Tumor-specific CD8+ T cells expressing interleukin-12 eradicate established cancers in lymphodepleted hosts.
T-cell-based immunotherapies can be effective in the treatment of large vascularized tumors, but they rely on adoptive transfer of substantial numbers ( approximately 20 million) of tumor-specific T cells administered together with vaccination and high-dose interleukin (IL)-2. In this study, we report that approximately 10,000 T cells gene-engineered to express a single-chain IL-12 molecule can be therapeutically effective against established tumors in the absence of exogenous IL-2 and vaccine. Although IL-12-engineered cells did not perist long-term in hosts, they exhibited enhanced functionality and were detected in higher numbers intratumorally along with increased numbers of endogenous natural killer and CD8(+) T cells just before regression. Importantly, transferred T cells isolated from tumors stably overproduced supraphysiologic amounts of IL-12, and the therapeutic effect of IL-12 produced within the tumor microenvironment could not be mimicked with high doses of exogenously provided IL-12. Furthermore, antitumor effects could be recapitulated by engineering wild-type open-repertoire splenocytes to express both the single-chain IL-12 and a recombinant tumor-specific T-cell receptor (TCR), but only when individual cells expressed both the TCR and IL-12, indicating that arrested migration of T cells at the tumor site was required for their activities. Successful tumor eradication was dependent on a lymphodepleting preconditioning regimen that reduced the number of intratumoral CD4(+) Foxp3(+) T regulatory cells. Our findings reveal an approach to genetically modify T cells to reduce the cell number needed, eliminate the need for vaccines or systemic IL-2, and improve immunotherapy efficacy based on adoptive transfer of gene-engineered T cells.
Kerkar
Sid P
SP
Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA. kerkars@mail.nih.gov
Muranski
Pawel
P
Kaiser
Andrew
A
Boni
Andrea
A
Sanchez-Perez
Luis
L
Yu
Zhiya
Z
Palmer
Douglas C
DC
Reger
Robert N
RN
Borman
Zachary A
ZA
Zhang
Ling
L
Morgan
Richard A
RA
Gattinoni
Luca
L
Rosenberg
Steven A
SA
Trinchieri
Giorgio
G
Restifo
Nicholas P
NP
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D016219:Immunotherapy, Adoptive / Q000379:methods*; D018664:Interleukin-12 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology* / Q000378:metabolism; D008546:Melanoma, Experimental / Q000276:immunology / Q000628:therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D015202:Protein Engineering / Q000379:methods; D012190:Retroviridae / Q000235:genetics; D014161:Transduction, Genetic
D018664:Interleukin-12