Publication Date:
2002-05-15
Description:
Reconstitution of human cytomegalovirus (HCMV)–specific cytotoxic T lymphocytes (CTLs), predominantly directed against pp65, provides protective immunity for the development of HCMV disease after allogeneic stem cell transplantation (SCT). To define pp65-derived CTL epitopes that would allow sensitive detection of HCMV-specific immune reconstitution, a computer-based epitope prediction was performed. Peptide-specific CTL responses were assessed by interferon-γ release. With this approach, pp65-derived epitopes presented by the HLA alleles A*0101, A*0201, A*1101, and B*0702 were identified. The frequency of CTLs in healthy HCMV-seropositive individuals ranged from about 0.1% to 3.3% of all CD8+ T cells. In patients at risk of HCMV infection after allogeneic SCT, HCMV-peptide–specific CTLs were found in 14 of 19 patients at a median of 90 days after SCT (range, 35-234 days) and HCMV-antigen–specific CD4+ T lymphocytes in 11 of 18 patients at a median of 90 days after SCT (range, 35-〉180 days). Peak counts of peptide-specific CD8+ T cells ranged from 0.14 to 60.6 cells/μL; those of protein-specific CD4+ T cells ranged from 0.64 to 18.97 cells/μL. Reconstitution of HCMV-peptide–specific CD8+ T cells and protein-specific CD4+ T cells was associated with clearance of HCMV infection (r2 = 0.89, P
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine