An unusual cysteine VL87 affects the antibody fragment conformations without interfering with the disulfide bond formation.

The Cys residues are almost perfectly conserved in all antibodies. They contribute significantly to the antibody fragment stability. The relevance of two natural contiguous Cys residues of an anti-recombinant human-follicle stimulation hormone (rhFSH) in a format of single-chain variable fragment (scFv) was studied. This scFv contains 5 Cys residues: VH22 and VH92 in the variable heavy chain (VH) and VL23, VL87 and VL88 in the variable light chain (VL). The influence of two unusual contiguous Cys at positions VL87 and VL88 was studied by considering the wild type fragment and mutant variants: VL-C88S, VL-C87S, VL-C87Y. The analysis was carried out using antigen-binding ability measurement by indirect specific ELISA and a detailed molecular modeling that comprises homology methods, long molecular dynamics simulations and docking. We found that VL-C87 affected the antibody fragment stability without interfering with the disulfide bond formation. The effect of mutating the VL-C87 by a usual residue at this position like Tyr caused distant structural changes at the VH region that confers a higher mobility to the VH-CDR2 and VH-CDR3 loops improving the scFv binding to the antigen.

Toxocaríase experimental em hamster / Experimental toxocariasis in hamsters

INTRODUÇÃO: Toxocaríase é uma infecção parasitária de distribuição global, causada pela fase larval de Toxocara spp. Os hospedeiros naturais são cães e gatos, nos quais o parasita completa o ciclo chegando a fase adulta. Outros hospedeiros podem ser infectados pela fase larval do parasita, após ingestão de ovos embrionados do solo, mãos contaminadas, fomites, ou ingestão de carne ou vísceras de animais infectados. Em hospedeiros paratênicos o parasita não completa o ciclo, invadindo em estágio larval vísceras ou outros tecidos, onde podem sobreviver e induzir a patologia. O presente estudo teve como objetivo caracterizar o hamster (Mesocricetus auratus), como modelo experimental de toxocaríase, inicialmente através do estudo das lesões histopatológicas em fígado, pulmão e rim. A caracterização da resposta imunológica do modelo, foi feita através do estudo de citocinas envolvidas nas respostas Th1 e Th2, e foi sugerida uma correlação entre alterações glomerulares e depósitos de complexos antígenos-anticorpo pré-formados na circulação. MÉTODOS: Hamsters foram inoculados com ovos embrionados de Toxocara canis, e mantidos no biotério do Instituto de Medicina Tropical de São Paulo. O estudo histopatológico foi desenvolvido utilizando-se cortes parafinados corados por hematoxilina e eosina. Para detecção de antígenos nos tecidos foram realizadas reações imunohistoquímicas, utilizando-se anticorpo monoclonal e policlonal anti- Toxocara canis. Utilizando-se o soro dos animais infectados e animais controle, foi realizada pesquisa de antígeno e anticorpo por ELISA. Para pesquisa de imunoglobulinas IgG e IgM e complemento, foram utilizados cortes congelados de rins para realização de reação de Imunofluorescência. Fragmentos de rins foram incluídos para utilização em microscopia eletrônica, para detecção de antígenos de toxocara e de imune complexos. Para caracterização de resposta imunológica foram estudadas citocinas envolvidas na resposta Th1 e Th2 por técnica de...

INTRODUCTION: Toxocariasis is a parasitic infection of global distribution, caused by the larval stage of Toxocara spp. The natural hosts are dogs and cats, in which the parasite completes the cycle reaching adulthood. Other hosts can be infected with the larval stage of the parasite, after ingestion of embryonated eggs from the soil, contaminated hands, fomites, or ingestion of meat or viscera of infected animals. In paratenics hosts the parasite not complete the cycle, encroaching on larval stage in viscera or other tissues where they can survive and induce pathology. The present study aimed to characterize the hamster, Mesocricetus auratus, as experimental model of toxocariasis, initially through the study of histopathological lesions in the liver, lung and kidney. The characterization of immune response model, was made through the study of cytokines Th1 and Th2 responses involved, and a correlation was suggested between glomerular changes and antibody-antigen complexes deposits preformed in the circulation. METHODS: Hamsters were inoculated with embryonated eggs of Toxocara canis, and kept in the bioterium of the Institute of Tropical Medicine of the São Paulo. The histopathologic study was developed using paraffin slides stained by hematoxylin and eosin. For detection of antigens in tissues immunohistochemistry reactions were performed using monoclonal and polyclonal anti-Toxocara canis sera. Using the serum of infected and control animals, search has been carried out of antigen and antibody by ELISA. For the search of immunoglobulins IgG, IgM and complement, were used slides prepared from frozen fragments of kidneys and a immunofluorescence reaction. Fragments of kidneys were included for electron microscopy to detect antigens of Toxocara and immune complexes. For characterization of Th1 and Th2 response cytokines involved were detected by RT-PCR technique. RESULTS: Histopathological findings demonstrated since the beginning of the...

