Inhibitory Markers Research Articles

Abstract 889: The efficacy and safety of PD-L1-specific CAR-T in advanced gastric cancer

Abstract [Purpose] Heterogeneity and the tumor microenvironment are major obstacles to overcoming incurable advanced gastric cancer (AGC). Although Epstein-Barr virus-positive and microsatellite instability subtypes can be detected early and properly treated, they are rare in AGC. In this regard, recent combinational therapy of immune checkpoint inhibitors (ICIs) such as PD-1/PD-L1 inhibitors and other various therapeutics has been tried, but there are clinically limited doses and drug resistance. We hypothesized that CAR-T targeting PD-L1, the common tumor-associated antigen (TAA), which expresses in most advanced cancer cells, would make a significant breakthrough in curing a solid tumor. This study aimed to evaluate the killing effects of anti-PD-L1 CAR-T against gastric cancer cell lines. Removal of PD-L1-expressing cells in the AGC TME will improve the clinical outcomes of current therapies. [Results] We constructed a second-generation PD-L1 CAR lentiviral vector targeting PD-L1, which has an intermediate affinity with PD-L1 in solid tumor TME. As the secondary signaling motif, CD28 was chosen and tested along with the CD3 zeta chain. The effector CAR-T, named Vax-CAR-T, specifically recognized the PD-L1-expressing AGC cell line, SNU638, and exhibited rapid and robust cytotoxic activity in vitro. When compared to untransduced T cells, the level of the CD25 activation marker was higher in Vax-CAR-T cells. Besides, the inhibitory markers of Tim3 and LAG3 were expressed even higher than the untransduced. Despite high Tim3 and LAG3 expression in the final manufacturing process, Vax-CAR-T cells significantly suppressed tumor growth in both bigger (>95mm3) and smaller (≤50mm3) AGC xenograft NSG mouse models. More importantly, Vax-CAR-T-treated mice have well tolerated the CAR-T therapy with no significant adverse events during the CRS monitoring period, 2 weeks after Vax-CAR-T injection and have gradually recovered weight gains 5 days after CAR-T cell injection. [Conclusion] We believe that a new autologous CAR-T targeting PD-L1 could be a promising new tool for removing heterogeneous solid tumors in TME, which would be a significant step forward in improving current conventional and immunotherapeutic strategies. Citation Format: Hye-Seong Park, Eun-Ji Choi, Jae-In Yu, Kyung-Sik Lee, Yeo-Jin Lim, Se-Ryeong Choi, Yoonjoo Choi, Bum Chan Park, Jae Eun Park, Mihwa Kim, Je-Jung Lee, Joon Haeng Rhee. The efficacy and safety of PD-L1-specific CAR-T in advanced gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 889.

The psychosis human connectome project: Design and rationale for studies of visual neurophysiology

Visual perception is abnormal in psychotic disorders such as schizophrenia. In addition to hallucinations, laboratory tests show differences in fundamental visual processes including contrast sensitivity, center-surround interactions, and perceptual organization. A number of hypotheses have been proposed to explain visual dysfunction in psychotic disorders, including an imbalance between excitation and inhibition. However, the precise neural basis of abnormal visual perception in people with psychotic psychopathology (PwPP) remains unknown. Here, we describe the behavioral and 7 tesla MRI methods we used to interrogate visual neurophysiology in PwPP as part of the Psychosis Human Connectome Project (HCP). In addition to PwPP (n = 66) and healthy controls (n = 43), we also recruited first-degree biological relatives (n = 44) in order to examine the role of genetic liability for psychosis in visual perception. Our visual tasks were designed to assess fundamental visual processes in PwPP, whereas MR spectroscopy enabled us to examine neurochemistry, including excitatory and inhibitory markers. We show that it is feasible to collect high-quality data across multiple psychophysical, functional MRI, and MR spectroscopy experiments with a sizable number of participants at a single research site. These data, in addition to those from our previously described 3 tesla experiments, will be made publicly available in order to facilitate further investigations by other research groups. By combining visual neuroscience techniques and HCP brain imaging methods, our experiments offer new opportunities to investigate the neural basis of abnormal visual perception in PwPP.

Voltage-gated calcium channel subunit α2δ-1 in spinal dorsal horn neurons contributes to aberrant excitatory synaptic transmission and mechanical hypersensitivity after peripheral nerve injury.

