RESUMEN
PURPOSE: We herein aimed to review the new insights into the impact of impaired thyroid function on male and female fertility, spacing from spontaneous pregnancy to ART, with the objective of providing an updated narrative revision of the literature. METHODS: This narrative review was performed for all available prospective, retrospective and review articles, published up to 2021 in PubMed. Data were extracted from the text and from the tables of the manuscript. RESULTS: Thyroid dysfunction is frequently associated with female infertility, whereas its link with male infertility is debated. Female wise, impaired function is detrimental to obstetric and fetal outcomes both in spontaneous pregnancies and in those achieved thanks to assisted reproduction technologies (ART). Furthermore, the reference range of TSH in natural pregnancy and ART procedures has recently become a matter of debate following recent reports in this field. On the other hand, the impact of thyroid function on the male reproductive system is less clear, although a possible role is suggested via modulation of Sertoli and Leydig cells function and spermatogenesis. CONCLUSION: Thyroid function should be carefully monitored in both male and female, in couples seeking spontaneous pregnancy as well as ART, as treatment is generally immediate and likely to improve chances of success.
Asunto(s)
Infertilidad Femenina , Infertilidad Masculina , Infertilidad , Embarazo , Masculino , Femenino , Humanos , Glándula Tiroides , Estudios Retrospectivos , Estudios Prospectivos , Infertilidad Masculina/etiología , Técnicas Reproductivas Asistidas , Infertilidad Femenina/etiología , Infertilidad Femenina/terapia , Infertilidad/terapiaRESUMEN
Spinophilin/neurabin 2 has been isolated independently by two laboratories as a protein interacting with protein phosphatase 1 (PP1) and F-actin. Gene analysis and biochemical approaches have contributed to define a number of distinct modular domains in spinophilin that govern protein-protein interactions such as two F-actin-, three potential Src homology 3 (SH3)-, a receptor- and a PP1-binding domains, a PSD95/DLG/zo-1 (PDZ) and three coiled-coil domains, and a potential leucine/isoleucine zipper (LIZ) motif. More than 30 partner proteins of spinophilin have been discovered, including cytoskeletal and cell adhesion molecules, enzymes, guanine nucleotide exchange factors (GEF) and regulator of G-protein signalling protein, membrane receptors, ion channels and others proteins like the tumour suppressor ARF. The physiological relevance of some of these interactions remains to be demonstrated. However, spinophilin structure suggests that the protein is a multifunctional protein scaffold that regulates both membrane and cytoskeletal functions. Spinophilin plays important functions in the nervous system where it is implicated in spine morphology and density regulation, synaptic plasticity and neuronal migration. Spinophilin regulates also seven-transmembrane receptor signalling and may provide a link between some of these receptors and intracellular mitogenic signalling events dependent on p70(S6) kinase and Rac G protein-GEF. Strikingly a role for spinophilin in cell growth was demonstrated and this effect was enhanced by its interaction with ARF. Here we review the current knowledge of the protein partners of spinophilin and present the available data that are contributing to the appreciation of spinophilin functions.
