RESUMO
Mucosal surfaces are protected specifically by secretory immunoglobulin A (SIgA) and SIgM generated through external translocation of locally produced dimeric IgA and pentameric IgM. Their active transport is mediated by the epithelial polymeric Ig receptor (pIgR), also called the transmembrane secretory component. Paracellular passive external transfer of systemic and locally produced antibodies also provides mucosal protection, making the biological importance of secretory immunity difficult to assess. Here we report complete lack of active external IgA and IgM translocation in pIgR knockout mice, indicating no redundancy in epithelial transport mechanisms. The knockout mice were of normal size and fertility but had increased serum IgG levels, including antibodies to Escherichia coli, suggesting undue triggering of systemic immunity. Deterioration of their epithelial barrier function in the absence of SIgA (and SIgM) was further attested to by elevated levels of albumin in their saliva and feces, reflecting leakage of serum proteins. Thus, SIgA did not appear to be essential for health under the antigen exposure conditions of these experimental animals. Nevertheless, our results showed that SIgA contributes to maintenance of mucosal homeostasis. Production of SIgA might therefore be a variable in the initiation of human immunopathology such as inflammatory bowel disease or gluten-sensitive enteropathy.
Assuntos
Imunoglobulina A Secretora/metabolismo , Mucosa Intestinal/imunologia , Receptores de Imunoglobulina Polimérica/genética , Receptores de Imunoglobulina Polimérica/imunologia , Animais , Anticorpos Antibacterianos/sangue , Transporte Biológico , Transporte Biológico Ativo , Escherichia coli/imunologia , Fertilidade , Glutens/imunologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/metabolismo , Intestino Delgado/imunologia , Lactobacillus/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Ratos , Receptores de Imunoglobulina Polimérica/deficiência , Mapeamento por Restrição , Saliva/imunologia , Albumina Sérica/metabolismoRESUMO
IgA antibodies reflecting airways or intestinal mucosal immune responses can be found in saliva and feces, respectively, and IgG antibodies reflecting serum antibodies can be found in saliva. In this study, antibodies were detected in samples of saliva and feces which had been air-dried at room temperature (+20 degrees C) or +37 degrees C, and stored at these temperatures for up to 6 months. In saliva the antibody levels increased, while the antibodies in feces decreased upon storage. The individual IgA antibody concentrations which were adjusted by using the ratios of specific IgA/total IgA were relatively stable in both saliva and feces, and correlated with corresponding antibody levels in samples which had been stored at -20 degrees C. The results indicate that air-dried saliva and feces can be used for semiquantitative measurements of mucosal antibodies, even after prolonged storage at high temperatures and lack of refrigeration.
Assuntos
Fezes/química , Imunoglobulina A/análise , Imunoglobulina G/análise , Mucosa Intestinal/imunologia , Mucosa Nasal/imunologia , Saliva/química , Congelamento , Humanos , Mucosa Intestinal/metabolismo , Mucosa Nasal/metabolismo , Manejo de Espécimes/métodosRESUMO
A whole-cell pertussis vaccine, each dose consisting of 250 microg of protein, was given intranasally four times at weekly intervals to six adult volunteers. All vaccinees responded with increases in nasal fluid IgA antibodies to Bordetella pertussis whole-cell antigen. Three vaccinees with high nasal antibody responses also developed increased serum IgA and IgG antibodies to this antigen. Salivary antibody responses to the whole-cell antigen, as well as antibodies in serum and secretions to pertussis toxin (PT) and filamentous haemagglutinin (FHA) were negligible, except for a moderate increase in nasal fluid antibodies to FHA. Unexpectedly, the same vaccinees developed significant rises in nasal and salivary IgA antibodies to meningococcal outer-membrane antigens, whereas corresponding serum IgA and IgG antibodies were unchanged. Thus it appears that mucosal immunisation may induce secretory antibodies with broader specificities than can be found in serum.
Assuntos
Anticorpos Antibacterianos/biossíntese , Bordetella pertussis/imunologia , Imunidade nas Mucosas , Vacina contra Coqueluche/administração & dosagem , Vacina contra Coqueluche/imunologia , Adesinas Bacterianas/imunologia , Administração Intranasal , Adulto , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Reações Cruzadas , Feminino , Hemaglutininas/imunologia , Humanos , Esquemas de Imunização , Imunoglobulina A/biossíntese , Imunoglobulina A/sangue , Imunoglobulina A Secretora/biossíntese , Imunoglobulina G/biossíntese , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/imunologia , Neisseria meningitidis/imunologia , Toxina Pertussis , Vacina contra Coqueluche/efeitos adversos , Porinas/imunologia , Saliva/imunologia , Fatores de Virulência de Bordetella/imunologiaAssuntos
Anticorpos Antibacterianos/análise , Colo/imunologia , Imunização/métodos , Imunoglobulina A/análise , Mucosa Intestinal/imunologia , Reto/imunologia , Vagina/imunologia , Absorção , Administração Intravaginal , Administração Oral , Administração Retal , Animais , Toxina da Cólera/administração & dosagem , Toxina da Cólera/imunologia , Feminino , Camundongos , Especificidade de Órgãos , Saliva/imunologia , Manejo de Espécimes/instrumentação , Manejo de Espécimes/métodosRESUMO
The soluble branched yeast beta-1,3-D-glucan (SBG) belongs to a group of carbohydrate polymers known to exert potent immunomodulatory effects when administered to animals and humans. A new oral solution of SBG has been developed for local application to the oropharyngeal and oesophageal mucosa in order to strengthen the defence mechanisms against microbial and toxic influences. In the present study oral administration of SBG has been investigated primarily for assessment of safety and tolerability in an early phase human pharmacological study (phase I). Eighteen healthy volunteers were included among non-smoking individuals. The study was an open 1:1:1 dose-escalation safety study consisting of a screening visit, an administration period of 4 days and a follow-up period. Groups of six individuals received SBG 100 mg/day, 200 mg/day or 400 mg/day, respectively, for 4 consecutive days. The dose increase was allowed after a careful review of the safety data of the lower dose group. No drug-related adverse event, including abnormalities in vital signs, was observed. By inspection of the oral cavity only minor mucosal lesions not related to the study medication were seen in seven subjects. Repeated measurements of beta-glucan in serum revealed no systemic absorption of the agent following the oral doses of SBG. In saliva, the immunoglobulin A concentration increased significantly for the highest SBG dose employed. SBG was thus safe and well tolerated by healthy volunteers, when given orally once daily for 4 consecutive days at doses up to 400 mg.