Neuropathic pain, an intractable pain symptom that occurs after nerve damage, is caused by the aberrant excitability of spinal dorsal horn (SDH) neurons. Gabapentinoids, the most commonly used drugs for neuropathic pain, inhibit spinal calcium-mediated neurotransmitter release by binding to α2δ-1, a subunit of voltage-gated calcium channels, and alleviate neuropathic pain. However, the exact contribution of α2δ-1 expressed in SDH neurons to the altered synaptic transmission and mechanical hypersensitivity following nerve injury is not fully understood. In this study, we investigated which types of SDH neurons express α2δ-1 and how α2δ-1 in SDH neurons contributes to the mechanical hypersensitivity and altered spinal synaptic transmission after nerve injury. Using in situ hybridization technique, we found that Cacna2d1, mRNA coding α2δ-1, was mainly colocalized with Slc17a6, an excitatory neuronal marker, but not with Slc32a1, an inhibitory neuronal marker in the SDH. To investigate the role of α2δ-1 in SDH neurons, we used clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system and showed that SDH neuron-specific ablation of Cacna2d1 alleviated mechanical hypersensitivity following nerve injury. We further found that excitatory post-synaptic responses evoked by electrical stimulation applied to the SDH were significantly enhanced after nerve injury, and that these enhanced responses were significantly decreased by application of mirogabalin, a potent α2δ-1 inhibitor, and by SDH neuron-specific ablation of Cacna2d1. These results suggest that α2δ-1 expressed in SDH excitatory neurons facilitates spinal nociceptive synaptic transmission and contributes to the development of mechanical hypersensitivity after nerve injury.

Antitumor effect of neoantigen-reactive T cells combined with PD1 inhibitor therapy in mouse lung cancer.

Neoantigens produced from mutations in tumors are important targets of T-cell-based immunotherapy and immune checkpoint blockade has been approved for treating multiple solid tumors. We investigated the potential benefit of adoptive neoantigen-reactive T (NRT) cells in combination with programmed cell death protein 1 inhibitor (anti-PD1) for treating lung cancer in a mouse model. NRT cells were prepared by co-culturing T cells and neoantigen-RNA vaccine-induced dendritic cells. Then, adoptive NRT cells in combination with anti-PD1 were administered to tumor-bearing mice. Pre- and post-therapy cytokine secretion, antitumor efficacy, and tumor microenvironment (TME) changes were determined both in vitro and in vivo. We successfully generated NRT cells based on the 5 neoantigen epitopes identified in this study. NRT cells exhibited an enhanced cytotoxic phenotype in vitro and the combination therapy led to attenuated tumor growth. In addition, this combination strategy downregulated the expression of the inhibitory marker PD-1 on tumor-infiltrating T cells and promoted the trafficking of tumor-specific T cells to the tumor sites. The adoptive transfer of NRT cells in association with anti-PD1 therapy can exert an antitumor effect on lung cancer, and is a feasible, effective, and novel immunotherapy regimen for treating solid tumors.

Modeling the marmoset brain using embryonic stem cell-derived cerebral assembloids

Studying the non-human primate (NHP) brain is required for the translation of rodent research to humans, but remains a challenge for molecular, cellular, and circuit-level analyses in the NHP brain due to the lack of in vitro NHP brain system. Here, we report an in vitro NHP cerebral model using marmoset (Callithrix jacchus) embryonic stem cell-derived cerebral assembloids (CAs) that recapitulate inhibitory neuron migration and cortical network activity. Cortical organoids (COs) and ganglionic eminence organoids (GEOs) were induced from cjESCs and fused to generate CAs. GEO cells expressing the inhibitory neuron marker LHX6 migrated toward the cortical side of CAs. COs developed their spontaneous neural activity from a synchronized pattern to an unsynchronized pattern as COs matured. CAs containing excitatory and inhibitory neurons showed mature neural activity with an unsynchronized pattern. The CAs represent a powerful in vitro model for studying excitatory and inhibitory neuron interactions, cortical dynamics, and their dysfunction. The marmoset assembloid system will provide an in vitro platform for the NHP neurobiology and facilitate translation into humans in neuroscience research, regenerative medicine, and drug discovery.

Decrease in cell counts and alteration of phenotype characterize peripheral NK cells of patients with anti-MDA5-positive dermatomyositis

ObjectiveTo investigate the levels and phenotypes of peripheral natural killer (NK) cells in anti-MDA5+ dermatomyositis (DM) patients, and their association with clinical features. MethodsPeripheral NK cell counts (NKCCs) were retrospectively collected from 497 patients with idiopathic inflammatory myopathies and 60 healthy controls. Multi-color flow cytometry was used to determine the NK cell phenotypes in additional 48 DM patients and 26 healthy controls. The association of NKCC and NK cell phenotypes with the clinical features and prognosis were analyzed in anti-MDA5+ DM patients. ResultsNKCC was significantly lower in anti-MDA5+ DM patients than in those with other IIM subtypes and healthy controls. A significant decrease in NKCC was associated with disease activity. Furthermore, NKCC < 27 cells/μL was an independent risk factor for 6-month mortality in anti-MDA5+ DM patients. In addition, identification of the functional phenotype of NK cells revealed significantly increased expression of the inhibitory marker CD39 in CD56brightCD16dimNK cells of anti-MDA5+ DM patients. CD39+NK cells of anti-MDA5+ DM patients showed increased expression of NKG2A, NKG2D, Ki-67, decreased expression of Tim-3, LAG-3, CD25, CD107a, and reduced TNF-α production. ConclusionDecreased cell counts and inhibitory phenotype are significant characteristics of peripheral NK cells in anti-MDA5+ DM patients.

