- Email: [email protected]
Chimeric T-Cells for Therapy of CD30+ Hodgkin and Non-Hodgkin Lymphomas (HL & NHL)
Abstracts / Biol Blood Marrow Transplant 22 (2016) S19eS481
primed Treg with irradiated peripheral blood from acute GvHD (aGvHD) affected mice for 24h and then transferred the treated cells in a GvHD model where allogeneic CD4+ and CD8+ T cells (Tcon) have been used for GvHD induction. Primed Treg were injected at day 0 after HCT for preventing GvHD or at day 7 as GvHD treatment. Primed Treg improved mouse survival when used for both GvHD prevention (p¼0.01) and treatment (p¼0.04) in comparison to unprimed Treg. Primed Treg did not limit Tcon mediated anti-tumor activity as allogeneic Tcon killed A20 tumor cells even in the presence of primed Treg (p<0.001). In addition Treg primed with aGvHD animal blood after removing the serum lose their functional advantage (p>0.05), so we tested the ability of several inflammatory cytokines secreted during GvHD such as IFNg, IL6, IL12 and TNFa to enhance Treg function. We found that TNFɑ selectively activated Treg without impacting CD4+FoxP3- T cells. TNFɑ priming increased Treg expression of the activation markers CD69 (p<0.0001), CD25 (p<0.0001), and LAG3 (p¼0.0002), induced a greater production of the suppressive cytokines IL10 (p¼0.03) and TGFb (p<0.0001), and enhanced the expression of CD62L (p¼0.005), a critical homing marker. TNFɑ effects on Treg are exclusively mediated by TNFɑ receptor 2 since after its selective blockade, Treg lose their ability to upregulate CD69 (p¼0.0007) and CD25 (p¼0.0008) and to increase TGFb production (p¼0.0001). We further injected TNFɑ-primed and unprimed luc+ Tcon in allogeneic transplanted mice and BLI showed reduced TNFɑ-primed Tcon in vivo proliferation (p¼0.01). Allogeneic transplanted mice (C57BL/6 -> BALB/c) that received TNFɑ-primed Tcon had a milder GvHD and survived longer than mice treated with unprimed Tcon (p¼0.01). Finally, in a GvHD prevention mouse model TNFɑ-primed Treg infused at 1:10 Treg/Tcon ratio ameliorated animal survival as compared to unprimed Treg (p¼0.02), demonstrating enhanced efficacy of TNFɑ primed Treg in vivo. In summary, our study demonstrates that Treg respond to TNFɑ acquiring an activated status resulting in increased function. As TNFɑ is produced by several immune cells during inflammation, our work elucidates aspects of the physiologic mechanisms of Treg function. Furthermore TNFɑ priming of Treg in vitro provides a new tool to optimize Treg cellular therapy also allowing for the use of a lower cell number for GvHD prevention and treatment.
176 A Single Centre Experience on the Use of DONOR Lymphocyte Infusion in Children Transplanted for Benign Disorders Revathi Raj 1, Ramya Uppuluri Jr. 2, Divya Subburaj 2, Sreejith Ramachandran Jr. 2, Atish Bakane Jr. 3, V. Lakshmanan Sr. 2. 1 Pediatric Hematology, Apollo Hopsitals, Chennai, Tamilnadu, India; 2 Blood and Marrow Transplantation, Apollo Speciality Hospital, Chennai, India; 3 320 Padma Complex, Apollo Speciality Hospital, Chennai, India Introduction: The use of donor lymphocyte infusions have been used to prevent graft rejection in HSCT patients. There is limited data available regarding the use of paediatric donors as a source of donor lymphocyte infusion. We report here our experience in the use of DLI in a tertiary referral centre in benign disorders including haemoglobinopathies and primary immune deficiency disorders. Patients and Methods: The use of reduced intensity conditioning commenced in our centre in December 2009. Fludarabine and treosulphan based conditioning regimens were
S145
used in a total of 176 children with 134 in the haemoglobinopathy group and 42 in the primary immunedeficiency disorders group. Chimerism was monitored post transplant using FISH for sex mismatched transplants and DNA method for same sex donors. The first step was to withdraw immunosuppressive drugs when chimerism dropped to less than 90%. The child was reassessed after 10 days. With further drop in chimerism, donor lymphocyte infusion at 1 x 105 / kg was initiated after obtaining written consent from the parents. A single injection of 2 to 5 ml of peripheral blood was sufficient in most children as it had sufficient numbers of CD3 cells. Only one donor with major blood group incompatibility had to undergo mobilisation of DLI on the COBE SPECTRA. Results: There were no adverse events in any f the donors. Withdrawal of immunosuppression could result in graft salvage in 3 out of 13 children. Seven children donated DLI including 3 who needed DLI on 2 occasions with successful salvage of the graft in all children. Prior to our DLI experience, 11 out of 176 children (6.25) experienced graft rejection and needed a second transplant. Conclusion: Donor lymphocyte infusion is a safe and feasible option in paediatric transplantation. The use of DLI has helped prevent an expensive and difficult second transplant in children undergoing reduced intensity conditioning for benign disorders.
