Individual expression and processing of hepatitis C virus E1/E2 epitopes-based DNA vaccine candidate in healthy humans' peripheral blood mononuclear cells.

Purpose: The development and study of hepatitis C virus (HCV) vaccine candidates' individualized responses are of great importance. Here we report on an HCV DNA vaccine candidate based on selected envelope (E1/E2) epitopes. Besides, we assessed its expression and processing in human peripheral blood mononuclear cells (PBMCs) and in vivo cellular response in mice. Materials and Methods: HCV E1/E2 DNA construct (EC) was designed. The antigen expression of EC was assayed in PBMCs of five HCV-uninfected donors via a real-time quantitative polymerase chain reaction. Serum samples from 20 HCV antibody-positive patients were used to detect each individual PBMCs expressed antigens via enzyme-linked immunosorbent assay. Two groups, five Swiss albino mice each, were immunized with the EC or a control construct. The absolute count of lymph nodes' CD4+ and CD8+ T-lymphocytes was assessed. Results: Donors' PBMCs showed different levels of EC expression, ranging between 0.83-2.61-fold in four donors, while donor-3 showed 34.53-fold expression. The antigens expressed in PBMCs were significantly reactive to the 20 HCV antibody repertoire (all p=0.0001). All showed comparable reactivity except for donor-3 showing the lowest reactivity level. The absolute count % of the CD4+ T-cell significantly increased in four of the five EC-immunized mice compared to the control group (p=0.03). No significant difference in CD8+ T-cells % was observed (p=0.89). Conclusion: The inter-individual variation in antigen expression and processing dominance was evident, showing independence in individuals' antigen expression and reactivity levels to antibodies. The described vaccine candidate might result in a promising natural immune response with a possibility of CD4+ T-cell early priming.

Carbohydrates Metabolic Signatures in Immune Cells: Response to Infection.

Introduction: Metabolic reprogramming in immune cells is diverse and distinctive in terms of complexity and flexibility in response to heterogeneous pathogenic stimuli. We studied the carbohydrate metabolic changes in immune cells in different types of infectious diseases. This could help build reasonable strategies when understanding the diagnostics, prognostics, and biological relevance of immune cells under alternative metabolic burdens. Methods: Search and analysis were conducted on published peer-reviewed papers on immune cell metabolism of a single pathogen infection from the four known types (bacteria, fungi, parasites, and viruses). Out of the 131 selected papers based on the PIC algorithm (pathogen type/immune cell/carbohydrate metabolism), 30 explored immune cell metabolic changes in well-studied bacterial infections, 17 were on fungal infections of known medical importance, and 12 and 57 were on parasitic and viral infections, respectively. Results and Discussion: While carbohydrate metabolism in immune cells is signaled by glycolytic shift during a bacterial or viral infection, it is widely evident that effector surface proteins are expressed on the surface of parasites and fungi to modulate metabolism in these cells. Conclusions: Carbohydrate metabolism in immune cells can be categorized according to the pathogen or the disease type. Accordingly, this classification can be used to adopt new strategies in disease diagnosis and treatment.

TLR3\TLR7 as Differentially Expressed Markers Among Viral, Nonviral, and Autoimmune Diseases in Egyptian Patients.

Toll-like receptors (TLRs) represent the immune link between the innate and the adaptive immune signals against various pathogens. This study aimed to evaluate the TLRs3 and 7 as immune-markers in differentiating between hepatitis C virus (HCV)-infected and -uninfected patients. Also, the use of the TLR3 and TLR7 as immune markers was compared with the prevalent bio and immune markers for autoimmune diseases in HCV-infected or -uninfected patients. The levels of GPT, GOT, B cell activated factors, tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-10 were measured in plasma, while the levels of TLR3 and TLR7 were quantified in lysates of peripheral blood mononuclear cells from healthy donors, HCV-infected patients, nonalcoholic fatty liver (NAFL) patients without autoimmune diseases and with autoimmune diseases (HCV-infected patients with autoimmune diseases [HCV+auto], nonalcoholic fatty liver patients with autoimmune diseases [NAFL+auto]), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE) patients. The relative expression of TLR3, TLR7, TNF, and IL-10 in cell lysates was assessed against glyceraldehyde 3-phosphate dehydrogenase (GAPDH) by quantitative real time-polymerase chain reaction (qRT-PCR). Results showed that TLRs 3 and 7 levels were significantly higher in SLE, RA, HCV, HCV+auto, and the NAFL patients compared to the normal control. The cell lysates from SLE patients expressed TLR3 at relatively significantly higher mRNA levels compared to normal subjects or other patient groups. The NAFL+auto patients expressed TLR7 at relatively significantly high mRNA levels compared to normal subjects or other patients. The RA patients expressed TLR7 at relatively significantly higher mRNA levels when compared to HCV, HCV+auto, and NAFL+auto patients. Conclusions: At the protein level, TLR7 can differentiate between HCV and NAFL patients. In addition, both TLRs3 and 7 can serve as potent markers in differentiating between NAFL and NAFL+auto.