Identification and validation of a novel survival prediction model based on the T-cell phenotype in the tumor immune microenvironment and peripheral blood for gastric cancer prognosis

BackgroundThe correlation and difference in T-cell phenotypes between peripheral blood lymphocytes (PBLs) and the tumor immune microenvironment (TIME) in patients with gastric cancer (GC) is not clear. We aimed to characterize the phenotypes of CD8+ T cells in tumor infiltrating lymphocytes (TILs) and PBLs in patients with different outcomes and to establish a useful survival prediction model.MethodsMultiplex immunofluorescence staining and flow cytometry were used to detect the expression of inhibitory molecules (IMs) and active markers (AMs) in CD8+TILs and PBLs, respectively. The role of these parameters in the 3-year prognosis was assessed by receiver operating characteristic analysis. Then, we divided patients into two TIME clusters (TIME-A/B) and two PBL clusters (PBL-A/B) by unsupervised hierarchical clustering based on the results of multivariate analysis, and used the Kaplan–Meier method to analyze the difference in prognosis between each group. Finally, we constructed and compared three survival prediction models based on Cox regression analysis, and further validated the efficiency and accuracy in the internal and external cohorts.ResultsThe percentage of PD-1+CD8+TILs, TIM-3+CD8+TILs, PD-L1+CD8+TILs, and PD-L1+CD8+PBLs and the density of PD-L1+CD8+TILs were independent risk factors, while the percentage of TIM-3+CD8+PBLs was an independent protective factor. The patients in the TIME-B group showed a worse 3-year overall survival (OS) (HR: 3.256, 95% CI 1.318–8.043, P = 0.006), with a higher density of PD-L1+CD8+TILs (P < 0.001) and percentage of PD-1+CD8+TILs (P = 0.017) and PD-L1+CD8+TILs (P < 0.001) compared to the TIME-A group. The patients in the PBL-B group showed higher positivity for PD-L1+CD8+PBLs (P = 0.042), LAG-3+CD8+PBLs (P < 0.001), TIM-3+CD8+PBLs (P = 0.003), PD-L1+CD4+PBLs (P = 0.001), and LAG-3+CD4+PBLs (P < 0.001) and poorer 3-year OS (HR: 0.124, 95% CI 0.017–0.929, P = 0.015) than those in the PBL-A group. In our three survival prediction models, Model 3, which was based on the percentage of TIM-3+CD8+PBLs, PD-L1+CD8+TILs and PD-1+CD8+TILs, showed the best sensitivity (0.950, 0.914), specificity (0.852, 0.857) and accuracy (κ = 0.787, P < 0.001; κ = 0.771, P < 0.001) in the internal and external cohorts, respectively.ConclusionWe established a comprehensive and robust survival prediction model based on the T-cell phenotype in the TIME and PBLs for GC prognosis.

Abstract WP231: Timecourse Characterization Of Neuronal Activation In The Contralesional Cortex After Stroke

Introduction: Functional neuroimaging studies have reported increased activation in the contralesional cortex in both experimental and clinical settings of stroke. However, the dynamics of activation and neuronal subtypes involved is unclear. In this study we performed a time course analysis of neuronal activation and its subtypes in the contralesional cortex during post-stroke recovery using neuronal activity marker and cell type-specific markers. Methods: C57BL6 male mice (11-13 weeks old) underwent transient middle cerebral artery occlusion (MCAO, 30 minutes). Infarct was visualized by T2-weighted MRI and/or histology. Time course study used brains collected at PD1, 3, 7, 15, 21 and 28 and were processed for immunostaining using activity-dependent marker Early growth response 1 (Egr1). Egr1 positive cells were quantitatively assessed in the primary motor cortex (M1), pre-motor cortex (M2), and somatosensory cortex (SS) regions in the contralesional hemispheres. Cell type markers for NeuN (mature neurons), CaMKII and SATB2 (excitatory neurons), Parvalbumin (GABAergic neurons) and GFAP (astrocytes) were co-stained with Egr1 to identify its cell type specificity. Results: In the contralesional cortex, Egr1 predominantly co-localized with NeuN, indicating mature neurons. After stroke, contralesional cortical activity of Egr1 is detected at PD1-3 and peaks at PD7-15. Activity of Egr1 in contralesional cortex persisted at PD21-28 but begins to decrease in some regions. In-depth analysis of specific regions indicate that these changes occurred at contralesional M1, M2 and SS. Cell type co-localization analysis showed that Egr1 expressing cells are mostly colocalized with excitatory markers SATB2 and CaMKII but not inhibitory neuronal marker Parvalbumin, suggesting activated neurons in these contralesional cortical regions are mostly excitatory. Conclusion: Our results show that Egr1 expression is increased in excitatory neurons in the contralesional cortex after stroke, particularly in somatosensory and primary motor cortex. These data reveal dynamic changes of excitatory neuronal activity in the contralesional cortex post-stroke and highlight its involvement in post-stroke recovery.

