Radiation-Free Anti-CD3-Conditioning Regimen Maintains Tissue Protection Mechanisms and Prevents GVHD: Role of Tissue Expression of B7H1

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 62-62 ◽  
Author(s):  
Ying Chen ◽  
Chia-Lei Lin ◽  
Nainong Li ◽  
Gong Du ◽  
Lieping Chen ◽  
...  

Abstract We reported that donor CD8+ T cells mediated graft versus leukemia (GVL) activity without causing graft versus host disease (GVHD) in anti-CD3-conditioned recipients, although the same dose of donor CD8+ T cells caused lethal GVHD in recipients conditioned with sublethal total body irradiation (TBI) (J. Immunol. 2007). We recently observed that donor CD8+ T cells from the liver of anti-CD3-conditioned recipients showed a marked reduction in proliferation in response to anti-CD3/CD28 stimulation, as compared to those from TBI-conditioned recipients, indicating that donor CD8+ T cells are tolerized in the tissues of anti-CD3-conditioned recipients. B7H1, a co-inhibitory molecule, is constitutively expressed by hematopoietic cells and expressed by parenchymal cells after IFN-γ induction. B7H1 tolerizes T cells by interaction with its ligand PD-1 on activated T cells. To explore the role of B7H1 in GVHD prevention in anti-CD3-conditioned recipients, donor C57BL/6 CD8+ T cells (20×106) and bone marrow cells (100×106) were transplanted into anti-CD3-conditioned wild-type or B7H1−/− BALB/c recipients. While the wild-type recipients all survived for more than 100 days without signs of GVHD, the B7H1−/− recipients developed severe GVHD with diarrhea, weight-loss, and hair-loss, and 70% of them died 60 days after transplantation. Similarly, while donor CD8+ T and BM cells induced little GVHD in unconditioned Rag-2−/− BALB/c recipients, they induced severe lethal GVHD in B7H1−/− Rag-2−/− BALB/c recipients. Furthermore, donor CD8+ T and BM cells still induced lethal GVHD in unconditioned chimeric B7H1−/−Rag-2−/− recipients reconstituted with B7H1+/+Rag-2−/− BM. In addition, we observed upregulation of B7H1 expression by hepatocytes and intestine epithelial cells of anti-CD3-conditioned BALB/c or unconditioned Rag-2−/− recipients after donor cells infusion, as judged by RT-PCR, flow cytometry analysis, and histoimmunostaining of B7H1. In vivo bioluminescent imagine showed much more severe tissue infiltration of donor T cells in B7H1−/− recipients as compared to B7H1+/+ recipients, and the in vitro proliferation of donor CD8+ T cells from the liver of the former recipients was much more vigorous than that of the latter recipients. These results demonstrate that B7H1 expression by tissue parenchymal cells rather than hematopoietic cells tolerizes infiltrating donor T cells in GVHD target tissues and prevents GVHD; and that the radiation-free anti-CD3-conditioning regimen can maintain this tissue protection mechanism. (This study is surpported by Marcus Foundation and NIH R01 AI 066008).

1995 ◽  
Vol 182 (5) ◽  
pp. 1415-1421 ◽  
Author(s):  
T C Wu ◽  
A Y Huang ◽  
E M Jaffee ◽  
H I Levitsky ◽  
D M Pardoll

Introduction of the B7-1 gene into murine tumor cells can result in rejection of the B7-1 transductants and, in some cases, systemic immunity to subsequent challenge with the nontransduced tumor cells. These effects have been largely attributed to the function of B7-1 as a costimulator in directly activating tumor specific, major histocompatibility class I-restricted CD8+ T cells. We examined the role of B7-1 expression in the direct rejection as well as in the induction of systemic immunity to a nonimmunogenic murine tumor. B-16 melanoma cells with high levels of B7-1 expression did not grow in C57BL/6 recipient mice, while wild-type B-16 cells and cells with low B7-1 expression grew progressively within 21 d. In mixing experiments with B7-1hi and wild-type B-16 cells, tumors grew out in vivo even when a minority of cells were B7-1-. Furthermore, the occasional tumors that grew out after injection of 100% B-16 B7-1hi cells showed markedly decreased B7-1 expression. In vivo antibody depletions showed that NK1.1 and CD8+ T cells, but not CD4+ T cells, were essential for the in vivo rejection of tumors. Animals that rejected B-16 B7-1hi tumors did not develop enhanced systemic immunity against challenge with wild-type B-16 cells. These results suggest that a major role of B7-1 expression by tumors is to mediate direct recognition and killing by natural killer cells. With an intrinsically nonimmunogenic tumor, this direct killing does not lead to enhanced systemic immunity.


