RESUMEN
The PvCelTOS, PvCyRPA, and Pvs25 proteins play important roles during the three stages of the P. vivax lifecycle. In this study, we designed and expressed a P. vivax recombinant modular chimeric protein (PvRMC-1) composed of the main antigenic regions of these vaccine candidates. After structure modelling by prediction, the chimeric protein was expressed, and the antigenicity was assessed by IgM and IgG (total and subclass) ELISA in 301 naturally exposed individuals from the Brazilian Amazon. The recombinant protein was recognized by IgG (54%) and IgM (40%) antibodies in the studied individuals, confirming the natural immunogenicity of the epitopes that composed PvRMC-1 as its maintenance in the chimeric structure. Among responders, a predominant cytophilic response mediated by IgG1 (70%) and IgG3 (69%) was observed. IgM levels were inversely correlated with age and time of residence in endemic areas (p < 0.01). By contrast, the IgG and IgM reactivity indexes were positively correlated with each other, and both were inversely correlated with the time of the last malaria episode. Conclusions: The study demonstrates that PvRMC-1 was successfully expressed and targeted by natural antibodies, providing important insights into the construction of a multistage chimeric recombinant protein and the use of naturally acquired antibodies to validate the construction.
Asunto(s)
Malaria Vivax , Plasmodium vivax , Humanos , Plasmodium vivax/genética , Inmunidad Humoral , Proteínas Protozoarias/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes de Fusión/genética , Inmunoglobulina G , Inmunoglobulina M/genética , Antígenos de Protozoos/genéticaRESUMEN
The origin and function of blood IgM+IgD+CD27+ B cells is controversial, and they are considered a heterogeneous population. Previous staining of circulating B cells of healthy donors with rotavirus fluorescent virus-like particles allowed us to differentiate two subsets of IgM+IgD+CD27+: IgMhi and IgMlo B cells. Here, we confirmed this finding and compared the phenotype, transcriptome, in vitro function, and Ig gene repertoire of these two subsets. Eleven markers phenotypically discriminated both subsets (CD1c, CD69, IL21R, CD27, MTG, CD45RB, CD5, CD184, CD23, BAFFR, and CD38) with the IgMhi phenotypically resembling previously reported marginal zone B cells and the IgMlo resembling both naïve and memory B cells. Transcriptomic analysis showed that both subpopulations clustered close to germinal center-experienced IgM only B cells with a Principal Component Analysis, but differed in expression of 78 genes. Moreover, IgMhi B cells expressed genes characteristic of previously reported marginal zone B cells. After stimulation with CpG and cytokines, significantly (p < 0.05) higher frequencies (62.5%) of IgMhi B cells proliferated, compared with IgMlo B cells (35.37%), and differentiated to antibody secreting cells (14.22% for IgMhi and 7.19% for IgMlo). IgMhi B cells had significantly (p < 0.0007) higher frequencies of mutations in IGHV and IGKV regions, IgMlo B cells had higher usage of IGHJ6 genes (p < 0.0001), and both subsets differed in their HCDR3 properties. IgMhi B cells shared most of their shared IGH clonotypes with IgM only memory B cells, and IgMlo B cells with IgMhi B cells. These results support the notion that differential expression of IgM and IgD discriminates two subpopulations of human circulating IgM+IgD+CD27+ B cells, with the IgMhi B cells having similarities with previously described marginal zone B cells that passed through germinal centers, and the IgMlo B cells being the least differentiated amongst the IgM+CD27+ subsets.
