The matrix protein pp65(341-350): a peptide that induces ex vivo stimulation and in vitro expansion of CMV-specific CD8+ T cells in subjects bearing either HLA-A*2402 or A*0101 allele.
BACKGROUND
The stimulation of PBMNCs with HLA Class I restricted synthetic peptides derived from CMV phosphorylated matrix protein 65 (pp65) evokes CMV-specific cytotoxic T lymphocyte (CTL) activity, a necessary condition for initiating adoptive immunotherapy against CMV-related diseases in immune-compromised patients. It was previously demonstrated that the CMV decamer (10-mer) peptide pp65(341-350), QYDPVAALFF, was able to induce CMV-specific CTLs in HLA-A*2402 CMV-seropositive individuals.


METHODS
We investigated the ability of the peptide pp65(341-350) to reactivate memory CD8+ T cells in CMV-seropositive subjects bearing either the HLA-A24 or A1 allele. CTL responses were measured by IFN-gamma mRNA expression and IFN-gamma protein production as well as cytotoxic activity.


RESULTS
In this study it was found that peptide pp65(341-350) induced a specific reactivation of memory CD8+ T cells from CMV-seropositive donors expressing either HLA-A*2402 and/or HLA-A*0101. Moreover, a pp65(341-350)-specific selection and expansion using PBMNCs of CMV-seropositive donors bearing both HLA-A*2402 and HLA-A*0101 alleles produced cytotoxic CTLs to both HLA-A24 and A1 peptide-pulsed and autologous CMV-infected target cells.


CONCLUSIONS
The results demonstrate that pp65(341-350) induced a specific CTL activity at both molecular and protein levels and that the peptide is specifically processed, presented, and recognized by subjects bearing HLA-A*2402 and/or A*0101. These findings suggest that it may be possible to use this single immune dominant peptide to induce and expand CMV-reactive CTLs for the treatment of individuals with both HLA-A24 and A1 types.
Provenzano
Maurizio
M
Department of Transfusion Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, USA. mprovenzano@mail.cc.nih.gov
Lim
Jong-Baeck
JB
Mocellin
Simone
S
Monsurro
Vladia
V
Bettinotti
Maria
M
Marincola
Francesco M
FM
Stroncek
David F
DF
D000483:Alleles; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology*; D016923:Cell Death; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000097:blood; D003602:Cytotoxicity, Immunologic; D015234:HLA-A Antigens / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism* / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D014763:Viral Matrix Proteins / Q000378:metabolism* / Q000494:pharmacology*
D015234:HLA-A Antigens; D010446:Peptide Fragments; D010750:Phosphoproteins; D012333:RNA, Messenger; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa; D007371:Interferon-gamma