and 4E10) in suppressing viral rebound in six acutely and eight chronically HIV-1-infected individuals undergoing interruption of antiretroviral treatment (ART). Only two of eight chronically infected individuals showed evidence of a delay in viral rebound during the passive immunization. Rebound in antibody-treated acutely infected individuals upon cessation of ART was substantially later than in a control group of 12 individuals with acute infection. Escape mutant analysis showed that the activity of 2G12 was crucial for the in vivo effect of the neutralizing antibody cocktail. By providing further direct evidence of the potency, breadth and titers of neutralizing antibodies that are required for in vivo activity, these data underline both the potential and the limits of humoral immunity in controlling HIV-1 infection.
In persistent viral infections, the host's immune system is challenged by the constant exposure to antigen, potentially causing continuous activation of CD8 ؉ T cells with subsequent immunopathology. Here we demonstrate, for experimental chronic lymphocytic choriomeningitis virus and human HIV infection, that upon prolonged in vivo exposure to antigen, TCR-triggered Ca 2؉ flux, degranulation, and cytotoxicity are maintained on a cellular level, whereas cytokine production is severely impaired because of a selective defect in activation-induced NFAT nuclear translocation. During chronic infection, this differential regulation of pathways leading to diverse effector functions may allow CD8 ؉ T cells to sustain some degree of local viral control by direct cytotoxicity while limiting systemic immune pathology by silencing cytokine production.dysfunction ͉ cytotoxic T lymphocyte ͉ persistent infection ͉ cytokine production
Progressive human immunodeficiency virus type 1 (HIV-1) infection is often associated with high plasma virus load (pVL) and impaired CD8؉ T-cell function; in contrast, CD8 ؉ T cells remain polyfunctional in long-term nonprogressors. However, it is still unclear whether CD8 ؉ T-cell dysfunction is the cause or the consequence of high pVLs. Here, we conducted a longitudinal functional and phenotypic analysis of virusspecific CD8؉ T cells in a cohort of patients with chronic HIV-1 infection. During the initiation and maintenance of successful antiretroviral therapy (ART), we assessed whether the level of pVL was associated with the degree of CD8 ؉ T-cell dysfunction. Under viremic conditions, HIV-specific CD8 ؉ T cells were dysfunctional with respect to cytokine secretion (gamma interferon, interleukin-2 [IL-2], and tumor necrosis factor alpha), and their phenotype suggested limited potential for proliferation. During ART, cytokine secretion by HIVspecific CD8؉ T cells was gradually restored, IL-7R␣ and CD28 expression increased dramatically, and PD-1 levels declined. Thus, prolonged ART-induced reduction of viral replication and, hence, presumably antigen exposure in vivo, allows a significant functional restoration of CD8 ؉ T cells with the appearance of polyfunctional cells. These findings indicate that the level of pVL as a surrogate for antigen load has a dominant influence on the phenotypic and functional profile of virus-specific CD8 ؉ T cells.
BackgroundTackling the high non-communicable disease (NCD) burden among Syrian refugees poses a challenge to humanitarian actors and host countries. Current response priorities are the identification and integration of key interventions for NCD care into humanitarian programs as well as sustainable financing. To provide evidence for effective NCD intervention planning, we conducted a cross-sectional survey among non-camp Syrian refugees in northern Jordan to investigate the burden and determinants for high NCDs prevalence and NCD multi-morbidities and assess the access to NCD care.MethodsWe used a two-stage cluster design with 329 randomly selected clusters and eight households identified through snowball sampling. Consenting households were interviewed about self-reported NCDs, NCD service utilization, and barriers to care.We estimated the adult prevalence of hypertension, diabetes type I/II, cardiovascular- and chronic respiratory conditions, thyroid disease and cancer and analysed the pattern of NCD multi-morbidities. We used the Cox proportional hazard model to calculate the prevalence ratios (PR) to analyse determinants for NCD prevalence and logistic regression to determine risk factors for NCD multi-morbidities by calculating odds ratios (ORs).ResultsAmong 8041 adults, 21.8%, (95% CI: 20.9–22.8) suffered from at least one NCD; hypertension (14.0, 95% CI: 13.2–14.8) and diabetes (9.2, 95% CI: 8.5–9.9) were the most prevalent NCDs. NCD multi-morbidities were reported by 44.7% (95% CI: 42.4–47.0) of patients. Higher age was associated with higher NCD prevalence and the risk for NCD-multi-morbidities; education was inversely associated.Of those patients who needed NCD care, 23.0% (95% CI: 20.5–25.6) did not seek it; 61.5% (95% CI: 54.7–67.9) cited provider cost as the main barrier. An NCD medication interruption was reported by 23.1% (95% CI: 20–4-26.1) of patients with regular medication needs; predominant reason was unaffordability (63.4, 95% CI: 56.7–69.6).ConclusionThe burden of NCDs and multi-morbidities is high among Syrian refugees in northern Jordan. Elderly and those with a lower education are key target groups for NCD prevention and care, which informs NCD service planning and developing patient-centred approaches.Important unmet needs for NCD care exist; removing the main barriers to care could include cost-reduction for medications through humanitarian pricing models. Nevertheless, it is still essential that international donors agencies and countries fulfill their commitment to support the Syrian-crisis response.Electronic supplementary materialThe online version of this article (10.1186/s13031-018-0168-7) contains supplementary material, which is available to authorized users.
Xpert MTB/RIF is a major advance for TB diagnostics, especially for multidrug-resistant (MDR) TB and HIV-associated TB. But implementation concerns including cost, technical support requirements, and challenging demands of providing second-line TB drugs for diagnosed MDR-TB cases call for gradual, careful introduction based on country circumstances.
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