Adoptive Transfer of Immune Cells Into RAG2IL-2Rγ-Deficient Mice During Litomosoides sigmodontis Infection: A Novel Approach to Investigate Filarial-Specific Immune Responses

Despite long-term mass drug administration programmes, approximately 220 million people are still infected with filariae in endemic regions. Several research studies have characterized host immune responses but a major obstacle for research on human filariae has been the inability to obtain adult worms which in turn has hindered analysis on infection kinetics and immune signalling. Although the Litomosoides sigmodontis filarial mouse model is well-established, the complex immunological mechanisms associated with filarial control and disease progression remain unclear and translation to human infections is difficult, especially since human filarial infections in rodents are limited. To overcome these obstacles, we performed adoptive immune cell transfer experiments into RAG2IL-2Rγ-deficient C57BL/6 mice. These mice lack T, B and natural killer cells and are susceptible to infection with the human filaria Loa loa. In this study, we revealed a long-term release of L. sigmodontis offspring (microfilariae) in RAG2IL-2Rγ-deficient C57BL/6 mice, which contrasts to C57BL/6 mice which normally eliminate the parasites before patency. We further showed that CD4+ T cells isolated from acute L. sigmodontis-infected C57BL/6 donor mice or mice that already cleared the infection were able to eliminate the parasite and prevent inflammation at the site of infection. In addition, the clearance of the parasites was associated with Th17 polarization of the CD4+ T cells. Consequently, adoptive transfer of immune cell subsets into RAG2IL-2Rγ-deficient C57BL/6 mice will provide an optimal platform to decipher characteristics of distinct immune cells that are crucial for the immunity against rodent and human filarial infections and moreover, might be useful for preclinical research, especially about the efficacy of macrofilaricidal drugs.

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Immune cell composition in normal human kidneys

Scientific Reports ◽

10.1038/s41598-020-72821-x ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jun-Gyu Park ◽

Myeongsu Na ◽

Min-Gang Kim ◽

Su Hwan Park ◽

Hack June Lee ◽

...

Keyword(s):

T Cells ◽

Immune Cells ◽

Immune Cell ◽

Kidney Diseases ◽

Myeloid Cells ◽

Human Kidney ◽

Effector Memory ◽

Immune Cell Subsets ◽

Immunological Mechanisms ◽

Normal Human

Abstract An understanding of immunological mechanisms in kidney diseases has advanced using mouse kidneys. However, the profiling of immune cell subsets in human kidneys remains undetermined, particularly compared with mouse kidneys. Normal human kidneys were obtained from radically nephrectomised patients with urogenital malignancy (n = 15). Subsequently, human kidney immune cell subsets were analysed using multicolor flow cytometry and compared with subsets from C57BL/6 or BALB/c mice under specific pathogen-free conditions. Twenty kidney sections from healthy kidney donors or subjects without specific renal lesions were additionally analysed by immunohistochemistry. In human kidneys, 47% ± 12% (maximum 63%) of immune cells were CD3+ T cells. Kidney CD4+ and CD8+ T cells comprised 44% and 56% of total T cells. Of these, 47% ± 15% of T cells displayed an effector memory phenotype (CCR7− CD45RA− CD69−), and 48% ± 19% were kidney-resident cells (CCR7− CD45RA− CD69+). However, the proportions of human CD14+ and CD16+ myeloid cells were approximately 10% of total immune cells. A predominance of CD3+ T cells and a low proportion of CD14+ or CD68+ myeloid cells were also identified in healthy human kidney sections. In mouse kidneys, kidney-resident macrophages (CD11blow F4/80high) were the most predominant subset (up to 50%) but the proportion of CD3+ T cells was less than 20%. These results will be of use in studies in which mouse results are translated into human cases under homeostatic conditions or with disease.