Botryomycosis.

Botryomycosis is a chronic, granulomatous, infectious disease caused by several genera of bacteria with the formation of grains. The factors involved in its development are low virulence, an intermediate inoculum, and the immunologic status of the host. The pathogenesis of the disease is not well established, but the Splendore-Hoeppli phenomenon, which explains the formation of grains and the antigen-antibody reaction that characterizes the disease, is involved. Diagnosing botryomycosis includes clinical suspicion and microbiologic studies. Isolation of the causative agent and susceptibility tests are essential to provide appropriate treatment.

PLGA microspheres containing bee venom proteins for preventive immunotherapy.

Bee venom (BV) allergy is potentially dangerous for allergic individuals because a single bee sting may induce an anaphylactic reaction, eventually leading to death. Currently, venom immunotherapy (VIT) is the only treatment with long-lasting effect for this kind of allergy and its efficiency has been recognized worldwide. This therapy consists of subcutaneous injections of gradually increasing doses of the allergen. This causes patient lack of compliance due to a long time of treatment with a total of 30-80 injections administered over years. In this article we deal with the characterization of different MS-PLGA formulations containing BV proteins for VIT. The PLGA microspheres containing BV represent a strategy to replace the multiple injections, because they can control the solute release. Physical and biochemical methods were used to analyze and characterize their preparation. Microspheres with encapsulation efficiencies of 49-75% were obtained with a BV triphasic release profile. Among them, the MS-PLGA 34kDa-COOH showed to be best for VIT because they presented a low initial burst (20%) and a slow BV release during lag phase. Furthermore, few conformational changes were observed in the released BV. Above all, the BV remained immunologically recognizable, which means that they could continuously stimulate the immune system. Those microspheres containing BV could replace sequential injections of traditional VIT with the remarkable advantage of reduced number of injections.

Anticuerpos contra células del trofoblasto en el primer trimestre del embarazo / Antibodies against trophoblast cells in the first quarter of pregnancy

Las células del trofoblasto no expresan los antígenos HLA clásicos de clase I (A, B, C), pero sí los antígenos HLA G que pueden generar anticuerpos capaces de tener reacción cruzada con los primeros. Se estudiaron 24 mujeres en el primer trimestre del embarazo, sin antecedentes de embarazos o transfusiones de sangre, con anticuerpos reactivos contra leucocitos, plaquetas o ambos (9 antigranulocitarios y 15 anti-HLA), para determinar la presencia de anticuerpos antitrofoblasto, mediante técnica de inmunofluorescencia indirecta en lámina. El 54,16 por ciento presentó anticuerpos antitrofoblasto. El 86,66 por ciento de las embarazadas con anticuerpos anti-HLA, presentó anticuerpos contra trofoblasto, mientras que ninguno de los sueros con anticuerpos específicos de granulocitos reaccionó con las células trofoblásticas (p=0,00). Después de la adsorción con tejido trofoblástico, los sueros con anticuerpos con especificidad granulocitaria mantuvieron la reactividad con leucocitos de sangre periférica, y solo 2 de los que presentaban especificidad HLA. Los resultados sugieren que la mayoría de los anticuerpos anti-HLA, reactivos con leucocitos, plaquetas o ambos, pueden estar dirigidos contra antígenos HLA-G del trofoblasto y muestran reacción cruzada con los antígenos HLA leucocitarios, lo cual favorece el bloqueo de la respuesta de los leucocitos maternos contra las células fetales, lo que pudiera explicar, además, la alta prevalencia de anticuerpos anti-HLA en el embarazo temprano(AU)