177 Chimeric T-Cells for Therapy of CD30+ Hodgkin and Non-Hodgkin Lymphomas (HL & NHL) Carlos A. Ramos 1, Brandon Ballard 2, Enli Liu 2, Olga Dakhova 2, Zhuyong Mei 2, Hao Liu 3, Bambi Grilley 4, Cliona M. Rooney 4, Adrian P. Gee 4, Bill H. Chang 5, Catherine M. Bollard 4, Malcolm K. Brenner 6, Gianpietro Dotti 2, Helen E. Heslop 4, Barbara Savoldo 2. 1 Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital, Texas Children’s Hospital, Houston, TX; 2 Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital & Texas Children’s Hospital, Houston, TX; 3 Dan L. Duncan Cancer Center/Biostatistics, Baylor College of Medicine, Houston, TX; 4 Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, Houston Methodist Hospital, Houston, TX; 5 Oregon Health & Science University Knight Cancer Institute, Portland, OR; 6 Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital Cancer Center, Methodist Hospital Houston, Houston, TX Adoptive immunotherapy for HL associated with EBV infection has had considerable success, inducing >50% complete and sustained remission rates in patients (pts) with relapsed/ resistant disease. However, only 40% of HL pts express EBVassociated antigens. By contrast, almost all HL and some NHL (e.g., anaplastic large cell lymphoma e ALCL) express the CD30 antigen, and monoclonal antibodies (mAb) targeting CD30 produce objective antitumor responses. mAb, however, have restricted bio-distribution, and their effects may be limited in duration. We therefore expressed the antigen binding domain of a CD30 mAb as part of a chimeric antigen receptor (CAR) on T cells, coupled to the CD28 and z chain endodomains, in an effort to ensure prolonged persistence, active penetration of tumors, and activation of multiple lytic components of the immune system. We report here a preliminary analysis of our phase 1 dose escalation study of activated autologous CD30.CAR-T cells (CD30.CARTs) infused in pts with relapsed/refractory EBV-negative CD30+HL or NHL.
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Abstracts / Biol Blood Marrow Transplant 22 (2016) S19eS481
We manufactured CD30.CARTs for 18 pts using retroviral transduction. Starting from a median of 2.4107 PBMCs (range 3.6106 to 4.9107), we obtained 9.0108 CD30.CARTs (range 2.8108 to 2.9109) in 153 days of culture, with a transduction efficiency of 891%. The cell products comprised >99% T cells and phenotypic analysis showed 5829% CD8+ T cells, with a majority being effector T cells (947% CD45RO+ cells). 51Cr-release cytotoxicity assays confirmed that patients’ CD30.CARTs lysed a CD30+ tumor line, HDLM-2 (6013% killing at a 20:1 effector:target ratio), with negligible effects on CD30 target cells (<5% killing). Nine pts (7 with HL and 2 ALCL) have received CD30.CARTs: 8 had relapsed or progressed after treatment with the CD30 mAb brentuximab; 2 pts were treated on dose level (DL) 1 (2107 CD30.CAR+ T cells/m2), 2 on DL2 (1108), and 5 on DL3 (2108). No pt received conditioning before CART infusion. No attributable adverse events were seen; in particular, no pt had evidence of cytokine release syndrome. As CD30 can be transiently expressed by activated T cells (e.g., during infection with viruses), we monitored antiviral immunity in CART recipients. The frequency of T cells responding to CMV, adenovirus, influenza virus and EBV remained unchanged by treatment. The molecular signal from CARTs, assessed by QPCR in peripheral blood, was dose dependent and peaked at 1 wk following infusion (mean of 7020 copies/mg DNA for DL3 vs. 60 copies/mg for DL1), but decreased to near background by 4 wk. At 6 wk after treatment, 1 pt had a CR, 1 pt had a very good PR, and 4 pts had stable disease persisting for 11/2 to 8 months, while 3 pts had disease progression. Having found that DL3 is safe and associated with significant in vivo expansion and response, we will now explore the use of these cells after conditioning chemotherapy or autologous stem cell transplantation.
peptides or pepmix-pulsed lymphoblastoid cell lines (LCLs) HLA matched at a single class I or II allele as targets in cytotoxicity assays. We then constructed a database that contains the HLA restriction of the antigen specificity of each line. This strategy ensures we only choose lines with confirmed antigen-specific activity restricted by shared alleles between donor and recipient. The EBVSTs exhibited significant specificity (with 75% of donors recognizing 2 antigens) and cytotoxicity to pepmix-pulsed HLA-matched EBV-LCLs, with no activity against mismatched LCLs. The EBVSTs are polyclonal (with a predominantly central memory phenotype) and polyfunctional, expressing IFN-g and CD107a after coculture with HLA-matched LCLs (a phenotype associated with enhanced antitumor activity). An additional challenge will be ensuring our EBVSTs persist long enough to exert antitumor effect. A concern is that recipient NK cells may exert cytotoxicity against our T cells. Interestingly, when NK cells from patients with 1 KIR-ligand mismatch with donor VSTs (thus predicted to exert alloreactivity) were cultured with our EBVSTs, they exerted up to 30% cytotoxicity by 51Cr release, compared to no cytotoxicity in cases where the KIR-ligands were matched. This indicates we can use the KIR-ligand method to preferentially choose EBVSTs that are KIR-matched with the recipient. Based on our previous studies, we expect that our bank of only 25 highly characterized EBVSTs will cover >95% of referred patients (with matching at 2 class I and/or class II alleles) since our strategy ensures that a wide range of HLA haplotypes is covered. We have been able to identify 3-4 suitable lines using the above criteria for all patients referred thus far. Additionally, given the significantly increased specificity of our highly characterized donors, we expect to see significant anti-tumor activity even outside of the post-HSCT setting.
