Limits...
Modification of the carboxy-terminal flanking region of a universal influenza epitope alters CD4⁺ T-cell repertoire selection.

Cole DK, Gallagher K, Lemercier B, Holland CJ, Junaid S, Hindley JP, Wynn KK, Gostick E, Sewell AK, Gallimore AM, Ladell K, Price DA, Gougeon ML, Godkin A - Nat Commun (2012)

Bottom Line: The open ends of the MHC-II binding groove allow peptide epitopes to extend beyond a central nonamer core region at both the amino- and carboxy-terminus.We have previously found that these non-bound C-terminal residues can alter T cell activation in an MHC allele-transcending fashion, although the mechanism for this effect remained unclear.These data provide the first demonstration that changes in the C-terminus of the peptide-flanking region can substantially alter T-cell receptor binding affinity, and indicate a mechanism through which peptide flanking residues could influence repertoire selection.

View Article: PubMed Central - PubMed

Affiliation: Institute of Infection and Immunity, Cardiff University School of Medicine, The Henry Wellcome Building, Cardiff CF14 4XN, Wales, UK.

ABSTRACT
Human CD4(+) αβ T cells are activated via T-cell receptor recognition of peptide epitopes presented by major histocompatibility complex (MHC) class II (MHC-II). The open ends of the MHC-II binding groove allow peptide epitopes to extend beyond a central nonamer core region at both the amino- and carboxy-terminus. We have previously found that these non-bound C-terminal residues can alter T cell activation in an MHC allele-transcending fashion, although the mechanism for this effect remained unclear. Here we show that modification of the C-terminal peptide-flanking region of an influenza hemagglutinin (HA(305-320)) epitope can alter T-cell receptor binding affinity, T-cell activation and repertoire selection of influenza-specific CD4(+) T cells expanded from peripheral blood. These data provide the first demonstration that changes in the C-terminus of the peptide-flanking region can substantially alter T-cell receptor binding affinity, and indicate a mechanism through which peptide flanking residues could influence repertoire selection.

Show MeSH

Related in: MedlinePlus

Immunoscope profiles from CD4+ T-cell lines expanded with Flu1 or Flu2 (Arg at P10).Short-term T-cell lines were generated from peripheral blood stimulated with either Flu1 or Flu2. Antigen-specific CD4+ cells were isolated on the basis of HLA-DR1/HA305−320 tetramer staining, and TCR repertoires were assessed by spectratyping. The profiles of pooled CDR3β lengths for four TRBV families are shown. In peripheral blood, the expected Gaussian distribution is observed. Altered profiles for the Flu1-specific and Flu2-specific populations indicate oligoclonal expansions. Differences in TRBV family usage are also apparent, suggesting that particular clonotypic expansions can be driven by a C-terminally modified peptide. A representative example from three independent experiments is shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3293629&req=5

f2: Immunoscope profiles from CD4+ T-cell lines expanded with Flu1 or Flu2 (Arg at P10).Short-term T-cell lines were generated from peripheral blood stimulated with either Flu1 or Flu2. Antigen-specific CD4+ cells were isolated on the basis of HLA-DR1/HA305−320 tetramer staining, and TCR repertoires were assessed by spectratyping. The profiles of pooled CDR3β lengths for four TRBV families are shown. In peripheral blood, the expected Gaussian distribution is observed. Altered profiles for the Flu1-specific and Flu2-specific populations indicate oligoclonal expansions. Differences in TRBV family usage are also apparent, suggesting that particular clonotypic expansions can be driven by a C-terminally modified peptide. A representative example from three independent experiments is shown.

Mentions: Peptides modified in their non-core bound C-terminal flanking region seemed to alter the degree of T-cell activation. To examine this observation further, we used modified peptides to expand CD4+ T cells from the influenza-specific memory pool of two HLA-DR1+ donors (known responders to HA305−320). Ten-day cultures of 106 peripheral blood mononuclear cells (PBMCs) with the peptides Flu1 (wild-type sequence) or Flu2 (Arg at P10) expanded ≥5×104 CD4+ HLA-DR1/HA305−320 tetramer-positive cells (data not shown). We investigated TCR usage by these amplified populations (Flu1 versus Flu2) to establish whether different repertoires were deployed against peptide epitopes with C-terminal modifications. Initially, we employed TCR spectratyping on HLA-DR1/HA305−320 tetramer-sorted cells, comparing the immunoscope profiles of each T-cell receptor beta variable (TRBV) family the relative representation of each TRBV family in background peripheral blood, CD4+ T-cell lines expanded with the wild-type Flu1 peptide and, CD4+ T-cell lines expanded with the basic tail Flu2 peptide (Fig. 2).