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Immune Checkpoint Blockade with Anti-PD-L1 Prevents Immune Dysfuntion and CLL Development in the TCL1 Adoptive Transfer Mouse Model

Blood ◽

10.1182/blood.v124.21.717.717 ◽

2014 ◽

Vol 124 (21) ◽

pp. 717-717

Author(s):

Bola Hanna ◽

Fabienne McClanahan ◽

Andrew James Clear ◽

Shaun Miller ◽

Peter Lichter ◽

...

Keyword(s):

Cell Proliferation ◽

T Cells ◽

T Cell ◽

Immune Responses ◽

Adoptive Transfer ◽

Immune Checkpoint ◽

Clinical Studies ◽

Immune Cell ◽

Immune Dysfunction

Abstract Background: Clinical studies have demonstrated that targeted immunotherapy using PD-1/PD-L1 antibodies induces tumor regression and prolongs disease stabilization in advanced solid cancers. Data on the clinical efficacy in hematological malignancies is largely missing, even though PD-L1/PD-1 interactions have been described as major mediators of immune dysfunction in several leukemias and lymphomas. They are therefore ideal to study if PD-L1/PD-1 blockade has the potential to control disease by restoring anti-tumor immune responses. Several groups showed that chronic lymphocytic leukemia (CLL) provokes immune evasion via PD-L1/PD-1 inhibitory signaling, and that this is very closely mirrored in the Eµ-TCL1 (TCL1) murine model for CLL. Our recent data suggest that in this model, aberrant PD-L1 expression in myeloid cells contributes to the immune defect in CLL. We further demonstrated that the T cell and myeloid cell immune defects in ageing leukemic mice can be induced in young wild-type (WT) mice by adoptive transfer (AT) of murine CLL. In the current study, we used the AT model to test if in vivoPD-L1 blockade corrects leukemia-induced cellular immune dysfunction in myeloid and T cells and enhances anti-tumor immunity. Methods: WT mice transplanted with 4x107 TCL1 splenocytes were randomized to treatment with 10 mg/kg α-murine-PD-L1 (n=15) or isotype antibody (n=10), which was administered i.p. every 3 days starting 1 day after AT, and sacrificed 31 days later. Matched non-transplanted WT mice (n=6) served as additional controls. Immune cell subsets, expression of immune checkpoint markers and T cell effector functions were analyzed by multicolor flow cytometry using cells isolated form spleen, peripheral blood (PB), bone marrow (BM) and peritoneal cavity (PC). Cell proliferation was measured by EdU incorporation in vivo. Immune synapse (IS) formation was assessed by confocal microscopy. Serum cytokines were quantified by multiplex bead arrays. Results: We first confirmed successful engraftment and presence of disease by immunohistochemistry. Compared to isotype controls, α-PD-L1 treated mice had significantly lower spleen weights (median 0.2 g vs 0.9 g, p<0.0001) and a highly significant lower relative frequency of CD19+CD5+ CLL lymphocytes in spleen (1.55% vs 71.69%), PB (10.5% vs 63.53%) and BM (0.26% vs 2.74%) demonstrating very effective tumor control. Compared to non-transplanted animals, α-PD-L1 treated mice showed alterations in almost all phenotypical and functional immune cell parameters, especially in regards to immune cell activation, indicating encounter with and immunological challenge by CLL cells. Along with disease control, α-PD-L1 treated mice had improved immune status as multiple inflammatory cytokines in the serum, including IL-10, TNF-α, CCL2 and GM-CSF were decreased and splenic infiltration of monocytes was reduced. While CLL development skewed monocytes towards Ly6Clow patrolling monocytes, α-PD-L1 treatment restored the presence of Ly6Chi inflammatory monocytes and decreased the expression of adhesion molecules ICAM-1 and PECAM-1. These monocytes regained their differentiation capacity as shown by increased numbers of macrophages and mature MHC-IIhi dendritic cells in the spleens of treated mice. In the T cell compartment, in vivo PD-L1 blockade prevented the CLL-induced CD4/CD8 ratio inversion, the loss of naïve CD8 T cells and the shift towards antigen-experienced and terminally differentiated T cells in spleen, BM and PB. Aberrant expression of immune checkpoint markers PD-1, KLRG-1, LAG-3, and 2B4 was also significantly reduced. The CLL-associated loss of intracellular IL-2 and the increased secretion of IL-4 and IFN-γ in CD4 T cells were prevented in α-PD-L1 treated mice. Respective cytokine patterns were observed in the serum. Functionally, PD-L1 blockade restored CD8 degranulation and IS formation to the level of healthy T cells, and significantly improved both ex vivo and in vivoT cell proliferation. Conclusion: Our in vivodata demonstrate that early PD-L1 blockade very effectively controls CLL development and enables complex effector function of myeloid and T cells, thus restoring anti-tumor immune responses. Targeting PD-L1/PD-1 interactions should therefore be further explored in clinical studies, potentially in combination with novel substances. BH/FM and MS/JGG contributed equally to first and last authorship. Disclosures No relevant conflicts of interest to declare.