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Establishment of a Highly Characterized Third-Party Virus-Specific T Lymphocyte Bank for Treatment of EBV+ Lymphoma Rayne Helen Rouce 1, Aarohi Thakkar 1, Gayatri Vyas 1, Sandhya Sharma 1, Serena K. Perna 1, Carlos A. Ramos 1, Natalia Lapteva 2, Amy Reyna 1, Ann M. Leen 3, Helen E. Heslop 2, Cliona M. Rooney 2. 1 Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital, Texas Children’s Hospital, Houston, TX; 2 Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, Houston Methodist Hospital, Houston, TX; 3 Baylor College of Medicine, Texas Children’s Hospital Cancer Center, Methodist Hospital Houston, Houston, TX
Rapid Expansion of Tumor-Specific T Cells Using Nanoparticle-Based Artificial Antigen Presenting Cells (aAPCs) Juan Carlos Varela 1, Christian Schuetz 2, Mathias Oelke 3, Jonathan Schneck 4. 1 Blood and Marrow Transplant Program, Medical University of South Carolina, Charleston, SC; 2 Division of Immunology, Paul-Elrlich, Langen, Germany; 3 NexImmune Inc, Gaithersburg, MD; 4 Department of Pathology, Johns Hopkins University, Baltimore, MD
Although donor-derived EBV-specific T cells (EBVSTs) have clinical efficacy for EBV+ lymphoma, the lengthy manufacture process reduces the feasibility of immediate use. An alternative approach is establishment of a pre-made third party bank that can provide access to EBVSTs for almost any patient. Although established banks consist primarily of donors from marrow registries or family members according to HLA genotype, a significant limitation to this approach is the generation of lines with limited specificity for targeted antigens through shared alleles. We chose to generate our bank from eligible donors initially chosen based on racial diversity, thus predicted to have HLA haplotypes representative of our diverse population. Donors were screened with IFN-g Elispot assays using overlapping peptide libraries (pepmixes) spanning the EBV Type 2 latency antigens (LMP1/2, EBNA1, BARF1), then selected based on highest antigen specificity. To characterize HLA restriction, we used
Background: Adoptive cell transfer (ACT) of tumor-specific T cells for the treatment of cancer has been used to mediate durable responses in multiple malignancies. However, despite its significant therapeutic potential, the routine use of ACT has been limited. This has been due, in large part, to the high cost, intricate and labor-intensive methods required to successfully generate autologous antigen-specific T cells. Here, we report on the application of a recently described novel nanoparticle-based method for expansion of tumorspecific T cells from normal human donors. Methods: CD8+ T cells were isolated from normal human donors and incubated with aAPCs specific for the melanoma antigen MART1. The mixture of T cells and aAPCs was passed through a magnetic column as per the “Enrichment and Expansion” (E+E) method described by Perica et al. The isolated T cells were plated and expanded for 14 days using autologous serum and T cell growth factor (TF). On days 0, 7 and 14, T cell cultures were evaluated for percent of antigen specificity, total cell number expansion, differentiation phenotype, polyfunctionality and expression of exhaustion markers.
primed Treg with irradiated peripheral blood from acute GvHD (aGvHD) affected mice for 24h and then transferred the treated cells in a GvHD model where allogeneic CD4+ and CD8+ T cells (Tcon) have been used for GvHD induction. Primed Treg were injected at day 0 after HCT for preventing GvHD or at day 7 as GvHD treatment. Primed Treg improved mouse survival when used for both GvHD prevention (p¼0.01) and treatment (p¼0.04) in comparison to unprimed Treg. Primed Treg did not limit Tcon mediated anti-tumor activity as allogeneic Tcon killed A20 tumor cells even in the presence of primed Treg (p<0.001). In addition Treg primed with aGvHD animal blood after removing the serum lose their functional advantage (p>0.05), so we tested the ability of several inflammatory cytokines secreted during GvHD such as IFNg, IL6, IL12 and TNFa to enhance Treg function. We found that TNFɑ selectively activated Treg without impacting CD4+FoxP3- T cells. TNFɑ priming increased Treg expression of the activation markers CD69 (p<0.0001), CD25 (p<0.0001), and LAG3 (p¼0.0002), induced a greater production of the suppressive cytokines IL10 (p¼0.03) and TGFb (p<0.0001), and enhanced the expression of CD62L (p¼0.005), a critical homing marker. TNFɑ effects on Treg are exclusively mediated by TNFɑ receptor 2 since after its selective blockade, Treg lose their ability to upregulate CD69 (p¼0.0007) and CD25 (p¼0.0008) and to increase TGFb production (p¼0.0001). We further injected TNFɑ-primed and unprimed luc+ Tcon in allogeneic transplanted mice and BLI showed reduced TNFɑ-primed Tcon in vivo proliferation (p¼0.01). Allogeneic transplanted mice (C57BL/6 -> BALB/c) that received TNFɑ-primed Tcon had a milder GvHD and survived longer than mice treated with unprimed Tcon (p¼0.01). Finally, in a GvHD prevention mouse model TNFɑ-primed Treg infused at 1:10 Treg/Tcon ratio ameliorated animal survival as compared to unprimed Treg (p¼0.02), demonstrating enhanced efficacy of TNFɑ primed Treg in vivo. In summary, our study demonstrates that Treg respond to TNFɑ acquiring an activated status resulting in increased function. As TNFɑ is produced by several immune cells during inflammation, our work elucidates aspects of the physiologic mechanisms of Treg function. Furthermore TNFɑ priming of Treg in vitro provides a new tool to optimize Treg cellular therapy also allowing for the use of a lower cell number for GvHD prevention and treatment.