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Proteínas de Microfilamentos/fisiología , Proteínas del Tejido Nervioso/fisiología , Transducción de Señal , Animales , Membrana Celular/metabolismo , Sistema Nervioso Central/metabolismo , Citoesqueleto/metabolismo , Humanos , Proteínas de Microfilamentos/química , Proteínas de Microfilamentos/genética , Modelos Biológicos , Proteínas del Tejido Nervioso/química , Proteínas del Tejido Nervioso/genéticaRESUMEN
The age-related and T cell-independent immunological properties of most capsular polysaccharides limit their use as vaccines, especially in children under 2 years of age. To overcome these limitations, polysaccharide antigens have been successfully conjugated to a variety of carrier proteins, such as diphtheria toxoid or tetanus toxoid (TT) and the diphtheria mutant (CRM197) to produce very successful glycoconjugate vaccines. The increasing demand for new conjugate vaccines requires the availability of additional carriers providing high and long-lasting T helper cell immunity. Here we describe the design and construction of three recombinant carrier proteins (N6, N10, N19) constituted by strings of 6, 10 or 19 human CD4(+) T cell epitopes from various pathogen-derived antigens, including TT and proteins from Plasmodium falciparum, influenza virus and hepatitis B virus. Each of these epitopes is defined as universal in that it binds to many human MHC class II molecules. When conjugated to Haemophilus influenzae type b (Hib) oligosaccharide, these carriers elicit a potent anti-Hib antibody response in mice. In the case of the N19-Hib conjugate, this response is at least as good as that observed with CRM197-Hib, a conjugate vaccine currently used for mass immunization. We also show that some of the universal epitopes constituting the recombinant carriers are specifically recognized by two human in vitro systems, suggesting that T cell memory is provided by the selected epitopes. The data indicate that rationally designed recombinant polyepitope proteins represent excellent candidates for the development and clinical testing of new conjugate vaccines.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Epítopos de Linfocito T , Vacunas contra Haemophilus/inmunología , Polisacáridos Bacterianos/inmunología , Vacunas Sintéticas/inmunología , Secuencia de Aminoácidos , Animales , Cápsulas Bacterianas , Activación de Linfocitos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Vacunas Conjugadas/inmunologíaRESUMEN
Infections with genital human papillomaviruses (HPV) are likely to be neutralised more efficiently if a mucosal immune response can be elicited at the viral entry site. Local IgA antibodies are highly induced when antigens are co-administered with mucosal adjuvants, such as cholera toxin (CT) and Escherichia coli heat labile enterotoxin (LT) which, however, are not expected to have wide application because of their pronounced toxicity. We have immunised mice intranasally with HPV-6b virus-like particles (VLPs) and a genetically modified LT-derived molecule with only residual toxicity, LTR72, and compared the humoral responses with those obtained following systemic immunisation with VLPs and the MF59 adjuvant. Titration of anti-HPV antibodies in sera and vaginal secretions established that LTR72 was able to elicit higher serum and mucosal IgA titers, in addition to IgG serum levels, comparable to those obtained by parenteral immunisation. These results confirm the potential of toxin-derived adjuvants and extend their use in combination with HPV antigens.
Asunto(s)
Adyuvantes Inmunológicos/farmacología , Anticuerpos Antivirales/biosíntesis , Toxinas Bacterianas/farmacología , Enterotoxinas/farmacología , Proteínas de Escherichia coli , Papillomaviridae/inmunología , Polisorbatos/farmacología , Escualeno/farmacología , Vacunas Virales/inmunología , Virión/inmunología , Administración Intranasal , Animales , Femenino , Inmunización , Inmunoglobulina A/biosíntesis , Inmunoglobulina G/biosíntesis , Ratones , Ratones Endogámicos BALB C , Vacunas Virales/administración & dosificaciónRESUMEN
The humoral immune response generated by two commercial influenza vaccines was evaluated in a randomised, double-blind trial performed in the Public Department of Dolo Health District (North-east Italy) during the winter season 1997-1998. Ninety-eight subjects were immunised with a split virus vaccine and ninety-six with a MF59-adjuvanted subunit virus vaccine (SU/MF59). The pre- and postvaccination (approximately 30 days) antibody titres were determined by hemagglutination inhibition test (HI). After immunisation protective titre rates (> or = 1:40) were near 100% against virus A strain and 82.5% against B strain. Both vaccines caused significant rises in geometric mean antibody titres (GMTs); however, people who received SU/MF59 vaccine were found to develop a greater immune response compared to the group immunised with SVV. According to logistic regression analysis the unprotective prevaccination immune status and the use of SU/MF59 were identified as independent factors significantly increasing the response to immunisation.
