RESUMEN
AIM: To use radioreceptor analysis for evaluating whether vasoactive intestinal peptide (VIP) receptors are present in chronic periapical lesions and to determine whether differences in its expression are found according to the size of the lesions. METHODOLOGY: Twelve periapical lesions were obtained from teeth diagnosed with chronic apical periodontitis and indicated for endodontic surgery; they were classified according to the size of the lesion in two groups of six samples (lesion size greater or smaller than 5 mm), and then processed and labelled with (125)I-VIP. Binding sites were identified by (125)I-VIP and standard VIP competition assays. Mann-Whitney's test was used to establish statistically significant differences in the VIP receptor expression between groups. RESULTS: Vasoactive intestinal peptide receptor expression was found in all periapical lesion samples. There was a statistically significantly higher expression in periapical lesions <5 mm (P < 0.001). CONCLUSION: Vasoactive intestinal peptide receptors were expressed in chronic periapical lesions with levels inversely proportional to lesion size.
Asunto(s)
Enfermedades Periapicales/patología , Receptores de Péptido Intestinal Vasoactivo/análisis , Adulto , Enfermedad Crónica , Progresión de la Enfermedad , Femenino , Humanos , Radioisótopos de Yodo , Masculino , Persona de Mediana Edad , Enfermedades Periapicales/clasificación , Periodontitis Periapical/patología , Radiofármacos , Péptido Intestinal VasoactivoRESUMEN
The recombinant Bm86-containing vaccine Gavac(TM) against the cattle tick Boophilus microplus has proved its efficacy in a number of experiments, especially when combined with acaricides in an integrated manner. However, tick isolates such as the Argentinean strain A, show low susceptibility to this vaccine. In this paper we report on the isolation of the Bm95 gene from the B. microplus strain A, which was cloned and expressed in the yeast Pichia pastoris producing a glycosylated and particulated recombinant protein. This new antigen was effective against different tick strains in a pen trial, including the B. microplus strain A, resistant to vaccination with Bm86. A Bm95-based vaccine was used to protect cattle against tick infestations under production conditions, lowering the number of ticks on vaccinated animals and, therefore, reducing the frequency of acaricide treatments. The Bm95 antigen from strain A was able to protect against infestations with Bm86-sensitive and Bm86-resistant tick strains, thus suggesting that Bm95 could be a more universal antigen to protect cattle against infestations by B. microplus strains from different geographical areas.
Asunto(s)
Antígenos/inmunología , Enfermedades de los Bovinos/prevención & control , Infestaciones por Garrapatas/veterinaria , Garrapatas/inmunología , Vacunas Sintéticas/inmunología , Animales , Formación de Anticuerpos , Antígenos/genética , Secuencia de Bases , Bovinos , Clonación Molecular , Femenino , Lactancia , Datos de Secuencia Molecular , Pichia/genética , Proteínas Recombinantes/aislamiento & purificación , Infestaciones por Garrapatas/prevención & control , VacunaciónRESUMEN
Cattle tick infestations constitute a major problem for the cattle industry in tropical and subtropical regions of the world. Traditional control methods have been only partially successful, hampered by the selection of chemical-resistant tick populations. The Boophilus microplus Bm86 protein was isolated from tick gut epithelial cells and shown to induce a protective response against tick infestations in vaccinated cattle. Vaccine preparations including the recombinant Bm86 are used to control cattle tick infestations in the field as an alternative measure to reduce the losses produced by this ectoparasite. The principle for the immunological control of tick infestations relies on a polyclonal antibody response against the target antigen and, therefore, should be difficult to select for tick-resistant populations. However, sequence variations in the Bm86 locus, among other factors, could affect the effectiveness of Bm86-containing vaccines. In the present study we have addressed this issue, employing data obtained with B. microplus strains from Australia, Mexico, Cuba, Argentina and Venezuela. The results showed a tendency in the inverse correlation between the efficacy of the vaccination with Bm86 and the sequence variations in the Bm86 locus (R2 = 0.7). The mutation fixation index in the Bm86 locus was calculated and shown to be between 0.02 and 0.1 amino acids per year. Possible implications of these findings for the immunoprotection of cattle against tick infestations employing the Bm86 antigen are discussed.