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PubMedDate not supplied

Immunity against the venom of Mexican scorpion Centruroides lumpidus limpidus induced by some proteins from this venom.

A protein fraction, which consisted of at least 12 proteins, was obtained from the venom of Mexican scorpion Centruroides limpidus limpidus. The molecular weights of these proteins ranged between 9,800 and 163,000 daltons. This fraction was separated from the rest of the venom components, which were almost all neurotoxins, by chromatographying the venom obtained by electrical stimulation through a Sephadex G-50M column. This fraction was non-toxic for mice, even at dose of 200 micrograms/mouse. The most important is that it was able to induce immunity against C. l. limpidus venom, since 92.8% of the animals inoculated with three doses survived after the challenge with 39.2 micrograms of venom (2 DL50 for mice of 20 g); on the contrary, 88 min after the challenge, 100% of the control mice had already died. In another experiment, this immunogen was inoculated into mice three times at variable doses. Seven days after the last injection, each mouse was challenged with 19.6 micrograms of venom. In all controls the typical envenomation picture produced by scorpion venom was developed, and death was registered in 19% of the animals. In contrast, 87% of mice immunized with the highest dose failed to show signs of envenomation or died throughout the observation time. Only two immunized animals (13%) showed mild tachycardia and hyperpnea at 120 min post-challenge. Immunoelectrophoresis and immunodiffusion tests revealed that these proteins induced antibodies against components of the most toxic fraction.

Animals↗
PubMed2005

Development of new IgE specificities to hymenoptera allergens during venom-specific immunotherapy.

BACKGROUND: Despite the benefits of specific immunotherapy (SIT) being clinically well documented for allergic diseases, new IgE specificities to SIT extract allergens could be induced during the treatment. The authors evaluated these changes in patients allergic to Hymenoptera. METHODS: Six patients allergic to Hymenoptera venom were included in the study. Specific IgE (sIgE) levels determination and IgE immunoblots to Apis mellifera, Vespula spp. and Polistes spp. venom were performed before and after one year of SIT. RESULTS: All patients had sIgE levels reduction, after the first year of treatment, except one in whom there was an increase in sIgE levels to Apis mellifera venom, and two patients that maintained a similar value for Vespula spp. venom sIgE before and after one year of treatment. The immunoblot analysis revealed that most of the bands detected before beginning SIT, decreased in intensity or disappeared after one year of treatment. 3/6 patients developed new IgE specificities to venom extracts: one patient to the venom allergens in the treatment, other patient to allergens in other venom and another patient to both. After one year of treatment one of these patients tolerated a field sting by the corresponding insect. The newly recognised proteins were all minor allergens. CONCLUSION: These results confirm that sIgE levels tend to reduce during SIT, and the bands identifying some allergens in the blot tend to decrease or disappear. Nonetheless venom SIT can be responsible for the induction of new sensitisations to other venom allergens, apparently without clinical relevance.

Adult↗
PubMed2006

PDB-Metrics: a web tool for exploring the PDB contents.

PDB-Metrics (http://sms.cbi.cnptia.embrapa.br/SMS/pdb_metrics/index.html) is a component of the Diamond STING suite of programs for the analysis of protein sequence, structure and function. It summarizes the characteristics of the collection of protein structure descriptions deposited in the Protein Data Bank (PDB) and provides a Web interface to search and browse the PDB, using a variety of alternative criteria. PDB-Metrics is a powerful tool for bioinformaticians to examine the data span in the PDB from several perspectives. Although other Web sites offer some similar resources to explore the PDB contents, PDB-Metrics is among those with the most complete set of such facilities, integrated into a single Web site. This program has been developed using SQLite, a C library that provides all the query facilities of a database management system.

Computer Graphics↗
PubMed1993

Activation of the contact system in insect-sting anaphylaxis: association with the development of angioedema and shock.

