scholarly journals 793 Targeting engineered interleukin-2 (IL-2) to antigen specific T cells via novel biologic platforms

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A828-A828
Author(s):  
Raymond Moniz ◽  
Ahmet Vakkasoglu ◽  
Zohra Merazga ◽  
Tina Daigneault ◽  
Steve Quayle ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Immune Cells ◽  
Interleukin 2 ◽  
Binding Pocket ◽  
Tumor Escape ◽  
Antigenic Peptides ◽  
T Cell Epitopes ◽  
Cell Repertoire

BackgroundA key challenge with IL-2 immunotherapy for cancers is lack of selectivity for anti-tumor immune cells and safety liabilities related to indiscriminate activation of immune cells. The CUE-100 series of Immuno-STATs (ISTs) are designed to selectively activate tumor-specific T cells while avoiding IL-2 toxicities due to systemic activation. CUE-100 series ISTs are rationally engineered Fc fusion proteins comprised of bivalent tumor-peptide-HLA (pHLA) complexes and four affinity-attenuated IL-2 molecules to preferentially engage and activate tumor-specific T cells directly in the patient. Emerging clinical data from our lead candidate CUE-101, which targets HPV-specific T cells in 2L+ R/M HNSCCC, provides PoC for the approach and builds confidence for broad applications in numerous cancers. Building on the CUE-100 series framework, our Neo-STAT (NST) platform contains HLA molecules manufactured with an “empty” peptide-binding pocket, into which diverse tumor-peptides can be chemically conjugated, hence addressing tumor heterogeneity in a cost- and time-efficient manner. Our RDI-STAT (Re-Directed Immuno-STAT) platform further expands the CUE-100 series by redirecting the pre-existing protective viral-specific T cell repertoire to target tumor cells via scFv moieties. RDI-STATs are designed to circumvent potential tumor escape mechanisms linked to HLA loss or defects in antigen-presenting pathways. We present here preclinical data supporting the mechanism of action of these platforms to enhance anti-tumor immune responses.MethodsNSTs were engineered with “empty” HLA-A*0201, into which relevant antigenic peptides were conjugated, and assessed for capacity to expand T cells. RDI-STATs were engineered with TAA-specific scFv and viral-specific pHLA complexes, and assessed for their capacity to induce redirected killing of tumor cells while avoiding systemic activation of all T cells.ResultsThe NST platform demonstrated that different T cell epitopes can be efficiently conjugated into the HLA-binding pocket, and that these molecules activate and expand antigen specific T cells in vitro. RDI-STATs were able to expand anti-viral T cell repertoires and drive anti-viral T cell redirected killing of TAA-expressing cells. In contrast to pan anti-CD3 bispecific molecules, RDI-STATs demonstrated significantly lower induction of pro-inflammatory cytokines.ConclusionsThe IST, NST, and RDI-STAT platforms provide novel opportunities for selective targeting of IL-2 to tumor-relevant T cells while avoiding global immune activation and cytokine release. The scalability and versatility of NSTs highlight the potential to target multiple TAA T cell responses, while RDI-STATs highlight a novel means to harness antiviral immunity against cancer, especially in cases where the tumor may escape immune detection due to loss of HLA.

Comprehensive analysis of melanoma antigen specific T cell repertoire: EPIMAX (EPItope MAXimum)

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 3016-3016
Author(s):  
A. Palucka ◽  
J. Banchereau ◽  
L. Vence ◽  
J. Connolly ◽  
J. Fay ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Cd4 T Cells ◽  
T Cell Epitopes ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Melanoma Antigen ◽  
Allogeneic Tumor

