1,163 research outputs found
Human herpesvirus 8 replicates in primary B lymphocytes and induces polyfunctional cytokine and chemokine responses
CD4 regulatory T cells Control CD8 T cell responses to human Herpesvirus 8 lytic and latency proteins
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Oral Cytokine Levels Are More Linked to Levels of Plasma and Oral HIV-1 RNA Than to CD4+ T-Cell Counts in People With HIV.
BackgroundWe determined the levels of 11 soluble immune mediators in oral washings of AIDS Clinical Trials Group A5254 participants with varying degrees of plasma viremia and CD4 T-cell counts to characterize the mucosal immune response at different stages of HIV-1 infection.MethodsA5254 was a multicenter, cross-sectional study in people with HIV (PWH) recruited into 4 strata based on CD4 count and levels of plasma viremia: stratum (St) A: CD4 ≤200 cells/mm3, HIV-1 RNA (viral load [VL]) >1000 cps/mL; St B: CD4 ≤200, VL ≤1000; St C: CD4 >200, VL >1000; St D: CD4 >200, VL ≤1000. Oral/throat washings were obtained from all participants. Soluble markers were tested in oral/throat washings using a multibead fluorescent platform and were compared across strata. Linear regression was used to determine the associations between cytokines and HIV-1 in plasma and oral fluid.ResultsSt A participants had higher levels of interleukin (IL)-1β, IL-6, IL-17, tumor necrosis factor alpha (TNFα), and interferon gamma (IFNγ) compared with St B and D (P = .02; P < .0001) but were not different from St C. IL-8, IL-10, and IL-12 were elevated in St A compared with the other 3 strata (P = .046; P < .0001). Linear regression demonstrated that oral HIV-1 levels were associated with IL-1β, IL-6, IL-8, and TNFα production (R > .40; P < .001) when controlling for CD4 count and opportunistic infections.ConclusionsOur results show that high levels of oral HIV-1, rather than low CD4 counts, were linked to the production of oral immune mediators. Participants with AIDS and uncontrolled viremia demonstrated higher levels of pro- and anti-inflammatory soluble immune mediators compared with participants with lower HIV-1 RNA. The interplay of HIV-1 and these immune mediators could be important in the oral health of PWH
EVALUATION OF THE RELATIONSHIP BETWEEN MORPHOLOGICAL CHARACTERISTICS AND PULLOUT RESISTANCE OF LIVE CUTTINGS OF Phyllanthus sellowianus (Klotzsch) MĂĽll.Arg.
This study aimed to evaluate the interdependence between the morphological characteristics and the pullout resistance of live cuttings of Phyllanthus sellowianus. Vertical pullout tests and shoot and root diameter and length measurements were performed in 144 live cuttings, with 2.5 cm in diameter and 50 cm in length, planted in 1x1 m spacing. The evaluations were performed at 60, 133, 186, 252, 320, and 421 days after planting, and the differences between mean growth and vertical pullout resistance values were analyzed using the Tukey test and linear regression equations. The plants showed the highest mean total shoot length (875 cm), total root length (405 cm), and vertical pullout resistance (1.5 kN) values between 252 and 421 days after planting. The plants increased their pullout resistance at an average rate of 0.20 kN/month in the most favorable growth periods, followed by average increments in the total shoot and root length of 118.4 and 57.1 cm/month, respectively. The pullout resistance showed positive correlations with all above- and below-ground morphological characteristics tested, but it was best explained by the cross-sectional area of shoots (mm²) which showed r² = 0.55. The biometric variables of P. sellowianus propagated from cuttings generally explained up to half of the variations in the species’ pullout resistance.