A postulated role of the contact system in anaphylactic reactions to insect stings was investigated. During prospective, in-hospital sting challenge, we collected serial blood samples from five normal volunteers and 16 patients with a history of insect-sting anaphylaxis. Activation of the contact system was assessed by measuring plasma levels of factor XIIa-C1-inhibitor and kallikrein-C1-inhibitor complexes as well as those of cleaved high molecular weight kininogen (HK). In addition, antigenic levels of (pre)kallikrein, factor XII, and HK were measured. No significant changes in contact system parameters were observed in any of the five volunteers or the four patients who did not develop an anaphylactic reaction after sting challenge. In contrast, significant changes in contact system parameters occurred in 7 of the 12 patients with anaphylactic symptoms after challenge. Peak levels of either C1-inhibitor complex were found 5 minutes after the onset of anaphylactic symptoms. The increase in C1-inhibitor was most pronounced in the 4 patients with angioedema, 2 of which also developed shock. However, activation of HK was observed in all four patients with angioedema, the two patients with shock but no angioedema, as well as in 1 of the remaining 6 patients with anaphylactic symptoms other than angioedema or shock. Thus, activation products of the contact system may be involved in the pathogenesis of angioedema and shock in insect-sting anaphylaxis.

Adult↗
PubMed1996

A conserved sequence region of scorpion toxins rendered immunogenic induces broadly cross-reactive, neutralizing antibodies.

Scorpion toxins constitute a family of proteins with a high degree of sequence diversity but a common mode of action. Neutralization of the toxic effects of scorpion stings by serotherapy is limited due to the various serotypes expressed by these proteins. We explored the possibility of raising antibodies to conserved parts of the toxins which could recognize several members of the family. We established the variability profile of a set of 25 scorpion toxin sequences, then evaluated systematically by peptide-scanning methods the antigenicity of one scorpion toxin. The most conserved regions were generally very poorly antigenic. One exception was the N-terminal region, which is both conserved and antigenic. Antibodies were raised in rabbits against an eight-residue synthetic peptide mimicking the N-terminal region. These peptide antibodies were cross-reactive with several scorpion toxins belonging to different serotypes and neutralized both the pharmacological effects (binding to rat brain synaptosomes) and the biological activity (toxicity in mice) of the parent toxin. The molecular model of the toxin indicates that antibody binding to residues 1-8 probably either masks some residue(s) of the N-terminus critical for the biological activity or overlaps with the epitope previously defined by neutralizing monoclonal antibody. These findings could open the way for new therapeutic strategies for the medical care of envenomations.

Amino Acid Sequence↗
PubMed1996

Allergen dose dependent cytokine production regulates specific IgE and IgG antibody production.

The elicitation of a specific immune response against allergens depends on the recognition of antigenic determinants (epitopes) by specific T and B lymphocytes. In order to determine the relevant epitopes for human T and B cells and their features in the regulation and production of specific IgE and/or IgG antibodies, we have investigated the immune response to bee venom phospholipase A2 (PLA) in allergic and non-allergic subjects. This enzyme represents the major allergen in bee sting allergy. It consists of 134 amino acid residues with a carbohydrate side chain at position 13 and is available as recombinant protein. We have developed PLA-specific T-cell clones from bee sting allergic and non-allergic human subjects. Using a panel of dodecapeptides overlapping in 10 residues and a large set of 18-25 mer overlapping peptides, we detected three epitopes that were recognized by peripheral blood T-cells and T-cell clones. A fourth determinant involved the carbohydrate moiety on Asn13 of PLA. Whereas the CHO-depending epitope seems to be mostly active in allergics, the other three epitopes are equally recognized by peripheral blood mononuclear cells (PBMC) of both allergic and non-allergic individuals. In T-cell clones, the ratio of IL-4/IFN gamma cytokines and the quality of the activating signal depend on the strength of the binding of the MHC-II/Ag/TcR complex between APC and T-cells. The number of antigen-specific APC-T-cell contact sites can be varied in vitro by changing the dose of antigen added to the cell culture. While isotype switch for both IgE and IgG4 requires IL-4, this cytokine suppresses antigen-specific IgG4 production by already switched B-cells. Therefore, IL-4 and IFN gamma display counter-regulatory effects on the production of IgE being responsible for atopic states and IgG4 antibodies which are signs of a normal immune response to allergen and act as protective antibodies. The combination of this counter-regulation of IgE and IgG4 antibodies with the fundamental law of mass action for chemical equilibrium reactions revealed that the antigen concentration governs to a great part the ratio of IL-4/IFN gamma secretion and therefore the formation of IgE and IgG and allergy or protection, together with the equilibrium constant K, which represents immunological individuality and a measure of Ag presentation.

