Enhancing safety of cytomegalovirus-based vaccine vectors by engaging host intrinsic immunity

Rhesus cytomegalovirus (RhCMV)–based vaccines maintain effector memory T cell responses (TEM) that protect ~50% of rhesus monkeys (RMs) challenged with simian immunodeficiency virus (SIV). Because human CMV (HCMV) causes disease in immunodeficient subjects, clinical translation will depend upon attenuation strategies that reduce pathogenic potential without sacrificing CMV’s unique immunological properties. We demonstrate that “intrinsic” immunity can be used to attenuate strain 68-1 RhCMV vectors without impairment of immunogenicity. The tegument proteins pp71 and UL35 encoded by UL82 and UL35 of HCMV counteract cell-intrinsic restriction via degradation of host transcriptional repressors. When the corresponding RhCMV genes, Rh110 and Rh59, were deleted from 68-1 RhCMV (ΔRh110 and ΔRh59), we observed only a modest growth defect in vitro, but in vivo, these modified vectors manifested little to no amplification at the injection site and dissemination to distant sites, in contrast to parental 68-1 RhCMV. ΔRh110 was not shed at any time after infection and was not transmitted to naïve hosts either by close contact (mother to infant) or by leukocyte transfusion. In contrast, ΔRh59 was both shed and transmitted by leukocyte transfusion, indicating less effective attenuation than pp71 deletion. The T cell immunogenicity of ΔRh110 was essentially identical to 68-1 RhCMV with respect to magnitude, TEM phenotype, epitope targeting, and durability. Thus, pp71 deletion preserves CMV vector immunogenicity while stringently limiting vector spread, making pp71 deletion an attractive attenuation strategy for HCMV vectors.

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Establishing CD8+ T Cell Immunity by Adoptive Transfer of Autologous, IL-15 Expanded, Anti-Tumor CTL with a Central/Effector Memory Phenotype Can Induce Objective Clinical Responses.

Blood ◽

10.1182/blood.v114.22.782.782 ◽

2009 ◽

Vol 114 (22) ◽

pp. 782-782 ◽

Cited By ~ 1

Author(s):

Marcus Butler ◽

Philip Friedlander ◽

Mary Mooney ◽

Linda Drury ◽

Martha Metzler ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Adoptive Transfer ◽

