RESUMO
The present paper describes important features of the immune response induced by the Cry1Ac protein from Bacillus thuringiensis in mice. The kinetics of induction of serum and mucosal antibodies showed an immediate production of anti-Cry1Ac IgM and IgG antibodies in serum after the first immunization with the protoxin by either the intraperitoneal or intragastric route. The antibody fraction in serum and intestinal fluids consisted mainly of IgG1. In addition, plasma cells producing anti-Cry1Ac IgG antibodies in Peyer's patches were observed using the solid-phase enzyme-linked immunospot (ELISPOT). Cry1Ac toxin administration induced a strong immune response in serum but in the small intestinal fluids only anti-Cry1Ac IgA antibodies were detected. The data obtained in the present study confirm that the Cry1Ac protoxin is a potent immunogen able to induce a specific immune response in the mucosal tissue, which has not been observed in response to most other proteins.
Assuntos
Anticorpos Antibacterianos/biossíntese , Bacillus thuringiensis/imunologia , Proteínas de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Endotoxinas/imunologia , Imunoglobulina G/biossíntese , Mucosa Intestinal/imunologia , Animais , Anticorpos Antibacterianos/sangue , Toxinas de Bacillus thuringiensis , Ensaio de Imunoadsorção Enzimática , Feminino , Proteínas Hemolisinas , Imunoglobulina G/sangue , Imunoglobulina M/biossíntese , Imunoglobulina M/sangue , Camundongos , Camundongos Endogâmicos BALB CRESUMO
The present paper describes important features of the immune response induced by the Cry1Ac protein from Bacillus thuringiensis in mice. The kinetics of induction of serum and mucosal antibodies showed an immediate production of anti-Cry1Ac IgM and IgG antibodies in serum after the first immunization with the protoxin by either the intraperitoneal or intragastric route. The antibody fraction in serum and intestinal fluids consisted mainly of IgG1. In addition, plasma cells producing anti-Cry1Ac IgG antibodies in Peyer's patches were observed using the solid-phase enzyme-linked immunospot (ELISPOT). Cry1Ac toxin administration induced a strong immune response in serum but in the small intestinal fluids only anti-Cry1Ac IgA antibodies were detected. The data obtained in the present study confirm that the Cry1Ac protoxin is a potent immunogen able to induce a specific immune response in the mucosal tissue, which has not been observed in response to most other proteins
Assuntos
Animais , Feminino , Anticorpos Antibacterianos/biossíntese , Bacillus thuringiensis/imunologia , Proteínas de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Imunoglobulina G/biossíntese , Mucosa Intestinal/imunologia , Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/administração & dosagem , Toxinas Bacterianas/administração & dosagem , Ensaio de Imunoadsorção Enzimática , Imunização , Imunoglobulina G/sangue , Imunoglobulina M/biossíntese , Imunoglobulina M/sangue , Mucosa Intestinal/metabolismo , Camundongos Endogâmicos BALB CRESUMO
Cry proteins from Bacillus thuringiensis have insecticidal properties. The function of domains I and II has been described but domain III has so far eluded understanding. Domain III from Cry1Ab and Cry1Ac has been cloned, expressed in E. coli and injected to rabbits with the aid of characterizing them immunologically. Interestingly, polyclonal antibodies against Cry1Ab fragment did not recognize either the native Cry1Ab toxin or the Cry1Ac fragment while those against the latter did recognize either the native Cry1Ac toxin or the Cry1Ab protein fragment. A combination of information from sequence comparison and hydrophobicity profile indicates that these protein fragments possibly adopt different spatial dispositions within the respective toxins.