Domain and cell type-specific immunolocalisation of voltage-gated potassium channels in the mouse striatum

Diverse classes of voltage-gated potassium channels (Kv) are integral to the variety of electrical activity patterns that distinguish different classes of neurons in the brain. A feature of their heterogenous expression patterns is the highly precise manner in which specific cell types target their location within functionally specialised sub-cellular domains. Although Kv expression profiles in cortical brain regions are widely reported, their immunolocalisation in sub-cortical areas such as the striatum, and in associated diseases such as Parkinson’s disease (PD), remain less well described. Therefore, the broad aims of this study were to provide a high resolution immunolocalisation analysis of various Kv subtypes within the mouse striatum and assess their potential plasticity in a model of PD. Immunohistochemistry and confocal microscopy revealed that immunoreactivity for Kv1.1, 1.2 and 1.4 overlapped to varying degrees with excitatory and inhibitory axonal marker proteins suggesting these Kv subtypes are targeted to axons innervating striatal medium spiny neurons (MSNs). Immunoreactivity for Kv1.3 strongly overlapped with signal for mitochondrial marker proteins in MSN somata and dendrites. Kv1.5 immunoreactivity was expressed in parvalbumin-immunopositive neurons whereas Kv1.6 was located in cells immunopositive for microglia. Signal for Kv2.1 was concentrated on the somatic and proximal dendritic plasma membrane of MSNs, whilst immunoreactivity for Kv4.2 was targeted to their distal dendritic regions. Finally, striatal Kv2.1 expression, at both the mRNA and protein levels, was decreased in alpha-synuclein overexpressing mice, yet increased in alpha-synuclein knockout mice, compared to wild-type counterparts. The data indicate a variety of Kv expression patterns that are distinctive to the striatum and susceptible to pathology that mirrors PD. Furthermore, these findings advance our understanding of the molecular diversity of various striatal cell types, and potentially have implications for the homeostatic changes of MSN excitability during associated medical conditions such as PD.

Immunohistochemical characterization of transient receptor potential vanilloid types 2 and 1 in a trinitrobenzene sulfonic acid-induced rat colitis model with visceral hypersensitivity

Transient receptor potential vanilloid type 2 (TRPV2) and type 1 (TRPV1) are originally identified as heat-sensitive TRP channels. We compared the expression patterns of TRPV2 and TRPV1 in the rat distal colon and extrinsic primary afferent neurons, and investigated their roles in visceral hypersensitivity in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis rats. Both TRPV2 and TRPV1 expressions in the colon, dorsal root ganglion (DRG), and nodose ganglion (NG) were significantly upregulated in the TNBS-induced colitis model. TRPV2 cell bodies co-localized with the intrinsic primary afferent marker NeuN and the inhibitory motor neuronal marker nNOS in the myenteric plexus. TRPV2 expressions were further detected in the resident macrophage marker ED2 in the mucosa. In contrast, no TRPV1-expressing cell bodies were detected in the myenteric plexus. Both TRPV2- and TRPV1-positive cell bodies in the DRG and NG were double-labeled with the neuronal retrograde tracer fluorescent fluorogold. Large- and medium-sized TRPV2-positive neurons were labeled with the A-fiber marker NF200, calcitonin gene-related peptide (CGRP), and substance P (SP) in the DRG while small-sized TRPV1-positive neurons were labeled with the C-fiber markers IB4, CGRP, and SP. TRPV2- and TRPV1-positive NG neurons were labeled with NF200 and IB4. TNBS treatment increased p-ERK1/2-positive cells in TRPV2 and TRPV1 neurons but did not affect the TRPV2 and TRPV1 subpopulations in the DRG and NG. Both TRPV2 and TRPV1 antagonists significantly alleviated visceral hypersensitivity in TNBS-induced colitis model rats. These findings suggest that intrinsic/extrinsic TRPV2- and extrinsic TRPV1-neurons contribute to visceral hypersensitivity in an experimental colitis model.

Co-inhibition of immunoproteasome subunits LMP2 and LMP7 enables prevention of transplant arteriosclerosis.

The loss of vascular wall cells in allotransplanted arteries is the initial event leading to transplant arteriosclerosis (TA) and ensuing loss of allograft function. Pharmacological agents able to prevent TA are currently lacking. We previously showed that selective inhibition of the immunoproteasome prevented the chronic rejection of renal allografts. However, the role and mechanisms of selective inhibition of a single immunoproteasome subunit to prevent immune-mediated vascular allograft rejection and TA is not clear. The effect and potential mechanism of combined or individual inhibition of peptidolytically active immunoproteasome LMP7 (β5i) and LMP2 (β1i) subunits on immune rejection-mediated TA was investigated using the epoxyketone inhibitor ONX 0914, and the recently developed LMP7-selective inhibitor KZR-329 and LMP2-selective inhibitor KZR-504 in a rat aorta transplantation model. We find that co-inhibition of LMP7 and LMP2 in allogeneic recipients significantly suppressed T-cell activation and function by expressing inhibitory surface markers and then activating inhibitory signals. Moreover, co-inhibition of LMP7 and LMP2 substantially reduced the number of immunoglobulin G-secreting cells and plasma cells and production of alloantibodies through activating the unfolded protein response and incapacitating the survival niche of plasma cells in the bone marrow. Consequentially, the accumulation of inflammatory cytokines, complement, and antibodies is reduced and the apoptosis of vascular wall cells decreased in aortic allografts via LMP7 and LMP2 co-inhibition with ONX 0914 treatment or combined KZR-329 and KZR-504 treatment. However, neither individual inhibition of LMP7 by KZR-329 nor individual inhibition of LMP2 by KZR-504 showed suppression of immune rejection and TA. We define a critical role of LMP7 and LMP2 in TA and strongly propose co-inhibition of both immunoproteasome subunits as promising therapeutic approach to suppress TA and allograft rejection.