2021 ◽  
Author(s):  
Qi Tian ◽  
Zengzi Zhou ◽  
Luying Wang ◽  
Xin Sun ◽  
Bernard Arulanandam ◽  
...  

Chlamydia is known to both ascend to the upper genital tract and spread to the gastrointestinal tract following intravaginal inoculation. The gastrointestinal Chlamydia was recently reported to promote chlamydial pathogenicity in the genital tract since mice intravaginally inoculated with an attenuated Chlamydia , which alone failed to develop pathology in the genital tract, were restored to develop hydrosalpinx by intragastric co-inoculation with wild type Chlamydia . Gastrointestinal Chlamydia promoted hydrosalpinx via an indirect mechanism since Chlamydia in the gut did not directly spread to the genital tract lumen. In the current study, we further investigated the role of CD8 + T cells in the promotion of hydrosalpinx by gastrointestinal Chlamydia . First, we confirmed that intragastric co-inoculation with wild type Chlamydia promoted hydrosalpinx in mice that were inoculated with an attenuated Chlamydia in the genital tract one week earlier. Second, the promotion of hydrosalpinx by intragastrically co-inoculated Chlamydia was blocked by depleting CD8 + T cells. Third, adoptive transfer of the gastrointestinal Chlamydia -induced CD8 + T cells was sufficient for promoting hydrosalpinx in mice that were intravaginally inoculated with an attenuated Chlamydia . These observations have demonstrated that CD8 + T cells induced by gastrointestinal Chlamydia are both necessary and sufficient for promoting hydrosalpinx in the genital tract. The study has laid a foundation for further revealing the mechanisms by which Chlamydia -induced T lymphocyte responses (as a 2 nd hit) promote hydrosalpinx in mice with genital Chlamydia -triggered tubal injury (as a 1 st hit), a continuing effort in testing the two-hit hypothesis as a chlamydial pathogenic mechanism.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 596-596
Author(s):  
Shoji Asakura ◽  
Daigo Hashimoto ◽  
Ken-ichi Matsuoka ◽  
Yukimi Sakoda ◽  
Mitsune Tanimoto ◽  
...  

