Hepatitis C Virus Hypervariable Region 1 Variants Presented on Hepatitis B Virus Capsid-Like Particles Induce Cross-Neutralizing Antibodies

Hepatitis C virus (HCV) infection is still a serious global health burden. Despite improved therapeutic options, a preventative vaccine would be desirable especially in undeveloped countries. Traditionally, highly conserved epitopes are targets for antibody-based prophylactic vaccines. In HCV-infected patients, however, neutralizing antibodies are primarily directed against hypervariable region I (HVRI) in the envelope protein E2. HVRI is the most variable region of HCV, and this heterogeneity contributes to viral persistence and has thus far prevented the development of an effective HVRI-based vaccine. The primary goal of an antibody-based HCV vaccine should therefore be the induction of cross-reactive HVRI antibodies. In this study we approached this problem by presenting selected cross-reactive HVRI variants in a highly symmetric repeated array on capsid-like particles (CLPs). SplitCore CLPs, a novel particulate antigen presentation system derived from the HBV core protein, were used to deliberately manipulate the orientation of HVRI and therefore enable the presentation of conserved parts of HVRI. These HVRI-CLPs induced high titers of cross-reactive antibodies, including neutralizing antibodies. The combination of only four HVRI CLPs was sufficient to induce antibodies cross-reactive with 81 of 326 (24.8%) naturally occurring HVRI peptides. Most importantly, HVRI CLPs with AS03 as an adjuvant induced antibodies with a 10-fold increase in neutralizing capability. These antibodies were able to neutralize infectious HCVcc isolates and 4 of 19 (21%) patient-derived HCVpp isolates. Taken together, these results demonstrate that the induction of at least partially cross-neutralizing antibodies is possible. This approach might be useful for the development of a prophylactic HCV vaccine and should also be adaptable to other highly variable viruses.     

Recent advances in lactic acid production by microbial fermentation processes

Fermentative production of optically pure lactic acid has roused interest among researchers in recent years due to its high potential for applications in a wide range of fields. More specifically, the sharp increase in manufacturing of biodegradable polylactic acid (PLA) materials, green alternatives to petroleum-derived plastics, has significantly increased the global interest in lactic acid production. However, higher production costs have hindered the large-scale application of PLA because of the high price of lactic acid. Therefore, reduction of lactic acid production cost through utilization of inexpensive substrates and improvement of lactic acid production and productivity has become an important goal. Various methods have been employed for enhanced lactic acid production, including several bioprocess techniques facilitated by wild-type and/or engineered microbes. In this review, we will discuss lactic acid producers with relation to their fermentation characteristics and metabolism. Inexpensive fermentative substrates, such as dairy products, food and agro-industrial wastes, glycerol, and algal biomass alternatives to costly pure sugars and food crops are introduced. The operational modes and fermentation methods that have been recently reported to improve lactic acid production in terms of concentrations, yields, and productivities are summarized and compared. High cell density fermentation through immobilization and cell-recycling techniques are also addressed. Finally, advances in recovery processes and concluding remarks on the future outlook of lactic acid production are presented.     

Response of white-tailed deer to infection with peste des petits ruminants virus

White-tailed deer (Odocoileus virginianus) were infected experimentally with two strains of peste des petits ruminants virus. The response varied from fatal consequence to subclinical infection. The clinical signs and gross lesions were similar to those in goats. Virus was recovered from all the infected deer, and survivors developed specific antibodies demonstrated by complement fixation and virus neutralization tests. Survivors also resisted challenge with virulent rinderpest virus that was lethal to a control deer.     

