Effector Cytokine Production Research Articles

IgG targeting distinct seasonal coronavirus- conserved SARS-CoV-2 spike subdomains correlates with differential COVID-19 disease outcomes.

Despite SARS-CoV-2 being a “novel” virus, early detection of anti-spike IgG in severe COVID-19 patients may be caused by the amplification of humoral memory responses against seasonal coronaviruses. Here, we examine this phenomenon by characterizing anti-spike IgG responses in non-hospitalized convalescent individuals across a spectrum of COVID-19 severity. We observe that disease severity positively correlates with anti-spike IgG levels, IgG cross-reactivity against other betacoronaviruses (β-CoVs), and FcγR activation. Analysis of IgG targeting β-CoV-conserved and non-conserved immunodominant epitopes within the SARS-CoV-2 spike protein revealed epitope-specific relationships: IgG targeting the conserved heptad repeat (HR) 2 region significantly correlates with milder disease, while targeting the conserved S2′FP region correlates with more severe disease. Furthermore, a lower HR2-to-S2′FP IgG-binding ratio correlates with greater disease severity, with ICU-hospitalized COVID-19 patients showing the lowest HR2/S2′FP ratios. These findings suggest that HR2/S2′FP IgG profiles may predict disease severity and offer insight into protective versus deleterious humoral recall responses.

Dietary iron deficiency impairs the functionality but not generation or establishment of memory T cells following influenza infection

Abstract Protection from viral respiratory tract infections (VRTIs) is dependent on the activation, differentiation, and maintenance of antigen specific memory T cells. Iron is essential for fundamental metabolic processes in the human body, with iron deficiency, the most prevalent micronutrient deficiency worldwide, resulting in increased morbidity and mortality to VRTIs. The role of iron in the establishment and maintenance of memory T cells is not fully defined. Using a murine model of dietary iron modulation, we define the impact of iron deficiency on anti-viral T cell memory formation, functionality, and resultant protection during primary and heterosubtypic influenza infections. Multi-parameter flow cytometry and stimulation assays were performed on T cells isolated from lung and spleen at effector and memory time points following primary (X31) infection, as well as 5 days post heterosubtypic (PR8) challenge. Strikingly, there was no significant difference in the numbers or proportions of CD4+ and CD8+ influenza specific memory T-cells at any time point when comparing iron deficient to iron replete mice. However, memory T cells generated by iron deficient mice displayed impaired production of key effector cytokines, most notably IFN-γ and IL-17a. Importantly, following heterosubtypic challenge, iron deficient mice exhibited increased morbidity, as defined by increased weight loss, and significantly diminished IFN-γ production by T cells across all sites. This work reveals that distinct iron profiles did not interfere with the generation or maintenance of influenza specific T cells but iron deficiency significantly impacts memory T cell anti-viral functionality resulting in impaired protective responses. Supported by -K23 AI141686 -UL1 TR001873

A temporal switch in T follicular helper cells controls the output of the GC response to influenza

Abstract T follicular helper (Tfh) cells are a specific subset of CD4 T cells that localize in the B cell follicle and are essential for the Germinal Center (GC) response. Under polarizing environments, Tfh cells produce effector cytokines, including IFN-γ and IL-4. Beyond promoting class switching, the role played by the different subsets of cytokine-producing Tfh cells remains largely unexplored. Using an influenza infection model, we show here that Tfh cells switch from producing IFN-γ early after infection to mainly producing IL-4 at later time points. Importantly, IFN-γ and IL-4-producing Tfh cells differently control the GC B cell response to influenza. Whereas IL-4-producing Tfh cells help GC maintenance late after infection, interaction with IFN-γ producing Tfh cells skews the GC B cell response towards the memory differentiation pathway early after infection. Consequently, lung-memory B cells fail to differentiate in the absence of IFN-γ producing Tfh cells. Collectively, our results support a model in which temporary changes in cytokine production by Tfh cells dynamically control the outcome of the GC response. Hence, our data provide new insights into GC fate decisions following influenza infection. Supported by grants from NIH (R56 AI162698, R01 AI110480)

Optimal CD8+ T cell effector function requires costimulation-induced RNA-binding proteins that reprogram the transcript isoform landscape

