CD8⁺ cytolytic T cell clones derived against the Plasmodium yoelii circumsporozoite protein protect against malaria

Importance of CD8 T cell-mediated immune response during intracellular parasitic infections and its implications for the development of effective vaccines

“…So far, to our knowledge, in mice vaccinated with radiation-attenuated sporozoites, CD8 lymphocytes were specific for a single epitope found in the C-terminal region of the P. berghei or P. yoelii CS protein (Romero et al 1989, Rodrigues et al 1991. This epitope is recognized by CD8 T cells restricted by H-2 Kd molecules.…”

“…Using this assay it was possible to demonstrate that there was a reduced amount of parasite rRNA in the liver of animals that received cells of a CD8 T cell clone 20 hours after the challenge with sporozoites. In contrast, control animals that did not receive T cells presented large amounts of parasite rRNA in their livers (Rodrigues et al 1991).…”

“…CD8 T cell clones were generated and characterized in vitro in terms of phenotype and specificity. These clones were Thy1+, αβ T-Cell Receptor+, CD4-and CD8+ and they recognized with high affinity a synthetic peptide represented by amino acids SYVPSAEQI present in the C-terminal portion of P. yoelii CS protein (Rodrigues et al 1991).…”

“…In addition, these cells secrete large amounts of IFN-γ , TNF-α and the enzyme BLTesterase when stimulated by the antigen in vitro (Rodrigues et al 1991(Rodrigues et al , 1992. Most important, when adoptively transferred to naïve BALB/c mice, some of these clones were capable to provide specific immunity against the challenge with viable P. yoelii sporozoites (Rodrigues et al 1991(Rodrigues et al , 1992.…”

Cytotoxic T Lymphocytes in Humans Exposed to Plasmodium falciparum by Immunization or Natural Exposure

“…ROMERO reported that adoptive transfer of CTL clones against the analogous epitope on the P. berghei CS protein completely protected against challenge in vivo. ROORIGUES (RODRIGUES et al 1991) subsequently reported that adoptive transfer of CTL clones against the P. yoelii CS protein protected even if transferred 3 h after sporozoites were inoculated, at a time when the sporozoites had left the circulation and were within hepatocytes. Infected hepatocytes were clearly the target of these CTL.…”