Asunto(s)
Formación de Anticuerpos , Vacunas contra la Influenza/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Método Doble Ciego , Femenino , Pruebas de Hemaglutinación , Humanos , Modelos Logísticos , Masculino , Persona de Mediana EdadRESUMEN
Zonula occludens toxin (Zot) is produced by toxigenic strains of Vibrio cholerae and has the ability to reversibly alter intestinal epithelial tight junctions, allowing the passage of macromolecules through the mucosal barrier. In the present study, we investigated whether Zot could be exploited to deliver soluble antigens through the nasal mucosa for the induction of antigen-specific systemic and mucosal immune responses. Intranasal immunization of mice with ovalbumin (Ova) and recombinant Zot, either fused to the maltose-binding protein (MBP-Zot) or with a hexahistidine tag (His-Zot), induced anti-Ova serum immunoglobulin G (IgG) titers that were approximately 40-fold higher than those induced by immunization with antigen alone. Interestingly, Zot also stimulated high anti-Ova IgA titers in serum, as well as in vaginal and intestinal secretions. A comparison with Escherichia coli heat-labile enterotoxin (LT) revealed that the adjuvant activity of Zot was only sevenfold lower than that of LT. Moreover, Zot and LT induced similar patterns of Ova-specific IgG subclasses. The subtypes IgG1, IgG2a, and IgG2b were all stimulated, with a predominance of IgG1 and IgG2b. In conclusion, our results highlight Zot as a novel potent mucosal adjuvant of microbial origin.
Asunto(s)
Adyuvantes Inmunológicos/farmacología , Toxina del Cólera/farmacología , Proteínas de Escherichia coli , Mucosa Nasal/inmunología , Administración Intranasal , Animales , Toxinas Bacterianas/farmacología , Endotoxinas , Enterotoxinas/farmacología , Femenino , Inmunidad Mucosa , Inmunización , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina G/clasificación , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/inmunologíaRESUMEN
Chronic infection of the gastroduodenal mucosae by the gram-negative spiral bacterium Helicobacter pylori is responsible for chronic active gastritis, peptic ulcers, and gastric cancers such as adenocarcinoma and low-grade gastric B-cell lymphoma. The success of eradication by antibiotic therapy is being rapidly hampered by the increasing occurrence of antibiotic-resistant strains. An attractive alternative approach to combat this infection is represented by the therapeutic use of vaccines. In the present work, we have exploited the mouse model of persistent infection by mouse-adapted H. pylori strains that we have developed to assess the feasibility of the therapeutic use of vaccines against infection. We report that an otherwise chronic H. pylori infection in mice can be successfully eradicated by intragastric vaccination with H. pylori antigens such as recombinant VacA and CagA, which were administered together with a genetically detoxified mutant of the heat-labile enterotoxin of Escherichia coli (referred to as LTK63), in which the serine in position 63 was replaced by a lysine. Moreover, we show that therapeutic vaccination confers efficacious protection against reinfection. These results represent strong evidence of the feasibility of therapeutic use of VacA- or CagA-based vaccine formulations against H. pylori infection in an animal model and give substantial preclinical support to the application of this kind of approach in human clinical trials.
Asunto(s)
Vacunas Bacterianas/administración & dosificación , Infecciones por Helicobacter/prevención & control , Helicobacter pylori/inmunología , Vacunas Sintéticas/administración & dosificación , Animales , Vacunas Bacterianas/inmunología , Infecciones por Helicobacter/inmunología , Humanos , Masculino , Ratones , Vacunación , Vacunas Sintéticas/inmunologíaRESUMEN
New generation pertussis vaccines, containing only purified Bordetella pertussis antigens, have been proven safe, immunogenic and efficacious. They have, however, raised new questions regarding the mechanism of protection from whooping cough and the duration of the immune response following vaccination. In addition to the antibody (Ab) titer, the level of pertussis toxin (PT) neutralizing antibodies may be very important in protection and the role of cell-ediated immunity needs to be defined. We have previously reported the safety and immunogenicity results of two phase I trials in adult volunteers with two acellular pertussis vaccines containing genetically detoxified PT alone or in combination with filamentous hemagglutinin (FHA) and 69K protein. In this work, we present the results of a long term follow-up study of the immune response in the same vaccinees. We evaluated the Ab response, the PT neutralizing titer and the peripheral blood T cell response up to 4 years following vaccination. Our results show that in adults the level of antibodies to PT, FHA and 69K and the PT neutralizing titers slightly decline between 2.5 and 12 months after the last vaccine dose, but they remain high in the following 2-4 years, showing levels 10-100 times higher than pre-vaccination values. The T cell responses were more heterogeneous among vaccinees but they did not show any significant decline throughout the period monitored.