De Novo ◽

Effector Memory ◽

Large Numbers ◽

Central Effector

Abstract Abstract 782 The goal of cellular immunotherapy is to build long-lasting anti-tumor immunologic “memory” in patients and reject tumors for a lifetime. Previously, we and others demonstrated that IL-15 promotes the generation of T cells with a central memory (CM) phenotype which have the capacity to persist and establish effective anti-tumor memory in vivo. Furthermore, it has been shown that CD83 delivers a CD80-dependent T cell stimulatory signal that allows T cells to be long-lived. Based on these findings, we developed a system to generate large numbers of long-lived antigen-specific CD8+ T cells with a memory phenotype. This in vitro culture system utilizes IL-15 and a standardized, renewable artificial antigen presenting cell (aAPC) which was produced by transducing CD80, CD83, and HLA-A*0201 to the human cell line, K562. This aAPC can uniquely support the priming and prolonged expansion of large numbers of antigen-specific CD8+ CTL which display a central/effector memory (CM/EM) phenotype, possess potent effector function, and can be maintained in vitro for >1 year without any feeder cells or cloning. We hypothesized that adoptive transfer of these CTL with a CM/EM phenotype should result in anti-tumor memory in humans even without lymphodepletion or high dose IL-2. For our “first-in-human” clinical study, we chose the melanoma antigen MART1 as a target antigen, since MART1-specific HLA-A*0201+-restricted precursor CTL are detectable in some melanoma patients and can be immunophenotyped pre-infusion. Autologous CD8+ T cells were stimulated weekly with peptide-pulsed human cell-based aAPC and expanded with low dose IL-2 and IL-15. After three weeks, polyclonal MART1 CTL were reinfused without additional lymphodepletion, chemotherapy, IL-2, or vaccination. Eight study participants have enrolled and received a total of 15 MART1 CTL infusions (31% MART1 multimer positivity, median). All but one subject received two reinfusions where the 2nd graft was produced from CD8+ T cells harvested two weeks after the 1st reinfusion. To date, ≥2×109 CTL with potent effector function and a CM/EM phenotype were successfully generated for all subjects. No dose limiting toxicities were observed at either Dose Level 1 (2×108/m2) or Dose Level 2 (2×109/m2). Clinical activity was observed with a response by RECIST criteria in 1 subject, which was confirmed by a negative PET/CT 100 days following the last CTL infusion. In addition, 1 patient experienced a mixed response, 1 had stable disease, 3 had progression, and 2 are currently on active therapy. Multimer staining showed that, immediately post infusion, the percentage of CD8+ T cells specific for MART1 temporarily increased in all subjects, with the highest (6.5%) observed in subject #7. In 4 subjects, sustained increases in the frequency of MART1 specific T cells by more than two-fold (range 2.0-10x) for ≥21 days were observed despite the fact that no exogenous cytokines or vaccination was administered. Moreover, an increase of detectable MART1 specific T cells which display a CM phenotype was observed in all evaluable subjects and was observed for ≥35 days in 6 of 8 subjects. In subject #2, the conversion of MART1 CTL immunophenotype from a naïve to a mixture of naïve/memory phenotypes was observed for more than 6 months. We identified 10 individual MART1 T cell clonotypes from peripheral CD45RA- memory T cells on day 21. Clonotypic TCR Vbeta CDR3 analysis revealed that CTL grafts contained 7 out of 10 of these clonotypes. Furthermore, 6 clonotypes persisted in the peripheral CD45RA- memory fraction on days 39, 67 and/or 132. In Subject #3, who showed a mixed clinical response, 5 individual MART1 T cell clonotypes were isolated from lung metastases. 4 out of 5 clones were included in the CTL grafts. This finding supports the possibility that infused CTL can traffic and localize to sites of disease. Intriguingly, in both subjects, we were able to identify MART1 CTL clonotypes that were not detectable in the CTL grafts but possibly emerged after CTL infusion, indicating that adoptive transfer of MART1-specific CTL may provoke a de novo antitumor response. Taken together, these results suggest that CM/EM MART1 CTL generated ex vivo using our cell-based artificial APC in the presence of IL-15 may persist in vivo and induce de novo anti-tumor responses. Further enhancement of anti-tumor activity may be achieved through vaccination, cytokine administration, and/or removal of cytokine sinks and inhibitory factors following appropriate lymphodepletion. Disclosures: No relevant conflicts of interest to declare.

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Rapid default transition of CD4 T cell effectors to functional memory cells

Journal of Experimental Medicine ◽

10.1084/jem.20070041 ◽

2007 ◽

Vol 204 (9) ◽

pp. 2199-2211 ◽

Cited By ~ 73

Author(s):

K. Kai McKinstry ◽

Susanne Golech ◽

Won-Ha Lee ◽

Gail Huston ◽

Nan-Ping Weng ◽

...

Keyword(s):

Gene Expression ◽

T Cell ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Cd4 T Cell ◽

Effector Memory ◽

Memory Cells ◽

Two Stages

The majority of highly activated CD4 T cell effectors die after antigen clearance, but a small number revert to a resting state, becoming memory cells with unique functional attributes. It is currently unclear when after antigen clearance effectors return to rest and acquire important memory properties. We follow well-defined cohorts of CD4 T cells through the effector-to-memory transition by analyzing phenotype, important functional properties, and gene expression profiles. We find that the transition from effector to memory is rapid in that effectors rested for only 3 d closely resemble canonical memory cells rested for 60 d or longer in the absence of antigen. This is true for both Th1 and Th2 lineages, and occurs whether CD4 T cell effectors rest in vivo or in vitro, suggesting a default pathway. We find that the effector–memory transition at the level of gene expression occurs in two stages: a rapid loss of expression of a myriad of effector-associated genes, and a more gradual gain of expression of a cohort of genes uniquely associated with memory cells rested for extended periods.

