Stem cell mobilization with G-CSF analogs: a rational approach to separate GVHD and GVL?

The separation of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) remains the “holy grail” of allogeneic stem cell transplantation, and improvements are urgently needed to allow more effective therapy of malignant disease. The use of G-CSF–mobilized peripheral blood as a clinical stem cell source is associated with enhanced GVL effects without amplification of significant acute GVHD. Preclinical studies have demonstrated that G-CSF modulates donor T cell function before transplantation, promoting TH2 differentiation and regulatory T cell function. In addition, the expansion of immature antigen-presenting cells (APCs) and plasmacytoid dendritic cells (DCs) favors the maintenance of this pattern of T cell differentiation after transplantation. Although these patterns of T cell differentiation attenuate acute GVHD, they do not have an impact on the cytolytic pathways of the CD8+ T cells that are critical for effective GVL. Recently, it has been demonstrated that modification of G-CSF, either by pegylation of the native cytokine or conjugation to Flt-3L, results in the expansion and activation of donor iNKT cells, which significantly augment CD8+ T cell–mediated cytotoxicity and GVL effects after transplantation. Given that these cytokines also enhance the expansion of regulatory T cells and APCs, they further separate GVHD and GVL, offering potential clinical advantages for the transplant recipient.

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Ontogeny of T cell function: Generation of cytotoxic function in T cells as a model for terminal cell differentiation

Developmental & Comparative Immunology ◽

10.1016/s0145-305x(78)80002-0 ◽

1978 ◽

Vol 2 (3) ◽

pp. 393-407 ◽

Cited By ~ 1

Author(s):

William R. Clark

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Cell Function ◽

Terminal Cell ◽

Function Generation ◽

T Cell Function ◽

Cytotoxic Function

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Trib1 regulates T cell differentiation during chronic infection by restraining the effector program

Journal of Experimental Medicine ◽

10.1084/jem.20190888 ◽

2020 ◽

Vol 217 (5) ◽

Author(s):

Kelly S. Rome ◽

Sarah J. Stein ◽

Makoto Kurachi ◽

Jelena Petrovic ◽

Gregory W. Schwartz ◽

...

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Cell Function ◽

T Cell Differentiation ◽

Negative Regulator ◽

Chronic Infections ◽

Tcr Signaling ◽

Viral Control ◽

Cell Immunity

In chronic infections, the immune response fails to control virus, leading to persistent antigen stimulation and the progressive development of T cell exhaustion. T cell effector differentiation is poorly understood in the context of exhaustion, but targeting effector programs may provide new strategies for reinvigorating T cell function. We identified Tribbles pseudokinase 1 (Trib1) as a central regulator of antiviral T cell immunity, where loss of Trib1 led to a sustained enrichment of effector-like KLRG1+ T cells, enhanced function, and improved viral control. Single-cell profiling revealed that Trib1 restrains a population of KLRG1+ effector CD8 T cells that is transcriptionally distinct from exhausted cells. Mechanistically, we identified an interaction between Trib1 and the T cell receptor (TCR) signaling activator, MALT1, which disrupted MALT1 signaling complexes. These data identify Trib1 as a negative regulator of TCR signaling and downstream function, and reveal a link between Trib1 and effector versus exhausted T cell differentiation that can be targeted to improve antiviral immunity.

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Restoration of HBV-specific CD8+ T cell function by PD-1 blockade in inactive carrier patients is linked to T cell differentiation

Journal of Hepatology ◽

10.1016/j.jhep.2014.07.005 ◽

2014 ◽

Vol 61 (6) ◽

pp. 1212-1219 ◽

Cited By ~ 134

Author(s):

Bertram Bengsch ◽

Bianca Martin ◽

Robert Thimme

Keyword(s):

Cell Differentiation ◽

T Cell ◽

Cell Function ◽

Cd8 T Cell ◽

T Cell Differentiation ◽

Inactive Carrier ◽

T Cell Function

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Enhanced T Cell Function in Patients with Hematological Malignanicies Undergoing Mobilization for Autologous Stem Cell Transplantation.

Blood ◽

10.1182/blood.v110.11.3288.3288 ◽

2007 ◽

Vol 110 (11) ◽

pp. 3288-3288

Author(s):

Adriana I. Colovai ◽

Joseph Schwartz ◽

Ronit Slotky ◽

Zhouru Liu ◽

Jianshe Fan ◽

...