Regulatory T Cell Suppression of Gag-Specific CD8+ T Cell Polyfunctional Response After Therapeutic Vaccination of HIV-1-Infected Patients on ART
We tested the hypothesis that therapeutic vaccination against HIV-1 can increase the frequency and suppressive function of regulatory, CD4+ T cells (Treg), thereby masking enhancement of HIV-1-specific CD8+ T cell response. HIV-1-infected subjects on antiretroviral therapy (N = 17) enrolled in a phase I therapeutic vaccine trial received 2 doses of autologous dendritic cells (DC) loaded with HIV-1 peptides. The frequency of CD4+CD25hiFOXP3+ Treg in blood was determined prior to and after vaccination in subjects and normal controls. Polyfunctional CD8+ T cell responses were determined pre- and post-vaccine (N = 7) for 5 immune mediators after in vitro stimulation with Gag peptide, staphylococcal enterotoxin B (SEB), or medium alone. Total vaccine response (post-vaccine–pre-vaccine) was compared in the Treg(+) and Treg-depleted (Treg-) sets. After vaccination, 12/17 subjects showed a trend of increased Treg frequency (P = 0.06) from 0.74% to 1.2%. The increased frequency did not correlate with CD8+ T cell vaccine response by enzyme linked immunosorbent assay for interferon γ production. Although there was no significant change in CD8+ T cell polyfunctional response after vaccination, Treg depletion increased the polyfunctionality of the total vaccine response (P = 0.029), with a >2-fold increase in the percentage of CD8+ T cells producing multiple immune mediators. In contrast, depletion of Treg did not enhance polyfunctional T cell response to SEB, implying specificity of suppression to HIV-1 Gag. Therapeutic immunization with a DC-based vaccine against HIV-1 caused a modest increase in Treg frequency and a significant increase in HIV-1-specific, Treg suppressive function. The Treg suppressive effect masked an increase in the vaccine-induced anti-HIV-1-specific polyfunctional response. The role of Treg should be considered in immunotherapeutic trials of HIV-1 infection
Detection of HIV-1 RNA/DNA and CD4 mRNA in feces and urine from chronic HIV-1 infected subjects with and without anti-retroviral therapy
HIV-1 infects gut associated lymphoid tissues (GALT) very early after transmission by multiple routes. The infected GALT consequently serves as the major reservoir for HIV-1 infection and could constantly shed HIV-1 and CD4+ T cells into the intestinal lumen. To examine this hypothesis, we monitored HIV-1 RNA/DNA and CD4 mRNA in fecal samples of chronically infected subjects with and without antiretroviral therapy (ART). We compared this to levels of HIV-1 RNA/DNA in urine and blood from the same subjects. Our results show that HIV-1 DNA, RNA and CD4 mRNA were detected in 8%, 19% and 31% respectively, of feces samples from infected subjects with detectable plasma viral load, and were not detected in any of subjects on ART with undetectable plasma viral load. In urine samples, HIV-1 DNA was detected in 24% of infected subjects with detectable plasma viral load and 23% of subjects on ART with undetectable plasma viral load. Phylogenetic analysis of the envelope sequences of HIV-1 revealed distinct virus populations in concurrently collected serum, feces and urine samples from one subject. In addition, our study demonstrated for the first time the presence of CD4 mRNA in fecal specimens of HIV-1 infected subjects, which could be used to assess GALT pathogenesis in HIV-1 infection
Dendritic Cells Reveal a Broad Range of MHC Class I Epitopes for HIV-1 in Persons with Suppressed Viral Load on Antiretroviral Therapy
Background: HIV-1 remains sequestered during antiretroviral therapy (ART) and can resume high-level replication upon cessation of ART or development of drug resistance. Reactivity of memory CD8+ T lymphocytes to HIV-1 could potentially inhibit this residual viral replication, but is largely muted by ART in relation to suppression of viral antigen burden. Dendritic cells (DC) are important for MHC class I processing and presentation of peptide epitopes to memory CD8+ T cells, and could potentially be targeted to activate memory CD8+ T cells to a broad array of HIV-1 epitopes during ART. Principal Findings: We show for the first time that HIV-1 peptide-loaded, CD40L-matured DC from HIV-1 infected persons on ART induce IFN gamma production by CD8+ T cells specific for a much broader range and magnitude of Gag and Nef epitopes than do peptides without DC. The DC also reveal novel, MHC class I restricted, Gag and Nef epitopes that are able to induce polyfunctional T cells producing various combinations of IFN gamma, interleukin 2, tumor necrosis factor alpha, macrophage inhibitory protein 1 beta and the cytotoxic de-granulation molecule CD107a. Significance: There is an underlying, broad antigenic spectrum of anti-HIV-1, memory CD8+ T cell reactivity in persons on ART that is revealed by DC. This supports the use of DC-based immunotherapy for HIV-1 infection. © 2010 Huang et al
INK- JET PRINTING DEVICE
An ink-jet printing device (1) is described, said device
comprising a first reservoir (4) designed to contain a first
volume of printing fluid at a first height with respect to a
reference plane, a supply system for forcing the printing
fluid towards the first reservoir (4) and a second reservoir
(5) designed to contain a second volume of printing fluid at
a second height with respect to the reference plane. The
second height is less than the first height. The device also
comprises a conduit (2) designed to receive the printing
fluid from the first reservoir (4) and conveys it towards the
second reservoir (5) and an ejection plane in which ejector
units (3) lie. The ejection plane is arranged in a position
higher than the average of the first height and the second
height, so as to generate a back pressure in the ejector units (3). The flow rate of the printing fluid is
between about 5 and about 10 times the maximum flowrate which can be ejected from said ejector units. The printing fluid may be a ceramic ink
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