Assuntos
Imunoglobulina A/análise , Fatores Imunológicos/administração & dosagem , Saliva/imunologia , beta-Glucanas/administração & dosagem , Administração Oral , Adulto , Feminino , Humanos , Imunoglobulina G/análise , Interleucina-1/análise , Interleucina-6/análise , Masculino , Estatísticas não Paramétricas , Estimulação Química , Fator de Necrose Tumoral alfa/análiseRESUMO
Sixty-five healthy adult volunteers were immunized four times at 1-week intervals with an inactivated whole-virus influenza vaccine based on the strain A/New Caledonia/20/99 (H1N1) without adjuvant. The vaccine was administered as nasal spray with a newly developed device to secure intranasal delivery (OptiMist, OptiNose AS, Oslo, Norway), as regular nasal spray, nasal drops or as an oral spray. Significant IgA-antibody responses in nasal secretions were induced in volunteers immunized intranasally but not after oral spray immunization. In saliva, IgA antibodies were only marginally amplified even after oral spray immunizations. At least 73% of the volunteers belonging to any group of vaccine delivery reached serum haemagglutination inhibition titres of 40 or higher, considered protective against influenza, after only two vaccine doses. Those who had the vaccine delivered intranasally also showed evidence from in vitro secretion of granzyme B that cytotoxic T cells had been stimulated. Although immunization with the breath-actuated OptiMist device and nasal drops were superior with respect to both mucosal and systemic immune responses, oral spray immunization might still be considered for studies of mucosal adjuvants that are not yet acceptable for intranasal use.
Assuntos
Anticorpos/metabolismo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Imunização/métodos , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Administração Intranasal , Adolescente , Adulto , Relação Dose-Resposta a Droga , Feminino , Humanos , Imunidade nas Mucosas , Imunoglobulina A/metabolismo , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/imunologia , Mucosa Nasal/metabolismo , Saliva/imunologia , Linfócitos T/imunologiaRESUMO
Mice immunized intranasally with a formalin-inactivated A/PR/8/34 (H1N1) influenza whole virus vaccine adjuvanted with cholera toxin, outer membrane vesicles from group B meningococci or formalin-inactivated whole cell Bordetella pertussis were protected against replication of the homologous virus in the nasal cavity. Only some mice were protected against clinical illness measured as weight loss and lowered body temperature. All mice immunized subcutaneously with one-tenth the intranasal vaccine dose without adjuvant were protected against clinical illness but not against local mucosal viral replication. Replicating virus was primarily found in animals with low concentrations of immunoglobulin (Ig)-A antibodies in saliva regardless of concentrations of IgG antibodies in serum. Clinical illness was seen only in those with low serum antibodies regardless of antibody levels in saliva. Nonreplicating nasal vaccines may not be sufficiently protective unless they also have a substantial influence on systemic immunity.
Assuntos
Anticorpos Antivirais/análise , Imunoglobulina A/análise , Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Vacinação , Adjuvantes Imunológicos , Administração Intranasal , Animais , Anticorpos Antivirais/sangue , Bordetella pertussis/imunologia , Toxina da Cólera/imunologia , Feminino , Imunidade nas Mucosas/imunologia , Imunoglobulina A/sangue , Injeções Subcutâneas , Camundongos , Mucosa Nasal/imunologia , Mucosa Nasal/virologia , Neisseria meningitidis Sorogrupo B/imunologia , Infecções por Orthomyxoviridae/imunologia , Saliva/imunologia , Replicação ViralRESUMO
In order to study the mucosal and serum antibody response to polysaccharide-encapsulated bacteria in mice, a preparation of heat-inactivated Streptococcus pneumoniae type 4 was administered, with and without cholera toxin, at various mucosal sites. It appeared that intranasal immunization of nonanesthesized animals was superior to either oral, gastric, or colonic-rectal antigen delivery with regard to the induction of serum immunoglobulin G (IgG) and IgA, as well as saliva IgA antibodies specific for pneumococci. The marked IgA antibody response in feces after intranasal, but not after oral or gastric, immunization is suggestive of a cellular link between the nasal induction site and the distant mucosal effector sites. Intranasal immunization also induced antibodies in serum and in mucosal secretions against type-specific capsular polysaccharide. IgA and IgG antibody levels in pulmonary lavage fluids correlated well with saliva IgA and serum IgG antibodies, respectively. Antibody determinations in pulmonary secretions may therefore be redundant in some cases, and the number of experimental animals may be reduced accordingly. After intraperitoneal challenge with type 4 pneumococci, mice immunized intranasally were protected against both systemic infection and death, even without the use of cholera toxin as a mucosal adjuvant. Thus, an efficient intranasal vaccine against invasive pneumococcal disease may be based on a very simple formulation with whole killed pneumococci.