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Adoptive transfer of simian immunodeficiency virus (SIV) naı̈ve autologous CD4+ cells to macaques chronically infected with SIV is sufficient to induce long-term nonprogressor status

Blood ◽

10.1182/blood.v99.2.590 ◽

2002 ◽

Vol 99 (2) ◽

pp. 590-599 ◽

Cited By ~ 49

Author(s):

Francois Villinger ◽

Gary T. Brice ◽

Ann E. Mayne ◽

Pavel Bostik ◽

Kazuyasu Mori ◽

...

Keyword(s):

T Cells ◽

Immune Responses ◽

Simian Immunodeficiency Virus ◽

Adoptive Transfer ◽

Cd4 T Cells ◽

Short Term ◽

Cell Compartment ◽

Immunodeficiency Virus ◽

Siv Infection

Abstract Adoptive transfer of autologous preinfection-collected peripheral blood mononuclear cells (PBMCs) or activated CD4+ T cells was performed in simian immunodeficiency virus (SIVmac239)–infected monkeys following short-term antiviral therapy with PMPA (9-R-[2-phosphonylmethoxypropyl] adenine). Short-term chemotherapy alone led to a transient decrease in plasma and cellular proviral DNA loads and transient rescue of gag/pol and env cytotoxic T-lymphocyte precursors (pCTLs). However, cessation of therapy allowed for SIV infection to resume its clinical course. PMPA chemotherapy coupled with infusions of either autologous pre-SIV infection–collected PBMCs or activated CD4+ T cells led to extended control of plasma and cellular proviral DNA loads after infusion, in spite of the fact that the transfused cells were not primed against SIV. However, qualitatively different antiviral defenses were induced by infusion of unfractionated and unmanipulated PBMCs versus purified and activated CD4+ T cells: PBMC infusions significantly favored development of SIVenv-specific pCTLs, neutralizing antibodies, and secretion of soluble noncytotoxic suppressor factors of SIV replication. In contrast, activated CD4+ T cells predominantly promoted CTL responses to SIVgag/pol and SIVenv. In addition, infusion of influenza-primed activated CD4+ T cells markedly enhanced influenza-specific pCTL responses, whereas infusion of similarly influenza-primed unfractionated PBMCs enhanced such pCTL responses only modestly, suggesting that the predominant immune defect after SIV infection lies in the T helper cell compartment rather than the effector cell compartment. Thus, adoptive immunotherapy with autologous “SIV naı̈ve” CD4+ lymphocytes was sufficient to rescue cell-mediated immune responses and induce long-term anti-SIV control and immune responses in the absence of continued antiviral chemotherapy.