Allergens↗
PubMed2003

Hydralysin, a novel animal group-selective paralytic and cytolytic protein from a noncnidocystic origin in hydra.

In Cnidaria, the production of neurotoxic polypeptides is attributed to the ectodermal stinging cells (cnidocytes), which are discharged for offensive (prey capture) and/or defensive purposes. In this study, a new paralysis-inducing (neurotoxic) protein from the green hydra Chlorohydra viridissima was purified, cloned, and expressed. This paralytic protein is unique in that it (1) is derived from a noncnidocystic origin, (2) reveals a clear animal group-selective toxicity, (3) possesses an uncommon primary structure, remindful of pore-forming toxins, and (4) has a fast cytotoxic effect on insect cells but not on the tested mammalian cells. The possible biological role of such a noncnidocystic toxin is discussed.

Amino Acid Sequence↗
PubMed1984

[Characteristic cerebrospinal fluid findings and clinical aspects of lymphocytic meningoradiculitis].

Clinical data and Cerebrospinal fluid (CSF) findings of 20 patients suffering from a meningoradiculitis were analyzed. Most patients had a tick bite or an erythema migrans before neurological symptoms occurred. All suffered from severe radicular pain. Predominant neurological symptoms were peripheral palsies of the facial nerve followed by motor paresis of the trunk and the extremities of mostly asymmetric distribution. Predominant CSF alterations were a long lasting inflammatory cellular reaction and an impairment of the blood-CSF barrier. In contrast to the CSF of 17 patients suffering from a polyradiculitis Guillain Barré with a similar total protein content, an intrathecal immunoglobulin IgG synthesis could be confirmed for the majority of the patients. CSF finding would be compatible to a viral as well as a borrelia etiology.

Bites and Stings↗
PubMed1991

Local edema induced by the black-bellied hornet (Vespa basalis) venom and its components.

The black-bellied hornet, Vespa basalis, is one of the most dangerous species of wasp in Taiwan. The hornet venom possesses a potent edema-inducing activity in addition to its lethal cardiovascular effect. Rat hind-paw edema induced by the venom was inhibited significantly by antiserotonin compounds (cyproheptadine and methysergide) but not by antihistaminics (chlorpheniramine and diphenhydramine), betamethasone, cromolyn, indomethacin plus nordihydroguaiaretic acid, cellulose sulfate, aprotinin or captopril. However, chlorpheniramine or betamethasone, when given in combination with cyproheptadine, showed a significant further inhibition of the venom-induced edema. Pretreating the rat with compound 48/80 reduced the edematous response to the venom. Four venom components, i.e. the lethal protein, mastoparan B, fraction 3 (containing protease) and fraction 15 (containing serotonin) were involved in the edematous effect of the venom. Paw edema induced by the crude venom and its protein components (lethal protein, mastoparan B and fraction 3) was similar in their responses to antiserotonin compounds and antihistamine (inhibited by cyproheptadine and methysergide but not by chlorpheniramine), while that induced by fraction 15 was inhibited by both. It is postulated that upon hornet stings, fraction 15 is acting as an exogenous serotonin, while the protein components, especially the lethal protein, are responsible for the release of endogenous autacoids in which serotonin plays the most important role in inducing local edema.

Animals↗
PubMed2001

Protection against tick-transmitted Lyme disease in dogs vaccinated with a multiantigenic vaccine.

In an effort to develop a safe and effective vaccine for the prevention of Lyme borreliosis that addresses concerns raised over currently available vaccines, dogs were vaccinated twice with a multiantigenic preparation of Borrelia burgdorferi, strain N40, on days 0 and 20 of the experiment. About 70 and 154 days after the first immunization, dogs were challenged by exposing them to field-collected Ixodes scapularis ticks harboring B. burgdorferi. Vaccinated dogs were completely protected from infection by all criteria utilized to assess infection, developed high-titer anti-B. burgdorferi serum antibodies and growth inhibitory activity which persisted for over 200 days, and did not demonstrate any untoward consequence of vaccination. Serum absorption experiments revealed that borreliacidal and most likely protective antibodies in dogs receiving the multiantigenic preparation were not only elicited against the OspA antigen, but were also produced against additional yet to be determined targets on B. burgdorferi organisms. These data demonstrate that a multiantigenic vaccine is effective in preventing Lyme disease transmitted via the natural vector.