Abstract Boosting T cell activation through costimulation directs defense against cancer and viral infections. Despite many studies targeting costimulation in clinical trials, the increased potency and reprogramming of T cells endowed by costimulation is poorly understood. Canonical dogma states that transcription mediates T cell activation. Here, we show that the spliceosome, controlling post-transcriptional alternative splicing and alternative polyadenylation, is the most significantly enriched pathway in T cells after CD134/CD137 costimulation. Costimulation of CD8+ T cells significantly increased expression of 29 RNA-binding proteins (RBPs) while RNA-seq uncovered over 1000 differential alternative splicing and polyadenylation events. Using in vivo mouse and in vitro human CRISPR models, we demonstrate that RBP Tardbp, among multiple other RBPs, is required for effector cytokine production, CD8+ T cell clonal expansion, and isoform regulation after costimulation. The prospect of immune response optimization through reprogramming of mRNA isoform production offered herein opens new avenues for experimentally and therapeutically tuning the activities of T cells. Supported by NIH grants AI136955 and R21AI139891.

The neuropeptide VIP potentiates intestinal innate type 2 and type 3 immunity in response to feeding.

The nervous system and the immune system both rely on an extensive set of modalities to perceive and act on perturbations in the internal and external environments. During feeding, the intestine is exposed to nutrients that may contain noxious substances and pathogens. Here we show that Vasoactive Intestinal Peptide (VIP), produced by the nervous system in response to feeding, potentiates the production of effector cytokines by intestinal type 2 and type 3 innate lymphoid cells (ILC2s and ILC3s). Exposure to VIP alone leads to modest activation of ILCs, but strongly potentiates ILCs to concomitant or subsequent activation by the inducer cytokines IL-33 or IL-23, via mobilization of cAMP and energy by glycolysis. Consequently, VIP increases resistance to intestinal infection by the helminth Trichuris muris and the enterobacteria Citrobacter rodentium. These findings uncover a functional neuro-immune crosstalk unfolding during feeding that increases the reactivity of innate immunity necessary to face potential threats associated with food intake.

Lack of Induction of RBD-Specific Neutralizing Antibodies despite Repeated Heterologous SARS-CoV-2 Vaccination Leading to Seroconversion and Establishment of T Cell-Specific Memory in a Patient in Remission of Multiple Myeloma.

Background: Prophylactic vaccination against infectious diseases may induce a state of long-term protection in the otherwise healthy host. However, the situation is less predictable in immunocompromised patients and may require adjustment of vaccination schedules and/or basic therapy. Methods: A patient in full remission of multiple myeloma since the last three years and on long-term maintenance therapy with pomalidomide, a drug inhibiting angiogenesis and myeloma cell growth, was vaccinated twice with Comirnaty followed by two vaccinations with Vaxzevria. Seroconversion and SARS-CoV-2-specific cellular responses were monitored. Results: No signs of seroconversion or T cellular memory were observed after the first “full immunization” with Comirnaty. Consequently, long-term-maintenance therapy with Pomalidomide was stopped and two additional shots of Vaxzevria were administered after which the patient seroconverted with Spike(S)-protein specific antibody levels reaching 49 BAU/mL, mild S-peptide pool-specific T cell proliferation, effector cytokine production (IL-2, IL-13), and T cellular activation with increased numbers of CD3+CD4+CD25+ T cells as compared to vaccinated and non-vaccinated control subjects. However, despite suspension of immunosuppression and administration of in total four consecutive heterologous SARS-CoV-2 vaccine shots, the patient did not develop neutralizing RBD-specific antibodies. Conclusions: Despite immunomonitoring-based adjustment of vaccination and/or therapy schedules vaccination success, with clear correlates of protection, the development of RBD-specific antibodies could not be achieved in the immunocompromised patient with current SARS-CoV-2 vaccines. Thus, our report emphasizes the need for improved active and passive immunization strategies for SARS-CoV-2 infections.

Nicotinamide breaks effector CD8 T cell responses by targeting mTOR signaling

SummaryNicotinamide (NAM) shapes T cell responses but its precise molecular mechanism of action remains elusive. Here, we show that NAM impairs naive T cell effector transition but also effector T cells themselves. Although aerobic glycolysis is a hallmark of activated T cells, CD8+ T cells exposed to NAM displayed enhanced glycolysis, yet producing significantly less IFNγ. Mechanistically, NAM reduced mTORC1 activity independently of NAD+ metabolism, decreasing IFNγ translation and regulating T cell transcriptional factors critical to effector/memory fate. Finally, the role of NAM in a biomedically relevant model of lung injury was tested. Specifically, a NAM-supplemented diet reduced systemic IL-2, antigen-specific T cell clonal expansion, and effector function after inhalation of Staphylococcus aureus enterotoxin A. These findings identify NAM as a potential therapeutic supplement that uncouples glycolysis from effector cytokine production and may be a powerful treatment for diseases associated with T cell hyperactivation.

Genetically targeting the BATF family transcription factors BATF and BATF3 in the mouse abrogates effector T cell activities and enables long-term heart allograft survival

T cells must be activated and become effectors first before executing allograft rejection, a process that is regulated by diverse signals and transcription factors. In this study, we studied the basic leucine zipper ATF-like transcription factor (BATF) family members in regulating T cell activities in a heart transplant model and found that mice deficient for both BATF and BATF3 (Batf-/- Batf3-/- mice) spontaneously accept the heart allografts long-term without tolerizing therapies. Similarly, adoptive transfer of wild type T cells into Rag1-/- hosts induced prompt rejection of heart and skin allografts, whereas the Batf-/- Batf3-/- T cells failed to do so. Analyses of graft-infiltrating cells showed that Batf-/- Batf3-/- T cells infiltrate the graft but fail to acquire an effector phenotype (CD44high KLRG1+ ). Co-transfer experiments in a T cell receptor transgenic TEa model revealed that the Batf-/- Batf3-/- T cells fail to expand in vivo, retain a quiescent phenotype (CD62L+ CD127+ ), and unable to produce effector cytokines to alloantigen stimulation, which contrasted sharply to that of wild type T cells. Together, our data demonstrate that the BATF and BATF3 are critical regulators of T effector functions, thus making them attractive targets for therapeutic interventions in transplant settings.

D2HGDH-mediated D2HG catabolism enhances the anti-tumor activities of CAR-T cells in an immunosuppressive microenvironment

The effect of immunotherapy is limited by oncometabolite D-2-hydroxyglutarate (D2HG). D2HGDH is an inducible enzyme that converts D2HG into the endogenous metabolite 2-oxoglutarate. We aimed to evaluate the impairment of CD8T lymphocyte function in the high-D2HG environment and to explore the phenotypic features and anti-tumor effect of D2HGDH-modified CAR-T cells. D2HG treatment inhibited the expansion of human CD8T lymphocytes and CAR-T cells, increased their glucose uptake, suppressed effector cytokine production, and decreased the central memory cell proportion. D2HGDH-modified CAR-T cells displayed distinct phenotypes, as D2HGDH knock-out (KO) CAR-T cells exhibited a significant decrease in central memory cell differentiation and intracellular cytokine production, while D2HGDH over-expression (OE) CAR-T cells showed predominant killing efficacy against NALM6 cancer cells in high-D2HG medium. Invivo xenograft experiments confirmed that D2HGDH-OE CAR-T cells decreased serum D2HG and improved the overall survival of mice bearing NALM6 cancer cells with mutation IDH1. Our findings demonstrated that the immunosuppressive effect of D2HG and distinct phenotype of D2HGDH modified CAR-T cells. D2HGDH-OE CAR-T cells can take advantage of the catabolism of D2HG to foster Tcell expansion, function, and anti-tumor effectiveness.

EFFECT OF ANDROGENS ON IMMUNE CELLS

I recent years, much attention of researchers has been paid to the role of testosterone in the regulation of immune cells and its influence on the course of autoimmune diseases and inflammatory diseases. Better understanding of testosterone-regulated cellular and molecular pathways and the role of androgens in stimulating tissue-specific differences in inflammation susceptibility can lead to the development of innovative treatment strategies for a variety of diseases depending on gender. The aim of this study is to analyze the latest research on the effect of androgens on immunocompetent cells. Sex differences in the functions of the immune system are genetically determined and mediated by the action of male and female sex hormones. Myeloid immune cells express sex hormone receptors and are sensitive to sex hormones. Androgens, including dihydrotestosterone and testosterone, inhibit the activity of immune cells. Effects of testosterone restricts the activity of NK cells, the surface expression of TLR4 on macrophages, the synthesis of proinflammatory products, including TNF-α and nitric oxide synthase, and the formation of leukotriene in neutrophils. Androgens also affect inducing stimuli that regulate the activity of monocyte-macrophages. Testosterone controls complement activation. Androgens have a suppressive effect on the expression of proinflammatory cytokines, reduce the production of prostaglandin E2 in monocytes. The presence of androgen receptors is important factor in regulating neutrophil differentiation. Androgen receptors regulate, first of all, the transition between the proliferation of precursors (myeloblasts, promyelocytes and myelocytes) and the maturation of neutrophils (metamyelocytes, band and segmented neutrophils). The number and activity of cells associated with innate immunity differ between the sexes. Males have a higher natural killer (NK) percentage than females. Phagocytic activity of neutrophils and macrophages in women is higher than in men. Antigen-presenting cells in women are more efficiently presented by peptides than in men. Sex differences are also observed in innate lymphoid cells, which are lymphocytes that regulate a number of tissue immune responses by producing effector cytokines.

Characterization of SARS-CoV-2-Specific Humoral and Cellular Immune Responses Induced by Inactivated COVID-19 Vaccines in a Real-World Setting.

While the immunogenicity of inactivated vaccines against coronavirus disease 2019 (COVID‐19) has been characterized in several well-conducted clinical trials, real-world evidence concerning immune responses against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) raised by such vaccines is currently missing. Here, we comprehensively characterized various parameters of SARS-CoV-2-specific cellular and humoral immune responses induced by inactivated COVID-19 vaccines in 126 individuals under real-world conditions. After two doses of vaccination, S-receptor binding domain IgG (S-RBD IgG) and neutralizing antibody (NAb) were detected in 87.06% (74/85) and 78.82% (67/85) of individuals, respectively. Female participants developed higher concentrations of S-RBD IgG and NAb compared to male vaccinees. Interestingly, a longer dosing interval between the first and second vaccination resulted in a better long-term SARS-CoV-2 S-RBD IgG response. The frequencies of CD4+ T cells that produce effector cytokines (IFN-γ, IL-2, and TNF-α) in response to stimulation with peptide pools corresponding to the SARS-CoV-2 spike (S), nucleocapsid (N) or membrane (M) protein were significantly higher in individuals received two doses of vaccine than those received one dose of vaccine and unvaccinated individuals. S, N, or M-specific CD4+ and CD8+ T cell responses were detectable in 95.83% (69/72) and 54.16% (39/72) of double-vaccinated individuals, respectively. The longitudinal analysis demonstrated that CD4+ T cell responses recognizing S, N, and M waned quickly after a single vaccine dose, but were boosted and became more sustained following a second dose. Overall, we provide a comprehensive characterization of immune responses induced by inactivated COVID-19 vaccines in real-world settings, suggesting that both humoral and cellular SARS-CoV-2-specific immunity are elicited in the majority of individuals after two doses of inactivated COVID-19 vaccines.

ArgD of Mycobacterium tuberculosis is a functional N-acetylornithine aminotransferase with moonlighting function as an effective immune modulator

Mycobacterium tuberculosis (M. tuberculosis) encodes an essential enzyme acetyl ornithine aminotransferase ArgD (Rv1655) of arginine biosynthetic pathway which plays crucial role in M. tuberculosis growth and survival. ArgD catalyzes the reversible conversion of N-acetylornithine and 2 oxoglutarate into glutamate-5-semialdehyde and L-glutamate. It also possesses succinyl diaminopimelate aminotransferase activity and can thus carry out the corresponding step in lysine biosynthesis. These essential roles played by ArgD in amino acid biosynthetic pathways highlight it as an important metabolic chokepoint thus an important drug target. We showed that M. tuberculosis ArgD rescues the growth of ΔargD E. coli grown in minimal media validating its functional importance. Phylogenetic analysis of M. tuberculosis ArgD showed homology with proteins in gram positive bacteria, pathogenic and non-pathogenic mycobacteria suggesting the essentiality of this protein. ArgD is a secretory protein that could be utilized by M. tuberculosis to modulate host innate immunity as its moonlighting function. In-silico analysis predicted it to be a highly antigenic protein. The recombinant ArgD protein when exposed to macrophage cells induced enhanced production of pro-inflammatory cytokines TNF, IL6 and IL12 in a dose dependent manner. ArgD also induced the increased production of innate immune effector molecule NOS2 and NO in macrophages. We also demonstrated ArgD mediated activation of the canonical NFkB pathway. Notably, we also show that ArgD is a specific TLR4 agonist involved in the activation of pro-inflammatory signaling for sustained production of effector cytokines. Intriguingly, ArgD protein treatment activated macrophages to acquire the M1 phenotype through the increased surface expression of MHCII and costimulatory molecules CD80 and CD86. ArgD induced robust B-cell response in immunized mice, validating its antigenicity potential as predicted by the in-silico analysis. These properties of M. tuberculosis ArgD signify its functional plasticity that could be exploited as a possible drug target to combat tuberculosis.

Distinct exhaustion features of T lymphocytes shape the tumor-immune microenvironment with therapeutic implication in patients with non-small-cell lung cancer

BackgroundReinvigoration of T-cell exhaustion with antibodies has shown promising efficacy in patients with non-small-cell lung cancer (NSCLC). However, the characteristics of T-cell exhaustion with regard to tumor-infiltrating lymphocytes (TILs) are...

Solid Tumor Microenvironment Can Harbor and Support Functional Properties of Memory T Cells

Robust T cell responses are crucial for effective anti-tumor responses and often dictate patient survival. However, in the context of solid tumors, both endogenous T cell responses and current adoptive T cell therapies are impeded by the immunosuppressive tumor microenvironment (TME). A multitude of inhibitory signals, suppressive immune cells, metabolites, hypoxic conditions and limiting nutrients are believed to render the TME non-conducive to sustaining productive T cell responses. In this study we conducted an in-depth phenotypic and functional comparison of tumor-specific T cells and tumor-nonspecific bystander memory T cells within the same TME. Using two distinct TCR transgenic and solid-tumor models, our data demonstrate that despite exposure to the same cell-extrinsic factors of the TME, the tumor-nonspecific bystander CD8 T cells retain the complete panoply of memory markers, and do not share the same exhaustive phenotype as tumor-reactive T cells. Compared to tumor-specific T cells, bystander memory CD8 T cells in the TME also retain functional effector cytokine production capabilities in response to ex vivo cognate antigenic stimulation. Consistent with these results, bystander memory T cells isolated from tumors showed enhanced recall responses to secondary bacterial challenge in a T cell transplant model. Importantly, the tumor-resident bystander memory cells could also efficiently utilize the available resources within the TME to elaborate in situ recall effector functions following intra-tumoral peptide antigen injection. Additionally, CRISPR-Cas9 gene deletion studies showed that CXCR3 was critical for the trafficking of both tumor antigen-specific and bystander memory T cells to solid tumors. Collectively, these findings that T cells can persist and retain their functionality in distinct solid tumor environments in the absence of cognate antigenic stimulation, support the notion that persistent antigenic signaling is the central driver of T cell exhaustion within the TME. These studies bear implications for programming more efficacious TCR- and CAR-T cells with augmented therapeutic efficacy and longevity through regulation of antigen and chemokine receptors.

BET Inhibition As a Targeted Epigenetic Approach to Reverse T Cell Dysfunction in Chronic Lymphocytic Leukemia

Introduction: Chronic Lymphocytic Leukemia (CLL) is characterized by the clonal expansion of mature CD19+/CD5+ lymphocytes in the peripheral blood and secondary lymphoid organs. The accumulation of B-CLL cells yields profound immune defects in the CLL tumor microenvironment (TME), promoting evasion of immune surveillance that contributes to tumor persistence and thus relapsed/refractory disease. The bromodomain and extra-terminal domain (BET) family of proteins are epigenetic readers that bind acetylated histone residues to regulate transcription of numerous genes involved in critical CLL protumor pathways. Of the BET family proteins, BRD4 is overexpressed in CLL and highly enriched at super-enhancers of genes that regulate CLL-TME interactions such as B cell receptor pathway components, chemokine/cytokine receptors, and immune checkpoint molecules. Pan BET inhibitors (BET-i), such as PLX51107 (Plexxikon Inc.) significantly improve survival in aggressive CLL murine models. Here we demonstrate that blocking BRD4 function with PLX51107 (PLX5) can alleviate the inherent immune defects observed in CLL, hence reducing B-CLL induced T cell dysfunction and allowing for robust B-CLL cell elimination. This therapeutic strategy may be vital in overcoming frequent drug resistance and/or bolstering the anti-tumor effect of current CLL therapies.Methods: Primary leukemic B cells were isolated from the peripheral blood of CLL patients and co-cultured with healthy donor T cells to evaluate the effect of PLX5 (0.1-0.5μM) on CLL-induced T cell immunosuppression ex vivo via an array of flow cytometry assays. T cell proliferation was assessed using CFSE after 96 h co-culture with α-CD3/α-CD28 stimulation. Effector cytokine production was evaluated after 48 h co-culture in the presence of PMA/ionomycin (final 6 h) and brefeldin A (final 5 h). Immune inhibitory molecule surface expression was measured following 48 h co-culture with α-CD3/α-CD28 stimulation. To further validate our ex vivo findings, the E μ-TCL1 adoptive transfer model was used. Once disease onset was confirmed in recipient WT B6 mice (>10% CD45+/CD19+/CD5+ peripheral blood lymphocytes), mice were randomized to receive either PLX5 (20 mg/kg) or vehicle (VEH) equivalent daily by oral gavage for 4 weeks. Following treatment, mouse spleens were processed to evaluate exhaustion marker expression, T cell proliferation (CellTrace™ Violet, 72 h a-CD3/α-CD28 stimulation ex-vivo), and T-cell effector function (ex-vivo mitogenic stimulation, 6 h).Results: T cell proliferation indices were reduced following ex vivo co-culture with primary B-CLL cells (mean ± SEM for T cells vs. co-culture, 2.0 ± 0.13 vs. 1.57 ± 0.05; P<0.01). This suppression was significantly alleviated in 0.5μM PLX5-treated co-cultures (1.84 ± 0.08; P<0.01). In a similar fashion, the percentage of polyfunctional TNF-α+/IFN-γ+ CD4+ T cells markedly increased in PLX5-treated co-cultures (VEH vs. 0.5μM PLX5, 10.0% ± 0.76% vs. 15.2% ± 0.92%; P<0.01). Notably, BET inhibition with PLX5 also bolstered T cell inflammatory function (%TNF-α+/IFN-γ+) in the absence of B-CLL cells (VEH vs. PLX5, 12.9% ± 1.0% vs. 15.3% ± 0.69%; P<0.05). Remarkably, the expression of numerous immune inhibitory molecules (e.g., PDL1, PD1, CTLA4, LAG3) was consistently reduced between 1.8- and 3-fold in PLX5-treated co-cultures (0.1μM). In the adoptive transfer E μ-TCL1 model, mice receiving PLX5 displayed reduced expansion of B-CLL cells and increased T cell infiltration in the spleen (Fig. 1A). Splenic CD4+ T cells from PLX5-treated mice had significantly greater proliferative capacity (Fig. 1B) and pro-inflammatory functionality (Fig. 1C). Finally, PLX5 treatment markedly reduced the surface expression of immune inhibitory molecules (e.g., PDL1, LAG3, VISTA) on CD4+ and CD8+ T cells in the spleen (Fig. 1D). Studies to evaluate the effects of PLX5 on malignant B-CLL and T cells within the bone marrow niche and soluble factors in the plasma are ongoing. Collectively, our data indicate that the novel BET-i, PLX5, exerts beneficial immunomodulatory effects on T cells within the CLL TME.Conclusion: Epigenetic-targeted therapies such as BET-i have the potential to alleviate CLL-induced T cell dysfunction while eliminating B-CLL cells and preventing tumor expansion. Future profiling studies are pending to further illuminate how BET proteins regulate immune function in CLL. [Display omitted] DisclosuresLunning: AstraZeneca: Consultancy; Legend: Consultancy; Acrotech: Consultancy; ADC Therapeutics: Consultancy; Kyowa Kirin: Consultancy; Myeloid Therapeutics: Consultancy; Beigene: Consultancy; Celgene, a Bristol Myers Squibb Co.: Consultancy; Verastem: Consultancy; Janssen: Consultancy; Daiichi-Sankyo: Consultancy; Morphosys: Consultancy; TG Therapeutics: Consultancy; Novartis: Consultancy; Karyopharm: Consultancy; AbbVie: Consultancy; Spectrum: Consultancy; Kite, a Gilead Company: Consultancy. Vose: Kite, a Gilead Company: Honoraria, Research Funding. Powell: Plexxikon Inc.: Current Employment.

Bispecific Vγ9Vδ2-T and Type 1 NKT Cell Engager Lava-051 As First-in-Class Clinical Candidate to Target CD1d Expressing CLL, MM and AML

Bispecific Vγ9Vδ2-T and Type 1 NKT Cell Engager Lava-051 As First-in-Class Clinical Candidate to Target CD1d Expressing CLL, MM and AML

Terraflow, a New High Parameter Data Analysis Tool, Reveals Systemic T-Cell Exhaustion and Dysfunctional Cytokine Production in Classical Hodgkin Lymphoma

BackgroundClassical Hodgkin lymphoma (cHL) is characterized by rare, malignant Hodgkin/Reed Sternberg (HRS) cells that shape their microenvironment (TME) to inhibit anti-tumor immune response. Systemic immune dysregulation may influence treatment response and toxicity, but the systemic influence of the TME is less well described. The wide variety of proteins measured in high-parmater flow cytometry make it a powerful tool for immune monitoring, but presents challenges in immuno-monitoring. Combinatorial expression of these proteins defines cell types that may influence disease. TerraFlow is a fully automated data analysis platform that evaluates millions of phenotypes and selects the populations that best predict clinical variables. The analysis can be performed using classical Boolean gates or a non-gating approach that approximates gates without using manual thresholds, allowing immunophenotypes to be comprehensively surveyed for disease associations. The platform was used to find phenotypes that discriminate healthy versus cHL patients (AUC = 1) and pre versus post treatment patient phenotypes(AUC = 0.79).MethodsHuman Subjects: Informed consent was obtained from cHL patients (N=44) treated at the Perlmutter Cancer Center (PCC) at NYU Langone Health and New York Presbyterian Weil Cornell (NYP) between 2011 and 2016. Blood samples were drawn at multiple time-points, for this study pre-treatment and 3 month post-treatment samples were used. Age-matched, cryopreserved healthy donor PBMC (n=25) were obtained from STEMCELL Technologies (Cambridge, MA).Patient-derived blood was processed for isolation of PBMC, stained analyzed on a Symphony Flow Cytometer (BD Biosciences, San Jose, CA).Analysis: Data was analyzed using an original platform called terraFlow. Many immune cell subsets are defined by the combinations of proteins they express. TerraFlow systematically evaluates millions of cell types by generating every possible combination of 1 to 5 markers. A network-based algorithm then selects the “best” phenotype from each set of inter-related combinations based on statistical power and ease of interpretation. Each phenotype is defined using a minimal gating strategy that can be replicated in a diagnostic panel or cell sorter. Together, phenotypes describe all the major differences between patient groups. A new platform developed by Epistemic AI was used to mine scientific literature and interpret selected phenotypes.ResultsWe observed clear perturbations in the cHL systemic T-cell compartment pre-treatment as shown in Figure 1. These include higher levels of activated (CD278+), exhausted (CD366+, PD1+, CD152+), and suppressive (GITR+) T-cells compared to healthy donors, and diminished levels of T-cells producing effector cytokines (like IFNγ and IL4). Subsets of cytokine-producing cells that co-express markers of exhaustion (i.e., TNF+ CD366+ cells) are also elevated in cHL patients. Finally, T-cells expressing CD127 a receptor for IL7 involved in homeostatic renewal of cells and observed on naive and central memory T-cells are reduced. Taken together, these findings suggest that in cHL the systemic T-cell compartment is shifted toward a more exhausted profile, and away from less differentiated cells, with the potential for self-renewal. Our data also demonstrates a shift from T-helper 1 and T-helper 2 type toward T-helper 17 cells suggesting that T-cell effector function may be reduced.ConclusionUsing a novel data analysis platform, TerraFlow we demonstrate dysregulation in systemic T cell function in cHL patients pre-treatment that persists within 3 months of completing therapy. Associations of phenotypes with clinical variables, and post-treatment phenotypes will be described in detail at the meeting. Our results detail new immunotherapy and biomarker research targets, and suggest novel strategies for combination therapies. [Display omitted] DisclosuresLi: BD Bioscience: Current Employment. Ruan: Kite Pharma: Consultancy; AstraZeneca: Research Funding; BMS: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Pharmacyclics: Research Funding; Seagen: Consultancy. Diefenbach: Incyte: Research Funding; Trillium: Research Funding; Celgene: Research Funding; IGM Biosciences: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Gilead: Current equity holder in publicly-traded company; AbbVie: Research Funding; Perlmutter Cancer Center at NYU Langone Health: Current Employment; MEI: Consultancy, Research Funding; Genentech, Inc./ F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; IMab: Research Funding; Morphosys: Consultancy, Honoraria, Research Funding; Merck Sharp & Dohme: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding.