Asunto(s)
Subgrupos de Linfocitos B/fisiología , Linfocitos B/inmunología , Centro Germinal/inmunología , Inmunoglobulina D/metabolismo , Inmunoglobulina M/metabolismo , Adulto , Perfilación de la Expresión Génica , Humanos , Inmunoglobulina D/genética , Cadenas Pesadas de Inmunoglobulina/genética , Inmunoglobulina M/genética , Región Variable de Inmunoglobulina/genética , Inmunofenotipificación , Fenotipo , Análisis de Componente Principal , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/metabolismoRESUMEN
Primary cutaneous marginal zone lymphoma (PCMZL) can be subdivided into 2 groups based on immunoglobulin (Ig) heavy chain usage: IgM-positive cases that constitute a less common and more T-helper type 1-driven process, and more common heavy chain class-switched cases that are predominantly T-helper type 2-driven. Although some report a significant IgG4-positive subset, others have found a much smaller proportion. To further evaluate the proportion of IgG4-positive PCMZL, to address whether IgG4-positive cases have any distinctive characteristics, and to assess whether additional features separating IgM-positive and class-switched cases could be identified, the clinicopathologic features of 26 PCMZL obtained from 19 patients were investigated. Twenty of 26 (77%) PCMZL were heavy chain class-switched (19 IgG-positive, 1 IgA-positive), including 9 that were IgG4-positive (35%). IgG4-positive and other class-switched PCMZL were morphologically similar. IgM-positive cases occurred in older individuals (median: 69 vs. 46.5 y; P=0.0001), more often involved the subcutis (P=0.002), demonstrated plasma cells diffusely scattered versus at the periphery of the lymphoid infiltrate (P=0.005), uniformly showed follicular colonization (P=0.0001), contained more numerous B cells (P=0.0004), and were more likely to have a T-cell CD4:CD8 ratio of <3:1 (P=0.03). None of the IgM-positive PCMZL harbored a MYD88 L265P mutation. No significant differences in clinical outcome were documented. These results highlight the high frequency of IgG4-positive PCMZL, which are otherwise similar to other class-switched cases, provide additional evidence supporting the distinction between class-switched and IgM-positive cases, and emphasize the indolent nature of at least the class-switched PCMZL, which may warrant their categorization as a clonal chronic lymphoproliferative disorder.
Asunto(s)
Biomarcadores de Tumor/genética , Cambio de Clase de Inmunoglobulina , Inmunoglobulina G/genética , Inmunoglobulina M/genética , Linfoma de Células B de la Zona Marginal/inmunología , Neoplasias Cutáneas/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Linfocitos B/inmunología , Femenino , Predisposición Genética a la Enfermedad , Humanos , Linfoma de Células B de la Zona Marginal/genética , Linfoma de Células B de la Zona Marginal/patología , Masculino , Persona de Mediana Edad , Mutación , Factor 88 de Diferenciación Mieloide/genética , Fenotipo , Células Plasmáticas/inmunología , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Linfocitos T/inmunologíaRESUMEN
X-linked agammaglobulinemia (XLA) is caused by BTK mutations, patients typically show <2% of peripheral B cells and reduced levels of all immunoglobulins; they suffer from recurrent infections of bacterial origin; however, viral infections, autoimmune-like diseases, and an increased risk of developing gastric cancer are also reported. In this work, we report the BTK mutations and clinical features of 12 patients diagnosed with XLA. Furthermore, a clinical revision is also presented for an additional cohort of previously reported patients with XLA. Four novel mutations were identified, one of these located in the previously reported mutation refractory SH3 domain. Clinical data support previous reports accounting for frequent respiratory, gastrointestinal tract infections and other symptoms such as the occurrence of reactive arthritis in 19.2% of the patients. An equal proportion of patients developed septic arthritis; missense mutations and mutations in SH1, SH2 and PH domains predominated in patients who developed arthritis.
Asunto(s)
Agammaglobulinemia/genética , Agammaglobulinemia/patología , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Enfermedades Genéticas Ligadas al Cromosoma X/patología , Mutación Missense/genética , Agammaglobulinemia/complicaciones , Agammaglobulinemia/diagnóstico , Artritis/complicaciones , Enfermedades Genéticas Ligadas al Cromosoma X/complicaciones , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina A/genética , Inmunoglobulina G/sangre , Inmunoglobulina G/genética , Inmunoglobulina M/sangre , Inmunoglobulina M/genética , MéxicoAsunto(s)