Animals↗
PubMed1990

Isolations of protein A and protein G from the bacterial surface.

Ten tested cultures each of Staphylococcus aureus (S. aureus) and of Streptococcus belonging to serological group G bound human IgG to a high extent. Protein A could be solubilized from strain Cowan I of S. aureus by lysozyme, mutanolysine, hydroxylammoniumchloride, hot acid extraction or lysostaphin and subsequently purified by affinity chromatography on human IgG-sepharose. The purified protein A preparation had molecular weights between 29,000 and 63,000 D and inhibited binding of 125I-labeled human IgG to S. aureus Cowan I. Protein G could be solubilized from strain 26540 of the G-streptococci with lysozyme or hot acid extraction and purified by affinity chromatography on human IgG-sepharose. The purified protein G revealed a molecular weight of 67,000 D and inhibited binding of human IgG to the G-streptococci.

Bacterial Proteins↗
PubMed2005

Decrease of mosquito salivary gland proteins after a blood meal: an implication for pathogenesis of mosquito bite allergy.

Salivary gland protein profiles ofAedes aegypti (L.) and Culex quinquefasciatus (Say) pre- and post-blood feeding were analyzed. SDS-PAGE studies before blood feeding of Ae. aegypti demonstrated 8 major polypeptide bands of 20, 35, 37, 42, 45, 47, 70 kDa and a high molecular weight band >118 kDa, whereas those of Cx. quinquefasciatus demonstrated 9 major polypeptide bands of 20, 26, 36, 38, 45, 47, 49 kDa and 2 high molecular weight bands >118 kDa. After a blood feeding, salivary gland polypeptides of Ae. aegypti at 35, 37, 45, 47, 70 kDa and high molecular weight band >118 kDa were depleted, while the polypeptide bands of 20, 26, 36, 38 kDa were depleted in Cx. quinquefasciatus. The presented study suggests that these major polypeptides were introduced into vertebrate hosts when a mosquito took a blood meal. Further investigation in molecular, biochemical and immunological aspects of these salivary gland polypeptides may provide information for better understanding in the role of these proteins in mosquito bite allergy.

Aedes↗
PubMed1997

Cross-reactivity of skin and serum specific IgE responses and allergen analysis for three mosquito species with worldwide distribution.

BACKGROUND: Allergic reactions to mosquito bites are a common problem worldwide. Cross-reactive immunologic responses have not been reported. OBJECTIVE: For the three most common mosquito species, Aedes (Ae.) vexans, Ae. aegypti, and Culex (Cx.) quinquefaciatus, we investigated skin and serum specific IgE responses and analyzed salivary allergens. METHODS: Locally, Ae. vexans is a major pest, but Ae. aegypti and Cx. quinquefaciatus are not found. We studied 41 subjects living in Manitoba, using (1) skin bite tests, (2) ELISA to measure serum mosquito saliva- or salivary gland-specific IgE, (3) ELISA inhibition tests, and (4) sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunoblotting. RESULTS: Twenty-nine of the 41 subjects had skin reactions to Ae. vexans bites. Twenty-two of the 29 also reacted to Ae. aegypti bites. Mean serum mosquito-IgE levels to each of the three species were significantly higher in the reactive subjects than in the nonreactive subjects. Significant intercorrelations were found among skin reactions and mosquito-specific IgE levels for the three species. The Ae. aegypti-IgE ELISA reaction could be inhibited by addition of each mosquito extract. The serum IgE and IgG from Manitobans reacted with the antigens of all three species. A 37 kd allergen in each of the three species was recognized by the antibody against a recombinant Ae. aegypti saliva protein. CONCLUSIONS: Strong cross-reactive skin and IgE responses and species-shared antigens exist among the three mosquito species studied.

Adult↗
PubMed2003

Dysregulation of apoptosis in scorpion envenomed children: its reflection on their outcome.