Glycolytic and immunological alterations in human U937 monocytes in response to H1N1 infection.

We monitored changes that took place in glycolytic enzymes, the pyruvate end product of glycolysis, tumor necrosis factor α (TNFα), and toll-like receptors (TLRs) both at the transcriptional and translational levels upon direct interaction between PR8-H1N1 and the human monocytes U937 in vitro system. U937 were first treated with H1N1 infectious viral particles or phorbol-12-myristate-13-acetate (PMA) or left untreated and later infected with the H1N1 virus. Levels of phosphofructokinase 1 (PFK1) and pyruvate were biochemically quantified. In addition, levels of TNFα, TLR3, and TLR7 were measured by ELISA. The transcriptional profiles of PFKs, inflammatory cytokines, TLR3 and TLR7 were relatively quantified by qRT-PCR. The results generally revealed significant changes in both the transcriptional and translational profiles of the studied biochemical and immunological parameters upon influenza infection in a time-dependent manner. In conclusion, H1N1 infection triggers transcriptional and translational changes in immortalized human monocytes, which might serve as markers for infection subject for further validation for their specificities.

H1N1 Infection Reduces Glucose Level in Human U937 Monocytes Culture.

Infection with influenza A (H1N1) virus contributes significantly to the global burden of acute respiratory diseases. Glucose uptake and metabolic changes are reported in different cell types after infections with different virus types, including influenza A virus. Alteration of glucose metabolism specifically in immune cells has major health consequences. The aim of this study was to monitor glucose concentration in unstimulated and stimulated U937 human monocytes with infectious or heat inactivated H1N1 or Staphylococcus aureus or in nonpathogenically stimulated monocytes with phorbol-12-myristate-13-acetate. Stimulated or unstimulated U937 human monocytes were subjected to H1N1 infection for different time points and the glucose profile in the growth medium was measured post infection. Results showed that regardless to whether the initial stimuli on U937 cells were of pathogen or nonpathogen origins, challenge infection by H1N1 causes a significant reduction of glucose levels 36 h post infection. In conclusion, H1N1 infection has a direct effect on the glucose uptake of U937 cells in vitro. This effect can be related to either H1N1 infection or cell differentiation status that might occur due to the exerted stimuli.

Immune responses to killed reassorted influenza virus supplemented with natural adjuvants.

In this study, we investigated the immunomodulatory effects of a supplemented killed influenza virus (V) by Echinacea purpurea (E) and Nigella sativa (N) extracts and effect of changing the route of immunization from intramuscular (IM) to intraperitoneal (IP). At the 2nd-, 3rd- and 4th-week post-IM immunizations (WPIMI), the supplemented V with N (VN) induced the most significant IgM response unlike N alone. At the 2nd WPIMI, V or VN induced the highest significant IgG levels. At the 2nd-week post-IP immunization (WPIPI), E and VN induced the most significant IgG levels. Both at the 3rd and 4th WPIMI or WPIPI, various treatments induced significant increases in IgG. At the 4th WPIMI, E, V, and V with E (VE) induced significant increases in the CD4+ thymocytes while all IP treatments caused significant increase in their counts. V and VN induced the most significant IM induction of CD8+ thymocytes while their best IP stimulation was induced by N, VE, and VN. At the 4th WPIMI, various treatments caused significant increases in the mesenteric lymph node (MLN) CD4+, CD8+ counts. WPIPI with V or VE caused significant increases in both the CD4+- and CD8+ MLN cells, whereas VN significantly induced CD8+ MLN cells only. WPIPI with various treatments caused significant increases in the B-cell counts and the peak was obtained by VN.

