ofSchistosoma Mansoni Research Articles

Potentiality of curcumin on ISHAK scoring system and the expressions of BAX, IL-17A, and EGF in the treatment ofSchistosoma mansoni infection using Swiss albino mice.

The present study evaluated the antiparasitic effect of curcumin extract on Schistosoma mansoni in Swiss albino mice. The experimental design included four groups of S. mansoni - infected mice; without treatment (controls), curcumin-treated, Praziquantel (PZQ)-treated, and PZQ +curcumin treated mice. The results showed that curcumin improved ISHAK confluent necrosis score up to zero. PZQ +curcumin showed a significant reduction in portal inflammation. Both activity and fibrosis demonstrated lower scores in all treated groups, however, PZQ revealed a marked increase in confluent necrosis and interface hepatitis. Besides, the lobular inflammation revealed worsening in the overall ISHAK score in all treated groups compared with the control. Few periocular granulomas were recovered by PZQ +curcumin treatment at day 35 post-treatment (6±1.2), P-value <0.05. Curcumin revealed a mild reduction (60±7.376). Curcumin-treated groups, with and without PZQ, resulted in higher significant Immunoreactivity score (IRS) for Bcl-2-associated X (BAX) and lower Interleukine- 17A (IL-17A), and Human epidermal growth factor (EGF), compared to the control. However, PZQ revealed a lower mean IRS value in BAX, higher IL-17A and EGF in the periovulatory granuloma. It was concluded that PZQ +curcumin treatment had a potent synergistic outcome through lessening the number of granulomas, the inflammatory events, and the expression of EGF, and amelioration of apoptosis in the periovulatory granulomas if compared with either PZQ or curcumin alone.

Synthesis of new 4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine derivatives with an incroporated thiazolidinone moiety and testing their possible serine protease and cercarial elastase inhibitory effects with a possible prospective to block penetration ofSchistosoma 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.

Local transient induction of inflammatory cytokines after intranasal administration of recombinantBordetella pertussis

Inflammatory cytokines have been described to play a critical role in the orientation and amplification of the IgA immune response. In this study, we show that the intranasal administration of aBordetella pertussisstrain expressing the protective antigen glutathione-S-transferase ofSchistosoma mansoni(Sm28GST) induced an inflammatory response in the lungs of mice, characterized by the production of inflammatory cytokines, such as Tumor Necrosis Factor α, Interleukin-6 and Transforming-Growth Factor β. The production and the secretion of these cytokines in lung tissues were early and transient. Their presence was observed only during the first week after administration despite the persistence of the bacteria for 1 month. Two weeks after inoculation, Interleukin-10 secretion was detected in the lungs, which could explain the decrease in the production of inflammatory cytokines. These inflammation-regulating cytokines, induced in the lungs by the presence of the bacterial vector, could be part of the process generating the local immune response, in particular the anti-Sm28GST IgA response.

B-Cell Outgrowth and Ligand-Specific Production of IL-10 Correlate with Th2 Dominance in Certain Parasitic Diseases

In many parasitic infections, dominant T helper cell (Th) type-2 CD4+T cell responses exacerbate the disease. We have previously demonstrated that lacto-N-fucopentaose-III (LNFPIII), a sugar found on soluble egg antigens (SEA) ofSchistosoma mansoni,stimulates splenic B cells from parasite-infected mice to proliferate and produce IL-10, a cytokine that promotes the generation of Th2 immune responses. In the present study, we extend our observations on ligand-specific activation of IL-10 producing B cells to leishmaniasis and lymphatic filariasis. We report here that infection withLeishmania majorincreases the splenic B220+B cell subset in BALB/c mice, but not BALB/c. xid (lacking B-1 cells and carrying defective B-2 cells). In addition, these B cells secrete large amounts of IL-10in vitroin response to stimulation with soluble leishmanial extract (LSE), LNFPIII, or SO4-Lewisx. We also observed that injection of LSE increased the level of peritoneal exudate (PeC) B-1 cells (CD5+B220+) in BALB/c mice, but not C57BL/6, as compared to buffer-injected controls. Further, LSE elicited PeC B cells secreted IL-10 in response to LSE as well as to the sugars tested. A similar differential secretion of IL-10 by splenic B cells from BALB/c and BALB/c.xid was seen afterS. mansoniinfection. Likewise, injection of soluble microfilarial extract (MFX) resulted in an increase in percentage of PeC B-1 cells in BALB/c mice, but not C57BL/6, and these cells secreted IL-10 in response to stimulation with MFX or phosphorylcholine (PC). Collectively, these results suggest a correlation between expansion of ligand-specific IL-10 producing B and B-1 cells with dominance of Th2-type T cells in mice with the susceptible phenotype for these diseases.