Asunto(s)
Anticuerpos Antibacterianos/biosíntesis , Inmunidad Celular , Toxina del Pertussis , Vacuna contra la Tos Ferina/inmunología , Factores de Virulencia de Bordetella/genética , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , Linfocitos T/inmunología , Factores de TiempoAsunto(s)
Madres/legislación & jurisprudencia , Mujeres Trabajadoras/legislación & jurisprudencia , Trabajo/legislación & jurisprudencia , Femenino , Humanos , Italia , Madres/estadística & datos numéricos , Embarazo , Factores de Riesgo , Mujeres Trabajadoras/estadística & datos numéricos , Trabajo/estadística & datos numéricosRESUMEN
Immunization of the female reproductive tract is important for protection against sexually transmitted diseases and other pathogens of the reproductive tract. However, intravaginal immunization with soluble antigens generally does not induce high levels of secretory immunoglobulin A (IgA). We recently developed safe mucosal adjuvants by genetically detoxifying Escherichia coli heat-labile enterotoxin, a molecule with a strong mucosal adjuvant activity, and here we describe the use of the nontoxic mutant LTK63 to induce a response in the mouse vagina against ovalbumin (Ova). We compared intravaginal and intranasal routes of immunization for induction of systemic and vaginal responses against LTK63 and Ova. We found that LTK63 is a potent mucosal immunogen when given by either the intravaginal or intranasal route. It induces a strong systemic antibody response and IgG and long-lasting IgA in the vagina. The appearance of vaginal IgA is delayed in the intranasally immunized mice, but the levels of vaginal anti-LTK63 IgA after repeated immunizations are higher in the intranasally immunized mice than in the intravaginally immunized mice. LTK63 also acts as a mucosal adjuvant, inducing a serum response against Ova, when given by both the intravaginal and intranasal routes. However, vaginal IgA against Ova is stimulated more efficiently when LTK63 and antigen are given intranasally. In conclusion, our results demonstrate that LTK63 can be used as a mucosal adjuvant to induce antigen-specific antibodies in vaginal secretions and show that the intranasal route of immunization is the most effective for this purpose.
Asunto(s)
Anticuerpos Antibacterianos/biosíntesis , Antígenos Bacterianos/inmunología , Toxinas Bacterianas/inmunología , Enterotoxinas/inmunología , Proteínas de Escherichia coli , Escherichia coli/inmunología , Vagina/inmunología , Animales , Anticuerpos Antibacterianos/sangre , Femenino , Inmunidad Mucosa , Inmunización , Inmunoglobulina A/biosíntesis , Inmunoglobulina G/biosíntesis , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/inmunologíaRESUMEN
Colonization of human gastric mucosa with cytotoxic strains of the bacterium Helicobacter pylori is associated with peptic ulcer and with chronic gastritis. Since little is known about the T-cell response to H. pylori, we investigated the CD4+ T-cell response both in peripheral blood mononuclear cells (PBMCs) and at the site of infection. First, we compared the bulk PBMC proliferative response to the bacterium in individuals with and without symptoms of gastroduodenal disease. We found that the PBMCs from virtually all individuals proliferate in response to heat-inactivated bacteria. Second, we cloned H. pylori-specific CD4+ T lymphocytes from the PBMCs of three patients and from both the gastric mucosa and PBMCs of a fourth patient. We have found that CD4+ T-cell clones specific for H. pylori from peripheral blood samples and gastric mucosae of infected patients are major histocompatibility complex class II restricted and discriminate between several cytotoxic and noncytotoxic bacterial strains. Moreover, they are polyclonal in terms of T-cell receptor usage and major histocompatibility complex restriction. Our results demonstrate that the T-cell response to the whole bacterium in PBMCs does not correlate with antibody response, infection, or disease. However, H. pylori-specific CD4+ T cells are detectable, at the clonal level, in both the periphery and gastric mucosa of infected patients. Localization of these cells at the site of disease suggests they are effectors of the immune response to the bacteria.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Mucosa Gástrica/inmunología , Helicobacter pylori/inmunología , Adulto , Células Productoras de Anticuerpos/inmunología , Linfocitos B/inmunología , Biopsia , Células Clonales/inmunología , Femenino , Mucosa Gástrica/citología , Antígenos HLA/inmunología , Humanos , Inmunoglobulinas/biosíntesis , Persona de Mediana Edad , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T Colaboradores-Inductores/inmunologíaRESUMEN
