Selective depletion of donor alloreactive T cells without loss of antiviral or antileukemic responses

Blood ◽  
2003 ◽  
Vol 102 (6) ◽  
pp. 2292-2299 ◽  
Author(s):  
Persis J. Amrolia ◽  
Giada Muccioli-Casadei ◽  
Eric Yvon ◽  
Helen Huls ◽  
Uluhan Sili ◽  
...  

Abstract Poor immune reconstitution after haploidentical stem cell transplantation results in a high mortality from viral infections and relapse. One approach to overcome this problem is to selectively deplete the graft of alloreactive cells using an immunotoxin directed against the activation marker CD25. However, the degree of depletion of alloreactive cells is variable following stimulation with recipient peripheral blood mononuclear cells (PBMCs), and this can result in graft versus host disease (GVHD). We have refined this approach using recipient Epstein-Barr virus (EBV)–transformed lymphoblastoid cell lines (LCLs) as stimulators to activate donor alloreactive T cells. Our studies demonstrate that allodepletion with an anti-CD25 immunotoxin following stimulation with HLA-mismatched host LCLs more consistently depleted in vitro alloreactivity than stimulation with host PBMCs, as assessed in primary mixed lymphocyte reactions (MLRs). Allodepletion using this approach specifically abrogates cytotoxic T-cell responses against host LCLs. In interferon-γ (IFN-γ) enzyme-linked immunospot (ELISPOT) assays, antiviral responses to adenovirus and cytomegalovirus (CMV) were preserved following allodepletion. Likewise, using HLA-A2–pp65 tetramers, we have shown that the frequency of CMV-specific T cells is unaffected by allodepletion. Moreover, the donor anti-EBV response is partially retained by recognition of EBV antigens through the nonshared haplotype. Finally, we studied whether allodepletion affects the response to candidate tumor antigens in myeloid malignancies. Using HLA-A2–PR1 tetramer analysis, we found that the frequency of T cells recognizing the PR1 epitope of proteinase 3 was not significantly different in allodepleted and unmanipulated PBMCs from patients with chronic myeloid leukemia (CML) undergoing transplantation. Based on these data, we have embarked on a phase 1 clinical trial of addback of allo-LCL–depleted donor T cells in the haplo-identical setting.

Blood ◽  
1984 ◽  
Vol 64 (3) ◽  
pp. 707-714 ◽  
Author(s):  
RL Edwards ◽  
D Perla

Abstract Human monocytes generate the procoagulant tissue factor (MTF) following exposure to a variety of immune stimuli in vitro. The generation of MTF is modified by T cells, lymphokines, and immunoregulatory lipoproteins, and recent studies have shown that MTF can be activated in an immune- specific manner following exposure to antigen. We have examined the role of serum factors in the regulation of MTF generation. Low concentrations (less than 1%) of heat-inactivated normal human serum greatly enhanced MTF generation in cultures of normal peripheral blood mononuclear cells. The stimulatory effect was observed in cultures of both unstimulated cells and cells exposed to bacterial lipopolysaccharide. Stimulation was not observed at high serum concentrations (greater than 10%) and could not be explained by endotoxin contamination or activation of the assay system. Stimulatory activity was present in plasma and BaSO4-adsorbed plasma as well as autologous and allogeneic serum, was not abolished by removal of serum lipoproteins, and did not require the presence of T cells for its expression. Sera from 28 different normal volunteers were screened for stimulatory activity and demonstrated a wide variation in potency. These results suggest that a potent factor is present in sera that enhances the expression of MTF activity in vitro. This factor is distinct from previously described lipoprotein regulators and may play a role in the initiation of coagulation in both normal hemostasis and pathologic states.


2021 ◽  
Vol 9 (1) ◽  
pp. e001762
Author(s):  
Punit Upadhyaya ◽  
Johanna Lahdenranta ◽  
Kristen Hurov ◽  
Sailaja Battula ◽  
Rachel Dods ◽  
...  

