Administration of rhIL-7 Is Associated with Increase in Precursor T-Cells in Bone Marrows of Patients with Idiopathic CD4 Lymphocytopenia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2747-2747
Author(s):  
Leah Osnos ◽  
Virginia Sheikh ◽  
Jamie Hahn ◽  
Ainhoa Perez-Diez ◽  
Irini Sereti ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Peripheral Blood ◽  
Double Positive ◽  
Bone Marrow Biopsies ◽  
Cell Counts ◽  
Bone Marrow Precursor ◽  
Precursor B Cells

Abstract Introduction Idiopathic CD4+ Lymphocytopenia (ICL) is a rare, likely heterogeneous syndrome characterized by persistent CD4+ lymphopenia (<300/μl) in the absence of HIV infection or other known immunodeficiency. The diverse clinical presentation may include opportunistic infections, malignancies, and autoimmune diseases. Though the etiology of ICL remains unknown, previous studies have suggested decreased production, proliferation, or survival of CD4+ T-cells. There is currently no FDA-approved therapy for ICL. Methods We analyzed bone marrow core biopsies of 12 ICL patients in a phase I/IIA NIH clinical trial designed to evaluate recombinant human Interleukin-7 (rhIL-7) as a potential therapy for ICL . Subjects received 3 injections of rhIL-7 over two 24-week periods. Bone marrow biopsies were performed at week 1 and week 24 to analyze numbers of T-cells and T-cell precursors at baseline and post rhIL-7 therapy. Peripheral blood T-cell counts were assessed in parallel. Double chromogenic immunohistochemical staining using anti-terminal deoxynucleotidyl transferase (TdT) and anti-CD3 antibodies was performed on fixed, paraffin-embedded samples using an automated stainer (Ventana). Single CD3-positive T-cells and double-positive TdT/CD3 precursor T-cells were counted in at least ten consecutive fields under a light microscope and results expressed as mean positive cell number per field before and after treatment with rhIL-7. Similar staining procedure using TdT and CD79a was performed to evaluate precursor B-cells in the same patient cohort. In addition, bone marrow biopsies from 10 healthy control subjects were analyzed in parallel. Results Compared to healthy controls, ICL patients showed no significant differences in the number of bone marrow precursor T-cells (p=0.069) but had lower levels of mature T-cells (p<0.0001) in marrow core biopsies. These data correlated with presence of peripheral blood T-lymphopenias. ICL patients had higher levels of precursor B-cells that were double positive for TdT/CD79a (p=0.016) compared to control marrows, but showed no significant differences in the number of mature B-cells (p=0.059). After treatment with rhIL-7, bone marrow precursor T-cells increased significantly between weeks 1-24 (p=0.016). Mature T-cells also increased significantly (p=0.031). Precursor B-cells and mature B-cells did not change significantly (p=0.313 and 0.375, respectively). During the same time, peripheral blood CD3+ T-cell counts and CD4+ T-cell counts also increased. Conclusion Novel histological technique for double chromogenic staining allows for the visualization of T-cell precursors in bone marrow biopsies. Our study revealed no evidence that lymphopenia in ICL patients is associated with lack of T-cell precursors in bone marrow, suggesting downstream defects in T-cell differentiation, proliferation or survival. Administration of rhIL-7 was associated with an increase in peripheral blood T-cells and increase in bone marrow precursor T-cells, while B-cell lineage cells remained unchanged. Disclosures No relevant conflicts of interest to declare.

The expression of Vpre-B/λ5 surrogate light chain in early bone marrow precursor B cells of normal and B cell-deficient mutant mice

Cell ◽  
1994 ◽  
Vol 77 (1) ◽  
pp. 133-143 ◽  
Author(s):  
Hajime Karasuyama ◽  
Antonius Rolink ◽  
Yoichi Shinkal ◽  
Faith Young ◽  
Frederick W. Alt ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Light Chain ◽  
Mutant Mice ◽  
Deficient Mutant ◽  
Surrogate Light Chain ◽  
Bone Marrow Precursor ◽  
Precursor B Cells

Overexpression of hTLX3 in Association with Mutant IL7Rα Is Sufficient to Generate T-ALL In Vivo and to Transform Thymocytes in Vitro

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 21-21
Author(s):  
Gisele Olinto Libanio Rodrigues ◽  
Julie Hixon ◽  
Hila Winer ◽  
Erica Matich ◽  
Caroline Andrews ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Cell Line ◽  
Lymphoblastic Leukemia ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Cell Counts