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Gene-Modified CD8+ T Cells Undergo Functional Polarization to Effector and Central Memory Cells in Response to Antigen Exposure.

Blood ◽

10.1182/blood.v112.11.1531.1531 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1531-1531

Author(s):

Paul Neeson ◽

Amanda Shin ◽

Tsin Tai ◽

Karen Chen ◽

Joanne Davis ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Effector Memory ◽

Ifn Gamma ◽

Lewis Antigen ◽

Negative Cell Line ◽

Ley Antigen

Abstract Adoptive transfer (AT) of autologous T cells genetically-redirected against tumor antigens has considerable potential as cancer immunotherapy [Kershaw, Nat Rev Immunol. 2005]. However, the in vivo persistence of AT T cells is critical for tumor control and requires the development (in vitro or in vivo) of a memory T cell subset. We investigated the generation of memory T cell subsets in a novel chimeric T cell receptor-expressing T cell product prior to, and after exposure to cognate antigen. Gene-modified T cells (LeY-T) express a chimeric receptor comprising a single chain variable fragment (scFv) specific for Lewis Y (LeY) antigen coupled to the intracellular signaling domains of CD3 zeta and CD28, capable of inducing T cell effector granule release and target killing [Westwood PNAS 2005]. To produce LeY-T cells, PBMC from healthy donors (n=20) or multiple myeloma patients (n=2) were cultured with anti-OKT3 (30ng/ml) and IL-2 (600IU/ml) for three days, followed by two rounds of transduction with retroviral supernatant. Subsequently, T cells were expanded in high dose IL-2 (600IU/ml) from day 5 onwards. T cells were harvested for this study on culture days 10–12, CD8+ and CD4+ T cells expressed the chimeric protein (50–60)%. LeY CD8+ T cell subsets were assessed as naïve (N), central memory (CM), effector memory (EM) or effector (E) based on three features:- phenotype (CD45RA, CCR7, CD28, CD27 and perforin); homeostatic cytokine (IL-15/IL-7) proliferation; response to Lewis antigen contact including cell proliferation and cytokine secretion. We repeatedly observed that CD8+ LeY-T cells analyzed directly from the initial expansion culture demonstrate an effector memory (EM) phenotype (CD45RA−/CCR7−/CD28+/perforinhi and variable CD27 expression) (Figure 1A). Furthermore in vitro expanded LeY CD8 T cells express IL- 15R beta (CD122) and the common gamma chain (CD132), they proliferate in response to IL-15 (86% cell division, division index 1.82), but less with IL-7 (30% cell division, division index 0.56). Baseline expanded CD8+ LeY-T cells respond to the presence of LeY antigen by proliferating and secreting IFN-gamma (4–8% of CD8 T cells) but not IL-2. Importantly, no IFN-gamma secretion was seen in control T cells transduced with empty vector (Figure 1B, OVCAR cells). Furthermore, no IFN-gamma was secreted by the control or the CD8+ LeY-T cells in response to the Lewis antigen negative cell line (Figure 1C, HCT116 cells). To explore the memory component further, we examined the functional status of the CD8+ LeY-T cells seven and 30 days following a 48-hour exposure to LeY antigen (OVCAR cells), and compared this to CD8+ LeY-T cell functional status at baseline. Thus, direct from transduction, expansion culture LeY CD8+ T cells were largely EM phenotype (95%) a small population of cells (1–5)% had a CM phenotype (CD45RA−/CCR7+/CD28+/perforinlo). In contrast, seven days after Lewis antigen contact the EM cells had decreased to (76–88)% and CM increased to (10–21)%; this distribution was retained up to day 30 post-antigen exposure. In addition, seven days after Lewis antigen exposure, CD8+ LeY-T cells retain the capacity to proliferate in response to Lewis antigen and to secrete IFN-gamma, at no stage do these cells secrete IL-2. In conclusion, the CD8+ LeY-T cells produced by in vitro transduction and expansion culture have an EM functional status direct from in vitro culture indicating that they are an appropriate starting population for in vivo adoptive transfer. After exposure to LeY expressed on tumor cell lines in vitro, CD8+ LeY T cells show further polarization to either EM or CM cells. These results suggest that the LeY-chimeric T cells have the potential to form long-term memory populations in vivo after adoptive transfer. Figure 1. LeY T cells have an effector memory phenotype and respond to Lewis antigen expressing cell lines by secreting IFN-gamma. Following the transduction culture, the CD8+ LeY-T cells (A) expressed high levels of perforin and an EM phenotype. In (B), LeY T or empty vector control T cells were co-cultured with tumour cells overnight and intracellular cytokine secretion assay performed. The LeY CD8+ T cells responded to Lewis antigen expressing OVCAR cells by secreting IFN-gamma, whereas no response was observed with the negative cell line HCT-116. Figure 1. LeY T cells have an effector memory phenotype and respond to Lewis antigen expressing cell lines by secreting IFN-gamma. Following the transduction culture, the CD8+ LeY-T cells (A) expressed high levels of perforin and an EM phenotype. In (B), LeY T or empty vector control T cells were co-cultured with tumour cells overnight and intracellular cytokine secretion assay performed. The LeY CD8+ T cells responded to Lewis antigen expressing OVCAR cells by secreting IFN-gamma, whereas no response was observed with the negative cell line HCT-116.