Compatibility of one Brazilian and two Venezuelan strains ofSchistosoma mansoni with various strains ofBiomphalaria glabrata

For evaluation of the degree of genetic heterogeneity in parasite and snail strains, the compatibility between Biomphalaria glabrata and Schistosoma mansoni from different geographical areas was studied. Venezuelan snails from Bárbula, Manuare (areas of schistosome transmission) and Tinaquillo (non-transmission area) and Brazilian BH snails were exposed to infection with miracidia of both the Venezuelan YT and SM strains and the Brazilian BH strain of S. mansoni. Snail-parasite compatibility was evaluated by quantifying the number of snails shedding cercariae during a period of 35 to 60 days post-infection. The best compatibility appeared to be between the Brazilian parasites and the Brazilian or Venezuelan snails. In contrast, the Brazilian snails appeared to be resistant to infection by the Venezuelan parasites tested. Paradoxically, the compatibility between the sympatric pair of Venezuelan parasites and Venezuelan snails appeared to be lower in comparison with the allopatric association of the Brazilian parasite and the Venezuelan snails. The results suggest an important degree of heterogeneity in the snail and parasite isolates studied and yield biological markers for both organisms.

Immunizing potential of ultraviolet-attenuated cercariae of Schistosoma mansoni in rodent hosts.

Schistosoma mansoni cercariae attenuated with ultraviolet (UV) irradiation (254 nm) at a dose of 18 mJ/cm2 induced partial resistance against a homologous challenge in male ICR mice and male Hartley guinea pigs. The reduction in the adult worm burden was 51% and 37% +/- 13%, respectively. On the other hand, male and female Mongolian gerbils (Meriones unguiculatus) vaccinated with UV-attenuated cercariae exhibited marginal resistance (13% +/- 9% and 22% +/- 10%, respectively). This raises the possibility that gerbils might have an unknown immune-characteristic nature. The usefulness of UV-attenuated cercariae is discussed with respect to the control of the disease.

Reactivity of anti-tegument monoclonal antibodies with target epitopes in different worm tissues and developmental stages ofSchistosoma mansoni

Sixteen monoclonal antibodies (MABs) were selected for their reactivity with adult schistosome tegument. The distribution of target epitopes in different tissues of the adult and in various developmental stages was investigated by indirect immunofluorescence. The distinct patterns of reactivity of the MABs permitted their classification into 9 groups. The distribution of epitopes in larvae, particularly 3 h schistosomula, generally mirrored that in adults. A change in distribution of epitopes coincided with transformation from cercaria to schistosomulum providing a marker for this process. Two MABs reacted with surface membranes of intact cercariae, and 5 with the surfaces of intact 3 h schistosomula. The target epitopes of these 5 MABs were present in the tegument of adults, but not accessible externally. These observations suggest masking of antigens, not shedding, in the course of development. Indeed, no MAB reacted with intact lung or liver worms unless they were damaged. Three MABs reacted with membranes of the tegument and most other tissues, implying properties in common. Evidence for shared functions between epithelia was provided by the reactivity of 2 MABs with the tegument and protonephridia. Eight MABs bound both to the tegument and its cell bodies. Since the latter contains the machinery for protein synthesis, it is difficult to explain why 5 MABs bound to the tegument alone. Little cross-reactivity was found with the tissues of the tapeworm Hymenolepis, rather more with the closely related Schistosoma japonicum. It was concluded that tegument antigens are to a degree tissue specific but definitely not stage specific.

Lectin studies of surface carbohydrates and induction of gland secretion in the free-living stages ofSchistosoma mansoni

Secretion from glands was observed when cercariae ofSchistosoma mansoni were exposed to certain lectins. Lectins fromMaclura pomifera, Pisum sativum, andTriticum vulgaris, were effective at 7.5 μ/ml. The effects of cercarial gland secretion caused byT. vulgaris agglutinin andArachis hypogaea agglutinin were blocked by pretreatment with the inhibiting glycan. Discharge of glands was not visualized after exposure of miracidia to lectins. The distribution of five labeled lectins was determined on live miracidia and cercariae. OnlyT. vulgaris agglutinin generally labeled the cercarial and miracidial bodies. Specific labeling occurred with the other lectins on the anterior, in glands or on their secretions, in flame cells in both stages, and on an unidentified ring of cells in miracidia. The possible mechanisms involved in changes caused by the lectins are discussed.