Neuronal cell types, projections, and spatial organization of the central amygdala.

The central amygdala (CEA) has been richly studied for interpreting function and behavior according to specific cell types and circuits. Such work has typically defined molecular cell types by classical inhibitory marker genes; consequently, whether marker-gene-defined cell types exhaustively cover the CEA and co-vary with connectivity remains unresolved. Here, we combined single-cell RNA sequencing, multiplexed fluorescent in situ hybridization, immunohistochemistry, and long-range projection mapping to derive a "bottom-up" understanding of CEA cell types. In doing so, we identify two major cell types, encompassing one-third of all CEA neurons, that have gone unresolved in previous studies. In spatially mapping these novel types, we identify a non-canonical CEA subdomain associated with Nr2f2 expression and uncover an Isl1-expressing medial cell type that accounts for many long-range CEA projections. Our results reveal new CEA organizational principles across cell types and spatial scales and provide a framework for future work examining cell-type-specific behavior and function.

Biomarkers of tumor-reactive CD4+ and CD8+ TILs associate with improved prognosis in endometrial cancer.

BackgroundDespite the growing interest in immunotherapeutic interventions for endometrial cancer (EC), the prevalence, phenotype, specificity and prognostic value of tumor infiltrating lymphocytes (TILs) in this tumor type remains unclear.MethodsTo better...

The Effect of TGFβ1 in Adipocyte on Inflammatory and Fibrotic Markers at Different Stages of Adipocyte Differentiation.

Transforming growth factor beta (TGFβ) is a versatile cytokine. Although a profibrotic role of TGFβ is well established, its effect on tissue inhibitor of metalloproteinase (TIMPs) and inflammatory mediators are incompletely described. This study investigates the profibrotic and pro-inflammatory role of TGFβ1 during adipocyte differentiation. NIH3T3L1 cells were used for the in vitro study and were differentiated by adding a standard differentiation mix either with rosiglitazone (R-Diff) or without (S-Diff). Recombinant TGFβ1 (2 ng/mL) was added to the undifferentiated preadipocyte during the commitment stage and at the terminal differentiation stage. TGFβ1 treatment significantly decreased adiponectin mRNA at both early commitment (>300 fold) and terminal differentiated cells [S-Diff (~33%) or R-Diff (~20%)]. TGFβ1 upregulated collagen VI mRNA and its regulators connective tissue growth factor (CCN2/CTGF), TIMP1 and TIMP3 mRNA levels in undifferentiated preadipocytes and adipocytes at commitment stage. But in the terminal differentiated adipocytes, changes in mRNA and protein of collagen VI and TIMP3 mRNA were not observed despite an increase in CCN2/CTGF, TIMP1 mRNA. Although TGFβ1 upregulated interleukin-6 (IL6) and monocyte chemoattractant protein-1 (MCP1) mRNA at all stages of differentiation, decreased tumor necrosis factor-α (TNFα) mRNA was observed early in adipocyte differentiation. This study highlights the complex role of TGFβ1 on extracellular matrix (ECM) remodeling and inflammatory markers in stimulating both synthetic and inhibitory markers of fibrosis at different stages of adipocyte differentiation.

Immune predictors of hepatitis B surface antigen seroconversion in patients with hepatitis B reactivation.

