Acute Bone Marrow GvHD Is Associated With Delayed B Cell Neogenesis and Impaired Natural Antibody Response After Allogeneic Hematopoietic Stem Cell Transplantation

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4605-4605
Author(s):  
Angela Mensen ◽  
Korinna Jöhrens ◽  
Ioannis Anagnostopoulos ◽  
Sonya Demski ◽  
Christoph Ochs ◽  
...  

Graft-versus-host disease (GvHD) and severe infections are main complications limiting the success of allogeneic hematopoietic stem cell transplantion (alloHSCT). Delayed B cell reconstitution followed by B cell immune dysfunction considerably contributes to an increased risk for life-threatening infections. Several studies have shown that B cell regeneration is impaired in patients with systemic GvHD. Bone marrow (BM) suppression is often observed in parallel as GvHD symptoms appear suggesting the BM as a target of GvHD. Thus far, little is known about mechanisms of BM dysfunction during GvHD in alloHSCT patients. In this study, we investigated the reconstitution kinetics of peripheral blood B cell subsets in adult acute leukemic patients (n=52) before and within six months after alloHSCT by flow cytometry and correlated the data with RT-PCR quantified numbers of kappa-deleting-recombination-excision-circles (KREC), which are stable episomal plasmids generated during BM B cell development. Furthermore, we determined specific B cell antibody responses after in vitrostimulation with CpG, CD40L and T cell cytokines by EliSPOT analysis. To investigate BM as a direct target of allo-reactive T cells we performed histopathological stainings of BM biopsy samples obtained 3-4 weeks after alloHSCT. T cells were detected by specific anti-CD3 antibody staining and osteoblasts were morphologically evaluated. We observed in all patients a profound B cell immune deficiency already pre-transplant that proceeded within the first months post alloHSCT (mean B cells/ml blood±SEM: 11±3 pretransplant, 3±1 day14, 3±1 day28 post alloHSCT; 83±13 healthy control). Onset of B cell reconstitution is characterized by transitional B cell recovery representing the first B cell subset which emigrates from the BM. B cell reconstitution occurred either early (37% of patients) with a strong increase of transitional B cells between days 60-90 (mean transitional B cells/ml blood±SEM: Day 60, 36±10) or late (33% of patients) with delayed recovering transitional B cells (Day 180, 5±2). KREC copy numbers correlated highly positive and significantly with transitional B cell numbers (Spearman 0.94, p=0.017). Less correlation was obtained with naïve and CD27+ memory B cell recovery. Delayed onset of B cell reconstitution was significantly associated with both presence of systemic acute GvHD and full-intensity conditioning therapy (GvHD 71% vs non-GvHD 32%, Fisher´s exact p=0.044; full-intensity 41% vs reduced-intensity 5%, p=0.016). Supporting the hypothesis of bone marrow GvHD we could show a stronger infiltration of CD3+ T cells in the BM in late than in early recovering patients (≥5% T cell infiltration: 64% vs 17%, p=0.010). This increased T-cell infiltration was associated with reduced numbers of osteoblasts, known in mice to support B cell lymphopoiesis (no/few osteoblasts: 65% vs 17%, p=0.011). Impaired B cell lymphopoiesis further resulted in a delayed naïve and IgM memory B cell recovery compared to early recovering patients. No recovery of switched-memory B cells was seen for both patient groups within the analyzed time-period. Functionally, ex vivoactivation of patient B cells revealed higher numbers of IgM producing B cells specific for pneumococcal polysaccharide (PnP) at day 180 post alloHSCT in early than in late recovering patients. Polyclonal IgG producing B cells were significantly diminished in all patients. We conclude from these data, that early onset of B cell reconstitution is characterized by strong increase in regenerating transitional B cells within three months after alloHSCT. Herein, KREC appears as a suitable biomarker to monitor BM B cell output post-transplant. B cell regeneration is significantly delayed in patients showing increased occurrence of systemic acute GvHD and stronger T cell infiltration with loss of osteoblasts in the BM. Thus, delayed onset of B cell reconstitution might result from acute BM GvHD in which alloreactive T cells lead to an osteoblast niche destruction. Increased PnP specific IgM antibody responses are most likely result of higher numbers of early reconstituted transitional and IgM memory B cells but not naïve B cells that were shown not to produce IgM upon CpG stimulation (Capolunghi F et al. 2008). Thus, early B cell reconstitution might provide a first natural antibody immunity after alloHSCT, emphasizing the importance of a functional bone marrow niche. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3148-3148
