Genomic stability and functional activity may be lost in telomerase-transduced human CD8+ T lymphocytes.
To obtain the large amount of T cells required for adoptive immunotherapy in a clinical setting, T-cell lifespan extension by human telomerase reverse transcriptase (hTERT) transduction is of particular interest. However, constitutive expression of hTERT is associated with malignant transformation and thus warrants a detailed evaluation of the safety of hTERT-transduced T cells before clinical application. In view of this, we performed an extensive cytogenetic analysis of hTERT-transduced MART-1 (melanoma antigen recognized by T cell 1)-and human papillomavirus type 16 (HPV16) E7-specific human CD8+ cytotoxic T lymphocytes (CTLs), reactive against melanoma and cervical carcinoma, respectively. Our results, obtained by (spectral) karyotyping and array comparative genomic hybridization, showed the development of minor chromosomal aberrations in an hTERT-transduced MART-1-specific CTL clone, whereas severe clonal aberrations were detected in an hTERT-transduced HPV16 E7-specific CTL clone. Furthermore, hTERT transduction did not protect CTLs from immunosenescence, because the HPV16 E7-specific, hTERT-transduced CTL clone showed a decreased functional activity on prolonged culture. Although the general frequency of major chromosomal aberrations in hTERT-transduced CTLs and the in vivo significance of our observations remain still unclear at this point, the currently available data suggest that clinical application of hTERT-transduced CTLs should proceed with caution.
Department of Pathology, VU University Medical Center, de Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
Marco W J
MW
Schreurs
Mario A J A
MA
Hermsen
Ramon I Klein
RI
Geltink
Kirsten B J
KB
Scholten
Antoinette A T P
AA
Brink
Esther W M
EW
Kueter
Marianne
M
Tijssen
Chris J L M
CJ
Meijer
Bauke
B
Ylstra
Gerrit A
GA
Meijer
Erik
E
Hooijberg
D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D002460:Cell Line; D002470:Cell Survival; D020732:Cytogenetic Analysis; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D015894:Genome, Human; D042822:Genomic Instability; D006801:Humans; D007621:Karyotyping; D010641:Phenotype; D019098:Telomerase / Q000235:genetics* / Q000378:metabolism*; D014161:Transduction, Genetic
D004268:DNA-Binding Proteins; D019098:Telomerase