Carrier protein influences immunodominance of a known epitope: implication in peptide vaccine design.
We investigated how the processing of a given antigen by antigen presenting cells (APC) is dictated by the conformation of the antigen and how this governs the immunodominance hierarchy. To address the question, a known immunodominant sequence of bacteriophage lambda repressor N-terminal sequence 12-26 [λR(12-26)] was engineered at the N and C termini of a heterologous leishmanial protein, Kinetoplastid membrane protein-11 (KMP-11); the resulting proteins were defined as N-KMP-11 and C-KMP-11 respectively. The presence of λR(12-26) in N-KMP-11 and C-KMP-11 was established by western blot analysis with antibody to λR(12-26) peptide. N-KMP-11 but not C-KMP-11 could stimulate the anti λR(12-26) T-cell clonal population very efficiently in the presence of APCs. Priming of BALB/c mice with N-KMP-11 or C-KMP-11 generated similar levels of anti-KMP-11 IgG, but anti-λR(12-26) specific IgG was observed only upon priming with N-KMP-11. Interestingly, uptake of both N-KMP-11 and C-KMP-11 by APCs was similar but catabolism of N-KMP-11 but not C-KMP-11 was biphasic and fast at the initial time point. Kratky plots of small angle X-ray scattering showed that while N-KMP-11 adopts flexible Gaussian type of topology, C-KMP-11 prefers Globular nature. To show that KMP-11 is not unique as a carrier protein, an epitope (SPITBTNLBTMBK) of Plasmodium yoelii (PY) apical membrane protein 1[AMA-1 (136-148)], is placed at the C and N terminals of a dominant T-cell epitope of ovalbumin protein OVA(323-339) and the resulting peptides are defined as PY-OVA and OVA-PY respectively. Interestingly, only OVA-PY could stimulate anti-OVA T-cells and produce IgG response upon priming of BALB/c mice with it. Thus for rational design of peptide vaccine it is important to place the dominant epitope appropriately in the context of the carrier protein.
Division of Infectious diseases and Immunology, CSIR-Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata 700032, India.
Moumita
M
Ghosh
Ashish K
AK
Solanki
Koushik
K
Roy
Reema R
RR
Dhoke
Ashish
Syamal
S
Roy
D000818:Animals; D000906:Antibodies / Q000097:blood; D010582:Bacteriophage lambda / Q000235:genetics / Q000276:immunology; D002352:Carrier Proteins / Q000378:metabolism*; D004337:Drug Carriers / Q000378:metabolism*; D016056:Immunodominant Epitopes / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D007155:Immunologic Factors / Q000378:metabolism*; D007891:Leishmania / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D010047:Ovalbumin / Q000276:immunology; D010967:Plasmodium yoelii / Q000235:genetics / Q000276:immunology; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D022223:Vaccines, Subunit / Q000276:immunology*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology
D000906:Antibodies; D002352:Carrier Proteins; D004337:Drug Carriers; D016056:Immunodominant Epitopes; D007074:Immunoglobulin G; D007155:Immunologic Factors; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; D022223:Vaccines, Subunit; D014764:Viral Proteins; D010047:Ovalbumin
AMA-1; APC; Antigen processing; Antigen structure; C-KMP-11; Endoproteolysis; Immunodominance; KMP-11; N-KMP-11; OVA((323–339)); PY; an epitope of AMA-1((136–148)); antigen presenting cell; dominant T-cell epitope of ovalbumin protein; immunodominant sequence of bacteriophage lambda repressor N-terminal sequence; kinetoplastid membrane protein-11; plasmodium yoelii apical membrane protein 1; λR((12–26)); λR((12–26)) engineered at the C termini of KMP-11; λR((12–26)) engineered at the N termini of KMP-11