Trophoblast cells do not express classical HLA class I antigens (A, B, C), but they do express HLA G antigens which may generate antibodies capable of cross-reacting with the former. A study was conducted of 24 women in the first quarter of pregnancy, with no previous pregnancies or blood transfusions, with reactive antibodies against leukocytes, platelets or both (9 antigranulocytary and 15 anti-HLA), to determine the presence of antitrophoblast antibodies, by plate indirect immunofluorescence technique. 54.16 percent had antitrophoblast antibodies. 86.66 percent of the pregnant women with anti-HLA antibodies had antibodies against the trophoblast, whereas none of the sera with granulocyte specific antibodies reacted with trophoblastic cells (p=0,00). Following adsorption with trophoblastic tissue, the sera with antibodies showing granulocyte specificity remained reactive with peripheral blood leukocytes, as opposed to just 2 of those showing HLA specificity. Results suggest that most anti-HLA antibodies reactive with leukocytes, platelets or both, may be aimed against trophoblast HLA-G antigens, and cross-react with leukocyte HLA antigens, which facilitates blockage of the response of maternal leukocytes against fetal cells. This may also explain the high prevalence of anti-HLA antibodies during early pregnancy(AU)

Aspectos clínicos e patológicos em bovinos afetados por raiva com especial referência ao mapeamento do antígeno rábico por imuno-histoquímica / Clinical and pathological aspects in cattle affected by rabies with special reference to the rabies antigen mapping by immunohistochemistry

Este estudo retrospectivo incluiu achados clínicos e patológicos de 15 bovinos afetados por raiva. Em treze dos quinze casos, raiva foi confirmada por imunofluorescência direta. Bovinos entre 4 meses e 8 anos foram afetados. O curso clínico variou de três a sete dias. A forma paralítica foi a mais frequente e incluiu incoordenação, paresia e paralisia dos membros pélvicos, decúbito, movimentos de pedalagem e morte. Os principais achados histopatológicos foram meningoencefalite linfoplasmocitária associada com corpúsculos de Negri em 86,6 por cento dos casos. Todos os casos foram positivos na imuno-histoquímica para raiva, cujas reações foram mais evidentes no tronco encefálico, incluindo bulbo, ponte e mesencéfalo, além de gânglio trigêmeo. A imuno-histoquímica demonstrou o vírus da raiva em axônios, dendritos e pericário de neurônios, como agregados de grânulos ou em formações arredondadas associadas com números variáveis de corpúsculos de inclusão virais nos neurônios. Houve também marcação nos neurônios de Purkinje e de seus processos na camada molecular, nos núcleos do tronco encefálico e camada profunda do córtex telencefálico. A imuno-histoquímica pode ser importante ferramenta diagnóstica no diagnóstico da raiva, especialmente em situações nas quais não é possível manter refrigeração adequada das amostras e em casos com meningoencefalite não-supurativa e ausência de corpúsculos de inclusão.

This retrospective study included clinical and pathological findings from 15 cattle affected by rabies. Thirteen of the 15 cases were confirmed by direct immunofluorescence. Cattle between 4 months and 8 years of age were affected. Clinical course ranged from 3 to 7 days. Paralytical form was the most common clinical picture and included incoordination, paresis, and paralysis of the pelvic members, besides recumbence, paddling, and death. The main histopathological findings were lymphoplasmacytic meningoencephalitis associated with characteristic Negri bodies in 86.6 percent of the cases. All cases showed anti-rabies immunostaining, which were most prominent in the brainstem including medulla oblongata, pons, and midbrain, besides trigeminal ganglion. Positive labeling was present within axons, dendrites, and perikarya of neurons as aggregates of granules or round formations associated with varying numbers of inclusion bodies. Immunostaining was also observed in the Purkinje neurons and their processes in the molecular layer, in the neurons of of the brainstem, and deep layer of the telencephalic cortex. Immunohistochemistry may be an important auxiliary tool for the diagnosis of rabies, especially in circumstances in which refrigeration cannot be adequately maintained, and in cases characterized by nonsuppurative meningoencephalitis with absence of inclusion bodies.