Mutations of the IL-7Rα chain occur in approximately 10% of pediatric T-cell acute lymphoblastic leukemia cases. While we have shown that mutant IL7Ra is sufficient to transform an immortalized thymocyte cell line, mutation of IL7Ra alone was insufficient to cause transformation of primary T cells, suggesting that additional genetic lesions may be present contributing to initiate leukemia. Studies addressing the combinations of mutant IL7Ra plus TLX3 overexpression indicates in vitro growth advantage, suggesting this gene as potential collaborative candidate. Furthermore, patients with mutated IL7R were more likely to have TLX3 or HOXA subgroup leukemia. We sought to determine whether combination of mutant hIL7Ra plus TLX3 overexpression is sufficient to generate T-cell leukemia in vivo. Double negative thymocytes were isolated from C57BL/6J mice and transduced with retroviral vectors containing mutant hIL7R plus hTLX3, or the genes alone. The combination mutant hIL7R wild type and hTLX3 was also tested. Transduced thymocytes were cultured on the OP9-DL4 bone marrow stromal cell line for 5-13 days and accessed for expression of transduced constructs and then injected into sublethally irradiated Rag-/- mice. Mice were euthanized at onset of clinical signs, and cells were immunophenotyped by flow cytometry. Thymocytes transduced with muthIL-7R-hTLX3 transformed to cytokine-independent growth and expanded over 30 days in the absence of all cytokines. Mice injected with muthIL7R-hTLX3 cells, but not the controls (wthIL7R-hTLX3or mutIL7R alone) developed leukemia approximately 3 weeks post injection, characterized by GFP expressing T-cells in blood, spleen, liver, lymph nodes and bone marrow. Furthermore, leukemic mice had increased white blood cell counts and presented with splenomegaly. Phenotypic analysis revealed a higher CD4-CD8- T cell population in the blood, bone marrow, liver and spleen compared in the mutant hIL7R + hTLX3 mice compared with mice injected with mutant IL7R alone indicating that the resulting leukemia from the combination mutant hIL7R plus hTLX3 shows early arrest in T-cell development. Taken together, these data show that oncogenic IL7R activation is sufficient for cooperation with hTLX3 in ex vivo thymocyte cell transformation, and that cells expressing the combination muthIL7R-hTLX3 is sufficient to trigger T-cell leukemia in vivo. Figure Disclosures No relevant conflicts of interest to declare.

scholarly journals Anti-CD19 Chimeric Antigen Receptor T Cell Treatment of Relapsed /Refractory Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma Resistant to Bruton's Tyrosine Kinase (BTK) Inhibitor

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 36-36
Author(s):  
Weihong Chen ◽  
Xin Du ◽  
Wenyujing Zhou ◽  
Changru Luo ◽  
Xiaoqing LI
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Lymph Nodes ◽  
Peripheral Blood ◽  
Serum Levels ◽  
Car T Cell ◽  
Car T ◽  
Btk Inhibitor