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The immune response of T cells and therapeutic targets related to regulating the levels of T helper cells after ischaemic stroke

Journal of Neuroinflammation ◽

10.1186/s12974-020-02057-z ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Tian-Yu Lei ◽

Ying-Ze Ye ◽

Xi-Qun Zhu ◽

Daniel Smerin ◽

Li-Juan Gu ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

Immune System ◽

Immune Responses ◽

Ischaemic Stroke ◽

Immune Cells ◽

Tissue Injury ◽

Recovery Period ◽

Vital Functions ◽

Anti Inflammatory

AbstractThrough considerable effort in research and clinical studies, the immune system has been identified as a participant in the onset and progression of brain injury after ischaemic stroke. Due to the involvement of all types of immune cells, the roles of the immune system in stroke pathology and associated effects are complicated. Past research concentrated on the functions of monocytes and neutrophils in the pathogenesis of ischaemic stroke and tried to demonstrate the mechanisms of tissue injury and protection involving these immune cells. Within the past several years, an increasing number of studies have elucidated the vital functions of T cells in the innate and adaptive immune responses in both the acute and chronic phases of ischaemic stroke. Recently, the phenotypes of T cells with proinflammatory or anti-inflammatory function have been demonstrated in detail. T cells with distinctive phenotypes can also influence cerebral inflammation through various pathways, such as regulating the immune response, interacting with brain-resident immune cells and modulating neurogenesis and angiogenesis during different phases following stroke. In view of the limited treatment options available following stroke other than tissue plasminogen activator therapy, understanding the function of immune responses, especially T cell responses, in the post-stroke recovery period can provide a new therapeutic direction. Here, we discuss the different functions and temporal evolution of T cells with different phenotypes during the acute and chronic phases of ischaemic stroke. We suggest that modulating the balance between the proinflammatory and anti-inflammatory functions of T cells with distinct phenotypes may become a potential therapeutic approach that reduces the mortality and improves the functional outcomes and prognosis of patients suffering from ischaemic stroke.

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102 Cord-blood derived NK cells, and CAR-T cells, an attractive improved immunotherapy treatment to be considered for hematological malignancies

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0102 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A113-A113

Author(s):

Mireia Bachiller García ◽

Lorena Pérez-Amill ◽

Anthony Battram ◽

Alvaro Urbano-Ispizua ◽

Beatriz Martín-Antonio

Keyword(s):

T Cells ◽

Tumor Cell ◽

Cord Blood ◽

Immune Cells ◽

In Vivo Models ◽

Cell Clusters ◽

Cytotoxicity Assays ◽

Anti Tumor Activity

BackgroundMultiple myeloma (MM) remains an incurable hematological malignancy where a proportion of patients relapse or become refractory to current treatments. Administration of autologous T cells modified with a chimeric antigen receptor (CAR) against B cell maturation antigen (BCMA) has achieved high percentages of complete responses. Unfortunately, the lack of persistence of CART-BCMA cells in the patient leads to relapses. On the other side, cord-blood derived natural killer cells (CB-NK) is an off-the-shelf cellular immunotherapy option to treat cancer patients with high potential due to their anti-tumor activity. However, clinical results in patients up to date have been sub-optimal. Whereas CB-NK are innate immune cells and their anti-tumor activity is developed in a few hours, CART cells are adaptive immune cells and their activity develops at later time points. Moreover, we previously described that CB-NK secrete inflammatory proteins that promote the early formation of tumor-immune cell clusters bringing cells into close contact and thus, facilitating the anti-tumor activity of T cells. Therefore, we hypothesized that the addition of a small number of CB-NK to CART cells would improve the anti-tumor activity and increase the persistence of CART cells.MethodsT cells transduced with a humanized CAR against BCMA and CB-NK were employed at 1:0.5 (CART:CB-NK) ratio. Cytotoxicity assays, activation markers and immune-tumor cell cluster formation were evaluated by flow cytometry and fluorescence microscopy. In vivo models were performed in NSG mice.ResultsThe addition of CB-NK to CART cells demonstrated higher anti-MM efficacy at low E:T ratios during the first 24h and in long-term cytotoxicity assays, where the addition of CB-NK to CART cells achieved complete removal of tumor cells. Analysis of activation marker CD69 and CD107a degranulation from 4h to 24h of co-culturing proved differences only at 4h, where CD69 and CD107a in CART cells were increased when CB-NK were present. Moreover, CB-NK accelerated an increased formation of CART-tumor cell clusters facilitating the removal of MM cells. Of note, CB-NK addition did not increase total TNFα and IFNγ production. Finally, an in vivo model of advanced MM with consecutive challenge to MM cells evidenced that the addition of CB-NK achieved the highest efficacy of the treatment.ConclusionsOur results suggest that the addition of ‘off-the-shelf’ CB-NK to CART cells leads to a faster and earlier immune response of CART cells with higher long-term maintenance of the anti-tumor response, suggesting this combinatorial therapy as an attractive immunotherapy option for MM patients.