Síndromes de Inmunodeficiencia/inmunología , Infecciones Bacterianas/genética , Infecciones Bacterianas/inmunología , Ligando de CD40/genética , Ligando de CD40/inmunología , Conducta Cooperativa , Humanos , Inmunoglobulina M/genética , Inmunoglobulina M/inmunología , Síndromes de Inmunodeficiencia/genética , Síndromes de Inmunodeficiencia/microbiología , América Latina , Mutación/genética , Sistema de RegistrosRESUMEN
IL-4 plays an essential role in the activation of mature B cells, but less is known about the role of IL-4 in B cell maturation and tolerance checkpoints. In this study, we analyzed the effect of IL-4 on in vitro B cell maturation, from immature to transitional stages, and its influence on BCR-mediated negative selection. Starting either from purified CD19(+)IgM(-) B cell precursors, or sorted bone marrow immature (B220(low)IgM(low)CD23(-)) and transitional (B220(int)IgM(high)CD23(-)) B cells from C57BL/6 mice, we compared the maturation effects of IL-4 and BAFF. We found that IL-4 stimulated the generation of CD23(+) transitional B cells from CD23(-) B cells, and this effect was comparable to BAFF. IL-4 showed a unique protective effect against anti-IgM apoptotic signals on transitional B cell checkpoint, not observed with BAFF. IL-4 and BAFF strongly synergized to promote B cell maturation, and IL-4 also rendered it refractory to BCR-mediated cell death. IL-4 blocked upregulation of proapoptotic Bim protein levels induced by BCR crosslinking, suggesting that diminished levels of intracellular Bim promote protection to BCR-induced cell death. Evidence was obtained indicating that downmodulation of Bim by IL-4 occurred in a posttranscriptional manner. Consistent with data obtained in vitro, IL-4 in vivo was able to inhibit Bim upregulation and prevent cell death. These results contribute to the understanding of the role of IL-4 in B lymphocyte physiology, unveiling a previously undescribed activity of this cytokine on the maturation of B cells, which could have important implications on the breaking of B cell central tolerance in autoimmunity.
Asunto(s)
Proteínas Reguladoras de la Apoptosis/inmunología , Apoptosis/inmunología , Factor Activador de Células B/inmunología , Linfocitos B/inmunología , Regulación de la Expresión Génica/inmunología , Interleucina-4/inmunología , Proteínas de la Membrana/inmunología , Proteínas Proto-Oncogénicas/inmunología , Animales , Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/genética , Autoinmunidad/fisiología , Factor Activador de Células B/genética , Linfocitos B/citología , Proteína 11 Similar a Bcl2 , Regulación de la Expresión Génica/genética , Inmunoglobulina M/genética , Inmunoglobulina M/inmunología , Interleucina-4/genética , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos BALB C , Proteínas Proto-Oncogénicas/genética , Receptores de Antígenos de Linfocitos B/genética , Receptores de Antígenos de Linfocitos B/inmunología , Receptores de IgE/genética , Receptores de IgE/inmunologíaRESUMEN
Primary immunodeficiencies (PIDs) represent a large group of diseases that affect all age groups. Although PIDs have been recognized as rare diseases, there is epidemiological evidence suggesting that their real prevalence has been underestimated. We performed an evaluation of a series of 1,008 infants, children, adolescents and adults with well-defined PIDs from a single Brazilian center, regarding age at diagnosis, gender and PID category according to the International Union of Immunological Societies classification. Antibody deficiencies were the most common category in the whole series (61 %) for all age groups, with the exception of <2-year-old patients (only 15 %). In the >30-year-old group, antibody deficiencies comprised 84 % of the diagnoses, mostly consisting of common variable immunodeficiency, IgA deficiency and IgM deficiency. Combined immunodeficiencies represented the most frequent category in <2-years-old patients. Most congenital defects of phagocytes were identified in patients <5 -years of age, as were the diseases of immune dysregulation, with the exception of APECED. DiGeorge syndrome and ataxia-telangiectasia were the most frequent entities in the category of well-defined syndromes, which were mostly identified in patients <10-years of age. Males represented three-quarters and two-thirds of <2 -years-old and 2-5-years -old patients, respectively, whereas females predominated among the >30-year-old patients. Our data indicated that some PIDs were only detected at early ages, likely because affected patients do not survive long. In addition, our data pointed out that different strategies should be used to search for PIDs in infants and young children as compared to older patients.