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Comparison of the Genetic Organization, Expression Strategies and Oncogenic Potential of HTLV-1 and HTLV-2

Leukemia Research and Treatment ◽

10.1155/2012/876153 ◽

2012 ◽

Vol 2012 ◽

pp. 1-14 ◽

Cited By ~ 5

Author(s):

Francesca Rende ◽

Ilaria Cavallari ◽

Maria Grazia Romanelli ◽

Erica Diani ◽

Umberto Bertazzoni ◽

...

Keyword(s):

T Cell ◽

Leukemia Virus ◽

Spastic Paraparesis ◽

T Cell Leukemia ◽

Cell Leukemia ◽

Pathogenic Potential ◽

Adult T Cell Leukemia ◽

Human T Cell

Human T cell leukemia virus types 1 and 2 (HTLV-1 and HTLV-2) are genetically related complex retroviruses that are capable of immortalizing human T-cells in vitro and establish life-long persistent infections in vivo. In spite of these apparent similarities, HTLV-1 and HTLV-2 exhibit a significantly different pathogenic potential. HTLV-1 is recognized as the causative agent of adult T-cell leukemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). In contrast, HTLV-2 has not been causally linked to human malignancy, although it may increase the risk of developing inflammatory neuropathies and infectious diseases. The present paper is focused on the studies aimed at defining the viral genetic determinants of the pathobiology of HTLV-1 and HTLV-2 through a comparison of the expression strategies and functional properties of the different gene products of the two viruses.

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Application of Novel T Cell Immunotherapeutics to Drive Antigen-Specific Activation, Expansion, and Differentiation of CD19 Chimeric Antigen Receptor T Cells (CAR T-cells)

Blood ◽

10.1182/blood-2020-135997 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 34-35

Author(s):

Moriah Rabin ◽

Mengyan Li ◽

Scott Garforth ◽

Jacqueline Marino ◽

Jian Hua Zheng ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Cd8 T Cells ◽