Keyword(s):

T Cells ◽

Stem Cell ◽

T Cell ◽

Cell Function ◽

Stem Cell Mobilization ◽

Cell Reactivity ◽

Hematopoietic Stem ◽

Gm Csf ◽

T Cell Function ◽

Cell Mobilization

Abstract Various regimens used for hematopoietic stem cell mobilization have been optimized to mobilize a maximum number of CD34+ hematopoietic stem cells (HSC) into the peripheral blood. However, the effects of mobilization regimens on other bone marrow derived cell populations have not been carefully examined. Since T cells from HSC grafts play an important role in anti-tumor responses, we studied T cell function in 11 adult patients with hematological malignancies undergoing mobilization for autologous stem cell transplantation (SCT). Mobilization regimens consisted of G-CSF alone (3 patients) or in combination with: GM-CSF (1 patient), chemotherapy (2), GM-CSF and chemotherapy (3), or AMD3100 (2). T cell function was determined using ImmuKnow (Cylex) assay, an FDA approved test, which measures immune cell function in whole blood by quantifying the amount of ATP released by PHA-stimulated CD4+ T helper (Th) cells. Prior to mobilization treatment, average Th reactivity was 242±128 ng ATP/ml (normal range: 200–525 ng ATP/ml). With mobilization, Th reactivity increased gradually in all patients, reaching peak reactivity values (>525 ng ATP/ml) on day 4–6 of treatment. Efficient stem cell mobilization (≥10 CD34+ cells/ul of blood) was accomplished in 8 out of 11 patients. These 8 patients exhibited an average Th peak reactivity level of 701±126 ng ATP/ml. Stem cell mobilization failed in the remaining 3 patients (<10 CD34+ cells/ul). Two of these patients had received AMD3100 (a CXCR4 inhibitor) and G-CSF, and showed unusually high ATP levels (>1000 ng/ml). Chi-Square analysis indicated that there was an inverse correlation between CD34 stem cell counts and peak ATP levels (p=0.01). However, there was no direct relationship between the number of CD3+ or CD3+CD4+ T cells and Th reactivity. Immunophenotypic studies performed in 4 patients with CD34 counts ≥10 cells/ul and 2 patients with CD34 counts <10 cells/ul indicated that the agents used for stem cell mobilization triggered the expansion of CD4+CD25+ T cell population. However, the vast majority of these T cells did not co-express FoxP3, the characteristic marker of regulatory T cells, consistent with the enhanced T cell reactivity detected in these patients. It, therefore, results that mobilization agents have a “priming” effect on CD4+ T helper cells, inducing their robust activation. This effect may lead to improved anti-tumor surveillance and might contribute to the higher rate of complete remission and overall survival observed in patients with hematological malignancies, who have received autologous SCT in addition to chemotherapy. Thus, monitoring of T cell reactivity by Immuknow assay might help tailor therapy to maximize the patient’s potential to mount an immune response against the tumor and, at the same time, obtain efficient stem cell mobilization.

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Akt-Fas to Quell Aberrant T Cell Differentiation and Apoptosis in Covid-19

Frontiers in Immunology ◽

10.3389/fimmu.2020.600405 ◽

2020 ◽

Vol 11 ◽

Author(s):

Anthony J. Leonardi ◽

Rui B. Proenca

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Cell Function ◽

T Cell Differentiation ◽

Serine Threonine Kinase ◽

Cell Proliferation And Differentiation ◽

Proliferation And Differentiation ◽

T Cell Lymphopenia ◽

Infected Cells

Aberrant T cell differentiation and lymphopenia are hallmarks of severe COVID-19 disease. Since T cells must race to cull infected cells, they are quick to differentiate and achieve cytotoxic function. With this responsiveness, comes hastened apoptosis, due to a coupled mechanism of death and differentiation in both CD4+ and CD8+ lymphocytes via CD95 (Fas) and serine-threonine kinase (Akt). T cell lymphopenia in severe cases may represent cell death or peripheral migration. These facets depict SARS-Cov-2 as a lympho-manipulative pathogen; it distorts T cell function, numbers, and death, and creates a dysfunctional immune response. Whether preservation of T cells, prevention of their aberrant differentiation, and expansion of their population may alter disease course is unknown. Its investigation requires experimental interrogation of the linked differentiation and death pathway by agents known to uncouple T cell proliferation and differentiation in both CD4+ and CD8+ T cells.

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Akt Fas to Quell Aberrant T Cell Differentiation and Death in Covid-19

10.31219/osf.io/2egsm ◽

2020 ◽

Author(s):

Anthony Joseph Leonardi

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Cell Function ◽

T Cell Differentiation ◽

Serine Threonine Kinase ◽

Cell Proliferation And Differentiation ◽

Proliferation And Differentiation ◽

Hastened Death ◽

Infected Cells

Aberrant T cell differentiation and lymphopenia are hallmarks of severe COVID-19 disease. Since T cells must race to cull infected cells, they are quick to differentiate and achieve cytotoxic function. With this responsiveness, unfortunately, comes hastened death, due to a coupled mechanism of death and differentiation in both CD4+ and CD8+ lymphocytes via CD95 (Fas) and serine-threonine kinase (Akt). T cell lymphopenia in severe cases may represent cell death or peripheral migration. These facets depict SARS-Cov-2 as a lympho-manipulative pathogen; it distorts T cell function, numbers, and death, and creates a dysfunctional immune response. Whether preservation of T cells, prevention of their differentiation, and expansion of their population may alter disease course is unknown. Its investigation requires experimental interrogation of the linked differentiation and death pathway by agents known to uncouple T cell proliferation and differentiation in both CD4+ and CD8+ T cells.