176 A Single Centre Experience on the Use of DONOR Lymphocyte Infusion in Children Transplanted for Benign Disorders Revathi Raj 1, Ramya Uppuluri Jr. 2, Divya Subburaj 2, Sreejith Ramachandran Jr. 2, Atish Bakane Jr. 3, V. Lakshmanan Sr. 2. 1 Pediatric Hematology, Apollo Hopsitals, Chennai, Tamilnadu, India; 2 Blood and Marrow Transplantation, Apollo Speciality Hospital, Chennai, India; 3 320 Padma Complex, Apollo Speciality Hospital, Chennai, India Introduction: The use of donor lymphocyte infusions have been used to prevent graft rejection in HSCT patients. There is limited data available regarding the use of paediatric donors as a source of donor lymphocyte infusion. We report here our experience in the use of DLI in a tertiary referral centre in benign disorders including haemoglobinopathies and primary immune deficiency disorders. Patients and Methods: The use of reduced intensity conditioning commenced in our centre in December 2009. Fludarabine and treosulphan based conditioning regimens were
S145
used in a total of 176 children with 134 in the haemoglobinopathy group and 42 in the primary immunedeficiency disorders group. Chimerism was monitored post transplant using FISH for sex mismatched transplants and DNA method for same sex donors. The first step was to withdraw immunosuppressive drugs when chimerism dropped to less than 90%. The child was reassessed after 10 days. With further drop in chimerism, donor lymphocyte infusion at 1 x 105 / kg was initiated after obtaining written consent from the parents. A single injection of 2 to 5 ml of peripheral blood was sufficient in most children as it had sufficient numbers of CD3 cells. Only one donor with major blood group incompatibility had to undergo mobilisation of DLI on the COBE SPECTRA. Results: There were no adverse events in any f the donors. Withdrawal of immunosuppression could result in graft salvage in 3 out of 13 children. Seven children donated DLI including 3 who needed DLI on 2 occasions with successful salvage of the graft in all children. Prior to our DLI experience, 11 out of 176 children (6.25) experienced graft rejection and needed a second transplant. Conclusion: Donor lymphocyte infusion is a safe and feasible option in paediatric transplantation. The use of DLI has helped prevent an expensive and difficult second transplant in children undergoing reduced intensity conditioning for benign disorders.
177 Chimeric T-Cells for Therapy of CD30+ Hodgkin and Non-Hodgkin Lymphomas (HL & NHL) Carlos A. Ramos 1, Brandon Ballard 2, Enli Liu 2, Olga Dakhova 2, Zhuyong Mei 2, Hao Liu 3, Bambi Grilley 4, Cliona M. Rooney 4, Adrian P. Gee 4, Bill H. Chang 5, Catherine M. Bollard 4, Malcolm K. Brenner 6, Gianpietro Dotti 2, Helen E. Heslop 4, Barbara Savoldo 2. 1 Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital, Texas Children’s Hospital, Houston, TX; 2 Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital & Texas Children’s Hospital, Houston, TX; 3 Dan L. Duncan Cancer Center/Biostatistics, Baylor College of Medicine, Houston, TX; 4 Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, Houston Methodist Hospital, Houston, TX; 5 Oregon Health & Science University Knight Cancer Institute, Portland, OR; 6 Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital Cancer Center, Methodist Hospital Houston, Houston, TX Adoptive immunotherapy for HL associated with EBV infection has had considerable success, inducing >50% complete and sustained remission rates in patients (pts) with relapsed/ resistant disease. However, only 40% of HL pts express EBVassociated antigens. By contrast, almost all HL and some NHL (e.g., anaplastic large cell lymphoma e ALCL) express the CD30 antigen, and monoclonal antibodies (mAb) targeting CD30 produce objective antitumor responses. mAb, however, have restricted bio-distribution, and their effects may be limited in duration. We therefore expressed the antigen binding domain of a CD30 mAb as part of a chimeric antigen receptor (CAR) on T cells, coupled to the CD28 and z chain endodomains, in an effort to ensure prolonged persistence, active penetration of tumors, and activation of multiple lytic components of the immune system. We report here a preliminary analysis of our phase 1 dose escalation study of activated autologous CD30.CAR-T cells (CD30.CARTs) infused in pts with relapsed/refractory EBV-negative CD30+HL or NHL.