CASE PRESENTATION: A 68-year-old male was diagnosed with CLL/SLL in November 2007. Bone marrow asp/bx: 36.5% lymphocytes, 78% CD19, 65% ATM (11q22 deleted) positive cells, 13.5% D13S25 (13q14.3 deleted). On December 10, 2009, the patient took FCR scheme for five cycles, followed by FR scheme for one cycle, and then a month of Chlorambucil. On September 5, 2013, the patient took BR scheme for four cycles with no effect. From March 2015 to Feb 2016, 420 mg of Ibrutinib was administered daily. On January 15, 2016, the patient developed swollen lymph nodes in his right neck with intermittent lumps, fever and nausea. He was admitted into the hospital at Feb 2, 2016. Test results: multiple swollen superficial lymph nodes over the body, with the biggest measuring 60×30mm on the right neck, with no tenderness. Supplementary tests: peripheral white blood cells (WBC) 11.94×10E9/L, lymphocyte 7.5×10E9/L, CD19 cells 6.73×10E9/L, bone marrow lymphocyte 62%, peripheral blood lymphocyte 52%. Immunophenotype: CD5, CD19, CD20dim, CD23, CD11b dim, HLA-DR expression, visible CD5+CD19+ cell clusters, and visible immunoglobulin cKappa with restricted expression. On March 10, 2016, peripheral blood platelet 60 × 10E9/L, CD19 cells 1.94×10E9/L, lactate dehydrogenase 460U/L, FER 115.6ng/ml, hepatitis B virus carrier. Diagnosis: CLL/SLL IV stage, ATM (11q22) deletion, D13S25 (13q14. 3) positive, CD19 positive. Relapse of CLL/SLL occurred again after four months and at this stage the patient was considered for therapy in a clinical trial of CD19-specific chimeric antigen receptor (CAR-) T cell therapy. Ethical approval and informed consent were obtained for anti-CD19 CAR T Cell treatment of ibrutinib resistance in relapsed/refractory CLL/SLL. We infused autologous T cells transduced with a CAR T 19 retroviral vector with CLL/SLL at doses of 3.3 × 10E8 CART19 cells on Mar. 16 2016. Patients were monitored for responses, toxic effects, and the expansion and persistence of circulating CART19 cells. After CART19 cells were infused, the patient experienced chills, fever, headache, weak, anorexia, nausea, shortness of breath, chest tightness, heart palpitation, hypotension and shock for 9 days. The serum levels of IFN-Υ were at their highest at day 7 after CAR T cells infusion. Serum interleukin 6 (IL-6) was at 680pg/ml and CD3+ cells were 97.5%, CD8+ cells 72.8% (18.7-32.8%), FER was 1529.5ng/ml (Normal No. 22-322ng/ml) 14 days after CAR-T cell infusion. The serum levels of IL-6 were at their highest at day14. The patient was diagnosed as having cytokine release syndrome. After the patient took the anti-IL-6R antibody and anti-TNF antibody, he began to recover gradually. Enlarge lymph nodes shrunk after being infused with CART19 cells for 7 days. The peripheral blood CD19 B lymphocytes were 0 on day 14 after infused with CAR T19 cells. Q-PCR was used to detect the amount of the peripheral blood CART19 cells, which stood at 5485 copies/μl, 924 copies/μl, 191 copies/μl respectively 2 weeks, 6 weeks and 3 months after infusing with CART19 cells. The peripheral blood CART 19 cells were not detectable 4 months after infusing with CART19 cells until present. The lymphadenopathy was decreased gradually after 14 days of infusion. The MRI test showed that lymphadenopathy reduced markedly or disappeared after 6 months of infusion. ATM (11q22 deleted) negative, D13S25 (13q14.3 deleted) negative. After treatment with CAR T 19 cell therapy for 53 months, the patient remained disease-free, the patient's lymph nodes, lymphocytes and I mmunoglobulins were normal. CONCLUSIONS : Cancer immunotherapy as a method of cancer treatment is the most effective after conventional treatments such as radiotherapy, chemotherapy, and surgery. For BTK Inhibitor resistance in relapsed and refractory CD19+ CLL/SLL, CD19 is a favorable target, because the expression of CD19 is limited to B cells and not present in other tissues or cells. Currently, the efficacy of this treatment in treating CLL/SLL remains to be seen. The effects of chemotherapy on the patient's B cell lymphoma are negligible, due to the fact that his CLL/SLL have become relapsed and refractory. As a result we chose the CAR T19 cell therapy genetic engineering technique as a method of treatment, to which the patient has responded well. Therefor, CAR T cell technology overcome the limitations of existing cancer therapies and has great potential for development and application. Disclosures No relevant conflicts of interest to declare.

scholarly journals The Transcriptional Differences of Avian CD4+CD8+ Double-Positive T Cells and CD8+ T Cells From Peripheral Blood of ALV-J Infected Chickens Revealed by Smart-Seq2

2021 ◽  
Vol 11 ◽  
Author(s):  
Manman Dai ◽  
Li Zhao ◽  
Ziwei Li ◽  
Xiaobo Li ◽  
Bowen You ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Signaling Pathway ◽  
Cell Population ◽  
Peripheral Blood ◽  
T Cell Response ◽  
T Cell Subsets ◽  
High Expression ◽  
Receptor Interaction ◽  
Double Positive