Influence of bioactive sulfated polysaccharide-protein complexes on hepatocarcinogenesis, angiogenesis and immunomodulatory activities.

OBJECTIVE: To explore the in vivo anticancer, anti-angiogenesis and immunomodulatory efficacies of the bioactive polysaccharide isolated from cold aqueous extract of Jania rubens (JCEM) and Pterocladia capillacea (PCEM) as well as hot aqueous extract of Enteromorpha intestinalis (EHEM) against hepatocellular carcinoma rat model (HCC) and to study their chemical composition. METHODS: The sugars and amino acids composition of the bioactive polysaccharides of JCEM, PCEM and EHEM were determined using gas liquid chromatography and amino acid analyzer, respectively. These polysaccharide extracts (20 mg/kg b.wt. for 5 weeks) were assessed on hepatocarcinogenesis in rats and α-fetoprotein (AFP), carcinoembryonic antigen (CEA), glypican-3 (GPC-3), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) and Ig G levels were evaluated. RESULTS: The GLC analysis of JCEM, PCEM and EHEM polysaccharide revealed the presence of 10, 9 and 10 sugars, in addition the amino acid analyzer enable identification of 16, 15 and 15 amino acids, respectively. These polysaccharide extracts of JCEM, PCEM and EHEM produced significant decrease in serum AFP, CEA, GPC-3, HGF and VEGF compared with untreated HCC group. JCEM, PCEM and EHEM had an immunostimulatory responses by increasing the IgG levels as compared by naïve value (1.23, 1.53 and 1.17 folds), respectively. The bioactive polysaccharides in HCC induced rats improved the humoral immune response. The photomicrographs of liver tissue sections of the groups of HCC treated with polysaccharide extracts of Jania rubens and Enteromorpha intestinalis showed intact histological structure. Moreover, fractions HE1, HE4, HE7 obtained from polysaccharide of EHEM showed moderate cytotoxic activity against HepG2 in vitro with IC50 73.1, 42.6, 76.2 µg/mL. However, fractions of PCEM and JCEM show no or weak cytotoxicity against HepG2 in vitro where the cytotoxic activity of their crude polysaccharide extract proved synergetic effect. CONCLUSIONS: The pronounced antitumor activity of sulfated polysaccharide-protein complexes of JCEM and EHEM is due to direct cytotoxic activity, anti-hepatocarcinogenesis, and anti-angiogenesis. In addition, JCEM, PCEM and EHEM had an immunostimulatory response and improved the humoral immune response in HCC induced rats.

Bioimmunological responses to Schistosoma mansoni and Fasciola gigantica worm homogenates either with or without saponin.

BACKGROUND: In this study, we evaluated the biochemical, immunological, histopathological and antischistosomal activities of Schistosoma mansoni or Fasciola gigantica worm homogenates mixed either with or without saponin that was extracted from Atriplex nummularia. METHODOLOGY: The immunization schedule was based on subcutaneous administration of two doses (50 microg /100 microl PBS) of each homogenate with time intervals of 15 days. After 15 days of the last homogenate inoculation, all mice were challenged with 100 Schistosoma mansoni cercariae and sacrificed after two months. Free radical scavengers and liver function enzymes were determined in mice liver. Worm counting and the histopathological picture of the liver were also done. RESULTS: Immunization with Schistosoma or Fasciola worm homogenates, mixed either with or without saponin, recorded an amelioration of the free radical scavenger levels, liver function enzymes and reduction in worm burden, as well as improvement of the histological feature of the liver, the number and size of granuloma, evidence of increased immune reaction manifested by a lymphocytic cuff surrounding the granuloma, diminution of its fibrotic and collagen content, and destruction of Schistosoma ova. CONCLUSION: Fasciola or Schistosoma worm antigens mixed with or without saponin succeeded to eliminate the product of oxidative stress and assistance in immune-mediated destruction of eggs that ameliorate the histopathological picture of the liver cells and preserve its function.