Hepatitis B surface antigen (HBsAg) seroconversion is sometimes observed in hepatitis B reactivation (rHBV), probably due to immune resetting and differentiation. To investigate sequential immune differentiation and abrogation of tolerance in patients with rHBV who achieved HBsAg seroconversion. We included 19 patients with chronic hepatitis B (CHBV; HBV DNA log103-8 ), 67 with rHBV (raised ALT [>5XULN], HBV DNAlog104-8 ) and 10 healthy controls. Immune differentiation, tolerance and functional status of CD4, CD8, T regulatory cells (Tregs), B cells and follicular T helper (Tfh) cells were assessed at baseline and 24 weeks. At 24 weeks, 81% rHBV (n=67) lost HBV DNA and HBeAg (41%), and 12 (19%) lost HBsAg and made anti-HBs titers >10IU/ml. rHBV patients had higher Th1/17, TEM , Tfh, Tfh1/17, plasma and ATM B cells, and lower Tregs, Th2, Th17 and TEMRA expression. rHBV showed lower PD1, TIM3, LAG3, SLAM and TOX compared to CHBV. There was a significant increase in CD8, CD8EM, Tfh, Tfh1/17 and plasma B cells in seroconverters than non-seroconverters. At 24 weeks, we also observed increased plasma B cell frequency in seroconverters. While non-seroconverters showed higher expression of PD1, TIM3, LAG3, SLAM and TOX on CD4/CD8 T cells, blockade of PD1, TIM3, LAG3 and CTLA4 significantly enhanced IFN-γ, TNF-α, IL-4 and IL-21 expression on CD4/CD8 and Tfh cells in non-seroconverters. Non-seroconverters have increased inhibitory markers on CD4/CD8 T cells. There is a critical play of CD8, Tfh and B cells and subsets in seroclearance, along with checkpoint molecules as a potential therapy for non-seroconverters in HBV infection.

Sub-Chronic Restraint Stress Suppresses Sexual Potency and Erection Efficiency by Targeting the Hypothalamic-Pituitary-Testicular Axis and the Nitric Oxide/Cyclic Guanosine Monophosphate/Phosphodiesterase 5α Pathway in Adult Rats

Introduction: Male sexual potency and vigor are a complex neuroendocrine process and an important component of well-being. Psychological stress is one of the leading causes of male impotence worldwide. Therefore, to better understand the effects of psychological stress on male sexual potency, vigor, and the physiology of erection, we used the rat restraint stress (RS) model, which can most aptly simulate psychological stress. Methods: Adult male SD rats were exposed to RS for 1.5 or 3 h/day for 30 days. Neuromodulators and hormones of sexual potency and penile erection were quantified using ELISA kit. The histoarchitecture of the penis was examined using Masson trichrome staining. Immunoblotting and immunofluorescence were used to assess the expression and immunolocalization patterns of penile erection markers. To assess sexual potency and vigor, a noncontact erection and a copulatory test were performed. Results: RS exposure decreased the circulatory levels of gonadotropins and testosterone while increasing the serum corticosterone level. RS exposure altered the histomorphology of the penis by decreasing the smooth muscle/collagen ratio and increasing oxidative stress in penile tissue. Furthermore, RS adversely affected NO availability for penile erection by decreasing the neurotransmitter acetylcholine and other erection facilitatory markers such as p-Akt, nNOS, eNOS, and cGMP, while increasing the inhibitory marker PDE5α in the penis. RS exposure significantly reduced the frequencies of mount, intromission, and ejaculation, whereas it prolonged sexual exhaustion by increasing latencies of postejaculatory mount, intromission, and ejaculation. Conclusion: The current findings suggest that psychological stressors, such as RS, cause erectile dysfunction in adult male rats by modulating the hypothalamic-pituitary-testicular axis, oxidative balance, penile fibrosis, and the NO/cGMP/PDE5α pathway of penile erection.

Durable Response to CD19 CAR T Cell Therapy Is Associated with Cytotoxicity and Clonotypic Expansion of the Native T Cell Repertoire

Background: Axicabtagene ciloleucel (Axi-cel), a CD19 directed CAR T cell therapy, results in durable remission in a subset of patients with relapsed refractory large B cell lymphoma (LBCL) in the absence of persistent circulating CAR T cells. Aim: We postulated that long-term efficacy of CAR T therapy depends on the downstream triggering of native T cell immunity. To investigate this hypothesis, we performed single cell transcriptomic analysis of peripheral blood samples obtained at serial time points from patients participating in the ZUMA 1 Axi-cel study. We interrogated the T cell repertoire in patients who achieved durable remission compared to those experiencing disease relapse with respect to the expression of activated, cytotoxic, and inhibitory markers and clonotypic expansion of critical T cell subsets. Methods: Single cell immunoprofiling (expression + V(D)J sequencing) was performed using the 10x Genomics single cell 5' assay on PBMC samples from ZUMA-1 patients (N=32), collected at leukapheresis, 4 weeks, 6 months, and 12 months post Axi-cel. Based on clinical response, patients were divided into 3 groups: non-responders (N=8), relapsed within 1 year from CAR T infusion (N=9), and long-term responders (N=12). Three participants did not consent to the release of clinical outcomes. Results: A total of 405,775 cells passed quality check, capturing 73 cellular populations (Fig. 1a). T cells comprised the largest compartment with 28 different populations and 264,059 cells. Long-term responders demonstrated a distinct T cell landscape compared to relapsed patients, notable for a higher CD8/CD4 T cell ratio and increased expression of cytotoxic genes at all time points. Accordingly, activated CD8 cytotoxic effector memory T cell (Tem) populations were significantly increased in long-term responders compared to relapsed patients; especially two Tem populations, one characterized by high expression of CD44, GZMB and TGFB1 (Tem/TGFB1+), and a second highly expressing cytotoxic markers such as GZMA, GZMB, NKG7, CTS7, and CTSW (Tem/NKG7+). Following CAR T cell infusion, relapsed patients exhibited increased proportions of T regs and of T reg-like Th17 cells highly expressing FOXP3, IL2RA, and CTLA4. In contrast to all other CD4 populations, which were more abundant in the relapsed group, long-term responders presented higher abundance of CD4 cytotoxic T lymphocytes (CD4 CTL), characterized by high expression of both CD4-related and cytotoxic markers, including granzymes, and GNLY. Comparison of the TCR repertoire pre- and post-CAR T demonstrated a greater clonal expansion (TCRα/β-clonotype frequency > 1) of cytotoxic T cell populations in the long-term responders compared to relapsed and non-responder patients. In particular, higher clonotypic expansion was observed in the Tem/TGFB1+, Tem/NKG7+, and CD4 CTL populations (Fig. 1b). In contrast to our observations for the cytotoxic T cell populations, T regs were identified as more clonally expanded over time in the relapsed patients compared to the long-term responders. Conclusion: The application of single-cell immunoprofiling on longitudinal samples from CAR T cell treated LBCL patients from the ZUMA-1 trial demonstrated striking differences in cellular populations and clonal expansion patterns among patients who demonstrated long term remission compared to those who relapsed within 1 year following initial response. Reduced cytotoxic T cell expansion and increased proportions of immunomodulatory T cell populations were noted in relapsed patients compared to long term responders. These data provide insight into crucial factors that can be leveraged both to predict patient response and to further our understanding of long-term remission following CAR T cell treatment. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