In the present study, 46 children in Upper Egypt (less than 13 years old) were admitted to the Pediatric Intensive Care Unit for scorpion envenomation. They were compared with 20 apparently healthy children of matching age and sex as controls. Out of the studied victims, 25 children (54%) showed signs of severe envenomation and multiple organ dysfunction (MOD), while 21 victims (46%) showed signs of mild envenomation. The serum levels of apoptotic markers, soluble Fas (sFas), soluble Fas ligand (sFasL) and Bcl-2, were determined for both victims and controls. In addition, the serum levels of nitric oxide (NO) and lipid peroxides (LPO) were also measured. Scoring of MOD was evaluated using Logistic Organ Dysfunction System Score (LODS) for the severely envenomed victims. All victims (both severe and mild cases) showed significantly higher mean levels of sFas, LPO and NO and significantly lower serum levels of Bcl-2 in comparison to the controls. The level of sFasL was not detectable in the sera of the healthy control group. The case fatality rate was 15%. The severely envenomed children with MOD as well as the non-survivors showed significantly higher serum levels of sFas, sFasL, LPO and NO and significantly lower serum levels of Bcl-2 in comparison to the mild envenomed victims and the surviving victims of severe cases, respectively. The LODS score of the severely envenomed victims showed significant positive correlations with sFas and LPO and significant negative correlation with Bcl-2. In all victims, a significant positive correlation was detected between sFas and NO. On the other hand, Bcl-2 was significantly negatively correlated with both sFas and LPO. In conclusion, our study revealed that scorpion envenomation can increase apoptosis as shown by up-regulation of sFas/sFasL system and down-regulation of Bcl-2 that was associated by elevation of LPO and NO. This dysregulation of apoptosis was increased with the severity of scorpion envenomation and its extent increased as MOD score and outcome increased. Therefore, sFas and Bcl-2 may be of value in predicting the outcome of these cases. The increase of the extent of apoptosis detected in this study seems to play a role in the outcome of scorpion envenomation, and hence, should be taken into consideration for strategies of therapeutic regimen.

Animals↗
PubMed2003

Immunologic characterization of the recombinant fire ant venom allergen Sol i 3.

Individuals sensitized to fire ant stings show immunoglobulin (Ig)E antibodies against the venom protein Sol i 3. We determined the full-length complementary DNA (cDNA) sequence of this protein and expressed recombinant Sol i 3 in immunogenic form. The complete cDNA of Sol i 3 was obtained by reverse transcription polymerase chain reaction (RT-PCR) and PCR + 1 reactions using gene-specific oligonucleotides, and oligonucleotides designed from the amino acid sequence of this protein. The encoding cDNA is 705 bp in length corresponding to 235 amino acids. The first 22 amino acids are a leader sequence. The protein with an added C-terminal hexahistidine tag was expressed in insect cells using a baculovirus system. The recombinant protein was secreted into the supernatant and affinity purified with a cobalt chelating resin. The recombinant fire ant venom allergen Sol i 3 showed similar IgE binding activity to the native protein in radioallergosorbent test (RAST) and RAST inhibition assays. It was produced in both a glycosylated and an unglycosylated form. A three-dimensional reconstruction of Sol i 3 was compared with the experimentally determined structure of the related allergen Ves v 5. This model is supported by results of circular dichroism spectroscopy.

Allergens↗
PubMed2006

[Effect of Gleditsia sinensis stings on growth inhibition and expression of PCNA and p53 in mice bearing uterine cervical carcinoma (U14)].

OBJECTIVE: To study the antitumor effect of the stings of Gleditsia sinensis on mice bearing uterine cervical carcinoma (U14) and the expression of PCNA (proliferating cell nuclear antigen) and p53. METHOD: The effect of the ethanolic extract of G. sinensis stings on the inhibition rate of solid tumor and the life span of ascites tumor were calculated by the animal tumor model experiment in vivo. The positive cell numbers of PCNA and mutant p53 protein were measured by immunohistochemical SP method. RESULT: As compared with the control group, the ethanolic extract of G. sinensis stings (250, 500 and 1 000 mg x kg(-1) body weight, p.o.) and CTX (25 mg kg(-1) body weight, i.p.) administration significantly reduced the tumor weight of solid tumor and increased the life span of ascites tumor harboring mice (P < 0.01). The inhibition rate of solid tumor and the rate in life span were up to 47.44%, 59.49%, 63.92%, 73.42% and 52.21%, 67.26%, 78.76%, 95.58% respectively. Meanwhile,the expression of PCNA and mutant p53 protein also suppressed by ethanolic extract (P < 0.05, P < 0.01). CONCLUSION: The stings of G. sinensis showed antitumor activity and its possible mechanism might be related with the expression inhibition of PCNA and mutant p53 protein.

Animals↗