Abstract We previously demonstrated that alloantigen expression on host target epithelium is not necessary but augment acute GVHD (Nat Med 2002). Here, we tested the role of alloantigen expression on host target epithelium on the GVL effect. We created BM chimeras, [B6 → C3H.Sw] where only host hematopoietic cells express multiple minor histocompatibility antigens (mHAs) allogeneic to the donors but not on host target epithelium. Identically treated [B6 → B6] chimeras were created as controls where both hematopoietic and target cells express mHAs allogeneic to the donors. Four month later, these chimeras were reirradiated and were injected with 5×106 BM and 1×106 CD8 T cells harvested from C3H.Sw donors. Acute GVHD developed in [B6 → C3H.Sw] chimeras but was less severe in these chimeras than controls (Table). Next, animals were transplanted, as above, with the addition of 2500 B6-derived EL4 thymoma to the donor inoculum. The cause of death was determined by postmortem examination to be either GVHD or leukemia (presence of hepatic and/or splenic nodules). All [B6 → B6] recipients of C3H.Sw CD8+ cells died from leukemia, although their survival time was significantly prolonged compared to syngeneic controls (P<.01). Surprisingly, [B6 → C3H.Sw] chimeras displayed more potent GVL effects than controls (Table), in spite of reduced GVHD in these chimeras. Similar results were obtained in the other sets of chimeras [DBA → Balb/c] when injected with BM and T cells isolated from Balb/c donors together with DBA-derived P815 mastocytoma and [Balb/c → DBA] when injected with BM and T cells isolated from DBA donors and Balb/c-derived A20 lymphoma. These animals displayed more potent GVL effects compared to control chimeras (Table). To elucidate the mechanisms of this superior GVL effect in these chimeras, analysis of the spleen was performed 3 weeks after BMT. Expansion and activation of donor CD8+ T cells were greater in [B6 → C3H.Sw] recipients than those in [B6 → B6] recipients in spleens (P<.05). Thus, alloantigens expressed on host antigen-presenting cells stimulate host-reactive T cells but in the absence of alloantigen expression on host epithelium contraction of host-reactive T cells may be impaired, resulting in a superior GVL effect. These results provides a complete picture of the role of alloantigen expression on host epithelium in allogeneic hematopoietic cell transplantation; alloantigen expression on host target cells i) does not always necessary to induce acute GVHD, ii) augment GVHD, and iii) suppress GVL effects. These imply that allogeneic cellular therapy targeting at mHA preferentially expressed on hematopoietic cells may induce potent GVL effects while inducing less severe GVHD. Donor Recipients GVHD score (d21) GVHD mortality (d50) Leukemia mortality (d50) *P<.05. **not examined B6 CD8 [B6 → B6] 1.0 +/− 0.4 0% 100% C3H.Sw CD8 [B6 → B6] 3.7 +/− 0.3 33% 95% C3H.Sw TCD [B6 → C3H.Sw] NE** 0% 100% C3H.Sw CD8 [B6 → C3H.Sw] 2.1 +/− 0.4* 0%* 69%* Balb/c TCD [DBA → DBA] 0.2 +/− 0.3 NE** 100% Balb/c T [DBA→ DBA] 3.2 +/− 0.6 NE** 60% Balb/c TCD [DBA→ Balb/c] NE** NE** 100% Balb/c T [DBA→ Balb/c] 1.3 +/− 0.3* NE** 10%* DBA TCD [Balb/c→ Balb/c] 0.0 +/− 0.0 NE** 100% DBA T [Balb/c→ DBA] 1.8 +/− 0.6 NE** 100% DBA TCD [Balb/c→ Balb/c] NE** NE** 100% DBA T [Balb/c→ DBA] 0.8 +/− 0.3 NE** 30%*


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2974-2974
Author(s):  
Xiaofan Li ◽  
Wei He ◽  
Ruishu Deng ◽  
Can Liu ◽  
Miao Wang ◽  
...  