Effector Memory ◽

Mhc Molecules ◽

Car T Cells ◽

Car T

Background: While chimeric antigen receptor T cells (CAR T-cells) induce dramatic remissions of refractory or recurrent B cell malignancies, the durability of these remissions is frequently limited by subsequent reduction in circulating CAR T-cells and/or by diminution of their effector function. We hypothesized that we could overcome this therapeutic limitation and increase the functional activity and longevity of CAR T-cells by selectively deriving them from virus-specific effector memory T cells. We have developed biologics we termed synTacs (artificial immunological synapse for T-cell activation), which selectively activate and expand antigen-specific CD8+ T cells in vitro and in vivo by recapitulating signals delivered at the immunological synapse. The synTacs consist of dimeric Fc domain scaffolds linking CD28- or 4-1BB-specific ligands to HLA-A2 MHC molecules covalently tethered to virus-derived peptides. Treatment of PBMCs from CMV-exposed donors with synTacs presenting a CMV-derived peptide (pp65-NLVPMVATV) induce vigorous and selective ex vivo and in vivo expansion of highly functional CMV-specific CD8+ T cells, with potent antiviral activity. We used these synTacs to selectively generate CAR T-cells from CMV-specific effector memory CD8+ T cells, which could be further expanded by restimulation with the CMV-specific synTacs. Methods: We treated PBMCs from CMV-exposed donors in media supplemented with either IL-2 or IL-7/12/15 with a synTac containing the CMV-derived pp65 peptide presented by HLA-A2 MHC molecules linked to ligands capable of stimulating CD28- or 4-1BB-dependent costimulatory pathways. PBMCs activated either with anti-CD3/CD28 or the CMV-specific synTacs were transduced with lentivirus expressing an anti-CD19 CAR and a GFP reporter gene. CMV-specific CD8+ T cells were quantified by tetramer staining and CAR T-cells were detected by GFP expression determined by flow cytometric analysis. The functional activity of the CD19 CAR T-cells was determined by a B cell-specific cytotoxic assay. Results: After 7 days, treatment of PBMCs with CMV-specific synTacs rapidly induced robust activation and >50-fold expansion of CMV-specific CD8+ T cells expressing effector memory markers. Treatment of the PBMCs with CMV-specific synTacs selectively activated CMV-specific T cells and enabled them to be specifically transduced with a CD19-specific CAR lentivirus and converted into CD19 CAR T-cells. These CMV-specific CD19 CAR T-cells displayed potent dose-responsive cytotoxic activity targeting purified primary B cells. Furthermore, these CMV-specific CD19 CAR T-cells could be selectively expanded by in vitro treatment with CMV-specific synTacs. Conclusions: SynTacs are versatile immunotherapeutics capable of selective in vitro and in vivo activation and expansion of virus-specific CD8+ T cells with potent antiviral cytotoxic activity. After selective lentiviral transduction and conversion into CD19 CAR T-cells, their co-expression of the CMV-specific T cell receptor enabled them to be potently stimulated and activated by in vitro treatment with CMV synTacs. The modular design of synTacs facilitates efficient coupling of other costimulatory ligands - such as OX40 or GITRL - or cytokines, such as IL-2, IL-7, or IL-15, to enable the selective in vivo delivery of defined costimulatory signals or cytokines to the CAR T-cells expressing CMV-specific TCR. This strategy has the potential to boost the in vivo activity of tumor-specific CAR T-cells after infusion and enable more durable and potent treatment of refractory/recurrent B cell malignancies. Disclosures Almo: Cue Biopharma: Current equity holder in publicly-traded company, Patents & Royalties: Patent number: 62/013,715, Research Funding. Goldstein:Cue Biopharma: Research Funding.

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Naturally arising CD4+CD25+ regulatory T cells suppress the expansion of colitogenic CD4+CD44highCD62L− effector memory T cells

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00429.2005 ◽

2006 ◽

Vol 290 (5) ◽

pp. G1051-G1058 ◽

Cited By ~ 11

Author(s):

T. Kanai ◽

K. Tanimoto ◽

Y. Nemoto ◽

R. Fujii ◽

S. Makita ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Effector Memory ◽

Late Time ◽

Suppressive Activity ◽

Time Point

Naturally arising CD4+CD25+ regulatory T (TR) cells have been shown to prevent and cure murine T cell-mediated colitis. However, their exact mechanism of controlling colitogenic memory CD4+ T cells in in vivo systems excluding the initial process of naive T cell activation and differentiation has not been examined to date. Using the colitogenic effector memory (TEM) CD4+ cell-mediated colitis model induced by adoptive transfer of colitogenic CD4+CD44highCD62L− lamina propria (LP) T cells obtained from colitic CD4+CD45RBhigh T cell-transferred mice, we have shown in the present study that CD4+CD25+ TR cells are able not only to suppress the development of colitis, Th1 cytokine production, and the expansion of colitogenic LP CD4+ TEM cells but also to expand these cells by themselves extensively in vivo. An in vitro coculture assay revealed that CD4+CD25+ TR cells proliferated in the presence of IL-2-producing colitogenic LP CD4+ TEM cells at the early time point (48 h after culture), followed by the acquisition of suppressive activity at the late time point (96 h after culture). Collectively, these data suggest the distinct timing of the IL-2-dependent expansion of CD4+CD25+ TR cells and the their suppressive activity on colitogenic LP CD4+ TEM cells.