Portal serum constituents possible determinants for anatomical localization ofSchistosoma mansoni during maturation and reproduction

Coupled adult pairs ofSchistosoma mansoni were incubated in medium containing either peripheral or portal serum from rat, rabbit, hamster, or man, and egg production was measured daily. In all cases egg production was significantly increased for pairs in the presence of portal sera compared with that in the presence of peripheral sera. Fractionation of rabbit portal serum according to molecular weight demonstrated that the most active component(s) were in the range of 2000 to 50,000. Similarly, a rat portal serum fraction in the range of 2000 to 30,000 molecular weight was most stimulatory. These fractions were as effective in stimulating oviposition as whole portal serum. (1) portal serum factor(s) exist that stimulateS. mansoni oviposition in vitro; (2) they are present in susceptible and nonsusceptible hosts; and (3) the molecular weight range for the active components is larger than would be expected for simple carbohydrates, amino acids, or free fatty acids absorbed from the gastrointestinal tract.

Identification of sex-linked antigens ofSchistosoma mansoni by immunoelectrophoresis and immunoblotting

Immunoelectrophoresis and immunoblotting techniques, using sera from hyperimmune rabbits and infected mice, were used to analyze antigens ofSchistosoma mansoni. A comparison was made between the antigenic composition of adult male and female worms, isolated from monosexually and bisexually infected hamsters. A large number of female-specific and a few male-specific antigens were detected. The antigenic composition of females isolated from monosexually infected hamsters was shown to be very different from that of paired females. The presence of a major female-specific antigen with an apparent molecular weight of 32 kd in paired females only, suggests that synthesis of this antigen by female worms is initiated by the male partner. Analysis of the humoral immune response of mice receiving bisexual or monosexual infections showed that both mono- and bisexually infected mice develop a major humoral immune response to a 36-kd polypeptide antigen. A response to a major polypeptide antigen with an apparent molecular weight of 60 kd was observed in bisexually infected mice only. No antibodies reactive with this 60-kd polypeptide are formed during mon-osexual infections with either male or female worms. The 60-kd polypeptide was, however, present in monosexually reared females. This presence, and the presence in bisexually reared males, suggests a transfer of this antigen from females to males.

Developmental changes in energy metabolism ofSchistosoma mansoni and physiological role of oxygen in maintaining parasite function

The time course of the conversion from a cyanide-sensitive to a cyanide-insensitive energy metabolism in immatureSchistosoma mansoni was followed by correlating transitions in CO2 and lactate formation with physiological properties of the parasite. Volume conducted electrical potentials and measurement of CO2 evolution indicate that 3-hr posttransformational schistosomula are highly sensitive to 1 mM cyanide. By 24 hr after transformation, evolution of CO2 under control conditions is reduced by 77% from 3-hr levels, while lactate excretion rises by 84%. At the 24-hr stage, neither cyanide nor rotenone affects the frequency or magnitude of endogenous electrical transients, but cyanide does eliminate 83 % of the already reduced levels of CO2 evolved in 24-hr schistosomula. The adult parasite evolves a low level of CO2 which is reduced by 88% in the presence of 1 mM cyanide. No significant Pasteur effect is detected, however, and endogenous electrical activity as well as mechanical responses of the adult musculature are unaffected by cyanide exposure. Furthermore, adult schistosomes were not adversely affected in terms of the physiological parameters measured by 24-hr incubations in oxygen-free medium. Adults were only marginally affected by 24-hr exposure to several respiratory inhibitors, but responded rapidly to some uncouplers of oxidative phosphorylation, including 2,4-DNP, carbonyl cyanide 3-chlorphenylhydrazone, and closantel. Our results indicate that schistosomula continue to rely on cyanide-sensitive respiratory components for at least 3 hr after transformation; by 24 hr, however, the parasites are metabolically similar to the adult stage, i.e, they depend on lactate fermentation for most of their energy requirements.