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TAM Receptor Inhibition–Implications for Cancer and the Immune System

Cancers ◽

10.3390/cancers13061195 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1195

Author(s):

Pia Aehnlich ◽

Richard Morgan Powell ◽

Marlies J. W. Peeters ◽

Anne Rahbech ◽

Per thor Straten

Keyword(s):

T Cells ◽

Immune Responses ◽

Cancer Cells ◽

Immune Cells ◽

Tyrosine Kinases ◽

Apoptotic Cell ◽

Receptor Activation ◽

Mouse Tumor ◽

Oncogenic Signaling ◽

Tam Receptors

Tyro3, Axl and MerTK (TAM) receptors are receptor tyrosine kinases which play important roles in efferocytosis and in the balancing of immune responses and inflammation. TAM receptor activation is induced upon binding of the ligands protein S (Pros1) or growth arrest-specific protein 6 (Gas6) which act as bridging molecules for binding of phosphatidyl serine (PtdSer) exposed on apoptotic cell membranes. Upon clearance of apoptotic cell material, TAM receptor activation on innate cells suppresses proinflammatory functions, thereby ensuring the immunologically silent removal of apoptotic material in the absence of deleterious immune responses. However, in T cells, MerTK signaling is costimulatory and promotes activation and functional output of the cell. MerTK and Axl are also aberrantly expressed in a range of both hematological and solid tumor malignancies, including breast, lung, melanoma and acute myeloid leukemia, where they have a role in oncogenic signaling. Consequently, TAM receptors are being investigated as therapeutic targets using small molecule inhibitors and have already demonstrated efficacy in mouse tumor models. Thus, inhibition of TAM signaling in cancer cells could have therapeutic value but given the opposing roles of TAM signaling in innate cells and T cells, TAM inhibition could also jeopardize anticancer immune responses. This conflict is discussed in this review, describing the effects of TAM inhibition on cancer cells as well as immune cells, while also examining the intricate interplay of cancer and immune cells in the tumor microenvironment.

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Direct and Indirect endocrine-mediated suppression of human endometrial CD8+T cell cytotoxicity

Scientific Reports ◽

10.1038/s41598-021-81380-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Z. Shen ◽

M. Rodriguez-Garcia ◽

M. V. Patel ◽

C. R. Wira

Keyword(s):

T Cells ◽

T Cell ◽

Immune Responses ◽

Cytotoxic Activity ◽

Cd8 T Cells ◽

Immune Cells ◽

Cd8 T Cell ◽

Gynecological Cancers ◽

Protective Strategies ◽

T Cell Cytotoxicity

AbstractRegulation of endometrial (EM) CD8+T cells is essential for successful reproduction and protection against pathogens. Suppression of CD8+T cells is necessary for a tolerogenic environment that promotes implantation and pregnancy. However, the mechanisms regulating this process remain unclear. Sex hormones are known to control immune responses directly on immune cells and indirectly through the tissue environment. When the actions of estradiol (E2), progesterone (P) and TGFβ on EM CD8+T cells were evaluated, cytotoxic activity, perforin and granzymes were directly suppressed by E2 and TGFβ but not P. Moreover, incubation of polarized EM epithelial cells with P, but not E2, increased TGFβ secretion. These findings suggest that E2 acts directly on CD8+T cell to suppress cytotoxic activity while P acts indirectly through induction of TGFβ production. Understanding the mechanisms involved in regulating endometrial CD8+T cells is essential for optimizing reproductive success and developing protective strategies against genital infections and gynecological cancers.