Aspectos clínicos e patológicos em bovinos afetados por raiva com especial referência ao mapeamento do antígeno rábico por imuno-histoquímica / Clinical and pathological aspects in cattle affected by rabies with special reference to the rabies antigen mapping by immunohistochemistry

Este estudo retrospectivo incluiu achados clínicos e patológicos de 15 bovinos afetados por raiva. Em treze dos quinze casos, raiva foi confirmada por imunofluorescência direta. Bovinos entre 4 meses e 8 anos foram afetados. O curso clínico variou de três a sete dias. A forma paralítica foi a mais frequente e incluiu incoordenação, paresia e paralisia dos membros pélvicos, decúbito, movimentos de pedalagem e morte. Os principais achados histopatológicos foram meningoencefalite linfoplasmocitária associada com corpúsculos de Negri em 86,6 por cento dos casos. Todos os casos foram positivos na imuno-histoquímica para raiva, cujas reações foram mais evidentes no tronco encefálico, incluindo bulbo, ponte e mesencéfalo, além de gânglio trigêmeo. A imuno-histoquímica demonstrou o vírus da raiva em axônios, dendritos e pericário de neurônios, como agregados de grânulos ou em formações arredondadas associadas com números variáveis de corpúsculos de inclusão virais nos neurônios. Houve também marcação nos neurônios de Purkinje e de seus processos na camada molecular, nos núcleos do tronco encefálico e camada profunda do córtex telencefálico. A imuno-histoquímica pode ser importante ferramenta diagnóstica no diagnóstico da raiva, especialmente em situações nas quais não é possível manter refrigeração adequada das amostras e em casos com meningoencefalite não-supurativa e ausência de corpúsculos de inclusão.(AU)

This retrospective study included clinical and pathological findings from 15 cattle affected by rabies. Thirteen of the 15 cases were confirmed by direct immunofluorescence. Cattle between 4 months and 8 years of age were affected. Clinical course ranged from 3 to 7 days. Paralytical form was the most common clinical picture and included incoordination, paresis, and paralysis of the pelvic members, besides recumbence, paddling, and death. The main histopathological findings were lymphoplasmacytic meningoencephalitis associated with characteristic Negri bodies in 86.6 percent of the cases. All cases showed anti-rabies immunostaining, which were most prominent in the brainstem including medulla oblongata, pons, and midbrain, besides trigeminal ganglion. Positive labeling was present within axons, dendrites, and perikarya of neurons as aggregates of granules or round formations associated with varying numbers of inclusion bodies. Immunostaining was also observed in the Purkinje neurons and their processes in the molecular layer, in the neurons of of the brainstem, and deep layer of the telencephalic cortex. Immunohistochemistry may be an important auxiliary tool for the diagnosis of rabies, especially in circumstances in which refrigeration cannot be adequately maintained, and in cases characterized by nonsuppurative meningoencephalitis with absence of inclusion bodies.(AU)

[Alloimmunization]. / Aloimunização.

Alloimmunization is the formation of antibodies when there is an exposition of the individual to non-self antigens, as it occurs, for example, in the transfusion of incompatible blood and pregnancies, in whom the fetus express in its sanguineous cells antigens exclusively of paternal origin. This article is restricted to the alloimmunization against erythrocytes antigens in obstetric patients. Almost all the anti-erythrocytes antibodies can be fit in one of the 29 systems of already recognized sanguineous groups, being more implied in the hemolytic disease of the newborn anti-D, anti-c and anti-Kell, followed by anti-C, anti-E, anti e, anti-Fy feminine and anti-Jk feminine. The research of irregular antibodies, to permit the diagnosis of alloimmunizated people, and the modern genetic techniques have better characterized these patients for the prophylaxis and prenatal segment. The traditional accompaniment of the gestations of risk for hemolytic disease of the newborn, with the spectral analysis of the amniotic liquid and the intraperitoneal transfusion, has being quickly substituted for the Doppler ultrasound evaluation in the middle cerebral artery, the intravascular transfusion guided for ultrasonography in real time, beyond improvements in the materials and the quality of the blood, that in set, have raised the survival of the attempting fetus. Doubtlessly, the correct application of the prophylaxis with use of anti-D is successful with potential to reduce the alloimmunization cases.