BackgroundIn contrast to immune checkpoint inhibitors, the use of antibodies as agonists of immune costimulatory receptors as cancer therapeutics has largely failed. We sought to address this problem using a new class of modular synthetic drugs, termed tumor-targeted immune cell agonists (TICAs), based on constrained bicyclic peptides (Bicycles).MethodsPhage libraries displaying Bicycles were panned for binders against tumor necrosis factor (TNF) superfamily receptors CD137 and OX40, and tumor antigens EphA2, Nectin-4 and programmed death ligand 1. The CD137 and OX40 Bicycles were chemically conjugated to tumor antigen Bicycles with different linkers and stoichiometric ratios of binders to obtain a library of low molecular weight TICAs (MW <8 kDa). The TICAs were evaluated in a suite of in vitro and in vivo assays to characterize their pharmacology and mechanism of action.ResultsLinking Bicycles against costimulatory receptors (e.g., CD137) to Bicycles against tumor antigens (e.g., EphA2) created potent agonists that activated the receptors selectively in the presence of tumor cells expressing these antigens. An EphA2/CD137 TICA (BCY12491) efficiently costimulated human peripheral blood mononuclear cells in vitro in the presence of EphA2 expressing tumor cell lines as measured by the increased secretion of interferon γ and interleukin-2. Treatment of C57/Bl6 mice transgenic for the human CD137 extracellular domain (huCD137) bearing EphA2-expressing MC38 tumors with BCY12491 resulted in the infiltration of CD8+ T cells, elimination of tumors and generation of immunological memory. BCY12491 was cleared quickly from the circulation (plasma t1/2 in mice of 1–2 hr), yet intermittent dosing proved effective.ConclusionTumor target-dependent CD137 agonism using a novel chemical approach (TICAs) afforded elimination of tumors with only intermittent dosing suggesting potential for a wide therapeutic index in humans. This work unlocks a new path to effective cancer immunotherapy via agonism of TNF superfamily receptors.


2008 ◽  
Vol 76 (10) ◽  
pp. 4538-4545 ◽  
Author(s):  
William W. Kwok ◽  
Junbao Yang ◽  
Eddie James ◽  
John Bui ◽  
Laurie Huston ◽  
...  

ABSTRACT Cellular immune responses against protective antigen (PA) of Bacillus anthracis in subjects that received the anthrax vaccine adsorbed (AVA) vaccine were examined. Multiple CD4+ T-cell epitopes within PA were identified by using tetramer-guided epitope mapping. PA-reactive CD4+ T cells with a CD45RA− phenotype were also detected by direct ex vivo staining of peripheral blood mononuclear cells (PBMC) with PA-specific tetramers. Surprisingly, PA-specific T cells were also detected in PBMC of nonvaccinees after a single cycle of in vitro PA stimulation. However, PA-reactive CD4+ T cells in nonvaccinees occurred at lower frequencies than those in vaccinees. The majority of PA-reactive T cells from nonvaccinees were CD45RA+ and exhibited a Th0/Th1 cytokine profile. In contrast, phenotyping and cytokine profile analyses of PA-reactive CD4+ T cells from vaccinees indicated that vaccination leads to commitment of PA-reactive T cells to a Th2 lineage, including generation of PA-specific, pre-Th2 central memory T cells. These results demonstrate that the current AVA vaccine is effective in skewing the development of PA CD4+ T cells to the Th2 lineage. The data also demonstrated the feasibility of using class II tetramers to analyze CD4+ cell responses and lineage development after vaccination.


2021 ◽  
Author(s):  
Yannick D. Muller ◽  
Leonardo M.R. Ferreira ◽  
Emilie Ronin ◽  
Patrick Ho ◽  
Vinh Nguyen ◽  
...  

Infusion of regulatory T cells (Tregs) engineered with a chimeric antigen receptor (CAR) targeting donor-derived human leukocyte antigen (HLA) is a promising strategy to promote transplant tolerance. Here, we describe an anti-HLA-A2 CAR (A2-CAR) generated by grafting the complementarity-determining regions (CDRs) of a human monoclonal anti-HLA-A2 antibody into the framework regions of the Herceptin 4D5 single-chain variable fragment and fusing it with a CD28-zeta signaling domain. The CDR-grafted A2-CAR maintained the specificity of the original antibody. We then generated HLA-A2 mono-specific human CAR Tregs either by deleting the endogenous T-cell receptor (TCR) via CRISPR/Cas9 and introducing the A2-CAR using lentiviral transduction or by directly integrating the CAR construct into the TCR alpha constant locus using homology-directed repair. These A2-CAR+TCRdeficient human Tregs maintained both Treg phenotype and function in vitro. Moreover, they selectively accumulated in HLA-A2-expressing islets transplanted from either HLA-A2 transgenic mice or deceased human donors. A2-CAR+TCRdeficient Tregs did not impair the function of these HLA-A2+ islets, whereas similarly engineered A2-CAR+TCRdeficientCD4+ conventional T cells rejected the islets in less than 2 weeks. A2-CAR+TCRdeficient Tregs delayed graft-versus-host disease only in the presence of HLA-A2, expressed either by co-transferred peripheral blood mononuclear cells or by the recipient mice. Altogether, we demonstrate that genome-engineered mono-antigen-specific A2-CAR Tregs localize to HLA-A2-expressing grafts and exhibit antigen-dependent in vivo suppression, independent of TCR expression. These approaches may be applied towards developing precision Treg cell therapies for transplant tolerance.


