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PubMed · 8976201

CD8 beta increases CD8 coreceptor function and participation in TCR-ligand binding.

V Renard·P Romero·E Vivier·B Malissen·I F Luescher
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Abstract

To study the role of CD8 beta in T cell function, we derived a CD8 alpha/beta-(CD8-/-) T cell hybridoma of the H-2Kd-restricted N9 cytotoxic T lymphocyte clone specific for a photoreactive derivative of the Plasmodium berghei circumsporozoite peptide PbCS 252-260. This hybridoma was transfected either with CD8 alpha alone or together with CD8 beta. All three hybridomas released interleukin 2 upon incubation with L cells expressing Kd-peptide derivative complexes, though CD8 alpha/beta cells did so more efficiently than CD8 alpha/alpha and especially CD8-/- cells. More strikingly, only CD8 alpha/beta cells were able to recognize a weak agonist peptide derivative variant. This recognition was abolished by Fab' fragments of the anti-Kd alpha 3 monoclonal antibody SF1-1.1.1 or substitution of Kd D-227 with K, both conditions known to impair CD8 coreceptor function. T cell receptor (TCR) photoaffinity labeling indicated that TCR-ligand binding on CD8 alpha/beta cells was approximately 5- and 20-fold more avid than on CD8 alpha/a and CD8-/- cells, respectively. SF1-1.1.1 Fab' or Kd mutation D227K reduced the TCR photoaffinity labeling on CD8 alpha/beta cells to approximately the same low levels observed on CD8-/- cells. These results indicate that CD8 alpha/beta is a more efficient coreceptor than CD8alpha/alpha, because it more avidly strengthens TCR-ligand binding.

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Amino Acid SequenceAnimalsCD8 AntigensCell LineFlow CytometryH-2 AntigensHybridomasMicePeptide FragmentsPlasmodium bergheiProtozoan ProteinsT-LymphocytesT-Lymphocytes, CytotoxicThymomaThymus NeoplasmsJournal ArticleResearch Support, Non-U.S. Gov't

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V Renard, P Romero, E Vivier, B Malissen, I F Luescher. 1996-12-01. CD8 beta increases CD8 coreceptor function and participation in TCR-ligand binding.. https://doi.org/10.1084/jem.184.6.2439

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