3016 Background: We have demonstrated in phase I clinical trial treating 20 patients with metastatic melanoma that dendritic cells (DCs) loaded with killed allogeneic tumor cells can elicit immune and clinical responses. Loading DC vaccines with killed allogeneic tumor cells allows: i) presentation of antigens via both MHC class I and class II, ii) strong help, iii) applicability to any cancer, and iv) loading tumor antigen independent of HLA haplotype of the patient. However, this renders the immunomonitoring step complex as the antigens and their restriction elements are unknown. To address this issue, we developed EPIMAX. Methods: EPIMAX measures simultaneously cell proliferation and secretion of multiple cytokines that distinguish Type 1, Type 2 cytokines and IL-10 secretion using Luminex. Briefly, 5x105 CFSE-labeled PBMCs are plated with peptide pools of overlapping peptide libraries from appropriate antigens. After 48hrs, supernatants are transferred for cytokine determination. After an additional 6 days of culture, cell proliferation is analyzed by flow cytometry after staining for surface markers CD4 and CD8. Results: We demonstrated that EPIMAX permits us to assess: i) Specificity and breadth of induced immune responses, ii) Type of induced immunity (Type I, Type II, IL-10), and iii) Function of specific T cells as measured by cytokine secretion and proliferation. To date 8 patients with stage IV melanoma were analyzed at baseline and after vaccination with DCs loaded with killed allogeneic melanoma cells. We assessed epitopes derived from MART-1, NY-ESO1, TRP-1 and gp100. Analysis of CD8+T cells: We have identified 15 melanoma antigen CD8+T cell epitopes in 8 patients. These include: three Tc0 epitopes (IL2), and twelve Tc1 epitopes triggering IP-10 secretion. Analysis of CD4+T cells: We have identified 15 melanoma antigen CD4+T cell epitopes in 5 patients. These include: nine Th0 epitopes (IL2), four Th1 epitopes (IFNγ) and two Th2 epitopes (IL13). Finally, we analyzed secretion of IL-10 and found thus far IL-10 secreting CD4+T cells in seven patients. Further studies demonstrated that these T cells have regulatory function. Conclusions: EPIMAX permits comprehensive assessment of melanoma antigen specific T cell repertoire. No significant financial relationships to disclose.

scholarly journals Polyclonal expansion of TCR Vbeta 21.3+ CD4+ and CD8+ T cells is a hallmark of Multisystem Inflammatory Syndrome in Children

2021 ◽  
Vol 6 (59) ◽  
pp. eabh1516
Author(s):  
Marion Moreews ◽  
Kenz Le Gouge ◽  
Samira Khaldi-Plassart ◽  
Rémi Pescarmona ◽  
Anne-Laure Mathieu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Expansion ◽  
Healthy Children ◽  
Antigenic Peptides ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Hla Dr ◽  
T Cell Expansion ◽  
Inflammatory Syndrome

Multiple Inflammatory Syndrome in Children (MIS-C) is a delayed and severe complication of SARS-CoV-2 infection that strikes previously healthy children. As MIS-C combines clinical features of Kawasaki disease and Toxic Shock Syndrome (TSS), we aimed to compare the immunological profile of pediatric patients with these different conditions. We analyzed blood cytokine expression, and the T cell repertoire and phenotype in 36 MIS-C cases, which were compared to 16 KD, 58 TSS, and 42 COVID-19 cases. We observed an increase of serum inflammatory cytokines (IL-6, IL-10, IL-18, TNF-α, IFNγ, CD25s, MCP1, IL-1RA) in MIS-C, TSS and KD, contrasting with low expression of HLA-DR in monocytes. We detected a specific expansion of activated T cells expressing the Vβ21.3 T cell receptor β chain variable region in both CD4 and CD8 subsets in 75% of MIS-C patients and not in any patient with TSS, KD, or acute COVID-19; this correlated with the cytokine storm detected. The T cell repertoire returned to baseline within weeks after MIS-C resolution. Vβ21.3+ T cells from MIS-C patients expressed high levels of HLA-DR, CD38 and CX3CR1 but had weak responses to SARS-CoV-2 peptides in vitro. Consistently, the T cell expansion was not associated with specific classical HLA alleles. Thus, our data suggested that MIS-C is characterized by a polyclonal Vβ21.3 T cell expansion not directed against SARS-CoV-2 antigenic peptides, which is not seen in KD, TSS and acute COVID-19.

scholarly journals Protective Vaccine Efficacy of the Complete Form of PPE39 Protein from Mycobacterium tuberculosis Beijing/K Strain in Mice

2017 ◽  
Vol 24 (11) ◽  
Author(s):  
Ahreum Kim ◽  
Yun-Gyoung Hur ◽  
Sunwha Gu ◽  
Sang-Nae Cho
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Vaccine Development ◽  
Protective Efficacy ◽  
Interleukin 2 ◽  
T Cell Epitopes ◽  
Content Type ◽  
Complete Form ◽  
Ifn Γ

