Sensitive detection of human cytomegalovirus peptide-specific cytotoxic T-lymphocyte responses by interferon-gamma-enzyme-linked immunospot assay and flow cytometry in healthy individuals and in patients after allogeneic stem cell transplantation.
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-gamma 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/microL; those of protein-specific CD4(+) T cells ranged from 0.64 to 18.97 cells/microL. Reconstitution of HCMV-peptide-specific CD8(+) T cells and protein-specific CD4(+) T cells was associated with clearance of HCMV infection (r(2) = 0.89, P <.0001 and r(2) = 0.61, P =.0045, respectively). HCMV infection recurred after documentation of HCMV-specific T-cell reconstitution (n = 4) when immunosuppression was intensified. Patients in whom late-onset HCMV disease developed lacked HCMV-protein-specific T cells at 3 months after SCT. In conclusion, prospective monitoring of HCMV-specific CD4(+) and CD8(+) T-cell reconstitution can be performed rapidly by using flow cytometry after specific stimulation with HCMV peptides and proteins and might help to further improve clinical management of HCMV infection after allogeneic SCT.
Hebart
Holger
H
Medizinische Klinik II, Institut für Zellbiologie, and Medizinische Virologie, Eberhard-Karls-Universität Tübingen, Germany.
Daginik
Senay
S
Stevanovic
Stefan
S
Grigoleit
Ulrich
U
Dobler
Andrea
A
Baur
Manuela
M
Rauser
Georg
G
Sinzger
Christian
C
Jahn
Gerhard
G
Loeffler
Juergen
J
Kanz
Lothar
L
Rammensee
Hans-Georg
HG
Einsele
Hermann
H
D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000276:immunology; D001782:Blood Donors; D002460:Cell Line; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology / Q000517:prevention & control*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D000939:Epitopes / Q000276:immunology; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D007700:Kinetics; D007937:Leukapheresis; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D010455:Peptides / Q000276:immunology; D010750:Phosphoproteins / Q000276:immunology; D012680:Sensitivity and Specificity; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014184:Transplantation, Homologous; D014763:Viral Matrix Proteins / Q000276:immunology
D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D010455:Peptides; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa; D007371:Interferon-gamma