Author(s):  
Armin Rashidi ◽  
Tandon Bevan ◽  
Amanda F. Cashen

Abstract Background: The recently introduced concept of bone marrow graft-versus-host disease (BM-GvHD) representing destruction of the host hematopoietic niche in the marrow by allogeneic donor T-cells is loosely defined. Otherwise unexplained B lymphocytopenia and other cytopenias of unclear etiology that frequently occur in the early post-transplant period are often attributed to BM-GvHD. B lymphocytopenia can co-exist with systemic GvHD, supporting the theory of concurrent donor T-cell-induced damage to the marrow causing suppressed B lymphopoiesis. However, demonstration of such correlations has been difficult in humans due to the lymphotoxic effect of steroids which are the frontline therapy for GvHD. The best evidence comes from a recent study showing a correlation between delayed recovery of B lymphopoiesis and donor T-cell infiltration in the marrow 3-4 weeks post-transplant. The potential confounding effect of steroids was not evaluated. The purpose of the present study was to assess whether there is significant donor T-cell infiltration in the marrow at the time of B lymphocytopenia in carefully selected, fully chimeric allo-SCT recipients on minimal or no steroids and with minimal or no systemic GvHD. Methods: A total of 11 patients who underwent allo-SCT for myeloid malignancies were retrospectively studied. Inclusion criteria were: (i) bone marrow biopsy available on days 90-100 or 170-190 post-SCT concurrent with peripheral blood B-cell count using flow cytometry, (ii) full donor chimerism at the time of bone marrow biopsy, (iii) no B lymphodepleting therapy post-SCT, (iv) not on more than 15 mg/d of prednisone on the day of measurement, (v) no GvHD other than acute stage I skin GvHD, and (vi) delayed B-cell recovery defined as <10 CD19+ B-cells/µl on days 90-100 or <100 cells/µl on days 180-200. Peripheral B-cell count measurements were not due to specific clinical indications and were either based on the treating physician's routine practice or the protocols patients were enrolled to. Similar to previous studies, increased T-cell infiltration was defined as ≥5% of total nucleated cells in the core determined by anti-CD3 antibody labeling in a fully chimeric recipient. We determined the frequency of increased marrow T-cell infiltration (as a marker of acute BM-GvHD) on the same day when delayed B-cell recovery (as a marker of impaired B lymphopoiesis) was diagnosed. Results: 11 patients (10 males) with a median (range) age of 60 (32-67) years were studied. Measurements were made between days 90-100 and 170-190 post-SCT in 4 and 7 patients, respectively. The underlying diagnosis was acute myeloid leukemia (n = 7) or myelodysplastic syndrome (n = 4). The donor was a matched sibling (n = 1), matched unrelated donor (n = 4), or haploidentical donor (n = 6). Conditioning was ablative in 5 patients. Leukopenia, anemia, and thrombocytopenia were present in 3, 9, and 11 patients, respectively. The median (range) B-cell count on days 90-100 and 180-200 was 7 (0-9) and 19 (0-65) cells/µl, respectively. All patients had ≥5% T-cells/µl in the concurrent core biopsy with one exception. This patient had zero B-cells on day 180 but no evidence of concurrent BM-GvHD while on 12 mg/d of prednisone for appetite stimulation. Conclusions: Using a carefully selected cohort of fully chimeric allo-SCT recipients with delayed B lymphopoiesis, on no or minimal amounts of steroids, and with minimal or no systemic GvHD, we demonstrated a high frequency of concurrent increased marrow T-cell infiltration. These results support the recently introduced concept of BM-GvHD and highlight its negative effect on B lymphopoiesis. We show that bone marrow damage by allogeneic T-cells can occur even in the absence of systemic GvHD. Given the difficulties in quantification of marrow T-cells on the core, a more reproducible definition for BM-GvHD is needed. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (6) ◽  
pp. 963-972 ◽  
Author(s):  
Angela Mensen ◽  
Korinna Jöhrens ◽  
Ioannis Anagnostopoulos ◽  
Sonya Demski ◽  
Maike Oey ◽  
...  

Key Points Donor T-cell infiltration of the bone marrow is associated with impaired B-cell immunity after allogeneic HSCT. Quantification of κ-deleting recombination excision circles as a biomarker for bone marrow B-cell output in different clinical episodes.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1554-1554
Author(s):  
Lucy S. Hodge ◽  
Steve Ziesmer ◽  
Frank J Secreto ◽  
Zhi-Zhang Yang ◽  
Anne Novak ◽  
...  