Insecticidal activities of monoterpenes and phenylpropenes against <Emphasis Type="Italic">Sitophilus oryzae</Emphasis> and their inhibitory effects on acetylcholinesterase and adenosine triphosphatases

In the present study, six monoterpenes [(?)-citronellal, p-cymene, (?)-menthone, α-pinene, α-terpinene, and (?)-terpinen-4-ol] and two phenylpropenes [trans-cinnamaldehyde and eugenol] were evaluated for their contact and fumigant toxicities against Sitophilus oryzae adults. The effects of these compounds on the mortality of S. oryzae adults in stored wheat and their inhibitory effects on acetylcholinesterase (AChE) and adenosine triphosphatases (ATPases) were examined. The tested compounds showed varying degrees of contact toxicity, with trans-cinnamaldehyde (LC₅₀ = 0.01 mg/cm²) being the most potent compound, followed by (?)-menthone (LC₅₀ = 0.013 mg/cm²) and eugenol (LC₅₀ = 0.015 mg/cm²). In a fumigant toxicity assay, the monoterpenes α-terpinene, p-cymene, and (?)-menthone showed the highest toxicities (LC₅₀ = 50.79, 52.37, and 54.08 μl/L air, respectively). Trans-cinnamaldehyde, (?)-citronellal, and eugenol were the least toxic (LC₅₀ > 100 μl/L air). In general, the oxygenated compounds exhibited high contact toxicities while the hydrocarbon compounds exhibited high fumigant toxicities. When tested for their insecticidal activities against S. oryzae in stored wheat, trans-cinnamaldehyde was found to be the most potent compound, with 73.9% mortality at an application rate of 0.5 g/kg and complete mortality (100%) at 1 and 5 g/kg after 1 week of treatment. All of the tested compounds showed AChE inhibition, although (?)-citronellal and trans-cinnamaldehyde presented the strongest enzyme inhibition, with IC₅₀ values of 18.40 and 18.93 mM, respectively. On the other hand, (?)-terpinene-4-ol exhibited the highest inhibition of ATPases, followed by α-pinene and α-terpinene.     

Pretreatment Predictors of Response to PegIFN-RBV Therapy in Egyptian Patients with HCV Genotype 4

BackgroundEgypt has the highest prevalence of a difficult to treat chronic hepatitis C virus (HCV), genotype 4. Pretreatment factors could guide individualization of therapy which aids in treatment optimization and interleukin IL28B gene polymorphism has been shown to closely relate to HCV treatment response. Polymorphisms in genes encoding inhibitors of T-cell response, which have role in disease progression as Programmed Cell Death 1 (PD-1), and Cytotoxic T-Lymphocytes Antigen-4 (CTLA-4), could be candidate markers predicting treatment response.MethodsThis cohort study consisted of 200 chronic HCV genotype 4 infected patients treated with PegIFN α-2a and RBV in 2 hepatology centers. Genotyping of the polymorphisms in the IL28B gene region (rs12979860), PD1.3 (rs11568821) and CTLA-4 (rs231775) was performed on DNA collected from each patient using TaqMan^® genotyping assay. Groups were classified according to response into sustained virological responders (SVR), or non-responders (NR). A multivariate logistic regression analysis was used to identify potential markers, host pretreatment clinical and viral predictive factors including viral load, insulin resistance, and alpha fetoprotein (AFP) related to treatment response.ResultsOur results showed that in a multivariate analyses IL28B C/C genotype was the most significant predictor for SVR (OR = 10.86; p<0.0001) followed by AFP (OR = 0.915; p = 0.001) then CTLA-4/G genotypes (OR = 1.948; p = 0.022). However, PD-1.3/A genotypes and platelets count were significantly related to response in univariate analysis only (OR = 1.973; p = 0.023; OR = 1.007; p = 0.009 respectively).ConclusionIL28B SNP, AFP level, and CTLA-4 SNP could be used in conjunction to predict treatment response in HCV genotype 4 infected Egyptian patients.     

