Phenotypic characterization of Plasmodium berghei responsive CD8+ T cells after immunization with live sporozoites under chloroquine cover.
Malar J
; 13: 92, 2014 Mar 12.
Article
em En
| MEDLINE
| ID: mdl-24620841
ABSTRACT
BACKGROUND:
An effective malaria vaccine remains elusive. The most effective experimental vaccines confer only limited and short-lived protection despite production of protective antibodies. However, immunization with irradiated sporozoites, or with live sporozoites under chloroquine cover, has resulted in long-term protection apparently due to the generation of protective CD8+ T cells. The nature and function of these protective CD8+ T cells has not been elucidated. In the current study, the phenotype of CD8+ T cells generated after immunization of C57BL/6 mice with live Plasmodium berghei sporozoites under chloroquine cover was investigated.METHODS:
Female C57BL/6 mice, C57BL/6 mice B2 macroglobulin -/- [KO], or invariant chain-/- [Ic KO] [6-8 weeks old] were immunized with P. berghei sporozoites and treated daily with 800 µg/mouse of chloroquine for nine days. This procedure of immunization is referred to as "infection/cure". Mice were challenged by inoculating intravenously 1,000 infectious sporozoites. Appearance of parasitaemia was monitored by Giemsa-stained blood smears.RESULTS:
By use of MHC I and MHC II deficient animals, results indicate that CD8+ T cells are necessary for full protection and that production of protective antibodies is either CD4+ T helper cells dependent and/or lymphokines produced by CD4 cells contribute to the protection directly or by helping CD8+ T cells. Further, the phenotype of infection/cure P. berghei responsive CD8+ T cells was determined to be KLRG1high CD27low CD44high and CD62Llow.CONCLUSION:
The KLRG1high CD27low CD44high and CD62Llow phenotype of CD8+ T cells is associated with protection and should be investigated further as a candidate correlate of protection.
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Base de dados:
MEDLINE
Assunto principal:
Plasmodium berghei
/
Cloroquina
/
Imunização
/
Vacinas Antimaláricas
/
Linfócitos T CD8-Positivos
/
Esporozoítos
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article