Aloimunização: [revisão] / Alloimmunization: [review]

Aloimunização é a formação de anticorpos quando há a exposição do indivíduo a antígenos não próprios, como ocorre, por exemplo, na transfusão de sangue incompatível e nas gestantes, cujos fetos expressam em suas células sanguíneas antígenos exclusivamente de origem paterna. Este artigo se restringe à aloimunização contra antígenos eritrocitários em pacientes obstétricas. Quase todos os anticorpos antieritrocitários podem ser enquadrados em um dos 29 sistemas de grupos sanguíneos já reconhecidos, sendo os mais comumente implicados na doença hemolítica perinatal o anti-D, anti-c e anti-Kell, seguidos por anti-C, anti-E, anti e, anti-Fyª e anti-Jkª. A pesquisa de anticorpos irregulares permite o diagnóstico de indivíduos aloimunizados e modernas técnicas genéticas têm melhor caracterizado estas pacientes para a profilaxia e segmento pré-natal. O tradicional acompanhamento das gestações de risco para a doença hemolítica perinatal, com a espectrofotometria do líquido amniótico e a transfusão intraperitoneal, vem rapidamente sendo substituído pela doplervelocimetria na artéria cerebral média e a transfusão intravascular guiada por ultrassonografia em tempo real. É possível também citar como avanços melhorias nos materiais e na qualidade do sangue transfundido, que, em conjunto, têm elevado a sobrevivência de fetos acometidos. Indubitavelmente, a correta aplicação da profilaxia com uso do anti-D é exitosa com potencial para reduzir os casos de aloimunização.

Alloimmunization is the formation of antibodies when there is an exposition of the individual to non-self antigens, as it occurs, for example, in the transfusion of incompatible blood and pregnancies, in whom the fetus express in its sanguineous cells antigens exclusively of paternal origin. This article is restricted to the alloimmunization against erythrocytes antigens in obstetric patients. Almost all the anti-erythrocytes antibodies can be fit in one of the 29 systems of already recognized sanguineous groups, being more implied in the hemolytic disease of the newborn anti-D, anti-c and anti-Kell, followed by anti-C, anti-E, anti e, anti-Fyª and anti-Jkª. The research of irregular antibodies, to permit the diagnosis of alloimmunizated people, and the modern genetic techniques have better characterized these patients for the prophylaxis and prenatal segment. The traditional accompaniment of the gestations of risk for hemolytic disease of the newborn, with the spectral analysis of the amniotic liquid and the intraperitoneal transfusion, has being quickly substituted for the Doppler ultrasound evaluation in the middle cerebral artery, the intravascular transfusion guided for ultrasonography in real time, beyond improvements in the materials and the quality of the blood, that in set, have raised the survival of the attempting fetus. Doubtlessly, the correct application of the prophylaxis with use of anti-D is successful with potential to reduce the alloimmunization cases.

Human serum antibody reactivity towards Paracoccidioides brasiliensis antigens treated with sodium metaperiodate.

In this study, we evaluated the profile of anti-Paracoccidioides brasiliensis immunoglobulin isotypes in serum from patients with the acute and chronic forms of paracoccidioidomycosis, using the whole Paracoccidioides brasiliensis antigen and the antigen treated with sodium metaperiodate. All the immunoglobulin isotypes present in the serum from patients with the acute and chronic forms of paracoccidioidomycosis presented higher reactivity towards the whole antigen than to the antigen treated with metaperiodate (P < 0.05). The reactivity of IgG and IgM to the antigen treated with metaperiodate was greater in serum from patients with the acute form of the disease (P < 0.05), while IgA was more reactive in serum from patients with the chronic form (P < 0.05). There was greater reactivity of IgG1 and IgG2 to the whole antigen and the antigen treated with metaperiodate in the serum from patients with paracoccidioidomycosis than there was in serum from patients with other parasitic infections (P < 0.05). Furthermore, IgG1 from patients with the acute form recognized the 19kDa, 27kDa and 31kDa antigens in the western blot test. Thus, the results suggest that modifications to the epitopes of Paracoccidioides brasiliensis antigens may help to improve the immunodiagnosis of paracoccidioidomycosis.

