Data/hora: 12/06/2024 03:48:14

Biblioteca(s): | Embrapa Pantanal.
Data corrente: | 09/08/1995
Data da última atualização: | 05/04/2017
Autoria: | NANTULYA, V. M.; MUSOKE, A. J.; RURANGIRWA, F. R.; MOLOO, S. K.
Título: | Resistance of cattle to tsetse-transmitted challenge with Trypanosoma brucei or Trypanosoma congolense after spontaneous recovery from syringe passaged infections.
Ano de publicação: | 1984
Fonte/Imprenta: | Infection and Immunity, v.43, n.2, p.735-738, 1984.
Idioma: | Inglês
Conteúdo: | Groups of cattle were inoculated intravenously with cloned populations of bloodstream forms of Trypanosoma brucei or Trypanosoma congolense. All five steers infected with T. brucei IL Tat 2.1 and six of the eight sters infected with T. congolense IL 13-E14 became aparsitemic within 16 and 32 weeks postinfection, respectively. Examination of sera from animals infected with T. brucei by indirect immunofluorescence and neutralization assays revealed the presence of antibodies against all the metacyclic variable antigen types (VATs) of the infecting clone. The neutralizing capacity of the sera increased with the course of infection from 1:10 at 2 monts to 1:100 at 3 to 4 months postinfection. The recovered animals were completely immune to challenge by Glossina morsitans subsp. centralis infected with clone IL Tat 2.1 which had initiated the infection, as well as wich another clone (IL Tat 2.2) belonging to the same serodeme but they were susceptible to a tsetse-transmited heterologous challenge with isolate STIB 367-H. Similar results were obtained with sera from T. congolense IL 13-E14-infected steers. The six steers inbfected with a different T. congolense IL Nat 3.1 clone did not recover spotaneously; however, 2 months postinfection, sera from five of them also contained neutralizing antibodies against IL Nat 3.1 metacyclic VATs. These results indicate that some of the bloodstream VATs that arise during the course of a chronic infection possess surface epitopes in their variable surface glycoproteins that are identical to those of the metacyclic VATs. It is suggested that in chronic infection, the infecting trypanosomes could exhaust their VAT repertoire, including those that cross-react with metacyclies, threby leading to both self-cure and subsequent immunity to homologous cyclically transmited challenge.
Thesaurus Nal: | Trypanosoma brucei; Trypanosoma congolense.
Categoria do assunto: | --
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (29065-1) - ADD - SP - PP - SP14502 -  - 14502 - DIS