Modification of the carboxy-terminal flanking region of a universal influenza epitope alters CD4⁺ T-cell repertoire selection.

Cole DK, Gallagher K, Lemercier B, Holland CJ, Junaid S, Hindley JP, Wynn KK, Gostick E, Sewell AK, Gallimore AM, Ladell K, Price DA, Gougeon ML, Godkin A - Nat Commun (2012)

Immunoscope profiles from CD4+ T-cell lines expanded with Flu1 or Flu2 (Arg at P10).Short-term T-cell lines were generated from peripheral blood stimulated with either Flu1 or Flu2. Antigen-specific CD4+ cells were isolated on the basis of HLA-DR1/HA305−320 tetramer staining, and TCR repertoires were assessed by spectratyping. The profiles of pooled CDR3β lengths for four TRBV families are shown. In peripheral blood, the expected Gaussian distribution is observed. Altered profiles for the Flu1-specific and Flu2-specific populations indicate oligoclonal expansions. Differences in TRBV family usage are also apparent, suggesting that particular clonotypic expansions can be driven by a C-terminally modified peptide. A representative example from three independent experiments is shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3293629&req=5

f2: Immunoscope profiles from CD4+ T-cell lines expanded with Flu1 or Flu2 (Arg at P10).Short-term T-cell lines were generated from peripheral blood stimulated with either Flu1 or Flu2. Antigen-specific CD4+ cells were isolated on the basis of HLA-DR1/HA305−320 tetramer staining, and TCR repertoires were assessed by spectratyping. The profiles of pooled CDR3β lengths for four TRBV families are shown. In peripheral blood, the expected Gaussian distribution is observed. Altered profiles for the Flu1-specific and Flu2-specific populations indicate oligoclonal expansions. Differences in TRBV family usage are also apparent, suggesting that particular clonotypic expansions can be driven by a C-terminally modified peptide. A representative example from three independent experiments is shown.
Mentions: Peptides modified in their non-core bound C-terminal flanking region seemed to alter the degree of T-cell activation. To examine this observation further, we used modified peptides to expand CD4+ T cells from the influenza-specific memory pool of two HLA-DR1+ donors (known responders to HA305−320). Ten-day cultures of 106 peripheral blood mononuclear cells (PBMCs) with the peptides Flu1 (wild-type sequence) or Flu2 (Arg at P10) expanded ≥5×104 CD4+ HLA-DR1/HA305−320 tetramer-positive cells (data not shown). We investigated TCR usage by these amplified populations (Flu1 versus Flu2) to establish whether different repertoires were deployed against peptide epitopes with C-terminal modifications. Initially, we employed TCR spectratyping on HLA-DR1/HA305−320 tetramer-sorted cells, comparing the immunoscope profiles of each T-cell receptor beta variable (TRBV) family the relative representation of each TRBV family in background peripheral blood, CD4+ T-cell lines expanded with the wild-type Flu1 peptide and, CD4+ T-cell lines expanded with the basic tail Flu2 peptide (Fig. 2).

Bottom Line: The open ends of the MHC-II binding groove allow peptide epitopes to extend beyond a central nonamer core region at both the amino- and carboxy-terminus.We have previously found that these non-bound C-terminal residues can alter T cell activation in an MHC allele-transcending fashion, although the mechanism for this effect remained unclear.These data provide the first demonstration that changes in the C-terminus of the peptide-flanking region can substantially alter T-cell receptor binding affinity, and indicate a mechanism through which peptide flanking residues could influence repertoire selection.

View Article: PubMed Central - PubMed

Affiliation: Institute of Infection and Immunity, Cardiff University School of Medicine, The Henry Wellcome Building, Cardiff CF14 4XN, Wales, UK.

ABSTRACT
Human CD4(+) αβ T cells are activated via T-cell receptor recognition of peptide epitopes presented by major histocompatibility complex (MHC) class II (MHC-II). The open ends of the MHC-II binding groove allow peptide epitopes to extend beyond a central nonamer core region at both the amino- and carboxy-terminus. We have previously found that these non-bound C-terminal residues can alter T cell activation in an MHC allele-transcending fashion, although the mechanism for this effect remained unclear. Here we show that modification of the C-terminal peptide-flanking region of an influenza hemagglutinin (HA(305-320)) epitope can alter T-cell receptor binding affinity, T-cell activation and repertoire selection of influenza-specific CD4(+) T cells expanded from peripheral blood. These data provide the first demonstration that changes in the C-terminus of the peptide-flanking region can substantially alter T-cell receptor binding affinity, and indicate a mechanism through which peptide flanking residues could influence repertoire selection.

Show MeSH
Related in: MedlinePlus