The breakdown of the cytokine network subsequent to human immunodeficiency virus infection

The acquired immunodeflciency syndrome (AIDS) is a clinically multifaceted disease induced by infection with the human immunodeficiency virus (HIV). HIV infection results in a complex pattern of immunologic alterations that leads to the development of AIDS in the majority of HIV seropositive (HIV+) individuals. The reduction in CD4 T lymphocyte counts is the hallmark of HIV infection; nevertheless, long before the reduction in CD4 counts reaches critical levels, a series of profound and complex defects that impair the function of CD4 T lymphocytes can be detected. Thus, HIV infection is characterized by quantitative and qualitative defects affecting CD4 T lymphocytes. It was suggested recently that programmed cell death (PCD) is an important mechanism leading to CD4 depletion in HIV infection, and that susceptibility of peripheral lymphocytes to PCD is differentially regulated by diverse cytokines. Thus, type 1 cytokines would protect CD4 lymphocytes against PCD, whereas type 2 cytokines would not protect against, and could augment, PCD. We suggest that the qualitative alterations of the immune response provoke the CD4 depletion characteristic of HIV disease via type 2 cytokinemediated augmentation of PCD, and are therefore ultimately responsible for the progression of HIV infection. Finally, we summarize recent data showing that three correlates of disease progression: emergence of HIV strains with syncitium-inducing ability (SI), type 1-to-type 2 cytokine shift, and CD4 depletion, are significantly associated, suggesting a complex interconnected virologic-immunologic pathogenesis of HIV infection

Enzymatic Hydrolysis of Bacterial Cellulose for the Production of Nanocrystals for the Food Packaging Industry

Bacterial cellulose nanocrystals (BCNCs) obtained by enzymatic hydrolysis have been loaded in pullulan biopolymer for use as nanoparticles in the generation of high-oxygen barrier coatings intended for food packaging applications. Bacterial cellulose (BC) produced by Komagataeibacter sucrofermentans was hydrolyzed by two different enzymatic treatments, i.e., using endo-1,4-\u3b2-glucanases (EGs) from Thermobifida halotolerans and cellulase from Trichoderma reesei. The hydrolytic activity was compared by means of turbidity experiments over a period of 145 h, whereas BCNCs in their final state were compared, in terms of size and morphology, by atomic force microscopy (AFM) and dynamic light scattering (DLS). Though both treatments led to particles of similar size, a greater amount of nano-sized particles ( 48250 nm) were observed in the system that also included cellulase enzymes. Unexpectedly, transmission electron microscopy (TEM) revealed that cellulose nanoparticles were round-shaped and made of 4-5 short (150-180 nm) piled whiskers. Pullulan/BCNCs nanocomposite coatings allowed an increase in the overall oxygen barrier performance, of more than two and one orders of magnitude ( 480.7 mL\ub7m-2\ub724 h-1), of pure polyethylene terephthalate (PET) ( 48120 mL\ub7m-2\ub724 h-1) as well as pullulan/coated PET ( 486 mL\ub7m-2\ub724 h-1), with no significant difference between treatments (hydrolysis mediated by EGs or with the addition of cellulase). BCNCs obtained by enzymatic hydrolysis have the potential to generate high oxygen barrier coatings for the food packaging industry

Sterol metabolism modulates susceptibility to HIV-1 Infection

Background: 25-hydroxylase (CH25H) is an Interferon stimulated gene (ISG), which catalyzes the synthesis of 25-Hydroxycholesterol (25HC). 25HC intervenes in metabolic and infectious processes as controls cholesterol homeostasis and influences viral entry into host cells.We verified whether natural resistance to HIV-1 infection in HIV-1-exposed seronegative (HESN) individuals is at least partially mediated by particularities in sterol biosynthesis. Methods: Peripheral blood mononuclear cells (PBMCs) and monocyte-derived macrophages (MDMs) isolated from 15 sexually-exposed HESN and 15 healthy controls (HC) were in vitro HIV-1-infected and analyzed for: 1) percentage of IFN\u3b1-producing plasmacytoid Dendritic Cells (pDCs); 2) Cholesterol signaling and inflammatory response RNA expression; 3) resistance to HIV-1 infection. MDMs from 5 HC were in vitro HIV-1-infected in the absence/presence of exogenously added 25HC. Results: IFN\u3b1-producing pDCs were augmented in HESN compared to HCs both in unstimulated and in in vitro HIV-1-infected PBMCs (p<0.001). An increased expression of CH25H and of a number of genes involved in cholesterol metabolism (ABCA1, ABCG1, CYP7B1, LXR\u3b1, OSBP, PPAR\u3b3, SCARB1) was observed as well; this, was associated with a reduced susceptibility to in vitro HIV-1-infection of PBMCs and MDMs (p<0.01). Notably, addition of 25HC to MDMs resulted in increased cholesterol efflux and augmented resistance to in vitro HIV-1-infection. Conclusions: Results herein show that in HESN sterol metabolism might be particularly efficient. This could be related to the activation of the IFN\u3b1 pathway and results into a reduced susceptibility to in vitro HIV-1 infection. These results suggest a possible basis for therapeutic interventions to modulate HIV-1 infection