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TCR-transgenic lymphocytes specific for HMMR/Rhamm limit tumor outgrowth in vivo

Blood ◽

10.1182/blood-2011-06-357939 ◽

2012 ◽

Vol 119 (15) ◽

pp. 3440-3449 ◽

Cited By ~ 35

Author(s):

Stefani Spranger ◽

Irmela Jeremias ◽

Susanne Wilde ◽

Matthias Leisegang ◽

Lilian Stärck ◽

...

Keyword(s):

T Cell ◽

Effector Memory ◽

Memory Cells ◽

Lymphoid Leukemia ◽

Hematopoietic Stem ◽

Transgenic Expression ◽

Effector Memory Cells ◽

Tumor Outgrowth

Abstract The hyaluronan-mediated motility receptor (HMMR/Rhamm) is overexpressed in numerous tumor types, including acute lymphoid leukemia and acute myeloid leukemia (AML). Several studies have reported the existence of T-cell responses directed against HMMR in AML patients that are linked to better clinical outcome. Therefore, we explored the use of HMMR-specific TCRs for transgenic expression in lymphocytes and their in vivo impact on HMMR+ solid tumors and disseminated leukemia. We obtained TCRs via an in vitro priming approach in combination with CD137-mediated enrichment. Recipient lymphocytes expressing transgenic TCR revealed the specific tumor recognition pattern seen with the original T cells. Adoptive transfer experiments using a humanized xenograft mouse model resulted in significantly retarded solid tumor outgrowth, which was enhanced using IL-15–conditioned, TCR-transgenic effector memory cells. These cells also showed an increased potency to retard the outgrowth of disseminated AML, and this was further improved using CD8-enriched effector memory cells. To define a safe clinical setting for HMMR-TCR gene therapy, we analyzed transgenic T-cell recognition of hematopoietic stem cells (HSCs) and found on-target killing of HLA-A2+ HSCs. Our findings clearly limit the use of HMMR-TCR therapy to MHC- mismatched HSC transplantation, in which HLA-A2 differences can be used to restrict recognition to patient HSCs and leukemia.

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CD6 modulates thymocyte selection and peripheral T cell homeostasis

Journal of Experimental Medicine ◽

10.1084/jem.20151785 ◽

2016 ◽

Vol 213 (8) ◽

pp. 1387-1397 ◽

Cited By ~ 36

Author(s):

Marc Orta-Mascaró ◽

Marta Consuegra-Fernández ◽

Esther Carreras ◽

Romain Roncagalli ◽

Amado Carreras-Sureda ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immunological Synapse ◽

Cell Receptor ◽

Autoimmune Response ◽

Effector Memory ◽

Thymocyte Development ◽

Double Positive

The CD6 glycoprotein is a lymphocyte surface receptor putatively involved in T cell development and activation. CD6 facilitates adhesion between T cells and antigen-presenting cells through its interaction with CD166/ALCAM (activated leukocyte cell adhesion molecule), and physically associates with the T cell receptor (TCR) at the center of the immunological synapse. However, its precise role during thymocyte development and peripheral T cell immune responses remains to be defined. Here, we analyze the in vivo consequences of CD6 deficiency. CD6−/− thymi showed a reduction in both CD4+ and CD8+ single-positive subsets, and double-positive thymocytes exhibited increased Ca2+ mobilization to TCR cross-linking in vitro. Bone marrow chimera experiments revealed a T cell–autonomous selective disadvantage of CD6−/− T cells during development. The analysis of TCR-transgenic mice (OT-I and Marilyn) confirmed that abnormal T cell selection events occur in the absence of CD6. CD6−/− mice displayed increased frequencies of antigen-experienced peripheral T cells generated under certain levels of TCR signal strength or co-stimulation, such as effector/memory (CD4+TEM and CD8+TCM) and regulatory (T reg) T cells. The suppressive activity of CD6−/− T reg cells was diminished, and CD6−/− mice presented an exacerbated autoimmune response to collagen. Collectively, these data indicate that CD6 modulates the threshold for thymocyte selection and the generation and/or function of several peripheral T cell subpopulations, including T reg cells.