Blood ◽  
2021 ◽  
Author(s):  
Maissa Mhibik ◽  
Erika M. Gaglione ◽  
David Eik ◽  
Ellen K Kendall ◽  
Amy Blackburn ◽  
...  

Bruton Tyrosine Kinase inhibitors (BTKis) are a preferred treatment for patients with chronic lymphocytic leukemia (CLL). Indefinite therapy with BTKis, while effective, presents clinical challenges. Combination therapy can deepen responses, shorten treatment duration, and possibly prevent or overcome drug resistance. We previously reported on a CD19/CD3 bispecific antibody (bsAb) that recruits autologous T cell cytotoxicity against CLL cells in vitro. Compared to observations with samples from treatment-naïve patients, T cells from patients being treated with ibrutinib expanded more rapidly and exerted superior cytotoxic activity in response to the bsAb. In addition to BTK, ibrutinib also inhibits IL2 inducible T cell Kinase (ITK). In contrast, acalabrutinib, does not inhibit ITK. Whether ITK inhibition contributes to the observed immune effects is unknown. To better understand how BTKis modulate T-cell function and cytotoxic activity, we cultured peripheral blood mononuclear cells (PBMCs) from BTKi-naive, and ibrutinib- or acalabrutinib-treated CLL patients with CD19/CD3 bsAb in vitro. T-cell expansion, activation, differentiation, and cytotoxicity were increased in PBMCs from patients on treatment with either BTKi compared to that observed for BKTi-naïve patients. BTKi therapy transcriptionally downregulated immunosuppressive effectors expressed by CLL cells, including CTLA-4 and CD200. CTLA-4 blockade with ipilimumab in vitro increased the cytotoxic activity of the bsAb in BTKi-naïve but not BTKi-treated PBMCS. Taken together, BTKis enhance bsAb induced cytotoxicity by relieving T cells of immunosuppressive restraints imposed by CLL cells. The benefit of combining bsAb immunotherapy with BTKis needs to be confirmed in clinical trials.


Blood ◽  
1982 ◽  
Vol 59 (4) ◽  
pp. 844-850 ◽  
Author(s):  
RP Witherspoon ◽  
LG Lum ◽  
R Storb ◽  
ED Thomas

Abstract Immunoglobulin secretion was studied in 37 patients between 19 and 106 days after allogeneic HLA-identical (30 patients), allogeneic one HLA- haplotype-identical (three patients), syngeneic (three patients), or autologous (one patient) marrow grafting. E rosette-positive (T) and E rosette-negative (non-T) peripheral blood mononuclear cells were cocultured with pokeweed mitogen for 6 days. Polyvalent immunoglobulin secretion was determined by counting plaque forming cells in a reverse hemolytic plaque assay. The number of antibody secreting cells in cocultures of autologous T and non-T lymphocytes was low in 40 of 44 tests conducted on samples from the 37 patients. Mononuclear or non-T cells from 38 of 40 tests failed to produce antibody when cultured with normal helper T cells. T cells from 23 of 37 tests failed to help normal non-T cells secrete antibody. T lymphocytes from 23 of 41 tests suppressed antibody production greater than 80% by normal T and non-T cells. The suppressor cells were radiosensitive in 17 of the 25 tests. The abnormal function of lymphocyte subpopulations in patients during the first 3 mo after syngeneic, allogeneic or autologous marrow grafting was similar regardless of the type of graft or the presence of acute graft versus host disease.


Blood ◽  
1994 ◽  
Vol 84 (3) ◽  
pp. 841-846 ◽  
Author(s):  
MR Silva ◽  
R Hoffman ◽  
EF Srour ◽  
JL Ascensao

Abstract Human natural killer (NK) cells comprise 10% to 15% of peripheral blood mononuclear cells and have an important role in immune responses against tumors, viral infections, and graft rejection. NK cells originate in bone marrow (BM), but their progenitors and lineage development have not been completely characterized. We studied the generation of NK cells from purified CD34+HLADR- and CD34+HLADR+ BM progenitors and the influence of various cytokines on their production. We show that CD3-CD56+ cytotoxic NK cells can develop from both progenitors populations when interleukin-2 (IL-2) is present in an in vitro suspension culture system containing IL-1 alpha and stem cell factor. Up to 83.8% and 98.6% CD3-CD56+ cells were detected in CD34+HLADR- and CD34+DR+ cultures, respectively, after 5 weeks of culture; significant numbers of NK cells were first detected after 2 weeks. Cytotoxic activity paralleled NK cell numbers; up to 70% specific lysis at an effector:target ratio of 10:1 was observed at 5 weeks. IL-7 also triggered development of CD3-CD56+ cells from these immature progenitors (up to 24% and 55% appeared in CD34+HLADR- and CD34+HLADR+ cultures, respectively). Our data suggest that BM stromas are not necessary for NK cell development and that IL-2 remains essential for this lineage development and differentiation.