Schistosoma mansoni soluble egg antigens enhance HCV replication in mammalian cells.

BACKGROUND: This work demonstrates successful propagation of HCV in HepG2 and human blood cells as well as viral shedding into their culture media. The influence of Schistosoma mansoni crude soluble egg antigens (SEA) on the rate of viral propagation in both mammalian cells was also monitored. METHODOLOGY: HepG2 cells were inoculated with HCV viremic human sera and some wells were exposed to HCV infection in presence of SEA. Cells were harvested for RT-PCR and Western blotting analysis. HepG2 media was collected for HCV ELISA. Blood samples from HCV-infected humans were cultured in the presence and absence of SEA. Media were collected at different time points post culturing and subjected to HCV ELISA. RESULTS: The ELISA concentration of HCV antigens were generally higher in media of infected HepG2 cells compared to media of control cells at all time intervals post infection. Western blots showed reactivity to immunogenic peptides of different molecular weights in lysate of infected HepG2 cells that were not evidenced in uninfected cells. In presence of SEA, RT-PCR results revealed earlier detection of viral RNA in infected HepG2 cells compared to in absence of such bilharzial antigen. Also, ELISA results revealed higher levels of detected HCV antigens in media of both infected HepG2 and blood cells cocultured with S. mansoni SEA compared to that of cultured infected cells in absence of the parasite antigens. CONCLUSION: HepG2 cells as well as whole blood cultures maintain HCV replication. Furthermore, SEA has the potential to enhance HCV propagation.

Escherichia coli shares T- and B-lymphocyte epitopes with Schistosoma mansoni.

BACKGROUND: In this study, we tested the cross-reaction between crude Escherichia coli antigen (ECA) and 3 crude Schistosoma mansoni antigens. METHODOLOGY: The schistosomal antigens used were cercarial antigen preparation (CAP), soluble worm antigen preparation (SWAP), and soluble egg antigen (SEA). Four groups each of 3 mice received 2 intraperotineal immunizations with the above-mentioned antigens at a two-week interval. The dose of the ECA was 20 microg/100 microl PBS/mouse and that of any of the used schistosomal antigens was 50 microg/100 microl PBS/mouse. IgM and IgG reactivities and cross-reactivities were tested in individual immunized mice sera (IMS) against the above-mentioned antigens by ELISA and Western blotting. The changes in the B, CD4+ and CD8+ -T cells' counts post immunization were recorded. RESULTS: Priming with ECA caused significant increases in IgM (P<0.05) against CAP and SWAP, while both priming and boosting with ECA caused a significant elevation in the IgG only against SWAP. Priming and boosting with ECA or schistosomal antigens caused significant increases in IgM against ECA. Priming with ECA or SWAP caused significant elevation in IgG against ECA. In Western blotting, ECA-IMS recognized 16, 33, 38 and 94 kDa ECA peptides that cross-reacted with CAP-IMS. ECA peptides at 30 and 38 kDa cross-reacted among ECA, SWAP and SEA-IMS. CAP peptides at 40, 71, 85 and 97 kDa cross-reacted with ECA-IMS. A 59 kDa SWAP peptide cross-reacted with ECA. SEA peptides at approximately 55, 96 and 101 kDa cross-reacted with ECA-IMS. Immunization with ECA, CAP, SWAP or SEA caused significant increases in mesentric lymph nodes (MLN)-CD4+, CD8+ -T cells and MLN-B cells. For thymocytes, CD4+ -T cells significantly increased upon immunization with ECA and SWAP while CD8+-T cells significantly increased upon immunization with SWAP. CONCLUSION: It is necessary to include E. coli antigens as controls while establishing schistosomal antigens-based diagnostic tests to ensure the specificity of the detected immune responses. Characterization of the cross-reactive ECA antigens with protective potential against S. mansoni infection remains a future research objective.

Characterization of NS3 protease from an Egyptian HCV genotype 4a isolate.