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Inherited human OX40 deficiency underlying classic Kaposi sarcoma of childhood

Journal of Experimental Medicine ◽

10.1084/jem.20130592 ◽

2013 ◽

Vol 210 (9) ◽

pp. 1743-1759 ◽

Cited By ~ 78

Author(s):

Minji Byun ◽

Cindy S. Ma ◽

Arzu Akçay ◽

Vincent Pedergnana ◽

Umaimainthan Palendira ◽

...

Keyword(s):

T Cells ◽

Endothelial Cells ◽

T Cell ◽

Kaposi Sarcoma ◽

Cd4 T Cell ◽

Effector Memory ◽

Activated T Cells ◽

Human Herpes Virus 8

Kaposi sarcoma (KS), a human herpes virus 8 (HHV-8; also called KSHV)–induced endothelial tumor, develops only in a small fraction of individuals infected with HHV-8. We hypothesized that inborn errors of immunity to HHV-8 might underlie the exceedingly rare development of classic KS in childhood. We report here autosomal recessive OX40 deficiency in an otherwise healthy adult with childhood-onset classic KS. OX40 is a co-stimulatory receptor expressed on activated T cells. Its ligand, OX40L, is expressed on various cell types, including endothelial cells. We found OX40L was abundantly expressed in KS lesions. The mutant OX40 protein was poorly expressed on the cell surface and failed to bind OX40L, resulting in complete functional OX40 deficiency. The patient had a low proportion of effector memory CD4+ T cells in the peripheral blood, consistent with impaired CD4+ T cell responses to recall antigens in vitro. The proportion of effector memory CD8+ T cells was less diminished. The proportion of circulating memory B cells was low, but the antibody response in vivo was intact, including the response to a vaccine boost. Together, these findings suggest that human OX40 is necessary for robust CD4+ T cell memory and confers apparently selective protective immunity against HHV-8 infection in endothelial cells.

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563 ICT01, an anti-BTN3A mAb, and NL-201, an alpha-independent IL-2/IL-15 agonist, combine to elicit a potent anti-tumor response by synergistically stimulating Vg9Vd2 T cell activation and proliferation

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.563 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A592-A592

Author(s):