HPV in sperm is efficiently removed by washing: A suitable approach for assisted reproduction

Research question: Is it possible, by sperm-washing spermatozoa from clinically HPV-positive men, to obtain spermatozoa free of human papillomavirus (HPV) to be employed in assisted reproduction? Design: This was an observational study performed on HPV-positive men. Freshly ejaculated semen was collected and readily processed by gradient separation followed by swim-up from the washed pellet. The resulting fractions were seminal plasma, cell pellet, round cells, non-motile spermatozoa and motile spermatozoa. All fractions were then tested for the presence of HPV DNA. Results: Of the 15 clinically HPV-positive subjects, 67% were positive in at least one of the seminal fractions. If any postivity was detected, the plasma was always HPV positive. No consistent pattern was observed throughout different samples in the cell pellet, round cell and non-motile spermatozoa fractions. However, after the sperm-wash procedure, the fraction of motile spermatozoa was never found to be HPV-positive. Conclusions: The sperm-washing technique, which was previously successfully used to remove human immunodeficiency virus, can efficiently remove HPV from spermatozoa. However, the present study was conducted on a small population so a larger follow-up study is recommended. HPV screening should be performed in sperm samples and, upon HPV positivity, sperm-washing should be considered before assisted reproduction techniques are used

Endoplasmic Reticulum Associated Aminopeptidase 2 (ERAP2) is released in the secretome of activated MDMs and reduces in vitro HIV-1 infection

Background: Haplotype-specific alternative splicing of the endoplasmic reticulum (ER) aminopeptidase type 2 (ERAP2) gene results in either full-length (FL, haplotype A) or alternatively spliced (AS, haplotype B) mRNA. HapA/HapA homozygous (HomoA) subjects show a reduced susceptibility to HIV-1 infection, probably secondary to the modulation of the antigen processing/presenting machinery. ERAP1 was recently shown to be secreted from the plasma membrane in response to activation; we investigated whether ERAP2 can be released as well and if the secreted form of this enzyme retains its antiviral function. Methods: Human monocyte derived macrophages (MDMs) were differentiated from peripheral blood mononuclear cells (PBMCs) isolated from 6 HomoA healthy controls and stimulated with IFN\u3b3 and LPS. ERAP2-FL secretion was evaluated by mass spectrometry. PBMCs (14 HomoA and 16 HomoB) and CD8-depleted PBMCs (CD8-PBMCs) (4 HomoA and 4 HomoB) were in vitro HIV-infected in the absence/presence of recombinant human ERAP2-FL (rhERAP2) protein; p24 viral antigen quantification was used to assess viral replication. IFN\u3b3 and CD69 mRNA expression, as well as the percentage of perforin-producing CD8+ T Lymphocytes, were analyzed 3 and 7-days post in vitro HIV-1-infection, respectively. The effect of rhERAP2 addition in cell cultures on T cell apoptosis, proliferation, activation, and maturation was evaluated as well on 24 h-stimulated PBMCs. Results: ERAP2 can be secreted from human MDMs in response to IFN\u3b3/LPS stimulation. Notably, the addition of rhERAP2 to PBMC and CD8-PBMC cultures resulted in the reduction of viral replication, though these differences were statistically significant only in PBMCs (p < 0.05 in both HomoA and HomoB). This protective effect was associated with an increase in IFN\u3b3 and CD69 mRNA expression and in the percentage of perforin-expressing CD107+CD8+ cells. RhERAP2 addition also resulted in an increase in CD8+ activated lymphocyte (CD25+HLA-DRII+) and Effector Memory/Terminally differentiated CD8+ T cells ratio. Conclusions: This is the first report providing evidence for the release of ERAP2 in the secretome of immunocompetent cells. Data herein also indicate that exogenous ERAP2-FL exerts its protective function against HIV-1 infection, even in HomoB subjects who do not genetically produce it. Presumably, this defensive extracellular feature is only partially dependent on immune system modulation