Towards the definition of a chimpanzee and human conserved CD6 domain 1 epitope recognized by T1 monoclonal antibody.

Scavenger receptor cysteine-rich (SRCR) domains are evolutionally conserved modules that display complex structures stabilized by key amino acids, while some other residues have evolved with a relative independence, thus allowing the functional diversity of these receptors. CD6, a highly glycosylated membrane protein predominantly expressed on lymphocytes, contains three SRCR domains. The lack of CD6 domain crystal structure has limited the characterization of the binding sites for the interacting molecules. The interaction between CD6 and its ligand, activated leukocyte-cell adhesion molecule (ALCAM)/CD166, through the membrane-proximal SRCR3 domain, has low affinity and involves conserved sites in both molecules mediating a cross-species binding. The CD6-ALCAM interaction has been involved in cell adhesion, maturation, regulation of activation, and survival processes, suggesting the potential relevance of this target for therapeutic interventions. Several anti-CD6 monoclonal antibodies (MAb) have been described but their affinity and epitope definition remain unclear. We found the murine and humanized T1 MAb versions have similar CD6 recognition profiles and affinity constants of about 6 x 10(8). These antibodies do not block the CD6-ALCAM interaction and recognize a conformational epitope independent of the CD6 N-glycosylation. This epitope was additionally found in the chimpanzee and contains an RXE/Q consensus motif located in the membrane-distal SRCR1. These results, together with the therapeutic evidence previously obtained with these MAbs, suggest a differential contribution of CD6 domains to lymphocyte biology. Potential mechanisms for T1 MAb therapeutic effect different from CD6-CD166 interaction blocking would be dissected.

Human serum antibody reactivity towards Paracoccidioides brasiliensis antigens treated with sodium metaperiodate / Reatividade de anticorpos de soros humanos a antígenos de Paracoccidioides brasiliensis tratados com metaperiodato sódico

In this study, we evaluated the profile of anti-Paracoccidioides brasiliensis immunoglobulin isotypes in serum from patients with the acute and chronic forms of paracoccidioidomycosis, using the whole Paracoccidioides brasiliensis antigen and the antigen treated with sodium metaperiodate. All the immunoglobulin isotypes present in the serum from patients with the acute and chronic forms of paracoccidioidomycosis presented higher reactivity towards the whole antigen than to the antigen treated with metaperiodate (P < 0.05). The reactivity of IgG and IgM to the antigen treated with metaperiodate was greater in serum from patients with the acute form of the disease (P < 0.05), while IgA was more reactive in serum from patients with the chronic form (P < 0.05). There was greater reactivity of IgG1 and IgG2 to the whole antigen and the antigen treated with metaperiodate in the serum from patients with paracoccidioidomycosis than there was in serum from patients with other parasitic infections (P < 0.05). Furthermore, IgG1 from patients with the acute form recognized the 19kDa, 27kDa and 31kDa antigens in the western blot test. Thus, the results suggest that modifications to the epitopes of Paracoccidioides brasiliensis antigens may help to improve the immunodiagnosis of paracoccidioidomycosis.

Neste trabalho, foi avaliado o perfil de isotipos de imunoglobulinas anti-Paracoccidioides brasiliensis em soros de pacientes com formas crônica e aguda de paracoccidiodomicoses usando antígeno total e tratado com meta-periodato. Todos os tipos de imunoglobulinas presentes nos soros de pacientes com formas aguda e crônica apresentaram alta reatividade ao antígeno total quando comparado ao tratado com meta-periodato (P < 0,05). Houve maior reatividade de IgG e IgM anti-antígeno tratado com meta-periodato em soros de pacientes com forma aguda da doença (P < 0,05), enquanto IgA foi mais reativa em soros da forma crônica (P < 0,05). Houve maior reatividade de IgG1 e IgG2 com antígeno total e tratado com meta-periodato em soros de pacientes comparados aos com outras parasitoses (P < 0,05). Além disso, IgG1 de pacientes com a forma aguda reconhecem antígenos de 19kDa, 27kDa e 31kDa por western blot. Assim, os resultados sugerem que alterações nos epitopos de antígenos de Paracoccidioides brasiliensis podem auxiliar no aprimoramento do imunodiagnóstico da paracoccidioidomicose.