Asunto(s)
Síndromes de Inmunodeficiencia/epidemiología , Factores Sexuales , Adolescente , Adulto , Factores de Edad , Brasil , Niño , Preescolar , Femenino , Humanos , Inmunoglobulina A/genética , Inmunoglobulina M/genética , Síndromes de Inmunodeficiencia/inmunología , Lactante , Recién Nacido , Masculino , Fagocitos/patología , Grupos de Población , PrevalenciaRESUMEN
BACKGROUND: Plasmodium falciparum merozoite surface protein-1 (MSP1) has been extensively studied as a blood-stage malaria vaccine candidate, with most work focused on the conserved 19 kDa and semi-conserved 42 kDa C-terminal regions (blocks 16-17) and the hypervariable N-terminal repeat region (block 2). However, recent genotyping studies suggest that additional regions of MSP1 may be under selective pressure, including a locus of intragenic recombination designated as block 4 within the 3' region of the gene. METHODS: The current study examined the antibody response to the two parental and two recombinant forms of block 4 and to blocks 16-17 (3D7) in study populations from Colombia, Papua New Guinea and Cameroon that differ in malaria transmission intensity and ethnic composition. RESULTS: IgM and IgG antibodies were detected against parental and recombinant MSP1 block 4 peptides in all three populations. Overall, 32-44% of the individuals produced IgM to one or more of the peptides, with most individuals having IgM antibodies reactive with both parental and recombinant forms. In contrast, IgG seropositivity to block 4 varied among populations (range 15-65%), with the majority of antibodies showing specificity for one or a pair of block 4 peptides. The IgG response to block 4 was significantly lower than that to blocks 16-17, indicating block 4 is subdominant. Antibodies to block 4 and blocks 16-17 displayed distinct IgG subclass biases, with block 4 responses biased toward IgG3 and blocks 16-17 toward IgG1. These patterns of responsiveness were consistently observed in the three study populations. CONCLUSIONS: Production of antibodies specific for each parental and recombinant MSP1 block 4 allele in different populations exposed to P. falciparum is consistent with balancing selection of the MSP1 block 4 region by the immune response of individuals in areas of both low and high malaria transmission. MSP1 block 4 determinants may be important in isolate-specific immunity to P. falciparum.
Asunto(s)
Epítopos/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Malaria Falciparum/inmunología , Proteína 1 de Superficie de Merozoito/genética , Plasmodium falciparum/inmunología , Adolescente , Adulto , Anciano , Alelos , Anticuerpos Antiprotozoarios/genética , Anticuerpos Antiprotozoarios/inmunología , Camerún , Niño , Preescolar , Colombia , Reacciones Cruzadas/genética , Reacciones Cruzadas/inmunología , Epítopos/genética , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Inmunoglobulina G/genética , Inmunoglobulina M/genética , Lactante , Malaria Falciparum/transmisión , Masculino , Proteína 1 de Superficie de Merozoito/inmunología , Proteína 1 de Superficie de Merozoito/metabolismo , Persona de Mediana Edad , Papúa Nueva Guinea , Plasmodium falciparum/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Adulto JovenRESUMEN
In Cuba, on the basis of Measles Elimination Program, the incidence of this disease decline, and was necessary to test rubella virus as a possible etiology agent that produce fever and rash illness. To reach this goal, Cuba developed rubella elimination strategies with integrated epidemiologic and laboratory surveillance. In the country, the vaccination program against rubella started in 1982 by vaccinating 12-14 years old females, with a special surveillance program with laboratory study of all suspected cases. Through 1988-2000, the Serology Diagnosis Laboratory in the Virology Branch of Pedro Kouri Institute had the responsibility to do the measles and rubella surveillance and play a key roll in the elimination strategies of these diseases. For confirmation of all suspected cases, 8566 serum samples with the suspected diagnosis of measles or rubella from different provinces in Cuba were studied in the laboratory using different techniques as haemagglutination inhibition test (HIA), ultra micro analytic assay (UMA); and in 1995 by the newly introduced IgM ELISA, which was used taken only one sample in the acute phase of the disease. These techniques allowed knowing that the annual number of reported rubella cases in the country decreased substantially after the implementation, in 1986, of the second vaccine policy, that of vaccinating women of childbearing age. However, in 1989, was detected an outbreak of rubella virus infection that had occurred in young adults male 15-19 age groups in Matanzas' province. The last three indigenous cases of this disease were confirmed by our laboratory in 1995, after national vaccine coverage over 95%.