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Abstract 095: CD74 Deficient Mice are Resistant to Toll-Like Receptor-Induced Preeclampsia

Hypertension ◽

10.1161/hyp.64.suppl_1.095 ◽

2014 ◽

Vol 64 (suppl_1) ◽

Author(s):

Mohamad Hatahet ◽

Olga Y Gasheva ◽

Valorie L Chiasson ◽

Piyali Chatterjee ◽

Kelsey R Bounds ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Endothelial Dysfunction ◽

Mhc Class Ii ◽

Immune Cells ◽

Immune Cell ◽

Class Ii ◽

Poly I:C ◽

Hypertensive Disorder ◽

Toll Like Receptor

Preeclampsia (PE) is a pregnancy-specific hypertensive disorder characterized by vascular endothelial dysfunction and excessive immunity and inflammation. Activation of the dsRNA receptor Toll-like receptor 3 (TLR3) or the ssRNA receptor TLR7 elicits a pregnancy-dependent PE-like syndrome in mice by inducing a pro-inflammatory immune response. CD74 (MHC Class II invariant chain) acts as a chaperone for MHC Class II surface expression on immune cells during antigen presentation and is cleaved into Class II-Associated Invariant Peptide (CLIP) following polyclonal activation of immune cell TLRs. The presence of CLIP in the groove of MHC Class II prevents T cell-dependent death leading to persistent immune cell activation. We hypothesized that genetic deletion of CD74 and subsequent depletion of CLIP on immune cells prevents TLR-induced immune responses and the development of PE in mice. Pregnant WT and CD74 KO mice were given i.p. injections of normal saline (P), poly I:C (TLR3 agonist; P-PIC), or R837 (TLR7 agonist; P-R837) on gestational days 13, 15, and 17 and euthanized on day 18. P-PIC and P-R837 WT mice had significantly increased splenic levels of pro-inflammatory CD3+/gd T cells and plasma levels of the gd T cell-derived cytokines IFNg, TNFa, and IL-17 compared to P WT mice whereas P-PIC and P-R837 CD74 KO mice had significantly increased anti-inflammatory CD3+/gd T cells and no significant increases in plasma IFNg, TNFa, and IL-17 levels. P-PIC and P-R837 CD74 KO mice did not develop the hypertension (gd17 SBP in mmHg: P WT=102±3, P CD74 KO=100±3, P-PIC WT=147±4*, P-PIC CD74 KO=95±3, P-R837 WT=133±2*, P-R837 CD74 KO=97±1; *p<0.05 vs. P WT), endothelial dysfunction, proteinuria, or placental necrosis seen in P-PIC and P-R837 WT mice. In conclusion, CD74 is crucial for the development of TLR-induced PE-like symptoms in mice and CD74/CLIP depletion may be a promising therapeutic target for women with PE.

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Single Cell Profiling Reveals Unique CXCL13 Positive T Cell Subsets in the Tumor Microenvironment of Lymphocyte Rich Classic Hodgkin Lymphoma

Blood ◽

10.1182/blood-2020-134929 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 32-33

Author(s):