ABSTRACT The aim of this study was to evaluate the protective efficacy of MTBK_24820, a complete form of PPE39 protein derived from a predominant Beijing/K strain of Mycobacterium tuberculosis in South Korea. Mice were immunized with MTKB_24820, M. bovis Bacilli Calmette-Guérin (BCG), or adjuvant prior to a high-dosed Beijing/K strain aerosol infection. After 4 and 9 weeks, bacterial loads were determined and histopathologic and immunologic features in the lungs and spleens of the M. tuberculosis-infected mice were analyzed. Putative immunogenic T-cell epitopes were examined using synthetic overlapping peptides. Successful immunization of MTBK_24820 in mice was confirmed by increased IgG responses (P < 0.05) and recalled gamma interferon (IFN-γ), interleukin-2 (IL-2), IL-6, and IL-17 responses (P < 0.05 or P < 0.01) to MTBK_24820. After challenge with the Beijing/K strain, an approximately 0.5 to 1.0 log10 reduction in CFU in lungs and fewer lung inflammation lesions were observed in MTBK_24820-immunized mice compared to those for control mice. Moreover, MTBK_24820 immunization elicited significantly higher numbers of CD4+ T cells producing protective cytokines, such as IFN-γ and IL-17, in lungs and spleens (P < 0.01) and CD4+ multifunctional T cells producing IFN-γ, tumor necrosis factor alpha (TNF-α), and/or IL-17 (P < 0.01) than in control mice, suggesting protection comparable to that of BCG against the hypervirulent Beijing/K strain. The dominant immunogenic T-cell epitopes that induced IFN-γ production were at the N terminus (amino acids 85 to 102 and 217 to 234). Its vaccine potential, along with protective immune responses in vivo, may be informative for vaccine development, particularly in regions where the M. tuberculosis Beijing/K-strain is frequently isolated from TB patients.

scholarly journals Human CD8 transgene regulation of HLA recognition by murine T cells.

1995 ◽  
Vol 182 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
D M LaFace ◽  
M Vestberg ◽  
Y Yang ◽  
R Srivastava ◽  
J DiSanto ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hla Class I ◽  
Cell Receptor ◽  
Class I ◽  
Antigenic Peptides ◽  
Cell Repertoire ◽  
Repertoire Selection ◽  
Hla Class I Molecules ◽  
Cell Expression

A series of human CD8 transgenic (hCD8 Tg) mice with differential expression in the thymus and periphery were produced to investigate CD8 coreceptor regulation of repertoire selection and T cell responses. Expression of hCD8 markedly enhanced responses to both HLA class I molecules and hybrid A2/Kb molecules providing functional evidence for a second interaction site, outside of the alpha 3 domain, which is essential for optimal coreceptor function. Peripheral T cell expression of hCD8 was sufficient to augment responsiveness to HLA class I, as hCD8 Tg mice which lacked thymic expression responded as well as mice expressing hCD8 in the thymus and periphery. Both murine CD8+ and CD4+ T cells expressing hCD8 transgenes exhibited markedly enhanced responses to foreign HLA class I, revealing the ability of T cell receptor repertoires selected on either murine class I or class II to recognize human class I major histocompatibility complex (MHC). In contrast to recognition of foreign class I, thymic expression of hCD8 transgenes was absolutely required to enhance recognition of antigenic peptide restricted by self-HLA class I. Thus, our studies revealed disparate requirements for CD8 coreceptor expression in the thymus for selection of a T cell repertoire responsive to foreign MHC and to antigenic peptides bound to self-MHC, providing a novel demonstration of positive selection that is dependent on human CD8.

scholarly journals Low CD19 Antigen Density Diminishes Efficacy of CD19 CAR T Cells and Can be Overcome By Rational Redesign of CAR Signaling Domains

