Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

<jats:p> Recombinant DNA techniques have been used to express the proteins of influenza virus individually. Target cells expressing single viral proteins were then used to identify the molecules recognized by cytotoxic Tlymphocytes (CTLS). Results have shown that, contrary to expectation, the majority of the proteins recognized by class I major histocompatibility complex-restricted CTLS are not transmembrane glycoproteins. Experiments with deletion mutants of the nucleoprotein (NP) gene showed that transport of epitopes to the membrane for recognition by CTLS was independent of a definable signal sequence. In addition, the epitopes recognized were contained within short linear sequences of amino acids, and rapid degradation of large NP fragments within the target cell did not prevent recognition by CTLS. These results led to the suggestion that the epitopes recognized by class-I-restricted CTLS resulted from degradation of viral proteins. If so, the epitopes should, like those for class-II-restricted T cells, be replaceable <jats:italic>in vitro</jats:italic> with short synthetic peptides. Five different epitopes of NP have now been demonstrated that can be defined with short peptides <jats:italic>in vitro</jats:italic> . Each peptide is recognized with a specific class I molecule (D <jats:sup>b</jats:sup> , K <jats:sup>k</jats:sup> , K <jats:sup>d</jats:sup> and HLA B37). This has been extended to the influenza matrix protein, and a peptide epitope defined that is recognized by human CTLS in association with HLA -A2. T he question arose as to whether a similar phenomenon would be found with viral proteins which are naturally inserted in the target cell membrane. A mutant haemagglutinin has been produced that lacks a hydrophobic signal sequence. This protein is expressed as a short-lived, unglycosylated, intracellular protein. However, target cells expressing this molecule were recognized efficiently by CTLS raised to the wild-type haemagglutinin and vice versa. These and more recent results with nonviral glycoproteins are consistent with the existence of a mechanism for degrading viral (and perhaps host) proteins and exposing them at the cell surface for recognition by cytotoxic T cells in association with class I molecules of the major histocompatibility complex. </jats:p>

Original publication

DOI

10.1098/rstb.1989.0032

Type

Journal article

Journal

Philosophical Transactions of the Royal Society of London. B, Biological Sciences

Publisher

The Royal Society

Publication Date

12/06/1989

Volume

323

Pages

527 - 533