It is well known that chicken CD8+ T cell response is vital to clearing viral infections. However, the differences between T cell subsets expressing CD8 receptors in chicken peripheral blood mononuclear cells (PBMCs) have not been compared. Herein, we used Smart-Seq2 scRNA-seq technology to characterize the difference of chicken CD8high+, CD8high αα+, CD8high αβ+, CD8medium+, and CD4+CD8low+ T cell subsets from PBMCs of avian leukosis virus subgroup J (ALV-J)-infected chickens. Weighted gene co-expression network analysis (WGCNA) and Trend analysis revealed that genes enriched in the “Cytokine–cytokine receptor interaction” pathway were most highly expressed in the CD8high αα+ T cell population, especially T cell activation or response-related genes including CD40LG, IL2RA, IL2RB, IL17A, IL1R1, TNFRSF25, and TNFRSF11, suggesting that CD8high αα+ T cells rather than other CD8 subpopulations were more responsive to ALV-J infections. On the other hand, genes involved in the “FoxO signaling pathway” and “TGF-beta signaling pathway” were most highly expressed in the CD4+CD8low+ (CD8low+) T cell population and the function of CD4+CD8low+ T cells may play roles in negatively regulating the functions of T cells based on the high expression of CCND1, ROCK1, FOXO1, FOXO3, TNFRSF18, and TNFRSF21. The selected gene expressions in CD8+ T cells and CD4+CD8low+ double-positive T cells confirmed by qRT-PCR matched the Smart-Seq2 data, indicating the reliability of the smart-seq results. The high expressions of Granzyme K, Granzyme A, and CCL5 indicated the positive response of CD8+ T cells. Conversely, CD4+CD8+ T cells may have the suppressor activity based on the low expression of activation molecules but high expression of T cell activity suppressor genes. These findings verified the heterogeneity and transcriptional differences of T cells expressing CD8 receptors in chicken PBMCs.

CD8 Expression on B Cells in Chronic Lymphocytic Leukemia

2000 ◽  
Vol 124 (9) ◽  
pp. 1361-1363
Author(s):  
Anwarul Islam ◽  
Adrian O. Vladutiu ◽  
Theresa Donahue ◽  
Selina Akhter ◽  
Amy M. Sands ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Tract Infection ◽  
Respiratory Tract ◽  
Respiratory Tract Infection ◽  
Peripheral Blood ◽  
Lymphocytic Leukemia ◽  
Cell Antigen

Abstract The expression of CD8, a restricted T-cell antigen, on B cells in B chronic lymphocytic leukemia is rare, and its significance, if any, remains unknown. We report herein a patient with B chronic lymphocytic leukemia in whom CD8 was strongly expressed on all B cells, both in the bone marrow and peripheral blood. The patient required no therapy for 6 years after being diagnosed as having B chronic lymphocytic leukemia. Then, when the disease progressed, he was treated with conventional doses of fludarabine phosphate (25 mg/m2 daily for 5 days), but unlike other patients with B chronic lymphocytic leukemia he tolerated this therapy poorly. He received a total of only 4 series of fludarabine therapy, and following each course of treatment, he developed considerable myelosuppression. After the fourth course of therapy, his bone marrow failed to show any evidence of regeneration, and he died as a result of intercurrent respiratory tract infection 1 month after his last dose of fludarabine was given.

scholarly journals Imbalances within the peripheral blood T-helper (CD4+) and T-suppressor (CD8+) cell populations in the reconstitution phase after human bone marrow transplantation

Blood ◽  
1988 ◽  
Vol 71 (5) ◽  
pp. 1196-1200 ◽  
Author(s):  
A Velardi ◽  
A Terenzi ◽  
S Cucciaioni ◽  
R Millo ◽  
CE Grossi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Bone Marrow Transplantation ◽  
T Cell ◽  
Peripheral Blood ◽  
Marrow Transplantation ◽  
Allogeneic Bone Marrow Transplantation ◽  
T Cell Subsets ◽  
Allogeneic Bone ◽  
T Helper

Abstract Peripheral blood T cell subsets were evaluated in 11 patients during the reconstitution phase after allogeneic bone marrow transplantation and compared with 11 age-matched controls. The proportion of cells coexpressing Leu7 and CD11b (C3bi receptor) markers was determined within the CD4+ (T-helper) and the CD8+ (T-suppressor) subsets by two- color immunofluorescence analysis. CD4+ and CD8+ T cells reached normal or near-normal values within the first year posttransplant. In contrast to normal controls, however, most of the cells in both subsets coexpressed the Leu7 and CD11b markers. T cells with such phenotype display the morphological features of granular lymphocytes (GLs) and a functional inability to produce interleukin 2 (IL 2). These T cell imbalances were not related to graft v host disease (GvHD) or to clinically detectable virus infections and may account for some defects of cellular and humoral immunity that occur after bone marrow transplantation./

scholarly journals Brain cancer induces systemic immunosuppression through release of non-steroid soluble mediators