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 963-963 ◽  
Author(s):  
Robbie G. Majzner ◽  
Skyler P. Rietberg ◽  
Louai Labanieh ◽  
Elena Sotillo ◽  
Evan W. Weber ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Cytokine Production ◽  
Xenograft Model ◽  
Target Antigen ◽  
Tumor Escape ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract Target antigen density has emerged as a major factor influencing the potency of CAR T cells. Our laboratory has demonstrated that the activity of numerous CARs is highly dependent on target antigen density (Walker et al., Mol Ther, 2017), and high complete response rates in a recent trial of CD22 CAR T cells for B-ALL were tempered by frequent relapses due to decreased CD22 antigen density on lymphoblasts (Fry et al., Nat Med, 2018). To assess if antigen density is also a determinant of CD19 CAR T cell therapeutic success, we analyzed CD19 antigen density from fifty pediatric B-ALL patients treated on a clinical trial of CD19-CD28ζ CAR T cells. We found that patients whose CD19 expression was below a threshold density (2000 molecules/lymphoblast) were significantly less likely to achieve a clinical response than those whose leukemia expressed higher levels of CD19. In order to further understand this limitation and how it may be overcome, we developed a model of variable CD19 antigen density B-ALL. After establishing a CD19 knockout of the B-ALL cell line NALM6, we used a lentivirus to reintroduce CD19 and then FACS sorted and single cell cloned to achieve a library of NALM6 clones with varying CD19 surface densities. CD19-CD28ζ CAR T cell activity was highly dependent on CD19 antigen density. We observed decreases in cytotoxicity, proliferation, and cytokine production by CD19 CAR T cells when encountering CD19-low cells, with an approximate threshold of 2,000 molecules of CD19 per lymphoblast, below which, cytokine production in response to tumor cells was nearly ablated. Given that a CD19-4-1BBζ CAR is FDA approved for children with B-ALL and adults with DLBCL, we wondered whether CARs incorporating this alternative costimulatory domain would have similar antigen density thresholds for activation. Surprisingly, CD19-4-1BBζ CAR T cells made even less cytokine, proliferated less, and had further diminished cytolytic capacity against CD19-low cells compared to CD19-CD28ζ CAR T cells. Analysis by western blot of protein lysates from CAR T cells stimulated with varying amounts of antigen demonstrated that CD19-CD28ζ CAR T cells had higher levels of downstream signals such as pERK than CD19-4-1BBζ CAR T cells at lower antigen densities. Accordingly, calcium flux after stimulation was also significantly higher in CD19-CD28ζ than CD19-4-1BBζ CAR T cells. In a xenograft model of CD19-low B-ALL, CD19-4-1BBζ CAR T cells demonstrated no anti-tumor activity, while CD19-CD28ζ CAR T cells eradicated CD19-low leukemia cells. Therefore, the choice of costimulatory domain in CAR T cells plays a major role in modulating activity against low antigen density tumors. CD28 costimulation endows high reactivity towards low antigen density tumors. We confirmed the generalizability of this finding using Her2 CAR T cells; Her2-CD28ζ CAR T cells cleared tumors in an orthotopic xenograft model of Her2-low osteosarcoma, while Her2-4-1BBζ CAR T cells had no effect. This finding has implications for CAR design for lymphoma and solid tumors, where antigen expression is more heterogeneous than B-ALL. To enhance the activity of CD19-4-1BBζ CAR T cells against CD19-low leukemia, we designed a CAR with two copies of intracellular zeta in the signaling domain (CD19-4-1BBζζ). T cells expressing this double-zeta CAR demonstrated enhanced cytotoxicity, proliferation, cytokine production, and pERK signaling in response to CD19-low cells compared to single-zeta CARs. Additionally, in a xenograft model, CD19-4-1BBζζ CAR T cells demonstrated enhanced activity against CD19-low leukemia compared to CD19-4-1BBζ CAR T cells, significantly extending survival. The addition of a third zeta domain (CD19-4-1BBζζζ) further enhanced the activity of CAR T cells. However, inclusion of multiple copies of the costimulatory domains did not improve function. In conclusion, CD19 antigen density is an important determinant of CAR T cell function and therapeutic response. CD19-CD28ζ CARs are more efficient at targeting CD19-low tumor cells than CD19-4-1BBζ CARs. The addition of multiple zeta domains to the CAR enhances its ability to target low antigen density tumors. This serves as proof of concept that rational redesign of CAR signaling endodomains can result in enhanced function against low antigen density tumors, an important step for extending the reach of these powerful therapeutics and overcoming a significant mechanism of tumor escape. Disclosures Lee: Juno: Consultancy.

scholarly journals Pre-B acute lymphoblastic leukemia cells may induce T-cell anergy to alloantigen

Blood ◽  
1996 ◽  
Vol 88 (1) ◽  
pp. 41-48 ◽  
Author(s):  
AA Cardoso ◽  
JL Schultze ◽  
VA Boussiotis ◽  
GJ Freeman ◽  
MJ Seamon ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
B Cell ◽  
Tumor Cells ◽  
Lymphoblastic Leukemia ◽  
Interleukin 2 ◽  
Human Tumor ◽  
Clinically Significant ◽  
Antigen Presenting