S146
Abstracts / Biol Blood Marrow Transplant 22 (2016) S19eS481
We manufactured CD30.CARTs for 18 pts using retroviral transduction. Starting from a median of 2.4107 PBMCs (range 3.6106 to 4.9107), we obtained 9.0108 CD30.CARTs (range 2.8108 to 2.9109) in 153 days of culture, with a transduction efficiency of 891%. The cell products comprised >99% T cells and phenotypic analysis showed 5829% CD8+ T cells, with a majority being effector T cells (947% CD45RO+ cells). 51Cr-release cytotoxicity assays confirmed that patients’ CD30.CARTs lysed a CD30+ tumor line, HDLM-2 (6013% killing at a 20:1 effector:target ratio), with negligible effects on CD30 target cells (<5% killing). Nine pts (7 with HL and 2 ALCL) have received CD30.CARTs: 8 had relapsed or progressed after treatment with the CD30 mAb brentuximab; 2 pts were treated on dose level (DL) 1 (2107 CD30.CAR+ T cells/m2), 2 on DL2 (1108), and 5 on DL3 (2108). No pt received conditioning before CART infusion. No attributable adverse events were seen; in particular, no pt had evidence of cytokine release syndrome. As CD30 can be transiently expressed by activated T cells (e.g., during infection with viruses), we monitored antiviral immunity in CART recipients. The frequency of T cells responding to CMV, adenovirus, influenza virus and EBV remained unchanged by treatment. The molecular signal from CARTs, assessed by QPCR in peripheral blood, was dose dependent and peaked at 1 wk following infusion (mean of 7020 copies/mg DNA for DL3 vs. 60 copies/mg for DL1), but decreased to near background by 4 wk. At 6 wk after treatment, 1 pt had a CR, 1 pt had a very good PR, and 4 pts had stable disease persisting for 11/2 to 8 months, while 3 pts had disease progression. Having found that DL3 is safe and associated with significant in vivo expansion and response, we will now explore the use of these cells after conditioning chemotherapy or autologous stem cell transplantation.
peptides or pepmix-pulsed lymphoblastoid cell lines (LCLs) HLA matched at a single class I or II allele as targets in cytotoxicity assays. We then constructed a database that contains the HLA restriction of the antigen specificity of each line. This strategy ensures we only choose lines with confirmed antigen-specific activity restricted by shared alleles between donor and recipient. The EBVSTs exhibited significant specificity (with 75% of donors recognizing 2 antigens) and cytotoxicity to pepmix-pulsed HLA-matched EBV-LCLs, with no activity against mismatched LCLs. The EBVSTs are polyclonal (with a predominantly central memory phenotype) and polyfunctional, expressing IFN-g and CD107a after coculture with HLA-matched LCLs (a phenotype associated with enhanced antitumor activity). An additional challenge will be ensuring our EBVSTs persist long enough to exert antitumor effect. A concern is that recipient NK cells may exert cytotoxicity against our T cells. Interestingly, when NK cells from patients with 1 KIR-ligand mismatch with donor VSTs (thus predicted to exert alloreactivity) were cultured with our EBVSTs, they exerted up to 30% cytotoxicity by 51Cr release, compared to no cytotoxicity in cases where the KIR-ligands were matched. This indicates we can use the KIR-ligand method to preferentially choose EBVSTs that are KIR-matched with the recipient. Based on our previous studies, we expect that our bank of only 25 highly characterized EBVSTs will cover >95% of referred patients (with matching at 2 class I and/or class II alleles) since our strategy ensures that a wide range of HLA haplotypes is covered. We have been able to identify 3-4 suitable lines using the above criteria for all patients referred thus far. Additionally, given the significantly increased specificity of our highly characterized donors, we expect to see significant anti-tumor activity even outside of the post-HSCT setting.
