Potentiation of FMD vaccines with polycationic-nucleic acid complexes

Summary The effect of various polycations on the immune response potentiated with poly I:C was studied. It was found that low molecular weight polycations had no potentiating effect. Polylysine was ineffective whereas protamine was superior to lysozyme, poly-arginine, poly-histidine, DEAE-Dextran and histone.A foot-and-mouth disease trivalent vaccine composed of strains A₂₄ Cruzeiro, O₁ Caseros and C₂ Resende elicited no immune response in swine when adjuvanted with aluminium hydroxide but was effective when emulsified in oil. In general, the immune response was potentiated ten-fold when the emulsion contained poly I:C. The antibody production was in most cases further potentiated by a factor of ten when the nucleic acid double-strand was complexed with 1:10 (w/w) DEAE-Dextran. Protamine was as effective, or perhaps even more, than DEAE-Dextran to this effect.Guinea pigs vaccinated with a water-in-oil emulsion type monovalent C₃ vaccine showed an increase in antibody production when the vaccine contained poly I:C or poly I:C complexed with 1:10 (w/w) protamine.With 4 Figures     

Soluble Antiapoptotic Molecules and Immune Activation in Chronic Heart Failure and Unstable Angina Pectoris

Programmed myocyte cell death and activation of the immune system have been shown to occur in patients with congestive heart failure. Besides, unstable angina episodes are likely to be associated with immune activation. Our aim was to evaluate the role of changes in circulating levels of soluble Fas (sFas), suggestive of an enhanced inhibitory response to ongoing apoptosis, and soluble IL2 receptor (sIL2-R), indicative of T-lymphocyte activation, in chronic heart failure and unstable angina pectoris. Thirty patients affected by chronic heart failure (20 idiopathic and 10 ischemic cardiomyopathy) and 13 patients with unstable angina were evaluated. Twenty healthy individuals matched for age and gender were used as controls. A complete biochemical determination of indexes of myocardial damage including cardiac troponin I (cTnI) and creatine kinase (MB/CK) was performed. The results demonstrated that mean levels of sFas and sIL2-R were significantly increased in patients affected by chronic heart failure and unstable angina and were not associated with changes in renal function or with serum levels of cTnI. Highest values of sFas were found in NYHA class IV patients (IV NYHA class = 7.39 ± 0.52 vs. controls = 1.34 ± 0.12 ng/ml; P < 0.01) and more elevated in idiopathic than in ischemic cardiomyopathy (3.64 ± 0.40 vs. 1.82 ± 0.37 ng/ml; P < 0.01). Moreover, in chronic heart failure patients sFas and ejection fraction were negatively correlated (P = 0.01), whereas sFas and sIL2-R were positively correlated (P < 0.01). In unstable angina patients too, sFas and sIL2-R appeared to be correlated (P = 0.03); whereas sFas (angina group = 3.18 ± 0.39 vs. controls = 1.34 ± 0.12 ng/ml; P < 0.01) and sIL2-R (angina group = 0.46 ± 0.11 vs. controls = 0.00 UI/ml; P < 0.01) were higher in angina group than in controls. In most of the cases, the increase of sFas was associated with comparable changes in sIL2-R serum levels, indicating that the activation of Fas system is strictly associated with autoimmune–inflammatory reactions. This phenomenon, both in chronic heart failure and in unstable angina, occurs in the absence of biochemical evidences of myocardial damage and seems to parallel the activation of T cell. Soluble Fas could have a role in sustaining inflammatory response and in prolonging the detrimental effects correlated with it in chronic heart failure and angina pectoris.     

Novel mutations affecting SRY DNA-binding activity: the HMG box N65H associated with 46,XY pure gonadal dysgenesis and the familial non-HMG box R30I associated with variable phenotypes

The SRY gene (sex-determining region of the Y chromosome) initiates the process of male sex differentiation in mammalians. In humans mutations in the SRY gene have been reported to account for 10-15% of the XY sex reversal cases. We describe here two novel missense mutations in the SRY gene after the screening of 17 patients, including 3 siblings, with 46,XY gonadal dysgenesis and 4 true hermaphrodites. One of the mutations, an A to C transversion within the HMG box, causes the N65H substitution and it was found in a patient presenting 46,XY pure gonadal dysgenesis. The Escherichia coli expressed SRY(N65H) protein did not present DNA-binding activity in vitro. The other mutation, a G to T transversion, causes the R30I substitution. This mutation was found in affected and nonaffected members of a family, including the father, two siblings with partial gonadal dysgenesis, a phenotypic female with pure gonadal dysgenesis, and three nonaffected male siblings. The G to T base change was not found in the SRY sequence of 100 normal males screened by ASO-PCR. The R30I mutation is located upstream to the HMG box, within the (29)RRSSS(33) phosphorylation site. The E. coli expressed SRY(R30I) protein was poorly phosphorylated and consequently showed reduced DNA-binding capacity in vitro.     