TLR Activation Pathways in HIV-1-Exposed Seronegative Individuals

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Evaluation of Th9 lymphocytes in peripheral blood of rheumatoid arthritis patients and correlation with anti-tumor necrosis factor therapy: results from an in vitro pivotal study

The aim of this study was to determine the prevalence of T helper 9 (Th9) lymphocytes in rheumatoid arthritis (RA) patients and to identify a possible association between the percentage of Th9 and the discontinuation of a biological treatment with an anti-tumor necrosis factor (TNF) (infliximab). We collected peripheral blood mononuclear cells (PBMCs) from 55 consecutive RA outpatients and 10 healthy controls. Among RA patients, 15 were not receiving any immunosuppressive drug, 20 were successfully treated with infliximab and 20 discontinued infliximab because of adverse events or inefficacy and were treated with other biological agents. PBMCs were cultured with/without infliximab 50 mg/L for 18 h, and the percentage of Th9 cells was assessed by means of flow cytometry. Th9 lymphocytes were identified as interferon gamma, interleukin (IL)4-, IL17-, IL9-secreting cluster of differentiation 4 (CD4)+ T cells. Cytometric analysis revealed no significant decrease in the percentage of Th9 cells after infliximab exposure in any of the groups, although it was lower in healthy controls than RA patients either before and after the infliximab stimulation assay. Th9 cells are IL-9-secreting T helper lymphocytes whose role in RA is still poorly known. IL-9 levels are increased in RA patients, in whom this cytokine plays a crucial role. Th9 cells are the major producers of IL-9, and their prevalence is higher in RA patients than in healthy subjects; however our experiment in vitro does not demonstrate an association between Th9 lymphocytes and the response to infliximab. Further studies are required to evaluate the real involvement of Th9 population in the immunogenicity of anti-TNF agents

The Role of TH9 Lymphocytes in Rheumatoid Arthritis

Background: Th9 cells are IL-9-secreting Th lymphocytes that are involved in the immunological responses underlying parasitic infections and allergic diseases. In the case of autoimmune diseases, Th9 cells seem to be involved in the pathogenesis of experimental autoimmune encephalomyelitis. No study has yet evaluated the effects of Th9 responses in rheumatic diseases such as rheumatoid arthritis (RA). Objectives: The aim of this study was determine the prevalence of Th9 lymphocytes in RA patients and identify their possible association with the discontinuation of biological treatment with infliximab (IFX). Methods: We enrolled 55 consecutive RA outpatients: 15 not receiving any immunosuppressive drug; 20 responders to IFX treatment; and 20 who had discontinued IFX because of adverse events or inefficacy and were being treated with other biological agents (ABA, TCZ, ETN or CTZ) and traditional immunosuppressive drugs. The matched control group consisted of 10 healthy subjects. After giving their informed consent, the subjects underwent blood sampling for the isolation of peripheral blood mononuclear cells (PBMCs). The PBMCs were cultured with/without IFX 50 mg/L for 18 hours, and the percentage of Th9 cells was assessed by means of flow cytometry. Th9 lymphocytes were identified as IFN\u3b3-, IL4-, IL17-, IL9-secreting CD4+ T cells. Results: Cytometric analysis revealed no significant decrease in the percentage of Th9 cells after IFX exposure in any of the groups, but there were significantly fewer cells in the healthy controls than the RA patients both before and after the IFX stimulation assay (Fig.1). The higher frequency of Th9 cells in the patients was not associated with higher levels of anti-nucleus autoantibodies or other auto-antibody subsets, or with a higher likelihood of experiencing an adverse event or lack of efficacy on IFX treatment. Conclusions IL-9 levels are increased in RA patients, in whom it plays a crucial role. Th9 cells are the major producers of IL-9, and their prevalence is higher in RA patients than in healthy subjects, although they do not seem to affect the outcome of biological therapies