The Impact of Chemotherapy on Phenotype and Function of Non-Malignant T-Cells in Patients with T-Cell Lymphoma

Background: An immune suppressive tumor microenvironment (TME) plays a significant role in the pathogenesis and progression of T-cell lymphomas (TCLs). Therapies that reverse the suppressive TME or increase tumor antigen presentation could be additive or synergistic with immunotherapeutic strategies. One concern with combining cytotoxic chemotherapy (chemo) with immunotherapy such as checkpoint blockade (CPB) is that it could reduce or eliminate anti-tumor effector cells, thus reducing efficacy. We performed a phase I clinical trial using the immune CPB nivolumab (Nivo) in combination with DA-EPOCH in newly diagnosed peripheral T-cell lymphomas (Haverkos et al., ASH. 2021) and studied the T-cell phenotype and function at baseline, during therapy, and at end of treatment (EOT) of patients (pts) receiving CPB + chemo compared to contemporaneous cohorts of TCL pts treated with chemo or CPB alone outside the context of a clinical trial. Methods: Peripheral blood was collected serially at baseline, during treatment, and end of treatment (EOT) in TCL pts treated on clinical trial with Nivo + DA-EPOCH, standard of care chemo, and single agent CPB (Figure 1). We isolated mononuclear cells and performed multi-color flow cytometry using three validated flow panels: T-cell Phenotype, T-cell Activation/Exhaustion, and Lymphocyte Cytokine. For the Phenotype Panel, T-cells were categorized as naïve (CD45RA+ CCR7+), central memory (CD45RA- CCR7+), effector memory (CD45RA- CCR7-) helper (CXCR3+, CCR4+, or CCR6+) and regulatory (FoxP3+). For the Activation/Exhaustion Panel, samples were stained with antibodies to identify expression of inhibitory receptors (TIM3, LAG3, PD-1), activation markers (CTLA-4), and effector cell transcription factors (T-bet, Eomes). For the Cytokine Panel, cells were stimulated with PMA/Ionomycin and cytokines including interferon-γ, TNFα, IL2, IL4, IL17, and granzyme B were measured. At each timepoint, we visualized differences in T-cell subset percents (%) of total lymphocytes between treatment cohorts using heat maps. We then tested differences in mean % of cells between treatment groups during treatment and at EOT using linear regression. Given limited sample size, differences where p<0.1 are being further studied using single cell and targeted RNA sequencing (RNAseq). Additionally, we are testing mean % changes within each cohort between timepoints. Results: First, we compared CPB + chemo vs. chemo alone cohorts using our three flow panels. With respect to cell Phenotype Panel, pts treated with CPB + chemo had higher % of total CD8+ (p=0.046), CD8+ memory (p=0.049), and CD4+ effector memory T-cells (p=0.059) during treatment (Figure 2). There were lower % of CD4+ and CD8+ naïve T-cells (p<0.001 and p=0.032, respectively) and CD4+ helper T-cells (p=0.058) during treatment. Higher % of CD8+ memory cells (p=0.030) and lower CD8+ naïve cells (p=0.013) persisted at EOT. There was no difference in the overall % of CD4+ cells during treatment or EOT (p=0.137 and p=0.535). Using the cell Activation/Exhaustion Panel, we identified lower % of CD4+ and CD8+ CTLA4+ memory cells (p=0.010 and p=0.013, respectively), CD8+ Eomes+ memory cells (p=0.013), CD4+ and CD8+ TIM3+ memory cells (p=0.042 and p=0.084, respectively), CD4+ PD1+ naïve cells (p=0.038), and CD4+ and CD8+ PD1+ memory cells (p=0.002 and p=0.003, respectively) during treatment. There were no statistically significant differences in activation/exhaustion markers at EOT. Lastly, the Cytokine Panel demonstrated higher % of CD8+ granzyme B positive T-cells during treatment (p=0.039) but no differences at EOT. Differences in cell makeup in the CPB only group (N=2) were similar to the changes in CPB + chemo group. Further validation of these findings by evaluating serial changes in T-cell subsets within each cohort and RNAseq is ongoing. Conclusions: Our results suggest that with the addition of CPB, CD8+ T-cells (as a % of all lymphocytes) increase initially, but there is a transition in cell phenotype during treatment. The combination of CPB + chemo may initially lead to an increase in anti-tumor immune effector cells, but these benefits could be temporary when chemo is continued for >2 cycles. Similarly, in our Nivo + DA-EPOCH clinical trial, we observed early initial clinical responses that did not persist. This data should be considered during development of future chemoimmunotherapeutic treatment strategies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Immunomodulatory Effects of Stereotactic Body Radiotherapy and Vaccination with Heat-Killed Mycobacterium Obuense (IMM-101) in Patients with Locally Advanced Pancreatic Cancer.