Strategies to determine the molecular basis of chemical communication by trematodes

The identification of pheromones and chemicals that may inhibit or stimulate growth and reproduction necessarily leads to the consideration of biochemical methods to isolate and characterize these molecules. Analysis ofSchistosoma mansoni surface antigens by direct radioiodination, metabolic labeling with tritiated and(14)C-tagged hexose precursors, affinity chromatography, isoelectric focusing, hydrophobic chromatography, and competitive inhibition is presented to illustrate methods of immunochemical analysis and antigen purification. Technical problems that may arise when investigating parasite molecular biology are described. Evidence of diminished fecundity of female worms in acutely infected mice supports the theory of a "crowding effect" in murine schistosomiasis and suggests the possibility that worm secretions or metabolites may function as chemical messages to inhibit oviposition. There is also evidence that the immune response of mice to an isolated surface antigen from adult worms results in the attenuation of hepatic granulomata of challenge infections. Several hypotheses are proposed to elucidate the molecular basis for chemical communication between trematodes and analytical approaches to test these hypotheses are outlined.

Mating preference inSchistosoma mansoni

We investigated the suitability of an in vitro culture system for measurement of mating behavior ofSchistosoma mansoni. The criteria used to evaluate this system were the level of phosphorylated nucleotides, egg production, and mating status of parasites. The level of ATP, ADP, AMP, and G6-P was measured at different time intervals during cultivation of worm pairs and remained essentially the same as that of control worms for up to 6 days. Egg production was observed in this system during 19 days of cultivation. Peak egg production occurred on day 4 with 72% of the total eggs being laid during the first week of cultivation. The variability in the number of eggs produced by different pairs ofS. mansoni necessitated the selection and matching of tubes with the same number of eggs after 48 hr. This permitted the detection of small changes in egg production by decreasing intertube variation. Mating recognition between male and femaleS. mansoni was evaluated by culturing separated adult worms with their original partner or with a different partner. During the first 24 hr, mating occurred among a greater percentage of worm pairs comprised of their original partner than among worm pairs comprised of different partners (P < 0.001). After 48 and 72 hr of cultivation, these differences were not statistically significant. Similar results were obtained with a culture of mixed males and females. Two drugs were studied for their effects on the mating ofS. mansoni in vitro. Aminoglutethimide (AG) at a concentration of 1 × 10(-4) had no effect on the frequency of mating whereas diethyldithiocarbamate (DDC) completely inhibited mating at a concentration of 3 × 10(-6) M and reduced the level of ATP in these worms.

Elemental changes during sexual maturation inSchistosoma mansoni

Changes in the elemental composition ofSchistosoma mansoni in relation to age and sexual status are described, and studies on the structural localization of calcium in adult worms and the elemental composition of the tegument-subtegumental tissues are reviewed. Some preliminary results on the distribution of Ca(2+)-dependent ATPase activity in the tegument of worms from both mixed and single-sex infections are also presented.

Migration of two Egyptian strains ofSchistosoma mansoni in hamsters

Migration of two Egyptian strains ofSchistosoma mansoni in hamsters

Presence of Schistosoma mansoni antigens in liver, spleen and kidney of infected mice: a sequential study.

In the present study the kinetics of the uptake and deposition of Schistosoma mansoni antigens in liver, spleen and kidney of S. mansoni infected Swiss mice have been investigated in relation to duration of infection and infection dose (50, 100, 200 cercariae). The presence of antigen was studied with a direct immunofluorescence reaction on frozen sections of the organs, using a number of fluorescein isothiocyanate (FITC)-labeled antisera produced against various antigen preparations isolated from different life-cycle stages of the parasite. The presence of antigen was demonstrable with two of the antisera, directed against the circulating anodic antigen (CAA) and against total soluble egg antigen (SEA). CAA was demonstrable from 1 week post infection (p.i.) onwards in Kupffer cells in the liver, from 2-3 weeks p.i. onwards in macrophages in the marginal zones in the spleen and from 3 weeks onwards in kidney glomeruli. Immunofluorescence reactions on CAA in kidney glomeruli, however, were only weak positive until 12 weeks p.i., whereafter strong positive reactions were found. SEA was demonstrable from 5 weeks p.i. onwards in Kupffer cells in the liver and from 4 weeks p.i. onwards in macrophages of the spleen. In contrast to CAA, SEA was not detectable in kidney glomeruli.

