Generation of cytomegalovirus (CMV)-specific CD4 T cell lines devoid of alloreactivity, by use of a mixture of CMV-phosphoprotein 65 peptides for reconstitution of the T helper repertoire.
BACKGROUND
CD8 cells specific for cytomegalovirus (CMV) provide valuable support in immunocompromised patients. Recent studies have focused on the generation of cytotoxic T lymphocyte (CTL) lines by use of new biotechnological techniques. Yet CD4 cells have been neglected, even though they contribute to the persistence of adoptively transferred CTLs.


METHODS
We identified novel T helper (Th) peptides recognized by CD4 cells on the immunodominant protein pp65. These peptides were used as a mixture to generate CD4 cell lines.


RESULTS
The peptide library, which, theoretically, is recognized by 85% of white individuals on the basis of the frequency of the relevant human leukocyte antigen class II alleles, was stimulatory for 82% of pp65 responders. T cell lines generated by use of the pool recognized protein antigens. Selection for CMV-specific cells resulted in rapid depletion of allospecific T cells. Selection with individual peptides allowed further selection against potential cross-alloreactivity. Cultured CD4 cells showed no signs of functional senescence. CD4 cells activated by use of a Th peptide helped expand CMV-specific CTLs.


CONCLUSIONS
By use of a simple procedure, an immunodominant peptide library can generate T cell lines from allodonors, for the perspective reconstitution of the Th repertoire in immunocompromised hemopoietic stem-cell transplant recipients.
Li Pira
Giuseppina
G
Laboratory of Clinical and Experimental Immunology, Viral Immunology Unit, G. Gaslini Institute, Largo Gaslini 5, 16148 Genoa, Italy.
Bottone
Laura
L
Ivaldi
Federico
F
Tagliamacco
Augusto
A
Fiordoro
Stefano
S
Ricciardi
Annamaria
A
Barbano
Giancarlo
G
Manca
Fabrizio
F
D019264:Adoptive Transfer / Q000379:methods*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D018929:Cell Culture Techniques / Q000379:methods; D002460:Cell Line; D003587:Cytomegalovirus / Q000276:immunology*; D006801:Humans; D010455:Peptides / Q000276:immunology; D010750:Phosphoproteins / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000276:immunology*
D010455:Peptides; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa