Increased α-Defensins 1-3 Production by Dendritic Cells in HIV-Infected Individuals Is Associated with Slower Disease Progression

Background

Defensins are natural endogenous antimicrobial peptides with potent anti-HIV activity and immuno-modulatory effects. We recently demonstrated that immature dendritic cells (DC) produce α-defensins1-3 and that α-defensins1-3 modulate DC generation and maturation. Since DC-HIV interaction plays a critical role during the first steps of HIV infection, we investigated the possible impact of α-defensins1-3 production by DC on disease progression.

Methodology/Principal Findings

Monocyte-derived DC (MDDC) were analyzed comparatively in healthy controls (HC) and HIV-infected patients, including untreated “elite” and “viremic” controllers, untreated viremic non-controllers and antiretroviral-treated patients. We found that production of α-defensins1-3 was significantly increased in MDDC from HIV-infected patients versus HC, and this increase was mainly due to that observed in controllers, while in non-controllers the increase was not statistically significant (controllers vs. HC, p<0.005; controllers vs. non-controllers p<0.05). Secreted α-defensins1-3 by immature MDDC positively correlated with CD4 T cell counts in controllers, but not in non-controllers. Moreover, independently of their clinical classification, HIV-infected patients with higher α-defensins1-3 secretion by immature MDDC showed slower disease progression, measured as no decrease in the number of CD4+ T-cells below 350 cell/mm³, lower increase of plasma viral load and no initiation of treatment over time. Plasma alpha-defensins1-3 levels lacked any relationship with immunologic and virologic parameters.

Conclusions/Significance

High production of α-defensins1-3 by immature DCs appears as a host protective factor against progression of HIV-1infection, suggesting potential diagnostic, therapeutic and preventive implications. This protective effect may arise from the activity of α-defensins1-3 to damage the virions prior and/or after their internalization by immature DC, and hence favoring a more efficient viral processing and presentation to HIV-specific CD4+ T cells, without or with a minor rate of transmission of infectious HIV-1 virions.     

New Culture Medium to Xanthan Production by <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv<Emphasis Type="Italic">. campestris</Emphasis>

Xanthan is a important biopolymer for commercial purpose and it is produced in two stages by Xanthomonas campestris. In the first one, the bacterium is cultivated in the complex medium enriched in nitrogen and the biomass produced is used as inoculum for the next stage in which the gum is produced in another medium. In this work a new medium for the first stage is proposed in place of currently used YM medium. Different formulated growth media were studied and the correspondent biomass produced was analysed as inoculum for the second stage. The inoculum and gum were produced by batch process in shaker at 27°C in pH 6.0 and at 30°C in pH 7.0, respectively. The gum was precipitated with ethanol (3:1 v/v). The dryed biomass and xathan gum produced were determined by drying in oven at 105 and 40°C, respectively. The viscosity of the fermentation broth and 1% gum solution in water were determined in Brookfield viscometer. The formulated medium presented the increase in gum production (30%), broth (136%) and 1% gum solution viscosity (60%) compared to YM, besides the inferior cost. The results showed the importance of the quality of the inoculum from the first stage of the culture which influenced on the gum viscosity in the second stage.     

Primary pulmonary non-Hodgkin lymphoma with myocardial infiltration

A case of primary pulmonary non-Hodgkin's lymphoma is presented. On this occasion, the lymphoma invaded the myocardium, an event which has not previously been reported in the literature. These neoplasms spread by proximity, and invasion of the pericardium, thoracic wall and oesophagus have been described. Our patient died from heart failure. Tumour myocardial infiltration may well have been the determinant cause through various mechanisms, including a decrease in myocardial contractility. Spread into the myocardium may be facilitated by bulky tumour infiltrates in the pleural space.     

Ecosystem carbon fluxes of a ryegrass and clover fodder crop in a Mediterranean environment

A mixture of ryegrass (Lolium italicum A. Braun) and clover (Trifolium alexandrinum L.) was sown in Eboli (Salerno, Southern Italy) in September 2007. Crop growth, leaf and canopy gas exchange and ecophysiological traits were monitored throughout the growth cycle. The gross primary production (GPP) was not affected by air temperature (T _air); on the contrary the ecosystem respiration (R _eco) decreased as T _air decreased while net ecosystem CO₂ exchange (NEE) increased. When was normalized with leaf area index (LAI), GPP decreased with T _air, a likely response to cold that down-regulated canopy photosynthesis in order to optimize the light use at low winter temperatures. Net photosynthetic rates (P _N), the effective quantum yield of PSII (Φ_PSII) and photosynthetic pigment content were higher in clover than ryegrass, in relation to the higher leaf N content. The lower Φ_PSII in ryegrass was linked to lower photochemical quenching coefficient (q_P) values, due to a reduced number of reaction centres, in agreement with the lowest Chl a content. This behaviour can be considered as an adaptive strategy to cold to avoid photooxidative damage at low temperature rather than an impairment of PSII complexes.     

Coagulant and antibacterial activities of the water-soluble seed lectin from Moringa oleifera

Aims: The aim of this work was to analyse the coagulant and antibacterial activities of lectin isolated from Moringa oleifera seeds that are used for water treatment. Methods and Results: The water‐soluble M. oleifera lectin (WSMoL) was separated from nonhemagglutinating components (NHC) by chitin chromatography. WSMoL fluorescence spectrum was not altered in the presence of ions that are often present in high concentrations in polluted waters. Seed extract, NHC and WSMoL showed coagulant activity on a turbid water model. Both NHC and WSMoL reduced the growth of Staphylococcus aureus, but only WSMoL caused a reduction in Escherichia coli. WSMoL was also more effective in reducing the growth of ambient lake water bacteria. Conclusions: Data obtained from this study indicate that WSMoL is a potential natural biocoagulant for water, reducing turbidity, suspended solids and bacteria. Significance and Impact of the Study: Moringa oleifera seeds are a material effective in the treatment of water.