Quantitative analysis of immunoglobulin E reactivity profiles in patients allergic or sensitized to natural rubber latex (Hevea brasiliensis).

BACKGROUND: Characterized native and recombinant Hevea brasiliensis (rHev b) natural rubber latex (NRL) allergens are available to assess patient allergen sensitization profiles. OBJECTIVE: Quantification of individual IgE responses to the spectrum of documented NRL allergens and evaluation of cross-reactive carbohydrate determinants (CCDs) for more definitive diagnosis. METHODS: Sera of 104 healthcare workers (HCW; 51 German, 21 Portuguese, 32 American), 31 spina bifida patients (SB; 11 German, 20 Portuguese) and 10 Portuguese with multiple surgeries (MS) were analysed for allergen-specific IgE antibody (sIgE) to NRL, single Hev b allergens and CCDs with ImmunoCAP technology. RESULTS: In all patient groups rHev b 5-sIgE concentrations were the most pronounced. Hev b 2, 5, 6.01 and 13 were identified as the major allergens in HCW and combined with Hev b 1 and Hev b 3 in SB. In MS Hev b 1 displayed an intermediate relevance. Different sIgE antibody levels to native Hevea brasiliensis (nHev b) 2 and rHev b 6.01 allowed discrimination of SB with clinical relevant latex allergy vs. those with latex sensitization. Sensitization profiles of German, Portuguese and American patients were equivalent. rHev b 5, 6.01 and nHev b 13 combined detected 100% of the latex-allergic HCW and 80.1% of the SB. Only 8.3% of the sera showed sIgE response to CCDs. CONCLUSIONS: Hev b 1, 2, 5, 6.01 and 13 were identified as the major Hev b allergens and they should be present in standardized latex extracts and in vitro allergosorbents. CCDs are only of minor relevance in patients with clinical relevant latex allergy. Component-resolved diagnostic analyses for latex allergy set the stage for an allergen-directed immunotherapy strategy.

Relevance of the recombinant lipid transfer protein of Hevea brasiliensis: IgE-binding reactivity in fruit-allergic adults.

BACKGROUND: Lipid transfer proteins (LTPs) are relevant allergens in certain plants. The role of the LTP of Hevea brasiliensis in the latex-fruit syndrome is widely unknown. OBJECTIVE: To study IgE reactivity with recombinant Hevea LTP in sera of fruit-allergic adults with and without natural rubber latex (NRL) allergy. METHODS: An LTP-specific complementary DNA of H brasiliensis leaves was amplified, subcloned into the pMAL expression system, and analyzed. The recombinant protein was coupled to ImmunoCAP, and the IgE-binding properties were studied in sera of 10 NRL-allergic patients without symptoms to fruit and 48 atopic patients with fruit allergy. Eleven of these 48 patients were also allergic to NRL, 14 displayed sensitization to NRL without symptoms on NRL exposure so far, and 23 had neither symptoms nor IgE antibodies to NRL. RESULTS: After expression in Escherichia coli, a soluble maltose-binding protein-rHev b 12 fusion protein was isolated and coupled to ImmunoCAP to determine rHev b 12 specific IgE reactivity. rHev b 12 specific IgE binding was found in 3 fruit-allergic patients with NRL sensitization (0.68, 0.88, and 0.96 kU/L) and in 3 fruit-allergic patients without NRL sensitization (1.58, 2.25, and 2.27 kU/L). The remaining 52 serum samples and all maltose-binding protein control test results were negative (< 0.35 kU/L). CONCLUSIONS: In these patients, rHev b 12 specific IgE reactivity seems to result from common cross-reactive epitopes with some of the fruit LTPs tested and underscores only an involvement in co-recognition. No clinical relevance of IgE binding to the LTP of H brasiliensis in association with NRL allergy was detected.

The conservative physiology of the immune system. A non-metaphoric approach to immunological activity.