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158 Inhibition of PI3Kδ improves tumor specific T cell immunity and metabolic fitness

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0158 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A172-A172

Author(s):

Guillermo Rangel Rivera ◽

Guillermo Rangel RIvera ◽

Connor Dwyer ◽

Dimitrios Arhontoulis ◽

Hannah Knochelmann ◽

...

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Cell Therapy ◽

Tumor Immunity ◽

Mitochondrial Function ◽

T Cell Differentiation ◽

Tumor Control ◽

T Cell Therapy

BackgroundDurable responses have been observed with adoptive T cell therapy (ACT) in some patients. However, current protocols used to expand T cells often exhibit suboptimal tumor control. Failure in these therapies has been attributed to premature differentiation and impaired metabolism of the infused T cells. Previous work done in our lab showed that reduced PI3Kδ signaling improved ACT. Because PI3Kγ and PI3Kδ have critical regulatory roles in T cell differentiation and function, we tested whether inhibiting PI3Kγ could recapitulate or synergize PI3Kδ blockade.MethodsTo test this, we primed melanoma specific CD8+ pmel-1 T cells, which are specific to the glycoprotein 100 epitope, in the presence of PI3Kγ (IPI-459), PI3Kδ (CAL101 or TGR-1202) or PI3Kγ/δ (IPI-145) inhibitors following antigen stimulation with hgp100, and then infused them into 5Gy total body irradiated B16F10 tumor bearing mice. We characterized the phenotype of the transferred product by flow cytometry and then assessed their tumor control by measuring the tumor area every other day with clippers. For metabolic assays we utilized the 2-NBDG glucose uptake dye and the real time energy flux analysis by seahorse.ResultsSole inhibition of PI3Kδ or PI3Kγ in vitro promoted greater tumor immunity and survival compared to dual inhibition. To understand how PI3Kδ or PI3Kγ blockade improved T cell therapy, we assessed their phenotype. CAL101 treatment produced more CD62LhiCD44lo T cells compared to IPI-459, while TGR-1202 enriched mostly CD62LhiCD44hi T cells. Because decreased T cell differentiation is associated with mitochondrial metabolism, we focused on CAL101 treated T cells to study their metabolism. We found that CAL101 decreased glucose uptake and increased mitochondrial respiration in vitro, indicating augmented mitochondrial function.ConclusionsThese findings indicate that blocking PI3Kδ is sufficient to mediate lasting tumor immunity of adoptively transferred T cells by preventing premature differentiation and improving mitochondrial fitness. Our data suggest that addition of CAL101 to ACT expansion protocols could greatly improve T cell therapies for solid tumors by preventing T cell differentiation and improving mitochondrial function.

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Potential Antiinflammatory Role of Insulin via the Preferential Polarization of Effector T Cells toward a T Helper 2 Phenotype

Endocrinology ◽

10.1210/en.2006-0686 ◽

2007 ◽

Vol 148 (1) ◽

pp. 346-353 ◽

Cited By ~ 95

Author(s):

Alexander Viardot ◽

Shane T. Grey ◽

Fabienne Mackay ◽

Donald Chisholm

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Insulin Receptor ◽

T Cell Differentiation ◽

Receptor Expression ◽

T Helper ◽

Type Response ◽

Helper Type

Hyperglycemia in critical illness is a common complication and a strong independent risk factor for morbidity and death. Intensive insulin therapy decreases this risk by up to 50%. It is unclear to what extent this benefit is due to reversal of glucotoxicity or to a direct effect of insulin, because antiinflammatory effects of insulin have already been described, but the underlying mechanisms are still poorly understood. The insulin receptor is expressed on resting neutrophils, monocytes, and B cells, but is not detectable on T cells. However, significant up-regulation of insulin receptor expression is observed on activated T cells, which suggests an important role during T cell activation. Exogenous insulin in vitro induced a shift in T cell differentiation toward a T helper type 2 (Th2)-type response, decreasing the T helper type 1 to Th2 ratio by 36%. This result correlated with a corresponding change in cytokine secretion, with the interferon-γ to IL-4 ratio being decreased by 33%. These changes were associated with increased Th2-promoting ERK phosphorylation in the presence of insulin. Thus, we demonstrate for the first time that insulin treatment influences T cell differentiation promoting a shift toward a Th2-type response. This effect of insulin in changing T cell polarization may contribute to its antiinflammatory role not only in sepsis, but also in chronic inflammation associated with obesity and type 2 diabetes.

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