Asunto(s)
Rubéola (Sarampión Alemán)/diagnóstico , Rubéola (Sarampión Alemán)/epidemiología , Adolescente , Adulto , Animales , Niño , Preescolar , Chlorocebus aethiops , Técnicas de Laboratorio Clínico , Cuba/epidemiología , Ensayo de Inmunoadsorción Enzimática , Femenino , Pruebas de Inhibición de Hemaglutinación , Humanos , Inmunoglobulina M/biosíntesis , Inmunoglobulina M/genética , Lactante , Masculino , Vigilancia de la Población , Rubéola (Sarampión Alemán)/virología , Células VeroRESUMEN
BACKGROUND: Hyper-IgM syndronie (HIGM) is a rare primary immunodeficiency used to describe a heterogeneous group of disorders characterized by recurrey bacterial infrctions, normal or elevated serum IgM levels and low or absent serum IgG, IgA and IgE. AIM: To make definitive diagnosis, detect mutations in carriers and perform genetic counseling in patients with HIGM. PATIENTS AND METHODS: We studied the expression of CD40L, CD40 and made a mutation analysis of the CD40L gene in 3 males of 2 unrelated Chilean families diagnosed as a possible syndrome of hyper-IgM and 3 relatives. RESULTS: We identified a deletion frameshift in the exon 2 (delA225) of the extracellular domain of GD40L gene in one patient and verified the carrier stains of his mother and sister. The other patients showed a low expression of GD40L in activated T cells (65.3% ammd 65.5%) and a normal expressiomi of CD40. No alterations were found in the single strand conformation polymorphism analysis of the CD40L. CONCLUSIONS: These result allowed us to make a definite diagnosis of HIGM1 of a patient, detect female carriers and suggest a HIGM of recessive inheritance with normal CD40 expression in the patients of the second family.
Asunto(s)
Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Ligando de CD40 , Hipergammaglobulinemia/genética , Inmunoglobulina M/genética , Mutación del Sistema de Lectura/genética , Ligando de CD40 , Asesoramiento Genético , Chile , Hipergammaglobulinemia/diagnóstico , Inmunoglobulina M/sangre , Péptidos y Proteínas Asociados a Receptores de Factores de Necrosis Tumoral , SíndromeRESUMEN
BACKGROUND: Hyper-IgM syndronie (HIGM) is a rare primary immunodeficiency used to describe a heterogeneous group of disorders characterized by recurrey bacterial infrctions, normal or elevated serum IgM levels and low or absent serum IgG, IgA and IgE. AIM: To make definitive diagnosis, detect mutations in carriers and perform genetic counseling in patients with HIGM. PATIENTS AND METHODS: We studied the expression of CD40L, CD40 and made a mutation analysis of the CD40L gene in 3 males of 2 unrelated Chilean families diagnosed as a possible syndrome of hyper-IgM and 3 relatives. RESULTS: We identified a deletion frameshift in the exon 2 (delA225) of the extracellular domain of GD40L gene in one patient and verified the carrier stains of his mother and sister. The other patients showed a low expression of GD40L in activated T cells (65.3% ammd 65.5%) and a normal expressiomi of CD40. No alterations were found in the single strand conformation polymorphism analysis of the CD40L. CONCLUSIONS: These result allowed us to make a definite diagnosis of HIGM1 of a patient, detect female carriers and suggest a HIGM of recessive inheritance with normal CD40 expression in the patients of the second family.
Asunto(s)
Ligando de CD40/genética , Mutación del Sistema de Lectura/genética , Hipergammaglobulinemia/genética , Inmunoglobulina M/genética , Péptidos y Proteínas Asociados a Receptores de Factores de Necrosis Tumoral/genética , Ligando de CD40/sangre , Niño , Preescolar , Chile , Femenino , Asesoramiento Genético , Humanos , Hipergammaglobulinemia/diagnóstico , Inmunoglobulina M/sangre , Lactante , Masculino , Síndrome , Factor 3 Asociado a Receptor de TNF , Péptidos y Proteínas Asociados a Receptores de Factores de Necrosis Tumoral/sangreAsunto(s)
Fiebre Mediterránea Familiar/genética , Expresión Génica/genética , Síndromes de Inmunodeficiencia/genética , Biología Molecular/métodos , Mutación/genética , Análisis Mutacional de ADN/métodos , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Humanos , Hipergammaglobulinemia/genética , Inmunoglobulina M/genética , Receptores del Factor de Necrosis Tumoral/genéticaRESUMEN
We report the case of an infant with severe respiratory infections, chronic diarrhea, failure to thrive, and disseminated Cryptosporidium parvum infection. Laboratory investigations disclosed a diagnosis of hyper-IgM syndrome caused by CD40 deficiency.