Abstract Abstract 1554 T cells in the tumor microenvironment influence the biology of malignant cells in many hematologic malignancies, often through cytokine-mediated interactions. Recent studies involving healthy B cells and CD4+T cells identified an interplay between IL-6 and IL-21, whereby IL-6 increased IL-21 production by T cells, driving the differentiation and IL-6 secretion of nearby B cells. In addition to their known effects on healthy B cell function, IL-6 and IL-21 have also been implicated in the pathology of various lymphomas. In Waldenstrom's macroglobulinemia (WM), IL-6 is elevated in the bone marrow and is associated with increased IgM production. However, the function of IL-21 in the WM tumor microenvironment and its relationship to IL-6 is poorly understood. Our objective in this study was to characterize IL-21 production and function in WM and to examine the role of IL-6 and IL-21 in regulating interactions between malignant B cells and T cells in the tumor microenvironment. Immunohistochemistry revealed significant IL-21 staining in bone marrows of patients with WM (n=5), but the areas of infiltration by WM in the bone marrow sections appeared negative for IL-21 staining. To better understand the origin of IL-21 in in the tumor microenvironment, IL-21 expression was assessed by PCR in the CD19−CD138− fraction of cells remaining in patient bone marrow aspirates after positive selection for malignant B cells (n=5). IL-21 transcript was detected in 4/5 samples. CD19−CD138− cells activated with anti-CD3 and anti-CD28 antibodies expressed higher levels of IL-21 transcript and secreted significantly higher levels of IL-21 protein compared to unstimulated cells, suggesting that IL-21 in the WM bone marrow is derived from activated T cells. Intracellular expression of IL-21 protein was confirmed in CD4+ and CD8+ cells within the CD19−CD138− population using flow cytometry. Furthermore, dual staining of WM bone marrow sections with antibodies against IL-21 and CD3 or CD20 revealed co-staining of IL-21 with CD3+ T cells but not with CD20+ B cells. The response of WM B cells to T-cell derived IL-21 was then assessed in positively selected CD19+CD138+ WM B cells (n=5) and in the MWCL-1 cell line. Using flow cytometry, both the IL-21 receptor and the required common gamma chain subunit were detected on all patient samples as well as on MWCL-1 cells. Treatment of MWCL-1 cells with IL-21 (100 ng/mL) for 72 h increased proliferation by 35% (p<0.05) and IgM secretion by 80% (p<0.005). Similarly, in primary CD19+CD138+ WM cells (n=5), proliferation increased on average by 38% and IgM secretion by 71%. No apoptotic effects were associated with IL-21 in WM. Characterization of STAT activation in response to IL-21 revealed significant phosphorylation of STAT3 in both CD19+CD138+ WM cells and MWCL-1 cells and was associated with increases in BLIMP-1 and XBP-1 protein and decreases in PAX5. As STAT3 activation is known to regulate IL-6, we assessed the effect of IL-21 on B cell-mediated IL-6 secretion using ELISA. IL-21 significantly increased IL-6 secretion by both primary CD19+CD138+ WM cells (n=4) and MWCL-1 cells (87.9 +/− 10.9 ng/mL vs. 297.8 +/− 129.2 ng/mL, p<0.05). Treatment with IL-6 and IL-21 together had no additional effect over IL-21 alone on proliferation or IgM secretion in MWCL-1 cells, but culturing anti-CD3/anti-CD28-activated CD19−CD138−cells from WM bone marrows with IL-6 significantly increased IL-21 secretion (n=3). Overall, these data indicate that T-cell derived IL-21 significantly promotes growth and immunoglobulin production by malignant WM B cells and that subsequent IL-6 secretion by malignant B cells may enhance the secretion of IL-21 by T cells within the bone marrow microenvironment. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2613-2613
Author(s):  
Marco L Davila ◽  
Christopher Kloss ◽  
Renier J Brentjens ◽  
Michel Sadelain

Abstract Abstract 2613 Recent work by our group and others demonstrates the therapeutic potential of CD19-targeted T cells to treat patients with indolent B cell malignancies. These studies make use of T cells that are genetically engineered with chimeric antigen receptors (CARs) comprising an scFv fused to various T cell activating elements. Whereas firs-generation CARs only direct T cell activation, second-generation CARs include two signal elements, such as CD3z and CD28 signaling domains (19–28z). We and our colleagues at MSKCC are currently evaluating the safety of 19–28z-transduced T cells in patients with acute leukemia (B-ALL) in a Phase I protocol (NCT01044069). Pre-clinical studies performed to date have mostly relied on xenogeneic models utilizing immunodeficient animals, which enable the evaluation of human engineered T cells but do not recapitulate all the interactions that may affect tumor eradication by CAR-modified T cells. We have therefore developed a pre-clinical immunocompetent mouse model of B-ALL, and addressed therein the impact of conditioning and T cell dose on the eradication of leukemia by syngeneic, CAR-targeted T cells. To establish an immunocompetent mouse model of B cell leukemia, we generated a clone from the lymph node of an Eμ-myc B6 transgenic mouse. The immunophenotype and gene-expression profile of clone Eμ-ALL01 is consistent with a progenitor B cell origin. Syngeneic B6 mice inoculated with this clone develop florid acute leukemia and die approximately 2–4 weeks after injection from progressive bone marrow infiltration. We created an anti-mouse CD19 CAR comprising all murine elements, including the CD8 signal peptide, a CD19-specific single chain variable fragment, the CD8 transmembrane region, and the CD28 and CD3z signaling domains. Transduction of the murine 19–28z CAR into mouse T cells was robust and successfully retargeted the T cells to B cells. In vitro assays demonstrated that m19–28 z transduced T cells mediated effective killing of CD19-expressing target cells and the production of effector cytokines such as IFNγ and TNFα. Cyclophosphamide either alone or in combination with control syngeneic T cells is insufficient to eradicate established Eμ-ALL01 in B6 