Abstract Even if neoplastic cells express tumor associated antigens they still may fail to function as antigen presenting cells (APC) if they lack expression of one or more molecules critical for the induction of productive immunity. These cellular defects can be repaired by physiologic activation, transfection, or fusion of tumor cells with professional APC. Although such defects can be repaired, antitumor specific T cells may still fail to respond in vivo if they may have been tolerized. Here, human pre-B cell acute lymphoblastic leukemia (pre-B ALL) was used as a model to determine if primary human tumor cells can function as alloantigen presenting cells (alloAPC) or alternatively whether they induce anergy. In the present report, we show that pre-B cell ALL express alloantigen and adhesion molecules but uniformly lack B7–1 (CD80) and only a subset express B7–2 (CD86). Pre-B ALL cells are inefficient or ineffective alloAPC and those cases that lack expression of B7–1 and B7–2 also induce alloantigen specific T- cell unresponsiveness. Under these circumstances, T-cell unresponsiveness could be prevented by physiologic activation of tumor cells via CD40, cross-linking CD28, or signaling through the common gamma chain of the interleukin-2 receptor on T cells. Taken together, these results suggest that pre-B ALL may be incapable of inducing clinically significant T-cell-mediated antileukemia responses. This defect may be not only due to their inability to function as APC, but also due to their potential to induce tolerance. Attempts to induce clinically significant antitumor immune responses may then require not only mechanisms to repair the antigen presenting capacity of the tumor cells, but also reversal of tolerance.

Tumor-derived activated cells: preliminary laboratory and clinical results.

1989 ◽  
Vol 35 (8) ◽  
pp. 1576-1580 ◽  
Author(s):  
R K Oldham ◽  
J R Maleckar ◽  
C S Friddell ◽  
W M Lewko ◽  
W H West ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Peripheral Blood ◽  
Tumor Antigens ◽  
Interleukin 2 ◽  
Limiting Factors ◽  
Limiting Factor ◽  
Clinical Effects ◽  
Lymphokine Activated Killer Cells

Abstract It is well known that T lymphocytes can mediate significant anti-tumor responses. A limiting factor has always been the ability to expand T cells, whether from the peripheral blood, spleen, or tumor. The recent availability of recombinant interleukin-2 (r-IL2) has demonstrated the feasibility of expanding T cells and the clinical efficacy of these cells as anti-tumor effectors in murine models. Concomitantly, researchers discovered that lymphokine-activated killer cells--peripheral blood cells functionally distinct from T cells--could be cultured, expanded, and re-infused in patients, with significant clinical effects. For many years, the infiltrating lymphocytes have been recognized in tumor biopsies and known to be cytolytically active. Major limiting factors were the ability to culture large numbers of these infiltrating cells and the limited understanding of the tumor antigens involved for T-cell stimulation. Restimulation by antigen (tumor cells) appears to provide the ongoing antigen stimulation needed to maintain selective killing of tumor cells. By defining various factors in the medium that support and enhance T-cell growth and activation, the components are becoming available to develop a broad attack on advanced cancer by using this laboratory-based technology of stimulation and expansion of tumor-derived activated cells.

scholarly journals Interleukin 2 abrogates the nonresponsive state of T cells expressing a forbidden T cell receptor repertoire and induces autoimmune disease in neonatally thymectomized mice.

1991 ◽  
Vol 173 (6) ◽  
pp. 1323-1329 ◽  
Author(s):  
J L Andreu-Sánchez ◽  
I M Moreno de Alborán ◽  
M A Marcos ◽  
A Sánchez-Movilla ◽  
C Martínez-A ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Peritoneal Cavity ◽  
Present Report ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Double Negative ◽  
Cell Repertoire

Under physiological conditions, the vast majority of T cells differentiate in the thymus, an organ that provides an optimal microenvironment for T cell maturation and shapes the T cell repertoire via positive and negative selection processes. In the present report, we demonstrate that neonatal thymectomy of CBA/H mice results in a diminution of T cells in peripheral lymphoid organs (spleen, lymph nodes), but is followed by a marked transient (12 wk) increase in Thy-1+ CD3+ cells in the peritoneal cavity. These cells exhibit predominantly a double-negative (CD4-CD8-) phenotype among which products of the T cell receptor (TCR) V beta 11 gene family (i.e., an I-E-reactive TCR normally deleted in I-E-bearing CBA/H mice) are selectively overexpressed. This observation suggests that, under athymic conditions, T cell differentiation and/or accumulation may occur in the peritoneal cavity. Intraperitoneal inoculation of an interleukin 2 (IL-2) vaccinia virus construct that releases high titers of human IL-2 in vivo induces conversion of these double-negative T cells to either CD4+ CD8- or CD4- CD8+ single positives, and allows in vitro stimulation of TCR V beta 11-bearing cells with a clonotypic anti-V beta antibody. Since IL-2 induces autoimmune manifestations (DNA autoantibodies, rheumatoid factors, and interstitial nephritis) in thymectomized CBA/H mice, but not in sham-treated littermates, this lymphokine is likely to enhance the autoaggressive function of T cells that bear forbidden, potentially autoreactive TCR gene products and that are normally deleted in the thymus.