Fructose production by immobilizedArthrobacter cells

Summary ImmobilizedArthrobacter cells (NRRL-B-3728) were used for continuous isomerization of glucose to fructose in a bioreactor system. The system utilized stationary phase (55h) cells (2.2×10⁹ CFU/ml saline) immobilized onto K-carrageenan (3% w/v) beads [cells were heated at 65°C for 10 min to inactivate endogenous proteolytic enzymes]. Immobilized-cell preparations were hardened using three different glutaraldehyde systems. Glutaraldehyde (0.2 M) treated-immobilized cells (pH 7.0, 5°C for 30 min) exhibited good gel strength and high glucose isomerase activities. Maximal bioreactor isomerization of 44% was achieved when a buffered feedstock containing 40% glucose was fed into the column (60°C) at a flow rate of 0.2 ml/min. The biological half-life of glucose isomerase activities in this system was 400 h. Scanning electron microscopy revealed large numbers of cells distributed within the beads. A thin layer surrounding the beads following glutaraldehyde treatment was mainly due to cross-linking reactions between cell proteins and glutaraldehyde. This layer prevented leaking of cells during continuous isomerization reaction.     

Optimization of some culture parameters and properties of β-glucosidase and β-xylosidase from Penicillium funiculosum NRRL – 13033

Penicillium funiculosum NRRL 13033 produced β-glucosidase and β-xylosidase activities when grown on wheat straw. The addition of some inducers (individually or in combination) to the fermentation medium were tested for the production of both enzymes. The relation of mycelial bound enzyme to cell free enzyme was studied during incubation period of fermentation. The optimum activity of β-glucosidase and β-xylosidase were found to be in the pH 4.5 using phosphate-citrate buffer at 50°C for 60 min and at 55°C for 40 min respectively. β-Glucosidase lost about 40% of its original activity by heating to 65°C for 60 min, while, β-xylosidase activity was found to be nearly stable with the same treatment. Both enzyme activities were greatly inhibited when 1.0% (w/v) of xylose and glucose were added to the assay mixture.     

Complement Fixation Reaction for the Diagnosis of Type II Avian (Marek''s) Leukosis

The present study was designed to find a complement fixation (CF) reaction for the diagnosis of type II lymphoid leukosis, to learn some of the characteristics of the CF antigen, and to investigate the development of CF antibody response to this infection. JM virus-specific antigen was demonstrated in tumorous chicken tissue, in JM virus-infected chick embryo material, in JM virus-infected chicken kidney, and in duck embryo fibroblast tissue culture by using JM virus-immune rabbit serum. This CF antigen did not show cross-reactivity with Rous sarcoma virus or with RIF-type viruses. It was partially heat-labile. The CF activity was restored at -70 C for 10 months and was resistant to intermittent freeze-thaw treatment. The CF antigen may be denatured by ethyl alcohol, but no significant deleterious effects were noted after ether or chloroform treatment. JM virus-specific CF antibody could not be demonstrated by the direct complement dilution method or by the indirect or inhibition form of the CF test in infected or immunized chicken sera.     

Physicochemical factors affecting ethanol adsorption by activated carbon

Powder and granular activated charcoal were evaluated for ethanol adsorptivity from aqueous mixtures using an adsorption isotherm. Ethanol adsorption capacity was more pronounced at 25 degrees C as compared to 5, 15, and 40 degrees C. When pH of the ethanol-buffer mixture (0.09 ionic strength) was changed from acidic (2.3) to neutral and then to alkaline (11.2), ethanol adsorption was decreased. Increasing ionic strength of the ethanol-buffer mixtures from 0.05 to 0.09 enhanced ethanol adsorption but a further increase to 0.14 showed no significant effect. Ethanol adsorption was more efficient from an aqueous ethanol mixture as compared to semidefined and nondefined fermentation worts, respectively. Heating granular charcoal to 400 degrees C for 1 h and 600 degrees C for 3 h in N(2) increased ethanol adsorptivity and heating to 1000 degrees C (1 h) in CO(2) decreased it when ethanol was removed from dilute solutions by simple pass adsorption in a carbon packed column. Granular charcoal was superior to powdered charcoal and an inverse relationship was noted between the weight of the granular carbon bed in the column and ethanol adsorbed/g carbon. Decreasing the column feed flow rate from 7.5 to 2.0 L aqueous ethanol/min increased the adsorption rate.