Aude De Gassart ◽

Patrick Brune ◽

Maelle Mairesse ◽

Sophie Agaugué ◽

Ryan Swanson ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

De Novo ◽

Phase 1 ◽

Effector Memory ◽

Immunotherapy Of Cancer

Backgroundγ9δ2 T-cells are attractive mediators of cancer immunotherapy due to their strong cytolytic and pro-inflammatory activities and the positive correlation between tumor infiltration and good prognosis [1,2]. ICT01, a novel anti-BTN3A mAb activating γ9δ2 T-cells, is being evaluated in a Phase 1/2a clinical study (NCT04243499)[3,4]. Previous studies have shown that IL-2 (Proleukin®) promotes γ9δ2 T-cells expansion following ICT01 stimulation, which may be clinically useful given that γ9δ2 T-cells are normally <5% of total T-cells [5]. However, the severe toxicity of IL-2 has limited its widespread use. NL-201 is a de novo alpha-independent IL-2/IL-15 agonist that preferentially stimulates CD8 T and NK cell proliferation at low concentrations, enabling a potentially wider therapeutic index than IL-2, and is being evaluated in a Phase 1 clinical study (NCT04659629)[6,7]. Here, we explore the potential of ICT01 and NL-201 to synergistically stimulate the activation and proliferation of γ9δ2 T-cells.MethodsFlow cytometry was used to assess IL-2R signaling (pSTAT5), and γ9δ2 T-cell activation and expansion after in vitro culture of huPBMCs with ICT01, NL201 or the combination. Tumor cell killing activity was monitored upon co-culture of huPBMCs with tumor cell lines (Incucyte). In vivo pharmacology was performed in NCG mice engrafted with 20x106 huPBMCs and treated with ICT01 (1 mg/kg IV)±NL-201 (1, 3 or 10 µg/kg IV). Immune cells were phenotyped by flow cytometry in blood and organs collected at sacrifice (Day 16).ResultsNL-201 is ~100X more potent than IL-2 in triggering IL-2R signaling in γ9δ2 T-cells, without preferential activity on Tregs. NL-201 plus ICT01 induces synergistic expansion of γ9δ2 T-cells, approaching ~50% of T-cells after 8 days versus ~10% with single agents. In addition, the combination of NL-201 and ICT01 promotes γ9δ2 T-cell effector memory differentiation, in contrast to IL-2, which induces primarily central memory phenotype. Importantly, NL-201 enhances ICT01-mediated killing of cancer cells by γ9δ2 T-cells.In mice, a dose-dependent expansion of peripheral γ9δ2 T-cells from ~1–2% at baseline to up to 40% of T-cells was observed in the ICT01+NL-201 combination groups. Consistently, γ9δ2 T-cell number and frequency increase in spleen and lungs of the ICT01+NL-201 treated animals as compared to controls. Expanded γ9δ2 T-cells in the combination groups display an effector memory phenotype, confirming our in vitro results.ConclusionsThese results demonstrate the ability of the ICT01+NL-201 combination to synergistically trigger γ9δ2 T-cell activation, expansion and anti-tumor activity and support clinical evaluation of this combination as a novel therapeutic approach for cancer patients.ReferencesGentles, A. J. et al. The prognostic landscape of genes and infiltrating immune cells across human cancers. Nat Med 21, 938-945, doi:10.1038/nm.3909 (2015).Tosolini, M. et al. Assessment of tumor-infiltrating TCRVgamma9Vdelta2 gammadelta lymphocyte abundance by deconvolution of human cancers microarrays. Oncoimmunology 6, e1284723, doi:10.1080/2162402X.2017.1284723 (2017).Gassart, A. d. et al. 687 Enhancement of anti-tumor immunity by ICT01: a novel g9d2 T cell-activating antibody targeting butyrophilin-3A (BTN3A). Journal for ImmunoTherapy of Cancer 8, A412-A413, doi:10.1136/jitc-2020-SITC2020.0687 (2020).Marabelle, A. et al. 316 EVICTION Study: Preliminary results in solid tumor patients with ICT01, a first-in-class, gamma9 delta2 T cell activating antibody targeting butyrophilin-3A. Journal for ImmunoTherapy of Cancer 8, A194-A195, doi:10.1136/jitc-2020-SITC2020.0316 (2020).Gassart, A. d. et al. 442 ICT01, an anti-BTN3A mAb that activates Vg9Vd2 T cells, plus interleukin-2: a potent and promising combination for cancer immunotherapy. Journal for ImmunoTherapy of Cancer 8, A268-A269, doi:10.1136/jitc-2020-SITC2020.0442 (2020).Walkey, C., Swanson, R., Ulge, U., Silva Manzano, D. A. & Drachman, J. 576 NL-201, a de novo IL-2 and IL-15 agonist, demonstrates enhanced in vivo antitumor activity in combination with multiple cancer immunotherapies. Journal for ImmunoTherapy of Cancer 8, A346-A346, doi:10.1136/jitc-2020-SITC2020.0576 (2020).Walkey, C. D. et al. Abstract 4518: Pre-clinical development of NL-201: A de novo α-independent IL-2/IL-15 agonist. Cancer Research 80, 4518–4518, doi:10.1158/1538-7445.Am2020-4518 (2020).Ethics ApprovalAll procedures involving animals described in this study have been reviewed and approved by the local ethic committee (CELEAG) and the French Ministry of Research.

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