Proteins to be used as vaccines are frequently treated with formaldehyde, although little is known about the effects of this treatment on protein antigenicity. To investigate the effect of formaldehyde treatment on antigen recognition by T cells, we compared the in vitro T-cell response to proteins that have been formaldehyde treated with the response to untreated proteins. We found that peripheral blood mononuclear cells from individuals vaccinated with three formaldehyde-treated proteins (pertussis toxin, filamentous hemagglutinin, pertactin) of Bordetella pertussis showed little or no response to the formaldehyde-treated proteins but proliferated very well in response to the corresponding untreated protein. These findings were further confirmed with CD4+ T-cell clones specific for defined epitopes of the bacterial proteins. We found that some epitopes are presented poorly or not at all when formaldehyde-treated proteins are used, whereas other epitopes are equally presented to T-cell clones when either formaldehyde-treated or untreated antigens are used. However, T-cell recognition could be restored by either antigen degradation before formaldehyde treatment or heat denaturation after such treatment. Parallel digestion with trypsin of both formaldehyde-treated and untreated proteins showed that fragments generated from the two forms of the same antigen were different in size. These results demonstrate that formaldehyde treatment can constrain antigen presentation to T cells and that this may be due to an altered proteolytic processing of formaldehyde-treated proteins.
Asunto(s)
Presentación de Antígeno/efectos de los fármacos , Formaldehído/farmacología , Linfocitos T/inmunología , Adulto , Proteínas de la Membrana Bacteriana Externa/inmunología , Células Cultivadas , Epítopos , Hemaglutininas/inmunología , Humanos , Toxina del Pertussis , Factores de Virulencia de Bordetella/inmunologíaRESUMEN
We have examined the role of 12 polymorphic residues of the beta-chain of the HLA-DR1 class II molecule in T cell recognition of an epitope of pertussis toxin. Murine L cell transfectants expressing wild-type or mutant DR1 molecules (containing single amino acid substitutions in DR(beta 1*0101)) were used as APC in proliferation assays involving nine DR1-restricted T cell clones specific for peptide 30-42 of pertussis toxin. Four different patterns of recognition of the mutants were found among the pertussis-specific clones. Residues in the third hypervariable region (HVR) of DR(beta 1*0101) are critically important for all the T cell clones; amino acid substitutions at positions 70 and 74 abrogated recognition by all of the T cell clones, and substitutions at positions 67 and 71 eliminated recognition by most of the clones. In contrast, most single amino acid substitutions in the first and second HVR, predicted to be located in the floor of the peptide binding groove, had little or no effect on the proliferative responses of these clones. However, the involvement of beta-chain first and second HVR residues was demonstrated by the inability of transfectants expressing wild-type DR(beta 1*0404) (DR4Dw14) or DR(beta 1*1402) (DR6Dw16) to present peptide to these clones. These beta-chains have completely different first and second HVR compared with DR(alpha,beta 1*0101) although the third HVR are identical. These results illustrate the functional importance of third HVR residues of DR(beta 1*0101) and allow definition of the molecular interactions of the DR1 molecule with the 30-42 peptide.