Asunto(s)
Antígenos CD40/genética , Criptosporidiosis/etiología , Enfermedades Genéticas Ligadas al Cromosoma X/complicaciones , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Hipergammaglobulinemia/complicaciones , Hipergammaglobulinemia/genética , Inmunoglobulina M/genética , Consanguinidad , Diagnóstico Diferencial , Femenino , Citometría de Flujo , Genes Recesivos/genética , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Enfermedades Genéticas Ligadas al Cromosoma X/terapia , Trastornos del Crecimiento/etiología , Humanos , Hipergammaglobulinemia/diagnóstico , Hipergammaglobulinemia/terapia , Inmunofenotipificación , Lactante , Linaje , Insuficiencia Respiratoria/etiología , Tomografía Computarizada por Rayos X , TurquíaRESUMEN
In this work, we have constructed two functional mouse/human chimeric antibodies (IgMkappa and IgG1kappa isotypes) by inserting genomic DNA fragments encoding VH and Vkappa variable regions of the murine monoclonal antibody IgMK-83D4 into mammalian expression vectors containing human mu, gamma1, and kappa constant exons, and by transfecting them into the nonsecreting mouse myeloma X-63 cell line. In previous works, we have demonstrated that 83D4 murine mAb reacts with Tn determinant (GalNAcalpha-O-Ser/Thr) expressed in 90% of breast, ovary, and colon carcinomas. Both expressed chimeric antibodies were purified from the transfected cell line supernatant by affinity chromatography, and their reactivities against Tn antigen were confirmed by ELISA on asialo ovine submaxilar mucin and immunofluorescence studies on MCF-7 breast carcinoma cell line. We have demonstrated by gel filtration chromatography, that the principal secreted forms were monomers for IgG1kappa and pentamers for IgMkappa. The binding affinities of these chimeric antibodies against synthetic Tn glycopeptides, were evaluated by surface plasmon resonance showing an affinity constant similar to that of 83D4 native antibody for IgMkappa and a lower affinity constant for IgG1kappa chimeric antibody. On the other hand, the replacement of mouse C regions with human C regions confers both chimeric antibodies the ability to activate human complement. These mouse/human chimeric antibodies should be much less immunogenic and could play an important role in the lysis of tumor cell expressing Tn-antigen. Therefore, these anti-Tn chimeric antibodies could be considered as potential tools for human in vivo studies.
Asunto(s)
Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/genética , Especificidad de Anticuerpos/genética , Antígenos de Carbohidratos Asociados a Tumores/inmunología , Antígenos de Carbohidratos Asociados a Tumores/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Animales , Anticuerpos Monoclonales/aislamiento & purificación , Fusión Celular , Vectores Genéticos , Humanos , Hibridomas/metabolismo , Inmunoglobulina G/biosíntesis , Inmunoglobulina G/genética , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Pesadas de Inmunoglobulina/aislamiento & purificación , Cadenas Ligeras de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/aislamiento & purificación , Inmunoglobulina M/biosíntesis , Inmunoglobulina M/genética , Cadenas kappa de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/aislamiento & purificación , Ratones , Ratones Endogámicos C57BL , Proteínas Recombinantes de Fusión/inmunología , Transfección , Células Tumorales CultivadasRESUMEN
cDNAs encoding IgM heavy chain constant region (Cmu) were isolated from two metatherians (marsupials)--the Australian common brushtail possum (Trichosurus vulpecula) and the South American grey short-tailed opossum (Monodelphis domestica). Analysis of the sequences suggested that they correspond to the secreted form of Cmu in both species. The domain size and structure of the marsupial Cmu sequences were compared with other Cmu sequences and a high degree of conservation throughout vertebrate evolution was observed. Amino acid sequence comparisons revealed a marked level of sequence similarity between the two marsupial sequences (79%), relatively high similarity between the marsupials and eutherians (63%), and lower similarities between marsupials and birds (45%), marsupials and amphibians (47%), marsupials and reptiles (45%) and marsupials and fish (37%). These data allow the incorporation of metatherians into the study of mammalian IgM evolution.