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Establishment of a Highly Characterized Third-Party Virus-Specific T Lymphocyte Bank for Treatment of EBV+ Lymphoma Rayne Helen Rouce 1, Aarohi Thakkar 1, Gayatri Vyas 1, Sandhya Sharma 1, Serena K. Perna 1, Carlos A. Ramos 1, Natalia Lapteva 2, Amy Reyna 1, Ann M. Leen 3, Helen E. Heslop 2, Cliona M. Rooney 2. 1 Center for Cell and Gene Therapy, Baylor College of Medicine, Houston Methodist Hospital, Texas Children’s Hospital, Houston, TX; 2 Center for Cell and Gene Therapy, Baylor College of Medicine, Texas Children’s Hospital, Houston Methodist Hospital, Houston, TX; 3 Baylor College of Medicine, Texas Children’s Hospital Cancer Center, Methodist Hospital Houston, Houston, TX
Rapid Expansion of Tumor-Specific T Cells Using Nanoparticle-Based Artificial Antigen Presenting Cells (aAPCs) Juan Carlos Varela 1, Christian Schuetz 2, Mathias Oelke 3, Jonathan Schneck 4. 1 Blood and Marrow Transplant Program, Medical University of South Carolina, Charleston, SC; 2 Division of Immunology, Paul-Elrlich, Langen, Germany; 3 NexImmune Inc, Gaithersburg, MD; 4 Department of Pathology, Johns Hopkins University, Baltimore, MD
Although donor-derived EBV-specific T cells (EBVSTs) have clinical efficacy for EBV+ lymphoma, the lengthy manufacture process reduces the feasibility of immediate use. An alternative approach is establishment of a pre-made third party bank that can provide access to EBVSTs for almost any patient. Although established banks consist primarily of donors from marrow registries or family members according to HLA genotype, a significant limitation to this approach is the generation of lines with limited specificity for targeted antigens through shared alleles. We chose to generate our bank from eligible donors initially chosen based on racial diversity, thus predicted to have HLA haplotypes representative of our diverse population. Donors were screened with IFN-g Elispot assays using overlapping peptide libraries (pepmixes) spanning the EBV Type 2 latency antigens (LMP1/2, EBNA1, BARF1), then selected based on highest antigen specificity. To characterize HLA restriction, we used
Background: Adoptive cell transfer (ACT) of tumor-specific T cells for the treatment of cancer has been used to mediate durable responses in multiple malignancies. However, despite its significant therapeutic potential, the routine use of ACT has been limited. This has been due, in large part, to the high cost, intricate and labor-intensive methods required to successfully generate autologous antigen-specific T cells. Here, we report on the application of a recently described novel nanoparticle-based method for expansion of tumorspecific T cells from normal human donors. Methods: CD8+ T cells were isolated from normal human donors and incubated with aAPCs specific for the melanoma antigen MART1. The mixture of T cells and aAPCs was passed through a magnetic column as per the “Enrichment and Expansion” (E+E) method described by Perica et al. The isolated T cells were plated and expanded for 14 days using autologous serum and T cell growth factor (TF). On days 0, 7 and 14, T cell cultures were evaluated for percent of antigen specificity, total cell number expansion, differentiation phenotype, polyfunctionality and expression of exhaustion markers.