Abstract
A recombinant immunotoxin was constructed from the hybridoma antibody TH-69 directed against human CD7, a surface antigen of leukemic T cells. The antibody was subcloned as a single chain Fv (scFv) fragment and genetically linked to a truncated Pseudomonas exotoxin A fragment containing the catalytic domains II and III but lacking the receptor binding domain I. Domain I was replaced by the scFv, thus conferring restricted specificity for CD7.positive cells. The bacterially expressed and purified toxin retained binding specificity for CD7-positive cells. It promoted apoptosis in two CD7-positive cell lines derived from T-lineage acute lymphoblastic leukemias, CEM and Jurkat, but not in the CD7-negative B-lymphoid lines REH, Nalm-6, and SEM. Maximum killing in excess of 95% was reached after 96 h in CEM and Jurkat cells with a single dose of 100 ng/ml. Cells treated with a similarly constructed scFv-exotoxin A immunotoxin against melanoma-associated chondroitin sulfate proteoglycan, an antigen absent from leukemic T cells, remained unaffected. Lysis of target cells occurred via apoptosis as evidenced by staining with Annexin V and specific cleavage of poly(ADP-ribose) polymerase. Approximately 20% of leukemic cells from a patient with CD7-positive acute T-cell leukemia kept in long-term primary culture for 30 cell generations were killed within 96 h after treatment with the toxin. These findings justify further evaluation of the agent in view of potential therapeutic applications.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2848-2855 |
| Number of pages | 8 |
| Journal | Cancer Research |
| Volume | 62 |
| Issue number | 10 |
| State | Published - May 15 2002 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Cancer Research
- Oncology
Cite this
A recombinant CD7-specific single-chain immunotoxin is a potent inducer of apoptosis in acute leukemic T cells. / Peipp, Matthias; Küpers, Heide; Saul, Domenica; Schlierf, Beate; Greil, Johann; Zunino, Susan J.; Gramatzki, Martin; Fey, Georg H.
In: Cancer Research, Vol. 62, No. 10, 15.05.2002, p. 2848-2855.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A recombinant CD7-specific single-chain immunotoxin is a potent inducer of apoptosis in acute leukemic T cells
AU - Peipp, Matthias
AU - Küpers, Heide
AU - Saul, Domenica
AU - Schlierf, Beate
AU - Greil, Johann
AU - Zunino, Susan J.
AU - Gramatzki, Martin
AU - Fey, Georg H.
PY - 2002/5/15
Y1 - 2002/5/15
N2 - A recombinant immunotoxin was constructed from the hybridoma antibody TH-69 directed against human CD7, a surface antigen of leukemic T cells. The antibody was subcloned as a single chain Fv (scFv) fragment and genetically linked to a truncated Pseudomonas exotoxin A fragment containing the catalytic domains II and III but lacking the receptor binding domain I. Domain I was replaced by the scFv, thus conferring restricted specificity for CD7.positive cells. The bacterially expressed and purified toxin retained binding specificity for CD7-positive cells. It promoted apoptosis in two CD7-positive cell lines derived from T-lineage acute lymphoblastic leukemias, CEM and Jurkat, but not in the CD7-negative B-lymphoid lines REH, Nalm-6, and SEM. Maximum killing in excess of 95% was reached after 96 h in CEM and Jurkat cells with a single dose of 100 ng/ml. Cells treated with a similarly constructed scFv-exotoxin A immunotoxin against melanoma-associated chondroitin sulfate proteoglycan, an antigen absent from leukemic T cells, remained unaffected. Lysis of target cells occurred via apoptosis as evidenced by staining with Annexin V and specific cleavage of poly(ADP-ribose) polymerase. Approximately 20% of leukemic cells from a patient with CD7-positive acute T-cell leukemia kept in long-term primary culture for 30 cell generations were killed within 96 h after treatment with the toxin. These findings justify further evaluation of the agent in view of potential therapeutic applications.
AB - A recombinant immunotoxin was constructed from the hybridoma antibody TH-69 directed against human CD7, a surface antigen of leukemic T cells. The antibody was subcloned as a single chain Fv (scFv) fragment and genetically linked to a truncated Pseudomonas exotoxin A fragment containing the catalytic domains II and III but lacking the receptor binding domain I. Domain I was replaced by the scFv, thus conferring restricted specificity for CD7.positive cells. The bacterially expressed and purified toxin retained binding specificity for CD7-positive cells. It promoted apoptosis in two CD7-positive cell lines derived from T-lineage acute lymphoblastic leukemias, CEM and Jurkat, but not in the CD7-negative B-lymphoid lines REH, Nalm-6, and SEM. Maximum killing in excess of 95% was reached after 96 h in CEM and Jurkat cells with a single dose of 100 ng/ml. Cells treated with a similarly constructed scFv-exotoxin A immunotoxin against melanoma-associated chondroitin sulfate proteoglycan, an antigen absent from leukemic T cells, remained unaffected. Lysis of target cells occurred via apoptosis as evidenced by staining with Annexin V and specific cleavage of poly(ADP-ribose) polymerase. Approximately 20% of leukemic cells from a patient with CD7-positive acute T-cell leukemia kept in long-term primary culture for 30 cell generations were killed within 96 h after treatment with the toxin. These findings justify further evaluation of the agent in view of potential therapeutic applications.
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UR - http://www.scopus.com/inward/citedby.url?scp=0037093199&partnerID=8YFLogxK
M3 - Article
C2 - 12019163
AN - SCOPUS:0037093199
VL - 62
SP - 2848
EP - 2855
JO - Journal of Cancer Research
JF - Journal of Cancer Research
SN - 0099-7013
IS - 10
ER -