Patients with locally advanced pancreatic cancer (LAPC) are treated with chemotherapy. In selected cases, stereotactic body radiotherapy (SBRT) can be added to the regimen. We hypothesized that adding an adjuvant containing a heat-killed mycobacterium (IMM-101) to SBRT may lead to beneficial immuno-modulatory effects, thereby improving survival. This study aims to investigate the safety of adding IMM-101 to SBRT and to investigate the immuno-modulatory effects of the combination treatment in the peripheral blood of LAPC patients. LAPC patients were treated with SBRT (40 Gy) and six intradermal vaccinations of one milligram IMM-101. The primary endpoint was an observed toxicity rate of grade 4 or higher. Targeted gene-expression profiling and multicolor flow cytometry were performed for longitudinal immune-monitoring of the peripheral blood. Twenty patients received study treatment. No treatment-related adverse events of grade 4 or higher occurred. SBRT/IMM-101 treatment induced a transient decrease in different lymphocyte subsets and an increase in CD14+CD16-CD11b+HLA-DRlow myeloid-derived suppressor cells. Importantly, treatment significantly increased activated ICOS+, HLA-DR+ and Ki67+PD1+ T and NK cell frequencies. This was not accompanied by increased levels of most inhibitory markers, such as TIM-3 and LAG-3. Combination therapy with SBRT and a heat-killed mycobacterium vaccine was safe and had an immune-stimulatory effect.

Disruption of grin2B, an ASD-associated gene, produces social deficits in zebrafish

BackgroundAutism spectrum disorder (ASD), like many neurodevelopmental disorders, has complex and varied etiologies. Advances in genome sequencing have identified multiple candidate genes associated with ASD, including dozens of missense and nonsense mutations in the NMDAR subunit GluN2B, encoded by GRIN2B. NMDARs are glutamate-gated ion channels with key synaptic functions in excitatory neurotransmission. How alterations in these proteins impact neurodevelopment is poorly understood, in part because knockouts of GluN2B in rodents are lethal.MethodsHere, we use CRISPR-Cas9 to generate zebrafish lacking GluN2B (grin2B−/−). Using these fish, we run an array of behavioral tests and perform whole-brain larval imaging to assay developmental roles and functions of GluN2B.ResultsWe demonstrate that zebrafish GluN2B displays similar structural and functional properties to human GluN2B. Zebrafish lacking GluN2B (grin2B−/−) surprisingly survive into adulthood. Given the prevalence of social deficits in ASD, we assayed social preference in the grin2B−/− fish. Wild-type fish develop a strong social preference by 3 weeks post fertilization. In contrast, grin2B−/− fish at this age exhibit significantly reduced social preference. Notably, the lack of GluN2B does not result in a broad disruption of neurodevelopment, as grin2B−/− larvae do not show alterations in spontaneous or photic-evoked movements, are capable of prey capture, and exhibit learning. Whole-brain imaging of grin2B−/− larvae revealed reduction of an inhibitory neuron marker in the subpallium, a region linked to ASD in humans, but showed that overall brain size and E/I balance in grin2B−/− is comparable to wild type.LimitationsZebrafish lacking GluN2B, while useful in studying developmental roles of GluN2B, are unlikely to model nuanced functional alterations of human missense mutations that are not complete loss of function. Additionally, detailed mammalian homologies for larval zebrafish brain subdivisions at the age of whole-brain imaging are not fully resolved.ConclusionsWe demonstrate that zebrafish completely lacking the GluN2B subunit of the NMDAR, unlike rodent models, are viable into adulthood. Notably, they exhibit a highly specific deficit in social behavior. As such, this zebrafish model affords a unique opportunity to study the roles of GluN2B in ASD etiologies and establish a disease-relevant in vivo model for future studies.