mice. However, treatment with cyclophosphamide and m19–28z-transduced T cells cured nearly all mice. Mice sacrificed six months after treatment exhibited a dramatic reduction of B cells in the bone marrow (BM), blood, and spleen. The few remaining B lineage cells found in the BM had a phenotype consistent with early pro-B cells, suggesting that endogenous reconstitution of the B cell compartment was thwarted by persisting, functional m19–28z+ T cells. Thus, T cells are retained at the site of antigen expression, which is maintained through regeneration of progenitor B cells. The persisting CD19-targeted T cells in the BM exhibited a cell surface phenotype consistent with effector and central memory cells. Using B cell aplasia as a surrogate endpoint for assessing in vivo T cell function and persistence, we evaluated how conditioning chemotherapy and T cell dose determine the level of B cell depletion induced by adoptively transferred CD19-targeted T cells. Overall, increasing the cyclophosphamide or T cell dose, increased the degree and duration of B cell depletion and the number of persisting CAR-modified T cells. Significantly, increasing the T cell dose at a set cyclophosphamide level had a lesser impact than increasing the conditioning intensity for a given T cell dose. In summary, the new Eμ-ALL01 syngeneic, immunocompetent B-ALL model we describe here is a valuable tool for modeling CD19 CAR therapies. Our results indicate that m19–28z transduced T cells are effective at eradicating B-ALL tumor cells and persist long-term, preferentially in bone marrow. Our findings further establish that conditioning intensity and T cell dose directly determine B cell elimination and long-term T cell persistence. These studies in mice will serve as an important framework to further model and perfect our studies in patients with B-ALL. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4117-4117
Author(s):  
Sumantha Bhatt ◽  
Kathleen Brown ◽  
Feng Lin ◽  
Michael P Meyer ◽  
Margaret V. Ragni ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Gm Csf ◽  

Abstract Abstract 4117 Background: Hemophilia is an X-linked bleeding disorder resulting from a mutation in coagulation factor VIII (F.VIII). A major drawback of current plasma-derived or recombinant F.VIII therapy is the formation of F.VIII antibodies (inhibitors). Inhibitor formation is a T cell-dependent, B cell-mediated immune response to foreign infused F.VIII. Myeloid derived suppressor cells (MDSCs) are potent suppressors of T cell and B cell responses and are currently under study for therapeutic applications in transplantation and autoimmune diseases. However, the mechanisms of MDSC development and function remain unknown, and in vitro propagation of MDSCs has been a challenge. We hypothesized that MDSCs might be effective in inhibiting F.VIII inhibitor formation in the hemophilia A model. Methods: We developed a novel method for generating MDSCs in vitro by culturing bone marrow cells from hemophilia A mice with hepatic stellate cells (HSCs), hereafter referred to as HSC-conditioned myeloid cells (H-MCs). DCs were propagated from the bone marrow with GM-CSF and IL-4, whereas H-MCs were propagated from the bone marrow with GM-CSF and HSCs. Granulocyte contaminants were removed on day 2 and the remaining monocytic populations were harvested on day 5. Expression of cell surface antigens was analyzed by flow cytometry. Arginase1 and iNOS levels were compared by qPCR, with or without LPS stimulation. The in vitro suppressive capacity of the H-MCs was determined by a mixed leukocyte reaction culture. Splenic T cells from hemophilia A mice were stimulated by irradiated DCs (at a 1–20 ratio, APC to T cell) and recombinant F.VIII. Additional irradiated DCs or H-MCs were added in graded numbers as regulators. The proliferative response was determined by 3H-thymidine incorporation. The phenotype of cultured CD4+ T cells was characterized by intracellular staining for Foxp3 and IFN-gamma and analyzed by flow cytometry. Inhibition of B cells by H-MCs was determined by a CFSE dilution assay. Purified splenic B cells were labeled with CFSE and stimulated by Ig-M and IL-4. APCs (spleen cells) or H-MCs were added at a ratio of 1:10 (APC to B cell). The proportion of proliferating B cells was determined by CFSE dilution of B220 stained cells. In the COX-2 suppression assay, CFSE labeled B cells were treated with varying concentrations of the selective inhibitor of COX-2, NS398. The suppressive effect of H-MCs on B cells in vivo was determined by simultaneously administering H-MCs (I.V) and F.VIII (I.V.) to hemophila A mice on day 0 and rechallenging with recombinant F.VIII on days 2 and 4. WT B6 mice and hemophilia A mice without H-MC transfer served as controls. Plasma anti-F.VIII antibody titers were measured on day 12 by a modified ELISA assay. Results: H-MCs expressed low levels of costimulatory molecules but high levels of the inhibitory molecule B7-H1 and immunoregulatory enzyme arginase-1. In contrast, DCs expressed high levels of costimulatory molecules and MHC class II. In vitro studies demonstrated that the H-MCs markedly inhibited antigen specific T cell proliferation induced by dendritic cells in response to recombinant F.VIII (Fig. 1). H-MCs altered the T cell response in hemophilia A mice by promoting the expansion of regulatory T cells and inhibiting IFN-γ producing CD4+ T cells. When the H-MCs were cocultured with B cells isolated from hemophilia A mice, in the presence of Ig-M and IL-4, the H-MCs abrogated B cell activation and proliferation directly (Fig. 2). H-MCs may be modulating the B cell response through the Cox-2 pathway, as inhibition of Cox-2 through NS398 led to the restoration of B cell proliferation. More importantly, adoptive transfer of H-MCs into hemophilia Amice, at the time of F.VIII infusion, markedly suppressed anti-F.VIII antibody formation (Fig. 3). Conclusion: These results suggest that HSC conditioned myeloid cells may represent a potential therapeutic approach to induction of immune tolerance in patients with hemophilia A andother immune disorders. Disclosures: No relevant conflicts of interest to declare.