Brain ◽  
2020 ◽  
Author(s):  
Katayoun Ayasoufi ◽  
Christian K Pfaller ◽  
Laura Evgin ◽  
Roman H Khadka ◽  
Zachariah P Tritz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Brain Cancer ◽  
Cd4 T Cell ◽  
Complex Class ◽  
Thymic Involution ◽  
Cell Counts ◽  
Histocompatibility Complex ◽  
Hallmark Feature

Abstract Immunosuppression of unknown aetiology is a hallmark feature of glioblastoma and is characterized by decreased CD4 T-cell counts and downregulation of major histocompatibility complex class II expression on peripheral blood monocytes in patients. This immunosuppression is a critical barrier to the successful development of immunotherapies for glioblastoma. We recapitulated the immunosuppression observed in glioblastoma patients in the C57BL/6 mouse and investigated the aetiology of low CD4 T-cell counts. We determined that thymic involution was a hallmark feature of immunosuppression in three distinct models of brain cancer, including mice harbouring GL261 glioma, B16 melanoma, and in a spontaneous model of diffuse intrinsic pontine glioma. In addition to thymic involution, we determined that tumour growth in the brain induced significant splenic involution, reductions in peripheral T cells, reduced MHC II expression on blood leucocytes, and a modest increase in bone marrow resident CD4 T cells. Using parabiosis we report that thymic involution, declines in peripheral T-cell counts, and reduced major histocompatibility complex class II expression levels were mediated through circulating blood-derived factors. Conversely, T-cell sequestration in the bone marrow was not governed through circulating factors. Serum isolated from glioma-bearing mice potently inhibited proliferation and functions of T cells both in vitro and in vivo. Interestingly, the factor responsible for immunosuppression in serum is non-steroidal and of high molecular weight. Through further analysis of neurological disease models, we determined that the immunosuppression was not unique to cancer itself, but rather occurs in response to brain injury. Non-cancerous acute neurological insults also induced significant thymic involution and rendered serum immunosuppressive. Both thymic involution and serum-derived immunosuppression were reversible upon clearance of brain insults. These findings demonstrate that brain cancers cause multifaceted immunosuppression and pinpoint circulating factors as a target of intervention to restore immunity.

scholarly journals Interleukin-2 production and response to interleukin-2 by peripheral blood mononuclear cells from patients after bone marrow transplantation: II. Patients receiving soybean lectin-separated and T cell-depleted bone marrow

Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1595-1603 ◽  
Author(s):  
K Welte ◽  
CA Keever ◽  
J Levick ◽  
MA Bonilla ◽  
VJ Merluzzi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Interleukin 2 ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

Abstract The ability of peripheral blood mononuclear cells (PBMC) to produce and respond to interleukin-2 (IL-2) was evaluated in 50 recipients of HLA- identical bone marrow (BM) depleted of mature T cells by soybean agglutination and E rosetting (SBA-E-BM). In contrast to our previous findings in recipients of unfractionated marrow, during weeks 3 to 7 post-SBA-E-BM transplantation (BMT), PBMC from the majority of patients spontaneously released IL-2 into the culture medium. This IL-2 was not produced by Leu-11+ natural killer cells, which were found to be predominant in the circulation at this time, but by T11+, T3+, Ia antigen-bearing T cells. The IL-2 production could be enhanced by coculture with host PBMC frozen before transplant but not by stimulation with mitogenic amounts of OKT3 antibody, thus suggesting an in vivo activation of donor T cells or their precursors by host tissue. Spontaneous IL-2 production was inversely proportional to the number of circulating peripheral blood lymphocytes and ceased after 7 to 8 weeks post-SBA-E-BMT in most of the patients. In patients whose cells had ceased to produce IL-2 spontaneously or never produced this cytokine, neither coculture with host cells nor stimulation with OKT3 antibody thereafter induced IL-2 release through the first year posttransplant. Proliferative responses to exogenous IL-2 after stimulation with OKT3 antibody remained abnormal for up to 6 months post-SBA-E-BMT, unlike the responses of PBMC from recipients of conventional BM, which responded normally by 1 month post-BMT. However, the upregulation of IL- 2 receptor expression by exogenous IL-2 was found to be comparable to normal controls when tested as early as 3 weeks post-SBA-E-BMT. Therefore, the immunologic recovery of proliferative responses to IL-2 and the appearance of cells regulating in vivo activation of T cells appear to be more delayed in patients receiving T cell-depleted BMT. Similar to patients receiving conventional BMT, however, the ability to produce IL-2 after mitogenic stimulation remains depressed for up to 1 year after transplantation.