Tomohiro Aoki ◽

Lauren C. Chong ◽

Katsuyoshi Takata ◽

Katy Milne ◽

Elizabeth Chavez ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cells ◽

Single Cell ◽

Immune Cells ◽

Research Funding ◽

Immune Cell ◽

Expression Patterns ◽

The Other ◽

Tfh Cells

Introduction: Classic Hodgkin lymphoma (CHL) features a unique crosstalk between malignant cells and different types of normal immune cells in the tumor-microenvironment (TME). On the basis of histomorphologic and immunophenotypic features of the malignant Hodgkin and Reed-Sternberg (HRS) cells and infiltrating immune cells, four histological subtypes of CHL are recognized: Nodular sclerosing (NS), Mixed cellularity, Lymphocyte-rich (LR) and Lymphocyte-depleted CHL. Recently, our group described the high abundance of various types of immunosuppressive CD4+ T cells including LAG3+ and/or CTLA4+ cells in the TME of CHL using single cell RNA sequencing (scRNAseq). However, the TME of LR-CHL has not been well characterized due to the rarity of the disease. In this study, we aimed at characterizing the immune cell profile of LR-CHL at single cell resolution. METHODS: We performed scRNAseq on cell suspensions collected from lymph nodes of 28 primary CHL patients, including 11 NS, 9 MC and 8 LR samples, with 5 reactive lymph nodes (RLN) serving as normal controls. We merged the expression data from all cells (CHL and RLN) and performed batch correction and normalization. We also performed single- and multi-color immunohistochemistry (IHC) on tissue microarray (TMA) slides from the same patients. In addition, an independent validation cohort of 31 pre-treatment LR-CHL samples assembled on a TMA, were also evaluated by IHC. Results: A total of 23 phenotypic cell clusters were identified using unsupervised clustering (PhenoGraph). We assigned each cluster to a cell type based on the expression of genes described in published transcriptome data of sorted immune cells and known canonical markers. While most immune cell phenotypes were present in all pathological subtypes, we observed a lower abundance of regulatory T cells (Tregs) in LR-CHL in comparison to the other CHL subtypes. Conversely, we found that B cells were enriched in LR-CHL when compared to the other subtypes and specifically, all four naïve B-cell clusters were quantitatively dominated by cells derived from the LR-CHL samples. T follicular helper (TFH) cells support antibody response and differentiation of B cells. Our data show the preferential enrichment of TFH in LR-CHL as compared to other CHL subtypes, but TFH cells were still less frequent compared to RLN. Of note, Chemokine C-X-C motif ligand 13 (CXCL13) was identified as the most up-regulated gene in LR compared to RLN. CXCL13, which is a ligand of C-X-C motif receptor 5 (CXCR5) is well known as a B-cell attractant via the CXCR5-CXCL13 axis. Analyzing co-expression patterns on the single cell level revealed that the majority of CXCL13+ T cells co-expressed PD-1 and ICOS, which is known as a universal TFH marker, but co-expression of CXCR5, another common TFH marker, was variable. Notably, classical TFH cells co-expressing CXCR5 and PD-1 were significantly enriched in RLN, whereas PD-1+ CXCL13+ CXCR5- CD4+ T cells were significantly enriched in LR-CHL. These co-expression patterns were validated using flow cytometry. Moreover, the expression of CXCR5 on naïve B cells in the TME was increased in LR-CHL compared to the other CHL subtypes We next sought to understand the spatial relationship between CXCL13+ T cells and malignant HRS cells. IHC of all cases revealed that CXCL13+ T cells were significantly enriched in the LR-CHL TME compared to other subtypes of CHL, and 46% of the LR-CHL cases showed CXCL13+ T cell rosettes closely surrounding HRS cells. Since PD-1+ T cell rosettes are known as a specific feature of LR-CHL, we confirmed co-expression of PD-1 in the rosetting cells by IHC in these cases. Conclusions: Our results reveal a unique TME composition in LR-CHL. LR-CHL seems to be distinctly characterized among the CHL subtypes by enrichment of CXCR5+ naïve B cells and CD4+ CXCL13+ PD-1+ T cells, indicating the importance of the CXCR5-CXCL13 axis in the pathogenesis of LR-CHL. Figure Disclosures Savage: BeiGene: Other: Steering Committee; Merck, BMS, Seattle Genetics, Gilead, AstraZeneca, AbbVie: Honoraria; Roche (institutional): Research Funding; Merck, BMS, Seattle Genetics, Gilead, AstraZeneca, AbbVie, Servier: Consultancy. Scott:Janssen: Consultancy, Research Funding; Celgene: Consultancy; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoString, Research Funding; NIH: Consultancy, Other: Co-inventor on a patent related to the MCL35 assay filed at the National Institutes of Health, United States of America.; Roche/Genentech: Research Funding; Abbvie: Consultancy; AstraZeneca: Consultancy. Steidl:AbbVie: Consultancy; Roche: Consultancy; Curis Inc: Consultancy; Juno Therapeutics: Consultancy; Bayer: Consultancy; Seattle Genetics: Consultancy; Bristol-Myers Squibb: Research Funding.