Targeting Pim2 for Improving T-Cell Effector Function and Promoting Cancer Immunotherapy

The Provirus Integration sites for Moloney murine leukemia virus (Pim) kinases are a highly conserved family of serine/threonine kinases. The Pim kinase family is composed of three different isoforms, Pim1, Pim2, and Pim3, which have been studied extensively in tumorigenesis and as a potential therapeutic target in various cancers. We previously reported an unexpected role of Pim2 in negatively regulates T-cell responses to alloantigen and tumor (JCI, 2015, PMID: 29781812). However, the mechanisms by which Pim2 modulates T-cell responses remain largely undefined. In the current study, using genetic Pim2-deficient mouse, we demonstrated a key role of Pim2 in regulating T-cell hemostatic and anti-tumor responses in aging, hematopoietic cell transplantation (HCT), and antigen-specific adoptive T-cell therapy (ACT). We observed that Pim2 was critical for T cells to retain quiescent in aged mice, as thymic Treg development was impaired while effector T-cell differentiation in lymphoid organs, including Tc1/Th1, Tc17/Th17 and follicular helper T cells, was increased in Pim2-deficient mice, but not in Pim1/Pim3-deficient mice. Furthermore, Pim2-deficient mice were capable to completely eradicate syngeneic breast cancer (NT2.5) growth (Figure A). During antigen specific anti-tumor response, adoptively transferred Pim2 -/- CD8 T cells showed enhanced ability for controlling established NT2.5 breast cancer and B16 melanoma (Figure B, C). Mechanistically, loss of Pim2 promoted G1 to S phase cell-cycle progression while reduced apoptosis in CD8 T cells. Pim2 -/- CD8 T cells exhibited elevated effector cytokine production while maintained higher levels of CD62L expression, leading to superior effector function, persistence and anti-tumor activity. Reduced differentiation of exhausted and suppressive subsets were observed in Pim2 -/- CD8 T cells after being adoptively transferred in tumor-bearing mice. In addition, Pim2 deficiency was associated with a higher metabolic potential, reflected by increased glycolysis and oxidative phosphorylation, which was at least partially attributed to a decreased level of autophagy in Pim2 -/- CD8 T cells. To further evaluate the clinical translation potential, we applied a Pim2-specific inhibitor (JP11646) and found that blocking Pim2 improved graft-versus-leukemia activity after autologous HCT and also enhanced CD8 T-cell mediated anti-melanoma effects after ACT in mice (Figure B, C). Furthermore, blocking Pim2 using JP11646 promoted human CD8 T-cell response during polyclonal stimulation and enhanced expansion, effector function and tumor killing ability of human melanoma antigen-specific CD8 T cells (data not shown) and CD19 CAR-T cells (Figure D). Our work demonstrated that Pim2 is a potent and distinct regulator of differentiation and maintenance of T effector cells through modulating metabolism and autophagy. Specifically target Pim2 can serve as a novel strategy for improving cancer immunotherapy. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Immune response in acute respiratory syndrome induced by the new coronavirus

Coronaviruses (CoVs) belong to the family Coronaviridae, which are enveloped and have a single-stranded RNA genome. The new coronavirus (SARS-CoV-2) is the seventh known coronavirus that can infect humans and cause serious illness, such as acute respiratory syndrome. The coronaviruses already identified have contributed to the understanding of the clinical manifestations caused by SARS-CoV-2, as well as their associations with the immune system. The aim of the present study was to carry out a narrative review of the literature on the host's immune response to infection by the new coronavirus. The review contains basic and summarized information on the main mechanisms involved in the immune response to SARS-CoV-2. The characteristics of the infection were considered according to the following: from the initial contact with the host through binding to angiotensin-converting enzyme 2 (ACE-2); the recognition of the pathogen by innate immunity cells; its containment mechanisms, including the production of effector cytokines and chemokines important in the development of the inflammatory process; and the participation of the complement system until the activation of the adaptive immune response. The probable occurrence of a host dysfunctional immune response and the escape mechanisms of the virus were also addressed. Despite numerous studies on the pathogenesis of SARS-CoV-2 infection, knowledge about the host's immune response in COVID-19 is not fully understood. The present work established the relationship between the new coronavirus and the immune system, but further studies are needed for all the mechanisms of the process to be elucidated.

Metformin reduces PD-L1 on tumor cells and enhances the anti-tumor immune response generated by vaccine immunotherapy

BackgroundPD-L1 is one of the major immune checkpoints which limits the effectiveness of antitumor immunity. Blockade of PD-L1/PD-1 has been a major improvement in the treatment of certain cancers, however,...