Historically, immunology emerged as a biomedical science, concerned with host defense and production of anti-infectious vaccines. In the late 50s, selective theories were proposed and from then on, immunology has been based in a close association with the neo-Darwinian principles, such as random generation of variants (lymphocyte clones), selection by extrinsic factors (antigens) - and, more generally, on genetic determinism and functionalism. This association has had major consequences: (1) immunological jargon is full of "cognitive" metaphors, founded in the idea of "foreignness"; (2) the immune system is described with a random clonal origin, coupled to selection by random encounters; and (3) physiological events are virtually absent from immunological descriptions. In the present manuscript, we apply systemic notions to bring forth an explanation including systemic mechanisms able to generate immunological phenomena. We replace "randomness plus selection" and the notion of foreignness by a history of structural changes which are determined by the coherences of the system internal architecture at any given moment. The importance of this systemic way of seeing is that it explicitly attends to the organization that defines the immune system, within which it is possible to describe the conservative physiology of the immune system. Understanding immune physiology in a systemic way of seeing also suggests mechanisms underlying the origin of immunopathogeny and therefore suggests new insights to therapeutic approaches. However, if seriously acknowledged, this systemic/historic approach to immunology goes along with a global conceptual change which modifies virtually everything in the domain of biology, as suggested by Maturana.

Evaluation of immunologic profile in patients with nickel sensitivity due to use of fixed orthodontic appliances.

The aim of this study was to develop a new approach to testing the impact of nickel antigen on in vitro cell-proliferation assay, to identify adverse reactions to casting alloys among orthodontic patients. Cell-proliferation assay in vitro was used as the basic methodology to assess the influence of such variables as source of nickel antigen, type of serum used to supplement the culture medium, and number of cells in the culture. We selected 35 orthodontic patients who were classified as nickel sensitive and non-nickel sensitive, based on their clinical records. Our results showed that hexahydrated nickel sulfate at 10 microg/mL, 10% of autologous sera, and 2 x 10(5) cells was the best condition for inducing the most marked nickel proliferation response in vitro. This optimized method was able to distinguish nickel-sensitive from non-nickel-sensitive dental patients and also to discriminate those with positive skin tests. Our data suggest that continuous exposure to nickel casting alloys might lead to oral tolerance mechanisms that modulate nickel sensitivity, as evidenced by the lower cell proliferation index in patients undergoing orthodontic treatment over 24 months. Finally, our findings demonstrated a known nickel-induced type 2 immune response and a marked lack of type 1 immunity (interferon gamma) as the hallmarks of nickel-sensitive patients. Further studies are needed to clarify the major cell phenotype associated with this type 2 immune response and the lack of type 1 immunity observed in nickel-sensitive people.

The conservative physiology of the immune system.

Current immunological opinion disdains the necessity to define global interconnections between lymphocytes and regards natural autoantibodies and autoreactive T cells as intrinsically pathogenic. Immunological theories address the recognition of foreignness by independent clones of lymphocytes, not the relations among lymphocytes or between lymphocytes and the organism. However, although extremely variable in cellular/molecular composition, the immune system preserves as invariant a set of essential relations among its components and constantly enacts contacts with the organism of which it is a component. These invariant relations are reflected, for example, in the life-long stability of profiles of reactivity of immunoglobulins formed by normal organisms (natural antibodies). Oral contacts with dietary proteins and the intestinal microbiota also result in steady states that lack the progressive quality of secondary-type reactivity. Autoreactivity (natural autoantibody and autoreactive T cell formation) is also stable and lacks the progressive quality of clonal expansion. Specific immune responses, currently regarded as the fundament of the operation of the immune system, may actually result from transient interruptions in this stable connectivity among lymphocytes. More permanent deficits in interconnectivity result in oligoclonal expansions of T lymphocytes, as seen in Omenn's syndrome and in the experimental transplantation of a suboptimal diversity of syngeneic T cells to immunodeficient hosts, which also have pathogenic consequences. Contrary to theories that forbid autoreactivity as potentially pathogenic, the physiology of the immune system is conservative and autoreactive. Pathology derives from failures of these conservative mechanisms.