Asunto(s)
Reacciones Antígeno-Anticuerpo/genética , Antígeno HLA-DR1/inmunología , Toxina del Pertussis , Factores de Virulencia de Bordetella/inmunología , Secuencia de Aminoácidos , División Celular/genética , Relación Dosis-Respuesta Inmunológica , Antígeno HLA-DR1/genética , Humanos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Polimorfismo Genético , Linfocitos T/fisiología , TransfecciónRESUMEN
The interaction of the immunodominant pertussis toxin peptide containing residues 30-42 (p30-42) with soluble DR1 molecules and the T-cell receptor (TCR) of 12 DR1-restricted human T-cell clones has been analyzed. Peptide analogues of p30-42 containing single alanine substitutions were used in DR1-binding and T-cell proliferation assays to identify the major histocompatibility complex and TCR contact residues. Each T-cell clone was found to recognize p30-42 with a different fine specificity. However, a common core comprising amino acids 33-39 was found to be important for stimulation of all T-cell clones. Within this core two residues, Leu33 and Leu36, interact with the DR1 molecule, whereas Asp34, His35, Thr37, and Arg39 are important for TCR recognition in most of the clones. Computer modeling of the structure of p30-42 showed that an alpha-helical conformation is compatible with the experimental data. The analysis of TCR rearrangement revealed that the peptide was recognized by T-cell clones expressing different variable region alpha (V alpha) and variable region beta (V beta) chains, although a preferential use of V alpha 8-V beta 13 and V alpha 11-V beta 18 combinations was found in clones from the same donor. Understanding the details of the interaction of antigenic peptides with the major histocompatibility complex and TCR molecules should provide the theoretical basis to design T-cell epitopes and obtain more immunogenic vaccines.
Asunto(s)
Antígeno HLA-DR1/inmunología , Toxina del Pertussis , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Factores de Virulencia de Bordetella/inmunología , Secuencia de Aminoácidos , Secuencia de Bases , Sitios de Unión , Células Clonales , Reordenamiento Génico de la Cadena alfa de los Receptores de Antígenos de los Linfocitos T , Reordenamiento Génico de la Cadena beta de los Receptores de Antígenos de los Linfocitos T , Humanos , Técnicas In Vitro , Modelos Moleculares , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos/química , Péptidos/química , Péptidos/inmunología , Unión Proteica , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Factores de Virulencia de Bordetella/químicaRESUMEN
An acellular pertussis vaccine composed of genetically detoxified pertussis toxin (PT-9K/129G), filamentous haemagglutinin (FHA) and pertactin (69 kDa protein) was evaluated in adult volunteers, in double blind, versus placebo. No fever was reported in either group. Mild local reactions were reported after injection of both vaccine and placebo. After the first dose a marked increase in antibodies to PT, FHA and 69 kDa protein was seen in vaccinated subjects with the exception of one who responded well to PT and FHA but did not show a humoral response to the 69 kDa protein. All vaccinees acquired cellular immunity against the three antigens. No significant variation was observed in the humoral or cellular responses after the second dose.
Asunto(s)
Adhesinas Bacterianas , Proteínas de la Membrana Bacteriana Externa/efectos adversos , Bordetella pertussis/inmunología , Hemaglutininas/efectos adversos , Vacuna contra la Tos Ferina/efectos adversos , Factores de Virulencia de Bordetella , Anticuerpos Antivirales/biosíntesis , Proteínas de la Membrana Bacteriana Externa/inmunología , Método Doble Ciego , Evaluación de Medicamentos , Ensayo de Inmunoadsorción Enzimática , Hemaglutininas/inmunología , Humanos , Inmunidad Celular/fisiología , Peso Molecular , Vacuna contra la Tos Ferina/inmunología , Vacunas de Productos Inactivados/efectos adversos , Vacunas de Productos Inactivados/inmunologíaRESUMEN
Human CD4+ T-cell clones specific for pertussis toxin and other Bordetella pertussis antigens have been tested for their cytotoxic activity, lymphokine production, and capacity to induce immunoglobulin synthesis. Clones specific for the S1 subunit of pertussis toxin were cytotoxic for autologous Epstein-Barr virus-transformed B cells, which had been pulsed with the native antigen, the recombinant S1 subunit of pertussis toxin, or synthetic peptides derived from the S1 amino acid sequence. The killing of antigen-pulsed target cells was class II restricted. All of the T-cell clones produced mostly interleukin-2 and gamma interferon and assisted allogeneic B cells in the production of immunoglobulins M and G but not immunoglobulin E. The potential in vivo role of the cytotoxic activity of these clones is discussed.