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641 Spatially organized multicellular immune hubs in MMRd and MMRp colorectal cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.641 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A670-A670

Author(s):

Jonathan Chen ◽

Karin Pelka ◽

Matan Hofree ◽

Marios Giannakis ◽

Genevieve Boland ◽

...

Keyword(s):

Colorectal Cancer ◽

T Cells ◽

T Cell ◽

Immune Responses ◽

Mismatch Repair ◽

Molecular Mechanisms ◽

Immune Cell ◽

Single Cells ◽

Large Set ◽

Colon Tissue

BackgroundImmune responses to cancer are highly variable, with DNA mismatch repair-deficient (MMRd) tumors exhibiting more anti-tumor immunity than mismatch repair-proficient (MMRp) tumors. Almost all tumors are infiltrated with immune cells, but the types of immune responses and their effects on tumor growth, metastasis and death, vary greatly between different cancers and individual tumors. Which of the numerous cell subsets in a tumor contribute to the response, how their interactions are regulated, and how they are spatially organized within tumors remains poorly understood.MethodsTo understand the rules governing these varied responses, we transcriptionally profiled 371,223 single cells from colorectal tumors and adjacent normal tissues of 28 MMRp and 34 MMRd treatment-naive patients. We developed a systematic approach to discover cell types, their underlying gene programs, and cellular communities based on single cell RNA-seq (scRNAseq) profiles and applied it to study the distinguishing features of human MMRd and MMRp colorectal cancer. Cellular communities discovered from this analysis were spatially mapped in tissue sections using multiplex RNA in situ hybridization microscopy.ResultsTo understand the basis for differential immune responses in CRC, we first determined and compared the immune cell composition of MMRd and MMRp CRC and normal colon tissue, finding dramatic remodeling between tumor and normal tissue and between MMRd and MMRp tumors, particularly within the myeloid, T cell, and stromal compartments. Among the clusters enriched in MMRd tumors were activated CXCL13+ CD8 T cells. Importantly, gene program co-variation analysis revealed multicellular networks. We discovered a myeloid cell-attracting hub at the tumor-luminal interface associated with tissue damage, and an MMRd-enriched immune hub within the tumor, with activated IFNG+ and CXCL13+ T cells together with malignant and myeloid cells expressing T-cell-attracting chemokines (figure 1).ConclusionsOur study provides a rich dataset of cellular states, gene programs and their transformations in tumors across a relatively large cohort of patients with colorectal cancer. Our predictions of several multicellular hubs based on co-variation of gene expression programs, and subsequent spatial localization of two major immune-malignant hubs, organizes a large set of cell states and programs into a smaller number of coordinated networks of cells and processes. Understanding the molecular mechanisms underlying these hubs, and studying their temporal and spatial regulation upon treatment will be critical for advancing cancer therapy.Ethics ApprovalThis study was approved by the DF-HCC institutional review board (protocols 03-189 and 02-240).Abstract 641 Figure 1A coordinated network of CXCL13+ T cells with myeloid and malignant cells expressing ISGs. Image shows a portion of formalin-fixed paraffin-embedded tissue from an MMRd CRC specimen stained with multiplex RNA ISH / IF for PanCK-IF, CD3E-ISH, CXCL10/CXCL11-ISH, CXCL13-ISH, and IFNG-ISH. Note IFNG+ and CXCL13+ cells in proximity to cells expressing the chemokines CXCL10/CXCL11

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