2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 76-76
Author(s):  
Young Kwang Chae ◽  
William Han Bae ◽  
Yeonjoo Choi ◽  
Young Suk Kim ◽  
Jonathan Forrest Anker ◽  
...  

76 Background: Compared to recent advances in our knowledge of T cell biology with success of immunotherapy, little progress has been made in understanding of the effects of B cells in tumor microenvironment and their interactions with T cells. Preclinical studies reported that B cells may have immune suppressive roles in tumor microenvironment via induction of T cell exhaustion. However, this association has not been shown in human tissues. We explored the landscape of tumor infiltrating B and T cells and their association with tumor microenvironment in various human cancers for which the FDA approved the use of immune checkpoint inhibitors. Methods: Expression patterns for 812 immune related genes from the TCGA database were utilized to define tumor infiltrating cells in 2951 patients with bladder urothelial carcinoma, renal clear cell carcinoma, skin cutaneous melanoma, lung squamous cell carcinoma, lung adenocarcinoma, and head and neck squamous cell carcinoma. Odds ratios (ORs) of the numbers of tumors with versus without activated B cell infiltration by the presence of activated CD8T cell infiltration were calculated. Results: Immune landscape of the six human cancers showed a consistent inverse association between tumor infiltrating activated B and CD8 T cells (OR = 0.18, p < 0.001). B cell infiltration was associated with increased expressions of immune checkpoints PD-L1, PD-1 and CTLA-4 and regulatory cytokines TGF-β, IL-10 and IL-35, which are known to be secreted by regulatory B cells. Angiogenic markers, such as angiopoietins, VEGF, MMP-9, CXCL10, CXCL11 and Tie2, showed differential expression patterns between B cell high and low groups. Conclusions: This is the first study that reports the inverse association between tumor infiltrating B and CD8 T cells in human tissues. The strong associations between B cell infiltration and increased expressions of suppressive cytokines and immune checkpoints suggest regulatory B cells may play a role in the T cell suppression in tumor microenvironment. Our results implicate that depleting B cells, leading to possible disinhibition of T cell activation, may be a future therapeutic option in potentiating T cell mediated immunity.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1094-1094
Author(s):  
Ji Young Lim ◽  
Sung-Eun Lee ◽  
Yoo-Jin Kim ◽  
Gyeongsin Park ◽  
Eun Young Choi ◽  
...  

Abstract Allogeneic hematopoietic stem cell transplantation is an important therapeutic modality used to treat malignancies of hematopoietic origin, such as leukemia and lymphoma. However, development of graft-versus-host disease (GVHD) causes non-relapse mortality and substantial morbidity of recipients. Myeloid differentiation factor 88 (MyD88), a major adaptor mediating TLR signaling, is also known to deliver pro-inflammatory signals. Activation of inflammatory signaling through MyD88 plays a key role in the expansion of myeloid-derived suppressor cells (MDSC) which are a heterogeneous population of immature myeloid ells with anti-inflammatory activity. To explore the contribution of MyD88 expressed by donor bone marrow (BM) cells to development of GVHD, we induced GVHD using T-cell-depleted BM (TCD-BM) isolated from MyD88-deficient (MyD88KO) mice and T cells isolated from wild-type (WT) mice. We employed C57BL/6 (H-2b) → B6D2F1 (H-2b/d) mouse model of GVHD, which differ at major and minor histocompatibility loci. Lethally irradiated B6D2F1 recipient mice were transplanted with either T cell-depleted bone marrow (TCD BM, 5 x 106) from either WT or MyD88KO mice together with WT spleen T cells (1 x 106). Transplantation with MyD88KO TCD BM aggravated GVHD; serious gut damage was evident, with infiltration of T cells specifically into the intestines of recipients. GVHD hosts transplanted with MyD88KO TCD BM exhibited markedly reduced expansion of MDSC. GVHD aggravation after transplantation with MyD88KO TCD-BM, associated with high-level T cell infiltration into the intestine and insignificant expansion of MDSC, was reproduced in another minor histocompatibility mismatch model (C57BL/6 → BALB.B). We next examined allogeneic T cells in the spleens of GVHD hosts in terms of the expression levels of CCR9, which are known to be associated with T cell migration to the intestinal mucosa and the proportion of CCR9 positive cells in CFSE low CD8+ T cells was higher in recipients of MyD88KO TCD BM than WT controls. In parallel, the levels of CCL25 were more highly expressed in the gut of MyD88KO recipients than WT controls. Mixed leukocyte cultures of CFSE- labeled C57BL/6 T cells and irradiated B6DF1 feeder cells were prepared in the presence of MDSC isolated from MyD88KO or WT mice. T cells, co-incubated with MDSC isolated from MyD88KO BM, exhibited a greater extent of CFSE dilution and less Annexin V staining, compared to T cells co-incubated with cells from WT BM. Moreover, MDSC from recipients of MyD88KO TCD BM exhibited a reduced suppressive function, compared to their WT counterparts. Next, we determined