scholarly journals Spontaneous and glucocorticoid-induced apoptosis in human mature T lymphocytes

Blood ◽  
1995 ◽  
Vol 86 (11) ◽  
pp. 4199-4205 ◽  
Author(s):  
M Brunetti ◽  
N Martelli ◽  
A Colasante ◽  
M Piantelli ◽  
P Musiani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Interleukin 2 ◽  
Cell Number ◽  
T Cell Subsets ◽  
Dependent Manner ◽  
Cell Repertoire ◽  
Induced Apoptosis ◽  
And Function ◽  
Dose Dependent

Glucocorticoid (GC)-induced apoptosis is a well-recognized physiologic regulator of murine T-cell number and function. We have analyzed its mechanisms in human mature T cells, which have been thought to be insensitive until recently. Peripheral blood T cells showed sensitivity to GC-induced apoptosis soon after the proliferative response to a mitogenic stimulation, and were also sensitive to spontaneous (ie, growth factor deprivation-dependent) apoptosis. CD8+ T cells were more sensitive to both forms than CD4+ T cells. Acquisition of sensitivity to GC-induced apoptosis was not associated with any change in number or affinity of GC receptors. Both spontaneous and GC-induced apoptosis were increased by the macromolecular synthesis inhibitors, cycloheximide (CHX) and puromycin. A positive correlation between the degree of protein synthesis inhibition and the extent of apoptosis was observed. Interleukin-2 (IL-2) IL-4, and IL-10 protected (IL-2 > IL-10 > IL-4) T cells from both forms of apoptosis in a dose-dependent manner. Our data suggest that spontaneous and GC-induced apoptosis regulate the human mature T-cell repertoire by acting early after the immune response and differentially affecting T-cell subsets.

scholarly journals Co-delivery of novel bispecific and trispecific engagers by an amplicon vector augments the therapeutic effect of an HSV-based oncolytic virotherapy

2021 ◽  
Vol 9 (7) ◽  
pp. e002454
Author(s):  
Divya Ravirala ◽  
Brandon Mistretta ◽  
Preethi H Gunaratne ◽  
Guangsheng Pei ◽  
Zhongming Zhao ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Cells ◽  
Therapeutic Effect ◽  
Immune Cells ◽  
Egf Receptor ◽  
Interleukin 2 ◽  
Oncolytic Virotherapy ◽  
Mutant Form ◽  
Sequencing Analysis ◽  
Chimeric Molecules

BackgroundAlthough oncolytic virotherapy has shown substantial promises as a new treatment modality for many malignancies, further improvement on its therapeutic efficacy will likely bring more clinical benefits. One plausible way of enhancing the therapeutic effect of virotherapy is to enable it with the ability to concurrently engage the infiltrating immune cells to provide additional antitumor mechanisms. Here, we report the construction and evaluation of two novel chimeric molecules (bispecific chimeric engager proteins, BiCEP and trispecific chimeric engager protein, TriCEP) that can engage both natural killer (NK) and T cells with tumor cells for enhanced antitumor activities.MethodsBiCEP was constructed by linking orthopoxvirus major histocompatibility complex class I-like protein, which can selectively bind to NKG2D with a high affinity to a mutant form of epidermal growth factor (EGF) that can strongly bind to EGF receptor. TriCEP is similarly constructed except that it also contains a modified form of interleukin-2 that can only function as a tethered form. As NKG2D is expressed on both NK and CD8+ T cells, both of which can thus be engaged by BiCEP and TriCEP.ResultsBoth BiCEP and TriCEP showed the ability to engage NK and T cells to kill tumor cells in vitro. Coadministration of BiCEP and TriCEP with an oncolytic herpes simplex virus enhanced the overall antitumor effect. Furthermore, single-cell RNA sequencing analysis revealed that TriCEP not only engaged NK and T cells to kill tumor cells, it also promotes the infiltration and activation of these important immune cells.ConclusionsThese novel chimeric molecules exploit the ability of the oncolytic virotherapy in altering the tumor microenvironment with increased infiltration of important immune cells such as NK and T cells for cancer immunotherapy. The ability of BiCEP and TriCEP to engage both NK and T cells makes them an ideal choice for arming an oncolytic virotherapy.

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