Densitometric thin-layer chromatographic analyses of cholesterol inSchistosoma mansoni (Trematoda) adults and their excretory-secretory products

Densitometric thin-layer Chromatographic analysis was used to quantitate cholesterol in 6-week-old male, female, and worm-pairs ofSchistosoma mansoni, and their excretory-secretory (E-S) products. Males extracted immediately after removal from mice had 1.2-1.5 μg cholesterol/worm, whereas those incubated for 0.5 hr in Earle's balanced solution at 37 ° C contained 0.8-1.5 μg cholesterol/ worm. Females extracted immediately after removal from hosts contained 130 ng cholesterol/worm. Females accumulated considerable cholesterol during incubation and had 420 ng cholesterol/ worm at 0.5 hr. Worm-pairs extracted at 0 hr had 1.9-2.8 μg cholesterol/pair and 1.2-1.5 μg cholesterol/ pair when extracted at 0.5 hr postincubation. Following incubation for 0.5 hr, males released 12-28 ng cholesterol/ worm (average 21), females released 8-13 ng cholesterol/ worm (average 11), and worm-pairs released 3-13 ng cholesterol/worm-pair (average 8).

Evaluation of lung recovery assay for schistosomula in mice immunized with X-irradiated cercariae ofSchistosoma mansoni

The lung recovery assay for schistosomula has recently been used as a rapid method for measuring the state of immunity of a challenged animal. Its merit rests on the fact that the peak day of schistosomular recovery in the lungs of both normal and immune hosts falls on the same day and the degree of immunity can be measured by the percent of schistosomular recovery on this particular day. An evaluation of this method for mice immunized with highly X-irradiated cercariae of Schistosoma mansoni was made. The results indicate that in the immunized mice the peak day for the schistosomular recovery was delayed and the number of schistosomula recovered on the peak day was decreased. The delay of the peak day was increased by the degree of host immunity, so its identification for a host of an unknown immunologic status was not a simple matter. In addition, this method measured only the immune effect which took place in the skin and on prepeak days in the lungs. It was not as competent as the conventional liver perfusion method which measures the total result of the immune effect of the skin, lungs, and liver. Our conclusion is that for measuring the immunizing effect of irradiated cercariae, the lung recovery method is not suitable for the determination of the state of immunity induced.

The effects of various treatments on the surfaces of the cercariae and schistosomula of Schistosoma mansoni.

In order to learn more about the nature of the chemical bonds stabilizing the surface membranes of the cercariae and schistosomula ofSchistosoma mansoni, these organisms were treated with a variety of reagents. The cercarial surface was dissolved by 8 M urea alone (pH 9·0) but was protected from such dissolution if a certain critical concentration of cation or anion was included in the 8 M urea solution. Divalent cations were more effective than monovalent cations in this protective effect. The 8 M urea was also unable to dissolve the cercarial surface at any pH below 5·8. The cercarial surface was very rapidly dissolved by sodium hydroxide solutions at pH 11·4 and above. The divalent cation calcium, if included in the sodium hydroxide solution, slowed down the rate of surface solution by sodium hydroxide. The schistosomular surface was stable to 8 M urea at pH 9·0 but was readily dissolved in 8 M urea at pH 10·7 and 11·7. The schistosomular surface was stable in aqueous sodium hydroxide solutions at pH 12·0. Anionic detergents were very effective in dissolving the cercarial surface at concentrations above 0·001%. Cationic and non-ionic detergents were ineffective at 0·01% or below. A saturated solution of digitonin if diluted 1:100 caused destruction of the cercarial surface. At higher concentrations it caused expansion and stabilization of this surface.It is suggested that in both the cercarial and the schistosomular surface, bonds between carboxyl (—COO′) and amino (—NH3+) groups are very important in maintaining structure. The origin of the —NH3+ group is possibly from —NH2lysyl group in cercariae, and a guanido group in schistosomula. The suggestion that cations are incorporated into the cercarial surface and stabilize it during and after penetration has been tested by treating schistosomula with EDTA. The EDTA had no visible effect on the surface, nor did it labilize the surface to other reagents.I should like to thank very warmly Dr S. A. Ibrahim, in whose Department this work was carried out. My grateful thanks are given to the Medical Research Council (U.K.) for a grant. I should also like to thank Mr J. R. Lauder, Mr Ahmed Gandour and Mr Saleh for their help during the work. I am very grateful to Dr J. A. Clegg and Dr S. R. Smithers for helpful discussions.

Comarative evolution of the fluorescent antibodies directed against the larval stages and the adults of Schistosoma mansoni. II. Experimental schistosomiasis in mice after treatment with niridazole.

Comarative evolution of the fluorescent antibodies directed against the larval stages and the adults of Schistosoma mansoni. II. Experimental schistosomiasis in mice after treatment with niridazole.