whether insufficient expansion of and ineffective suppression by MDSC caused severe GVHD in recipients of MyD88KO TCD BM. Supplementation of transplanted mice with MDSC from WT mice, not from MyD88KO mice, attenuated the severity of GVHD and reduced intestinal T cell infiltration in recipients of MyD88KO TCD BM. To verify the importance of MyD88-mediated signaling by MDSC in protection against severe GVHD, we determined if transplantation with TCD-BM cells containing high levels of MDSC attenuated the severity of GVHD. Pre-treatment of BM donors with lipopolysaccharide increased the frequencies of MDSC and the amounts of MyD88 transcripts in TCD-BM transplant, and alleviated the severity of GVHD and intestinal T-cell infiltration. To explore whether MDSC expansion levels could be used to predict the severity of intestinal GVHD, the T/MDSC ratios were calculated in blood of patients at the time of engraftment and were significantly higher in patients with intestinal GVHD ≥ grade 2. In conclusion, we have shown that MyD88-dependent MDSC expansion from donor BM is critical for protection against fatal acute intestinal GVHD. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2865-2865 ◽  
Author(s):  
James N. Kochenderfer ◽  
Mark E. Dudley ◽  
Maryalice Stetler-Stevenson ◽  
Wyndham H. Wilson ◽  
John E. Janik ◽  
...  

Abstract Abstract 2865 T cells can be genetically modified to express chimeric antigen receptors (CARs) that specifically recognize the B-cell antigen CD19. Adoptive transfer of autologous T cells expressing anti-CD19 CARs is an attractive new approach for treating B-cell malignancies. We have constructed a CAR that consists of the variable regions of a mouse-anti-human-CD19 antibody coupled to the signaling domains of CD28 and CD3-zeta. We have treated 5 patients with 2 doses of 60 mg/kg of cyclophosphamide and 5 doses of 25 mg/m2 of fludarabine followed by infusions of anti-CD19-CAR-transduced T cells and administration of high-dose IL-2. All of the patients received infusions of cells that produced cytokines in a CD19-specific manner. The percentage of the infused cells that expressed the anti-CD19 CAR as measured by flow cytometry ranged from 45% to 65%. The first patient enrolled on our trial has follicular lymphoma. He was treated twice. The patient obtained a partial remission (PR) from his first course of chemotherapy, 0.4×109 anti-CD19-CAR-transduced T cells, and IL-2 (reported in Kochenderfer et al. Blood First Edition); however, he subsequently developed progressive disease, and 40 weeks after his first CAR-transduced T cell infusion he received a second course of chemotherapy followed by 2×109 CAR-transduced T cells and IL-2. The second course of treatment resulted in an additional PR and was not associated with any toxicity that could be attributed to the CAR-transduced T cells. At last follow-up, a small amount residual disease detected only by positron emission tomography remained. In this first patient, the initial treatment course resulted in eradication of blood and bone marrow B-lineage cells for 39 weeks. In contrast to the prolonged eradication of B-lineage cells after the initial treatment course, the number of polyclonal blood B cells normalized 9 weeks after the second CAR-transduced T cell infusion. CAR-transduced T cells were present at a level of 0.1% of total peripheral blood mononuclear cells (PBMCs) one month after the first CAR-transduced T cell infusion. Despite the five-fold higher dose of CAR-transduced T cells administered with the second treatment, CAR-transduced T cells were not detected in the blood one month after the second CAR-transduced T cell infusion. The second patient treated on our protocol had follicular lymphoma and had received extensive prior therapy including autologous stem cell transplantation. After an initially uncomplicated course, this patient developed pneumonia caused by culture-proven influenza A virus and died 18 days after CAR-transduced T cell infusion. Quantitative PCR was used to measure the level of CAR-transduced cells in multiple tissues obtained from this patient at autopsy. CAR-transduced cells were widely distributed with the highest levels in the spleen and bone marrow. The third patient treated on our trial obtained a complete remission of advanced chronic lymphocytic leukemia (CLL) after treatment with chemotherapy, infusion of 2×109 anti-CD19-CAR-transduced T cells, and IL-2. At the time of last follow-up, three months after treatment, adenopathy had resolved, CLL cells were not detected by flow cytometry analysis of the blood and bone marrow, and the number of normal polyclonal B cells in the blood was below normal levels. This patient had a period of fever and hypotension 7 days after cell infusion that was associated with an elevated serum interferon-gamma level of 1532 pg/mL. At the time of the hypotensive episode 7 days after cell infusion, anti-CD19-CAR-transduced cells made up 2.1% of PBMCs. The fourth patient treated on our study obtained a PR of splenic marginal zone lymphoma that continues 2 months after treatment with chemotherapy, 2×109 CAR-transduced T cells, and IL-2. This patient did not have prolonged depletion of normal B cells after treatment, and he did not have any toxicity that could be attributed to the anti-CD19 CAR-transduced T cells. We recently treated a fifth patient who has CLL. Follow-up on this patient is too short to evaluate toxicity or response. In conclusion, we have shown that adoptive transfer of anti-CD19-CAR-transduced T cells with in vivo activity is feasible. The promising results obtained on this trial raise important questions for future research aimed at optimizing therapy with anti-CD19-CAR-transduced T cells. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4478-4478