Mezagitamab Induces Immunomodulatory Effect in Patients with Relapsed/Refractory Multiple Myeloma (RRMM)

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 9-9
Author(s):  
Michael Abadier ◽  
Jose Estevam ◽  
Deborah Berg ◽  
Eric Robert Fedyk
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
B Cells ◽  
Nk Cells ◽  
Peripheral Blood ◽  
Immune Cell ◽  
Cell Populations ◽  
Landscape Changes ◽  
Ki 67 ◽  
Immune Cell Subsets

Background Mezagitamab is a fully human immunoglobulin (Ig) G1 monoclonal antibody with high affinity to CD38 that depletes tumor cells expressing CD38 by antibody- and complement-dependent cytotoxicity. CD38 is a cell surface molecule that is highly expressed on myeloma cells, plasma cells, plasmablasts, and natural killer (NK) cells, and is induced on activated T cells and other suppressor cells including regulatory T (Tregs) and B (Bregs) cells. Data suggest that immune landscape changes in cancer patients and this may correlate with disease stage and clinical outcome. Monitoring specific immune cell subsets could predict treatment responses since certain cell populations either enhance or attenuate the anti-tumor immune response. Method To monitor the immune landscape changes in RRMM patients we developed a mass cytometry panel that measures 39-biomarkers to identify multiple immune cell subsets, including T cells (naïve, memory, effector, regulatory), B cells (naïve, memory, precursors, plasmablasts, regulatory), NK cells, NKT cells, gamma delta T cells, monocytes (classical, non-classical and intermediate), dendritic cells (mDC; myeloid and pDC; plasmacytoid) and basophils. After a robust analytical method validation, we tested cryopreserved peripheral blood and bone marrow mononuclear cells from 19 RRMM patients who received ≥ 3 prior lines of therapy. Patients were administered 300 or 600 mg SC mezagitamab on a QWx8, Q2Wx8 and then Q4Wx until disease progression schedule (NCT03439280). We compared the percent change in immune cell subsets at baseline versus week 4 and week 16. Results CD38 is expressed at different levels on immune cells and sensitivity to depletion by mezagitamab generally correlates positively with the density of expression. CD38 is expressed at high densities on plasmablasts, Bregs, NK-cells, pDC and basophils at baseline and this was associated with reductions in peripheral blood and bone marrow (plasmablasts, 95%, Bregs, 90%, NK-cells, 50%, pDC, 55% and basophils, 40%) at week 4 post treatment. In contrast, no changes occurred in the level of total T-cells and B-cells, which is consistent with low expression of CD38 on most cells of these large populations. Among the insensitive cell types, remaining NK-cells acquired an activated, proliferative and effector phenotype. We observed 60-150% increase in activation (CD69, HLA-DR), 110-200% increase in proliferation (Ki-67), and 40-375% increase in effector (IFN-γ) markers in peripheral blood and bone marrow. Importantly, NK-cells which did not express detectable CD38, also exhibited a similar phenotype possibly by a mechanism independent of CD38. Consistent with these data, the remaining CD4 and CD8 T-cell populations exhibited an activated effector phenotype as observed by 40-200% increase in activation, 60-200% increase in proliferation and 40-90% increase in effector markers in peripheral blood. A potential explanation for this acquisition of activated effector phenotypes could be a reduction in suppressive regulatory lymphocytes. Next, we measured levels of Tregs and Bregs, and observed that Bregs which are CD24hiCD38hi were reduced to 60-90% in peripheral blood and bone marrow. In contrast, total Tregs were reduced by only 5-25% because CD38 expression in Tregs appears as a spectrum where only ~10-20% are CD38+, and thus CD38+ Tregs were reduced more significantly (45-75%), reflecting the selectively of mezagitamab to cells expressing high levels of CD38. CD38+ Tregs are induced in RRMM patients, thus we looked at the phenotype of CD38-, CD38mid, and CD38high -expressing Tregs. We observed higher level of markers that correlate with highly suppressive Tregs such as Granzyme B, Ki-67, CTLA-4 and PD-1 in CD38high Tregs. Accordingly, the total Treg population exhibited a less active phenotype after exposure to mezagitamab, which selectively depleted the highly suppressive CD38+ Tregs. Conclusions Chronic treatment with mezagitamab is immunomodulatory in patients with RRMM, which is associated with reductions in tumor burden, subpopulations of B and T regulatory cells, and characterized by conventional NK and T cells exhibiting an activated, proliferative and effector phenotype. The immune landscape changes observed is consistent with the immunologic concept of converting the tumor microenvironment from cold-to-hot and highlights a key mechanistic effect of mezagitamab. Disclosures Berg: Takeda Pharmaceuticals Inc: Current Employment.

