CD8+ T cells eliminate liver-stage Plasmodium berghei parasites without detectable bystander effect

Infect Immun. 2014 Apr;82(4):1460-4. doi: 10.1128/IAI.01500-13. Epub 2014 Jan 13.

Abstract

Immunization with attenuated Plasmodium sporozoites or viral vectored vaccines can induce protective CD8(+) T cells that can find and eliminate liver-stage malaria parasites. A key question is whether CD8(+) T cells must recognize and eliminate each parasite in the liver or whether bystander killing can occur. To test this, we transferred antigen-specific effector CD8(+) T cells to mice that were then coinfected with two Plasmodium berghei strains, only one of which could be recognized directly by the transferred T cells. We found that the noncognate parasites developed normally in these mice, demonstrating that bystander killing of parasites does not occur during the CD8(+) T cell response to malaria parasites. Rather, elimination of infected parasites is likely mediated by direct recognition of infected hepatocytes by antigen-specific CD8(+) T cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Protozoan / immunology
  • Bystander Effect / immunology*
  • CD8-Positive T-Lymphocytes / physiology*
  • Hepatocytes / parasitology*
  • Liver / parasitology
  • Malaria / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Parasite Load
  • Plasmodium berghei / immunology*

Substances

  • Antigens, Protozoan