Asunto(s)
Regiones Constantes de Inmunoglobulina/genética , Inmunoglobulina M/genética , Cadenas mu de Inmunoglobulina/genética , Zarigüeyas/inmunología , Secuencia de Aminoácidos , Animales , Australia , Secuencia de Bases , ADN Complementario , Humanos , Regiones Constantes de Inmunoglobulina/clasificación , Regiones Constantes de Inmunoglobulina/aislamiento & purificación , Inmunoglobulina M/clasificación , Inmunoglobulina M/aislamiento & purificación , Cadenas mu de Inmunoglobulina/clasificación , Cadenas mu de Inmunoglobulina/aislamiento & purificación , Datos de Secuencia Molecular , Zarigüeyas/genética , América del SurRESUMEN
The interindividual variability of IgA, IgG, and IgM immunoglobulin levels was studied using path analysis in a northeastern Brazilian sample (nuclear families) to determine the genetic and/or environmental causes of their variation. The path analysis model decomposes the phenotype into genetic causes (autosomal and X-chromosome-linked genes) and environmental causes. A significant familial aggregation, mainly resulting from autosomal components, was detected for the 3 immunoglobulin levels. The values of genetic heritability were h2 = 0.410 +/- 0.030 for IgA, h2 = 0.617 +/- 0.020 for IgG, and h2 = 0.540 +/- 0.023 for IgM, and the values for environmental-cultural heritability were c2 = 0.085 +/- 0.034 for IgA, c2 = 0.084 +/- 0.027 for IgG, and c2 = 0.023 + 0.023 for IgM. Our results did not show a heritable component resulting from X-chromosome-linked genes on IgM levels, as suggested by some studies (Wood et al. 1969; Grundbacher 1972; Purtilo and Sullivan 1979). Some additional results were that (1) age and IgA concentration were positively correlated, with IgA level increasing gradually from childhood to adulthood (p < 0.001); (2) sex and the age X sex interaction act on IgG concentration (p < 0.01); (3) age and IgM concentration are correlated (with children presenting lower levels than adults, especially in males, p < 0.01); and (4) a significant association exists between sex and IgM level (with females presenting higher levels than males, p < 0.001).
Asunto(s)
Variación Genética/genética , Inmunoglobulina A/sangre , Inmunoglobulina A/genética , Inmunoglobulina G/sangre , Inmunoglobulina G/genética , Inmunoglobulina M/sangre , Inmunoglobulina M/genética , Adulto , Factores de Edad , Brasil , Niño , Ambiente , Femenino , Ligamiento Genético/genética , Humanos , Masculino , Modelos Genéticos , Factores Sexuales , Cromosoma X/genéticaRESUMEN
We report here the first amino acid sequence of an anti-Tn monoclonal antibody raised against human breast cancer cells and show that a single chain Fv fragment of this IgM retains the Tn-binding specificity as defined by functional assays with asialo-OSM and membrane extracts from MCF-7 cells. Sequence comparisons and molecular modeling of 83D4 indicate that the antibody combining site displays a cavity-like feature primarily defined by the CDR H1 and H2 loops. This pocket could accommodate a single Tn molecule, thus, suggesting a structural explanation for the predominant expression of a particular VH gene segment in a group of antibodies that recognize tumor-associated antigens arising from an aberrant O-glycosylation.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Antineoplásicos/inmunología , Antígenos de Carbohidratos Asociados a Tumores/inmunología , Fragmentos de Inmunoglobulinas/inmunología , Inmunoglobulina M/inmunología , Región Variable de Inmunoglobulina/inmunología , Cadenas kappa de Inmunoglobulina/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/genética , Anticuerpos Antineoplásicos/genética , Especificidad de Anticuerpos , Antígenos de Carbohidratos Asociados a Tumores/genética , Secuencia de Bases , Neoplasias de la Mama/inmunología , Carcinoma/inmunología , Clonación Molecular , Amplificación de Genes , Humanos , Hibridomas , Fragmentos de Inmunoglobulinas/genética , Inmunoglobulina M/genética , Región Variable de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/genética , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Proteínas Recombinantes de Fusión , Alineación de Secuencia , Análisis de Secuencia de ADN , Células Tumorales CultivadasRESUMEN
BACKGROUND: Homeostasis in the immune system is based on equilibrium between rates of cell renewal and cell death. Failure of elimination of undesirable autoreactive B cell clones may lead to autoimmune disorders. OBJECTIVE: To assess the participation of the Bcl-2 and Fas molecules in the regulation of B lymphocyte death. METHODS: We used two strains of mice known to have deficient mechanisms of apoptosis, namely the transgenic C57BL/6-E mu-bcl-2-22 expressing the bcl-2 transgene on B cells, and the C57BL/6-lpr/lpr mutant, lacking the expression of a functional Fas molecule. Both strains develop a systemic lupus erythematosus-like disease with serum autoantibodies and splenomegaly. We induced apoptosis by three different treatments: dexamethasone,gamma irradiation and hyperthermia. The proportion of cells in apoptosis was determined with the TUNEL method. RESULTS: Radiation or hyperthermia induced apoptosis was inhibited more effectively by having the lpr mutation than the proto-oncogene bcl-2, but the latter conferred higher resistance to apoptosis by dexamethasone. CONCLUSIONS: Our findings suggest that the role of molecules regulating cell death may relate to the stimuli used to induced apoptosis, and that both the lpr mutation and the overexpression of the proto-oncogene bcl-2 protect B cells from apoptosis induced by the three treatments tested.