Asunto(s)
Bordetella pertussis/inmunología , Linfocitos T CD4-Positivos/inmunología , Interferón gamma/biosíntesis , Interleucinas/biosíntesis , Linfocitos B , Células Clonales , Epítopos/análisis , Antígenos HLA-DR/inmunología , Herpesvirus Humano 4 , Humanos , Inmunoglobulina E/biosíntesis , Toxina del Pertussis , Factores de Virulencia de Bordetella/toxicidadRESUMEN
Filamentous hemagglutinin (FHA), a 220-kDa protein that mediates the adhesion of Bordetella pertussis to eukaryotic cells, is a component of acellular vaccines against whooping cough. To identify the subregions of FHA that are immunogenic for T cells, 16 human T-cell clones were raised against purified FHA and tested for the recognition of recombinant and proteolytic fragments. The clones were found to map either in the carboxy-terminal or the amino-terminal part of the FHA molecule, but none of them recognized the central region, which contains a sequence that is homologous to that of the eukaryotic protein fibronectin. These data suggest that subregions of FHA that do not contain sequences that are potentially cross-reactive with self proteins may be sufficient to induce an immune response against the whole protein.
Asunto(s)
Adhesinas Bacterianas , Epítopos/inmunología , Hemaglutininas/inmunología , Activación de Linfocitos , Linfocitos T/inmunología , Factores de Virulencia de Bordetella , Secuencia de Aminoácidos , Reacciones Cruzadas/inmunología , Humanos , Datos de Secuencia Molecular , Oligopéptidos/inmunología , Fragmentos de Péptidos/inmunología , Proteínas Recombinantes/inmunologíaRESUMEN
PT-9K/129G, a nontoxic mutant of pertussis toxin (PT) obtained by genetic manipulation, has been shown in animal models to be a promising candidate for new vaccines against whooping cough. To assess the safety and the immunogenicity of PT-9K/129G in humans, a pilot study has been performed in adult volunteers. The protein was found to be safe, capable of inducing high titers of toxin-neutralizing antibodies, and capable of generating immunological memory. In fact, vaccination caused an increase of cell-mediated response to PT, PT-9K/129G, S1 subunit, and B oligomer, indicating that memory T cells are induced by the vaccine. Since PT-9K/129G is mitogenic for T lymphocytes in vitro, it was investigated whether this activity is also present in vivo. No variation was observed in the proportion of T cells (CD3+), T helper cells (CD4+), and cytotoxic T cells (CD8+), as well as in that of other lymphoid populations, by FACS analysis. Interestingly, no thorough correlation was found between humoral and cellular responses. In one case, a very high cellular response was present in absence of detectable antibodies, suggesting that the antibody response, which is the only parameter measured in most clinical trials, may not give a complete picture of the response induced by a vaccine.
Asunto(s)
Formación de Anticuerpos/efectos de los fármacos , Inmunidad Celular/efectos de los fármacos , Toxina del Pertussis , Vacuna contra la Tos Ferina , Factores de Virulencia de Bordetella/inmunología , Adulto , Glucemia/metabolismo , Humanos , Insulina/sangre , Células Asesinas Naturales/inmunología , Recuento de Leucocitos , Mutación , Proyectos Piloto , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T Citotóxicos/inmunología , Factores de Virulencia de Bordetella/efectos adversos , Factores de Virulencia de Bordetella/genéticaRESUMEN
the introduction of two amino acid substitutions within the enzymatically active subunit S1 of pertussis toxin (PT) abolishes its ADP-ribosyltransferase activity and toxicity on CHO cells (Pizza et al., Science 246:497-500, 1989). These genetically inactivated molecules are also devoid of other in vivo adverse reactions typical of PT, such as induction of leukocytosis, potentiation of anaphylaxis, stimulation of insulin secretion, and histamine sensitivity. However, the mutant PT molecules are indistinguishable from wild-type PT in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and maintain all the physical and chemical properties of PT, including affinity for toxin-neutralizing poly- and monoclonal antibodies. Either alone or stabilized with formaldehyde, PT mutants are able to induce high levels of neutralizing antibodies and to protect mice in a dose-dependent fashion against intracerebral challenge with virulent B. pertussis. These results clearly show that these genetically inactivated PT molecules are nontoxic but still immunogenic and justify their development as a component of a new, safer acellular vaccine against whooping cough.