Author(s):  
Anushruti Sarvaria ◽  
Ahmad Khoder ◽  
Abdullah Alsuliman ◽  
Claude Chew ◽  
Takuya Sekine ◽  
...  

The immunosuppressive function of IL10 producing regulatory B cells (Bregs) has been shown in several murine models of inflammation and autoimmune disease. However, there is a paucity of data regarding the existence of an equivalent regulatory B cell subset in healthy individuals and their potential role in the pathogenesis of chronic graft-versus-host disease (cGVHD) remains unknown. Here, we examined the functional regulatory properties of peripheral blood (PB)-derived human B cell subsets from healthy individuals. In addition, we carried out studies to explore their role in cGVHD, using B cells from patients following allogeneic stem cell transplantation (HSCT). We first determined whether human IL-10 producing B cells are enriched within any othe previously described human B cell subsets: CD19+IgM+CD27+ IgM memory, CD19+IgM-CD27+ switched memory, CD19+IgM+CD27- naive, and and transitional CD19+CD24hiCD38hi. Following in vitro stimulation with CD40 ligand, the majority of IL-10 producing B cells were found within the CD24hiCD38hi transitional and CD19+IgM+CD27+B cell subsets. We next assessed the regulatory properties of the PB-derived B cell subsets, by sort-purifying IgM memory (CD19+IgM+CD27+), switched memory (CD19+IgM-CD27+), naïve (CD19+IgM+CD27-) and transitional (CD19+CD24hiCD38hi) B cells from healthy controls, and cultured them 1:1 with autologous magnetic-bead purified CD4+ T cells. CD3/CD28 stimulated CD4+ T cells cultured with either CD19+IgM+CD27- naïve or CD19+IgM-CD27+ switched memory B cells proliferated to the same extent and produced equivalent amounts of IFN-γ to cultures containing CD4+ T cells alone. In contrast, culture of CD4+ T cells with IgM memory and transitional B cells significantly suppressed CD4+ T cell proliferation [median percent proliferating CD4+ T cells 52.5%; (33%-75%)] and 51% (25%-63%)], respectively when compared with CD3/CD28 stimulated CD4+ T cells (positive control) [89.5% (75%-92%], p=0.0001. The inhibitory effect of IgM memory and transitional B cells on CD4+ T cell proliferation was cell dose dependent with the highest suppression observed at a ratio of 1:1. These data suggest that human PB transitional and IgM memory B cells are endowed with regulatory function. We next examined if the in vitro suppressive effect of transitional and IgM memory B cells is mediated by regulatory T cells (Tregs). For this purpose, CD4+ T cells were depleted of CD127lo CD25hi CD4+ T cells by magnetic cell purification. B cell subsets were cultured with CD3/CD28 stimulated CD4+ CD25- T cells at a ratio of 1:1. IgM memory and transitional B cells were able to significantly suppress the proliferation and Th1 cytokine response by CD4+ CD25- T cells compared to cultures containing CD4+ CD25-T cells alone, indicating that the suppressive activity of Bregs is independent of Tregs. To further understand the underlying mechanims though which Bregs exert T-cell suppression, we used antibody blockade experiments and showed that this suppressive effect was mediated partially via the provision of IL-10, but not TGF-ß. Using transwell experiments, we further determined that the suppressive function of Bregs is also partly dependent on direct T cell/B cell contact. We next assessed whether the activity of Breg cells might be altered in patients with cGVHD. B cells from patients with cGVHD were refractory to CD40 stimulation and produced less IL-10 when compared to patients without cGVHD post-SCT and healthy controls, [1.02% (0.22-2.26) vs.1.72% (0.8-5.52) vs. 2.16 (1.3- 5.6), p=0.001]. Likewise, the absolute number of IL-10 producing B cells was significantly lower in cGvHD patients compared to patients without cGVHD and healthy controls (p=0.007), supporting both a qualitative and quantitative defect in IL-10 producing B cells in cGvHD. Our combined studies provide important new data defining the phenotype of B cell populations enriched in regulatory B cells in healthy humans and provide evidence for a defect in the activity of such cells in patients with cGVHD post-SCT. In association with previous reports showing defects in Treg cell activity in GVHD, our results suggest the existence of a broad range of deficiencies in immune regulatory cell function in cGvHD patients. * Both Anushruti Sarvaria and Ahmad K contributed equally. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4542-4542
Author(s):  
Miki Iwamoto ◽  
Ken-ichi Matsuoka ◽  
Yusuke Meguri ◽  
Takeru Asano ◽  
Takanori Yoshioka ◽  
...  