Inhibition of HIV-1 infection by monoclonal antibodies to carbohydrates of Schistosoma mansoni

Patients infected with HIV-1 develop a potent humoral immune response against the virus, but HIV-1 primary isolates are remarkably resistant to neutralizing antibodies. Considering that the envelope glycoprotein of HIV-1 (gp120/41) is heavily glycosylated, we investigated whether anti-carbohydrate antibodies could inhibit HIV-1 infection in vitro. We studied the neutralizing activity of three monoclonal antibodies (mAbs) raised to carbohydrates of Schistosoma mansoni, against seven primary isolates of HIV-1. Assays were performed infecting peripheral blood mononuclear cells from normal donors with viral isolates previously treated with mAbs. Viral strains used were tropic for the coreceptors CCR5, CXCR4, and dual-tropic ones. We found that the anti-glycan mAbs vigorously inhibited HIV-1 infection, regardless of the preferential coreceptor usage of the isolate, in a dose-response manner. Importantly, five isolates were resistant to neutralization by two HIV-1 antibody-positive human sera endowed with potent anti-HIV-1 inhibitory activity. Our findings suggest that carbohydrates of the HIV-1 viral envelope may be a target of an effective humoral immune response elicited by vaccination.The first two authors contributed equally to this work     

Genetic variation and relationships at six VNTR loci in two distinct sample populations in Brazil

BACKGROUND: The Brazilian population has been the focus of intensive genetic study due to admixture characteristics whereas there are few reports on the variability of VNTR loci in Brazil. PRIMARY OBJECTIVE: The aim of this study was to analyse genetic parameters in sample populations from two geographically distant regions: S?o Luis City, in Maranh?o State and Campinas City, in S?o Paulo State. We investigated if distinct colonization influences could produce detectable differences in genetic background. SUBJECT AND METHODS: DNA samples from peripheral drained blood were obtained from unrelated individuals who underwent paternity testing. Allelic variation in six VNTR loci (D2S44, D4S139, D5S110, D8S358, DI0S28 and D17S79) was evaluated. The results were compared to reference databases available for general Latin-derived European and African-American populations as well as for other Brazilian groups. RESULTS: This study reveals that forensic population parameters did not show differences among regions, although we detected admixture values varying between the south-east and north-east of Brazil. CONCLUSIONS: Differences between the two samples are probably due to different admixture proportions of European- and African-derived alleles in each region: both populations are in Hardy Weinberg equilibrium. In addition, the allelic frequency for all loci, in both populations, can be used as database for forensic purposes.     

Role of macrophages,interferon gamma and procoagulant activity in the resistance of genetic heterogeneous mouse populations to mouse hepatitis virus infection

Summary Genetic heterogeneous mouse populations selected for high (H_III) and low (L_III) antibody response were used to study some aspects of mouse hepatitis virus 3 (MHV3) infection, such as the resistance pattern, virus replication in the liver and peritoneal exudate or in cultured peritoneal macrophages, the interferon (IFN) synthesis in the serum and peritoneal exudate and the procoagulant activity (PCA) of the peritoneal exudate (PEC) and spleen cells (SC). The H_III mice, when compared to their L_III mice counterparts, were susceptible to MHV3 infection showing higher virus titres in the liver and peritoneal exudate, comparable IFN alpha/beta or IFN gamma titres in the peritoneal exudate or in the serum, and higher levels of PCA of PEC and SC. A higher virus titre was detected in the supernatants of H_III mouse macrophages infected with MHV3. The activation of H_III mouse macrophages with LPS, IFN alpha/beta or IFN gamma, in contrast to that of L_III mouse macrophages, did not induce an antiviral effect with partial restriction of the MHV3 replication. The LPS antiviral activity was shown to be partially exerted by IFN alpha/beta synthesis. The IFN gamma was shown to be more effective in inducing an antiviral state in L_III macrophages, when compared to IFN alpha/beta. The data obtained are consistent with the notion that the resistance mechanisms to the MHV3 infection involve the PCA and the sensitivity of macrophages to IFN.     

Quantitative differences in lipid raft components between murine CD4<Superscript>+</Superscript> and CD8<Superscript>+</Superscript> T cells

Background  

Lipid rafts have been shown to play a role in T cell maturation, activation as well as in the formation of immunological synapses in CD4⁺ helper and CD8⁺ cytotoxic T cells. However, the differential expression of lipid raft components between CD4⁺ and CD8⁺ T cells is still poorly defined. To examine this question, we analyzed the expression of GM1 in T cells from young and aged mice as well as the expression of the glycosylphosphatidylinositol (GPI)-linked protein Thy-1 and cholesterol in murine CD4⁺ and CD8⁺ T cell subpopulations.     

The Steatocrit Test: a semiquantitative method to evaluate the fecal fat excretion--method standardization

The main objective of this study was to introduce among us this technique. In a first step, steatocrit was compared to Van de Kamer test for 30 fecal samples. A significant positive correlation was found. In a second step, a steatocrit value was determined for normal children aged 0 to 72 months. In children from 0 to 3 months of age, no influence was found of diet (whether exclusively maternal milk or artificial one) on steatocrit value. However, upto the age of 3 months a significant and negative correlation was found between age and steatocrit value. Finally, three age groups were identified with different steatocrit values, as follows: 0-1 month, 4.04%; 1-3 months, 1.38%, 3-72 months, 0.29%. Thus the steatocrit test for fecal fat excretion was again shown to be not only simple, rapid, painless and inexpensive but also a reliable one.