The role of the NS3 protease in HCV replication was demonstrated by the ability of a protease inhibitor cocktail (10 microg/ml) to abolish the induced cytopathic effect in RAW macrophages upon infection with Egyptian sera. The HCV protease gene was amplified from Egyptian sera by nested PCR and cloned downstream of the CMV promotor in a mammalian expression plasmid, which was then used to transform bacteria. Colonies carrying the gene in the correct orientation were subjected to large-scale plasmid purification followed by sequencing. Phylogenetic comparison of the sequence obtained with published sequences from different genotypes confirmed that our sequence belongs to genotype 4a. Of the other genotypes, the most closely related ones were from genotype 1. Multiple alignments of protease peptides showed that the catalytic triads and binding residues for substrate, Zn2+ and the NS4 cofactor are conserved among different isolates, including ours, and confirmed the closer homology between NS3 of genotypes 4 and 1. The HCV-protease-encoding construct was successfully transcribed in both mammalian cells and mice. Mouse antibodies produced against the protease-encoding-construct detected the 18-kDa enzyme in lysates of cells transfected with the construct by Western blotting, and in the media of infected cells by ELISA.

Cross-reactivity of Schistosoma mansoni-Fasciola gigantica influenced by saponins.

The aim of the present work was to investigate the Schistosoma mansoni and Fasciola gigantica cross-reactivity between adult worms and egg homogenates of the parasites. Immunoprophylactic effects of crude Schistosoma mansoni worms and egg antigens mixed with or without saponins extracted from Atriplex nummularia were studied followed by challenge with 80 cercariae of Schistosoma mansoni. Our results showed that post 1st immunization with schistosome egg antigens (SEA) there was a significant change (P approximately 0.05) in the IgM levels against Fasciola egg homogenate (FgEH) without saponins. Post 2nd immunization with SEA mixed with saponins the levels of IgM increased significantly (P approximately 0.05) against Fasciola worm homogenate (FgWH) as compared with a non-immunized group. Post 2nd immunization the level of IgG was significantly elevated (P approximately 0.05) by SEA mixed with saponins against FgWH. Post 2nd immunizations with SEA mixed with saponins showed a significant change (P approximately 0.05) in IgG levels against FgEH. These results clearly demonstrated that there is a cross-reactivity between Schistosoma mansoni eggs and Fasciola gigantica worms and eggs. Saponins were found to be immunostimulatory adjuvants in our study.

Synthesis of new 4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine derivatives with an incorporated thiazolidinone moiety and testing their possible serine protease and cercarial elastase inhibitory effects with a possible prospective to block penetration of Schistosoma mansoni cercariae into the mice skin.

5-Substituted 4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine were synthesized by interaction of 4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-sulfonylhydrazide with some aldehydes to give the corresponding Schiff-bases, which after cyclization gave corresponding thiazolidinones. For some of the thiazolidinones, Mannich bases reaction was carried out. All the derivatives were tested for their possible inhibitory effect on Schistosoma mansoni cercarial elastase (CE). Only, N-(4-methylbenzyledine)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-sulfonylhydrazide was found to have potent inhibitory effect on the CE activity with IC50 = 264 microM. Upon its use as a paint for mice tails before infection with S. mansoni cercariae, the compound formulated in jojoba oil caused a significant reduction (93%; P-value = 0.0002) in the worm burden. IgG & IgM in mice sera were measured by using several S. mansoni antigens by ELISA. Sera from treated infected mice (TIM) 2, 4, and 6 weeks (W) post infection (PI) showed 1.2 folds lower, 1.2 folds higher, 1.7 folds lower IgM reactivity against soluble cercarial antigenic preparation (CAP), respectively, when compared with sera collected from infected untreated mice (IUM). Sera from TIM 2, 4, and 6WPI showed 1.3, 1.6, and 1.7 folds higher IgG reactivity, respectively against CAP than the IgG reactivity from IUM. Sera from TIM 2, 4 and 6WPI showed 1.5, 1.2 folds lower and 1.4 folds higher IgM reactivity, respectively against soluble worm antigenic preparation (SWAP) when compared with sera collected from IUM. Sera from TIM 2, 4, and 6WPI showed 1.4, 1 folds lower and 1 fold higher IgG reactivity, respectivley to SWAP when compared with sera from IUM. Sera from TIM 2, 4, and 6WPI had generaly lower IgM and IgG reactivities against soluble egg antigen (SEA) when compared with sera from IUM.