2019 ◽  
Vol 20 (5) ◽  
pp. 1139 ◽  
Author(s):  
Tsui Mao ◽  
Carol Miao ◽  
Yi Liao ◽  
Ying Chen ◽  
Chia Yeh ◽  
...  

γδ-T-cells have attracted attention because of their potent cytotoxicity towards tumors. Most γδ-T-cells become activated via a major histocompatibility complex (MHC)-independent pathway by the interaction of their receptor, Natural Killer Group 2 Member D (NKG2D) with the tumor-specific NKG2D ligands, including MHC class I-related chain A/B (MICA/B) and UL16-binding proteins (ULBPs), to kill tumor cells. However, despite their potent antitumor effects, the treatment protocols specifically targeting ovarian tumors require further improvements. Ovarian cancer is one of the most lethal and challenging female malignancies worldwide because of delayed diagnoses and resistance to traditional chemotherapy. In this study, we successfully enriched and expanded γδ-T-cells up to ~78% from peripheral blood mononuclear cells (PBMCs) with mostly the Vγ9Vδ2-T-cell subtype in the circulation. We showed that expanded γδ-T-cells alone exerted significant cytotoxic activities towards specific epithelial-type OVCAR3 and HTB75 cells, whereas the combination of γδ-T cells and pamidronate (PAM), a kind of aminobisphosphonates (NBPs), showed significantly enhanced cytotoxic activities towards all types of ovarian cancer cells in vitro. Furthermore, in tumor xenografts of immunodeficient NSG mice, γδ-T-cells not only suppressed tumor growth but also completely eradicated preexisting tumors with an initial size of ~5 mm. Thus, we concluded that γδ-T-cells alone possess dramatic cytotoxic activities towards epithelial ovarian cancers both in vitro and in vivo. These results strongly support the potential of clinical immunotherapeutic application of γδ-T-cells to treat this serious female malignancy.


Blood ◽  
1988 ◽  
Vol 72 (3) ◽  
pp. 956-963
Author(s):  
GC Barbano ◽  
A Schenone ◽  
S Roncella ◽  
R Ghio ◽  
A Corcione ◽  
...  

Abstract Human peripheral blood mononuclear cells (PBMC) were stimulated in vitro with anti-lymphocyte globulin (ALG), and the phenotypic and functional properties of the blasts obtained were investigated. When stained with monoclonal antibodies (MoAbs), all of the blasts were identified as T cells that expressed predominantly the CD4 phenotype (70% of the cells). The remaining blasts were CD8+. These findings demonstrate that ALG stimulates both helper-inducer and cytotoxic- suppressor cells at random since the CD4 to CD8 ratio in the stimulated blasts was the same as in resting PBMC. This ratio is different from that observed in short-term cultures of T cells stimulated with phytohemagglutinin (PHA) under the same conditions (CD4 to CD8 ratio less than 1). ALG-stimulated T cells were cloned by limiting dilution in the presence of recombinant Interleukin-2 (rIL-2). The clones obtained were expanded and maintained in long term cultures with rIL-2. Thirty-two clones were tested for their capacity of producing colony stimulating activity (CSA) or burst promoting activity (BPA). Twenty- eight of them produced CSA and 12 produced BPA. No correlation was found between the surface phenotype and the ability of the clones to produce CSA or BPA (ie, both the CD4+ and CD8+ clones released the cytokines). When 16 of the same clones were tested for II-2 and gamma interferon (gamma IFN) production, 12 were found to be gamma INF and IL- 2 producers. All of the gamma IFN producers also released IL-2, whereas in the single clones no correlation was found with the capacity of releasing BPA and CSA. Supernatants from selected T-cell clones were also tested for hematopoietic growth factor activities in the presence of neutralizing antisera to human granulocyte-macrophage colony stimulating factor (GM-CSF) or to Interleukin-3 (IL-3). It was found that most CSA was attributable to GM-CSF, whereas BPA was mainly related to the presence of IL-3.


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