Asunto(s)
Apoptosis/fisiología , Enfermedades Autoinmunes/patología , Linfocitos B/patología , Lupus Eritematoso Sistémico/patología , Proteínas Proto-Oncogénicas c-bcl-2/fisiología , Bazo/patología , Receptor fas/fisiología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Apoptosis/efectos de la radiación , Enfermedades Autoinmunes/genética , Linfocitos B/efectos de los fármacos , Linfocitos B/efectos de la radiación , Células Cultivadas , Dexametasona/farmacología , Rayos gamma , Calor , Inmunoglobulina M/genética , Lupus Eritematoso Sistémico/genética , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Ratones Transgénicos , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-bcl-2/deficiencia , Proto-Oncogenes , Proteínas Recombinantes de Fusión/fisiología , TransgenesRESUMEN
Hemolytic disease of the newborn develops mainly when an Rh negative (D-) mother becomes sensitized and produces anti-Rh possitve (anti-D) antibodies capable of hemolysing D+ fetal erythrocytes. Maternal alloimmunization can be prevented by the administration of anti-D gamma-globulin immediately after the birth of each Rh positive child. In order to identify the frequency of prevention of alloimmunization at the Instituto Mexicano del Seguro Social(IMSS), the amount of mothers at risk of sensitization from 1985 to 1995 was estimated from Rh and ABO blood group frequencies and with the number of deliveries and abortions at the Medical Institutions. Also, information in regard to the dose of gamma-globulin units purchased by the Institute of Social Security from 1985 to 1993 was obtained. The number of mothers at risk stedily increased from 16,616 in 1985 to 21,071 in 1995, amounting to a total of 203,203 in the 10-year period, while only 120,800 gamma-globulin units were purchased in that same period. The findings in this study suggest the need to define reasonable policies for the acquisition of gamma-globulin lots to prevent alloisoimmunization of mothers at risk
Asunto(s)
Humanos , Enfermedades Hematológicas/genética , Eritroblastosis Fetal/genética , Genética de Población , Inmunoglobulina M/genética , Globulina Inmune rho(D)/genética , Factores de Riesgo , Sistema del Grupo Sanguíneo Rh-Hr/genéticaRESUMEN
cDNA clones coding for the constant region of the Mexican axolotl (Ambystoma mexicanum) mu heavy immunoglobulin chain were selected from total spleen RNA, using a cDNA polymerase chain reaction technique. The specific 5'-end primer was an oligonucleotide homologous to the JH segment of Xenopus laevis mu chain. One of the clones, JHA/3, corresponded to the complete constant region of the axolotl mu chain, consisting of a 1362-nucleotide sequence coding for a polypeptide of 454 amino acids followed in 3' direction by a 179-nucleotide untranslated region and a polyA+ tail. The axolotl C mu is divided into four typical domains (C mu 1-C mu 4) and can be aligned with the Xenopus C mu with an overall identity of 56% at the nucleotide level. Percent identities were particularly high between C mu 1 (59%) and C mu 4 (71%). The C-terminal 20-amino acid segment which constitutes the secretory part of the mu chain is strongly homologous to the equivalent sequences of chondrichthyans and of other tetrapods, including a conserved N-linked oligosaccharide, the penultimate cysteine and the C-terminal lysine. The four C mu domains of 13 vertebrate species ranging from chondrichthyans to mammals were aligned and compared at the amino acid level. The significant number of mu-specific residues which are conserved into each of the four C mu domains argues for a continuous line of evolution of the vertebrate mu chain. This notion was confirmed by the ability to reconstitute a consistent vertebrate evolution tree based on the phylogenic parsimony analysis of the C mu 4 sequences.