Abstract Posttransplant cyclophosphamide (PTCy) is an effective prophylaxis for both acute and chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). Recent studies reported that PTCy has been associated with low incidence of viral infections and EB-LPD, suggesting PTCy-based immune modulation leads the favorable immune reconstitution after transplant. However, the immune reconstitution dynamics of each subset after HSCT using PTCy remains poorly understood. To address this issue, we explored the impact and role of PTCy on the early lymphocyte reconstitution by using murine BMT model. Irradiated B6D2F1 mice were transplanted with 5x106 spleen cells from the CD45.1 B6 mice together with 5x106 TCD-BM from CD45.2 B6 donors. Cyclophosphamide 100mg/kg or control vehicle was administered at day 3 after transplant. Peripheral blood mononuclear cells (PBMCs) and splenic cells were sequentially obtained at day7, 14 and 21.The chimeric balances among host-residual H-2kd+ cells, donor graft-derived cells and donor BM-derived cells in CD8+ T cells, CD4+ Tcons, Tregs, B cells and NK cells were monitored separately. To evaluate the homeostatic stability of each lymphocyte subset at various time points, proliferation marker Ki-67 and anti-apoptotic BCL-2 were also quantitatively examined in each subset. To evaluate the clonal diversity of T and B cells, we performed the TCR- and BCR- repertoire analysis at day 21. Between day 0, transplanted recipients were developed severe acute GVHD, however, recipients received PTCy at day 3 promptly showed the recovery of the weight and improvement of the clinical GVHD score after day 5, whereas control continue to lose weight, suggesting the effect of PTCy to ameliorate acute GVHD. At day 7, all T cell subsets were critically depleted from both peripheral blood and spleen. The number of T cells was markedly lower in PTCy group than in control group (CD8 T+ cells; 5.1 vs 155.1/mm2, P<0.01: CD4 Tcons; 5.2 vs 61.2/mm2, P<0.01: Treg; 0.02 vs 0.52/mm2, P<0.01, respectively). Especially, Ki-67+ proliferating cells, including Tcons and Tregs, were completely depleted, indicating these activated cells are very sensitive to cyclophosphamide intervention. However, interestingly, surviving T cells in recipients just after cyclophosphamide intervention showed significantly high-levels of BCL-2 expression than control recipients (MFI: CD8 T cells; 2.8 vs 10.0: CD4 Tcns; 2.9 vs 9.9: Treg; 1.8 vs 5.3, respectively). Based on the elevated anti-apoptotic elements, T cell in PTCy-treated recipients undergo aggressive homeostatic proliferation and the number of CD4 T cell subset, especially Tregs, took over that of control recipient by day 14. CD8+ T cell proliferation after PTCy was less aggressive than CD4 T cells, resulting Treg ratio to CD8 T cells in PTCy recipents was greatly higher than in control (Treg/CD8: 0.061 vs 0.031, P<0.05). During 3 weeks, T cell recovery was basically maintained by donor graft-derived cell, though PTCy recipents involved averagely 10% of host-residual T cells. In comparison to T cells, main reconstitution of B cells was maintained by donor stem cell-derived cell. In PTCy recipients, CD23+CD24+ Transitional-2 naïve B cell and CD21-CD24+ mature follicular B cell overwhelmingly increased by Day 21(Follicular B cells in PTCy group and control; 1.22e6 vs 1.31e5, P<0.0001). BCR-repertoire diversity analysis demostrated that PTCy resulted in the broad diversity of B cell repertoire (Inverse Simpson Index; 40.5 vs 13.9). Our data clearly indicated that PTCy contributes the favorable immune reconstitution by modulating coordinate T and B cell recovery. These findings might provide important information to promote immune tolerance after PTCy-based transplant. Disclosures Maeda: Mundipharma KK: Research Funding.


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