High expression of antiviral proteins in mucosa from individuals exhibiting resistance to human immunodeficiency virus

ABSTARCT: Several soluble factors have been reported to have the capacity of inhibiting HIV replication at different steps of the virus life cycle, without eliminating infected cells and through enhancement of specific cellular mechanisms. Yet, it is unclear if these antiviral factors play a role in the protection from HIV infection or in the control of viral replication. Here we evaluated two cohorts: i) one of 58 HIV-exposed seronegative individuals (HESNs) who were compared with 59 healthy controls (HCs), and ii) another of 13 HIV-controllers who were compared with 20 HIV-progressors. Peripheral blood, oral and genital mucosa and gut-associated lymphoid tissue (GALT) samples were obtained to analyze the mRNA expression of ELAFIN, APOBEC3G, SAMHD1, TRIM5α, RNase 7 and SerpinA1 using real-time PCR. RESULTS: HESNs exhibited higher expression of all antiviral factors in peripheral blood mononuclear cells (PBMCs), oral or genital mucosa when compared with HCs. Furthermore, HIV-controllers exhibited higher levels of SerpinA1 in GALT. CONCLUSIONS: These findings suggest that the activity of these factors is compartmentalized and that these proteins have a predominant role depending on the tissue to avoid the infection, reduce the viral load and modulate the susceptibility to HIV infection

Mutation of Archaeal Isopentenyl Phosphate Kinase Highlights Mechanism and Guides Phosphorylation of Additional Isoprenoid Monophosphates

I sopentenyl diphosphate (IPP) and its isomeric part-ner dimethylallyl diphosphate (DMAPP) are precur-sors for a diverse collection of primary and second-ary isoprenoid metabolites in all organisms. Following its formation, successive units of IPP are used together either with DMAPP, formed by the action of types I or II IPP isomerases, or with the IPP extended isoprenoid diphosphate chain, to biosynthesize C10, C15, or C20 oligoprenyl diphosphates known as geranyl diphos-phate (GPP), farnesyl diphosphate (FPP), and gera-nylgeranyl diphosphate (GGPP), respectively, as well as larger isoprenoid diphosphates. In plants and some mi-croorganisms, GPP, FPP, and GGPP also serve as start-ingmaterials for the biosynthesis of a large class of spe-cialized and often cyclic terpene hydrocarbons (1). FPP is the most ubiquitous of the three isoprenoid diphos-phate building blocks, as it resides at the juncture of bi

Prolastin, a pharmaceutical preparation of purified human α1-antitrypsin, blocks endotoxin-mediated cytokine release

BACKGROUND: α1-antitrypsin (AAT) serves primarily as an inhibitor of the elastin degrading proteases, neutrophil elastase and proteinase 3. There is ample clinical evidence that inherited severe AAT deficiency predisposes to chronic obstructive pulmonary disease. Augmentation therapy for AAT deficiency has been available for many years, but to date no sufficient data exist to demonstrate its efficacy. There is increasing evidence that AAT is able to exert effects other than protease inhibition. We investigated whether Prolastin, a preparation of purified pooled human AAT used for augmentation therapy, exhibits anti-bacterial effects. METHODS: Human monocytes and neutrophils were isolated from buffy coats or whole peripheral blood by the Ficoll-Hypaque procedure. Cells were stimulated with lipopolysaccharide (LPS) or zymosan, either alone or in combination with Prolastin, native AAT or polymerised AAT for 18 h, and analysed to determine the release of TNFα, IL-1β and IL-8. At 2-week intervals, seven subjects were submitted to a nasal challenge with sterile saline, LPS (25 μg) and LPS-Prolastin combination. The concentration of IL-8 was analysed in nasal lavages performed before, and 2, 6 and 24 h after the challenge. RESULTS: In vitro, Prolastin showed a concentration-dependent (0.5 to 16 mg/ml) inhibition of endotoxin-stimulated TNFα and IL-1β release from monocytes and IL-8 release from neutrophils. At 8 and 16 mg/ml the inhibitory effects of Prolastin appeared to be maximal for neutrophil IL-8 release (5.3-fold, p < 0.001 compared to zymosan treated cells) and monocyte TNFα and IL-1β release (10.7- and 7.3-fold, p < 0.001, respectively, compared to LPS treated cells). Furthermore, Prolastin (2.5 mg per nostril) significantly inhibited nasal IL-8 release in response to pure LPS challenge. CONCLUSION: Our data demonstrate for the first time that Prolastin inhibits bacterial endotoxin-induced pro-inflammatory responses in vitro and in vivo, and provide scientific bases to explore new Prolastin-based therapies for individuals with inherited AAT deficiency, but also for other clinical conditions