Plasma and Intracellular Concentration of TNF and Its Receptors in Peripheral Blood and Bone Marrow in Different Stages of B-CLL.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4781-4781
Author(s):  
Jacek Rolinski ◽  
Agnieszka Bojarska-Junak ◽  
Iwona Hus ◽  
Anna Dmoszynska
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
B Cells ◽  
B Lymphocytes ◽  
Peripheral Blood ◽  
Biological Effects ◽  
Leukemic Cells ◽  
Control Group ◽  
Stage Of Disease ◽  
Positive Correlation

Abstract TNF has been proposed to play a role in the regulation of growth and death of leukemic B-CLL cells. However, the biological effects of TNF on leukemic cells, as well as its role as a prognostic factor need to be further investigated. The aim of the study was to eevaluate the correlation of TNF and its receptors in peripheral blood (PB) and bone marrow (BM) with the stage of B-CLL and some other clinical parameters. PB and BM were taken from 44 newly diagnosed, untreated B-CLL. patients. The control group consisted of 20 healthy subjects. We used flow cytometry technique to assess the capability of T and B lymphocytes to produce TNF and ELISA method to measure plasma levels of TNF and their soluble receptors. We found, that PB and BM plasma TNF concentration in the patients was significantly higher than in the healthy control (2.61 pg/ml. vs 0.62 pg/ml; and 2.91 pg/ml vs 0.75 pg/ml, respectively p<0.001). TNF concentration in PB and BM was significantly higher in Rai stage III–IV than in early stages (p<0.01). There was a correlation between the PB and BM TNF level and lymphocytosis (p<0.005) and the total tumor mass (TTM) (p<0.0001). The PB and BM TNF concentration positively correlated with the percentage of T CD3+ lymphocytes producing intracellular TNF (p<0.01). The percentage of T cells from PB an BM expressing cytoplasmic TNF was significantly higher in patients (PB:39.11±16.97%; BM:40.73±18.19%) than in normal controls (PB:15.74±7.95%; BM:18.80±12.93%) (p< 0.00001; p<0.005, respectively). In PB and BM from B-CLL patients the percentage of CD3+ cells expressing intracellular TNF was significantly higher than the percentage of CD19+/TNF+ cells (p<0.0001). Besides, it was found that the percentage of T cells expressing cytoplasmic TNF positively correlated with the stage of disease (p<0.01). In PB positive correlation were found between the number of T CD3+/TNF+ cells and lymphocytosis (p<0.05) and TTM (p<0.001). The percentage of leukaemic B cells positive for TNF did not correlate with the stage of disease. There was increased expression of TNF-RI and TNF-RII in leukaemic B cells in comparison to normal B-cells was observed (p<0.0001). We found positive correlation between the number of CD5+ B lymphocytes and the levels of soluble TNF-RII (sTNF-RII) (p< 0.05). The sTNF-RII levels in PB and BM significantly correlated with the stage of disease acc. Rai (p<0.0001). Furthermore, the sTNF-RII concentration positively correlated with lymphocytosis and TTM (p<0.0001). These results strongly support the key role TNF in B-CLL pathogenesis. Our results suggest that TNF may function as growth factor for B-CLL cells. CD3+T cells may be the important source of this cytokine in advanced B-CLL. It seems that changes in T cells capability to produce cytoplasmic TNF are associated with disease progression. However, further studies are required to confirm the key role of TNF in B-CLL pathogenesis.

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