Abstract Abstract 2974 Alloreactive donor CD8+ T cells facilitate engraftment and mediate graft versus leukemia (GVL) effects but also cause graft versus host disease (GVHD) in murine and human recipients after allogeneic hematopoietic cell transplantation (HCT). B7-H1 (PD-L1) expression by antigen-presenting cells has an important role in tolerizing activated T cells by binding to PD-1. We and others previously reported that disruption of binding between B7-H1 and PD-1 augments acute GVHD. Parenchymal cells do not usually express B7-H1 but can be induced by inflammatory cytokines (i.e. IFN-g) to express B7-H1. The role of B7-H1 expression by parenchymal tissue cells in regulating the expansion and persistence of donor CD8+ cells in tissues of mice with GVHD has not yet been evaluated. In the current studies, we evaluated the role of B7-H1 expression by GVHD target tissues in regulating donor CD8+ T cell function in 3 different experimental GVHD systems, using in vivo bioluminescent imaging (BLI), in vivo BrdU-labeling, and in vitro proliferation assays. The first system evaluated the role of B7-H1 expression in TBI-conditioned recipients. In these recipients, injected donor CD8+ T cells showed two waves of expansion that correlated with two phases of clinical GVHD. The first wave of donor CD8+ T cell expansion was associated with upregulated expression of B7-H1 in GVHD target tissues and only weak clinical GVHD. The second wave of donor CD8+ T cell expansion was associated with loss of B7-H1 expression, vigorous donor CD8+ T proliferation and expansion in the GVHD target tissues, and lethal GVHD. In a gain-of-function experiment, B7-H1 expression was induced in hepatocytes by hydrodynamic injection of B7-H1 cDNA during the second wave of T cell expansion in mice with GVHD; this subsequently decreased T cell expansion in the liver and ameliorated GVHD. The second system evaluated the role of B7-H1 expression in anti-CD3-conditioned recipients. In wild-type recipients, injected donor CD8+ T cells had only a single wave of expansion, and the mice had no signs of GVHD. B7-H1 expression by tissue cells (i.e. hepatocytes) was up-regulated, and the tissue infiltrating donor CD8+ T cells were anergic. In B7-H1−/− recipients, injected donor CD8+ T cells proliferated vigorously in GVHD target tissues and caused lethal GVHD.The third system evaluated the role of B7-H1 in unconditioned Rag-2−/− recipients after administration of blocking anti-B7-H1 and in the B7-H1−/−Rag-2−/− chimeras with B7-H1 sufficient Rag-2−/− bone marrow cells, in which B7-H1 deficiency was only in tissue parenchymal cells. Both blockade of B7-H1 and B7-H1 deficiency in parenchymal cells resulted in vigorous donor CD8+ T proliferation in GVHD target tissues and caused lethal GVHD. Taken together, these results show that expression of B7-H1 in GVHD target tissue parenchymal cells plays an important role in regulating the proliferation of infiltrating donor CD8+ T cells and preventing the persistence of GVHD. Our studies also indicate that TBI but not anti-CD3 conditioning can lead to loss of GVHD target tissue cell expression of B7-H1 and persistence of GVHD. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2000 ◽  
Vol 96 (9) ◽  
pp. 2973-2980 ◽  
Author(s):  
Jonathan S. Serody ◽  
Susan E. Burkett ◽  
Angela Panoskaltsis-Mortari ◽  
Judith Ng-Cashin ◽  
Eileen McMahon ◽  
...  

To investigate the mechanism by which macrophage inflammatory protein-1α (MIP-1α) affects graft-versus-host disease (GVHD), the expression and function of MIP-1α in 2 murine models of GVHD were evaluated. In irradiated class I and class II disparate recipients, the expression of messenger RNA (mRNA) and protein for MIP-1α was significantly increased in GVHD target organs after transfer of allogeneic lymphocytes compared to syngeneic lymphocytes. When lymphocytes unable to make MIP-1α were transferred, there was a decrease in the production of MIP-1α in the liver, lung, and spleen of bm1 (B6.C-H2bm1/By) and bm12 (B6.C-H2bm12/KhEg) recipients compared to the transfer of wild-type splenocytes. At day 6 there was a 4-fold decrease in the number of transferred CD8+ T cells in the lung and approximately a 2-fold decrease in the number of CD8+ T cells in the liver and spleen in bm1 recipients after transfer of MIP-1α–deficient (MIP-1α−/−) splenocytes compared to wild-type (MIP-1α+/+) splenocytes. These differences persisted for 13 days after splenocyte transfer. In contrast, the number of donor CD4+ T cells found in the liver and lung was significantly increased after the transfer of MIP-1α−/− compared to wild-type splenocytes in bm12 recipients from day 6 through day 10. Thus, the transfer of allogeneic T cells was associated with the enhanced expression of MIP-1α in both a class I and class II mismatch setting. However, the increased expression only led to enhanced recruitment of CD8+, but not CD4+, donor T cells. Production of MIP-1α by donor T cells is important in the occurrence of GVHD and functions in a tissue-dependent fashion.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 941-941
Author(s):  
Brian Wadugu ◽  
Amanda Heard ◽  
Joseph Bradley ◽  
Matthew Ndonwi ◽  
Jin J Shao ◽  
...  

Abstract Somatic mutations in U2AF1, a spliceosome gene involved in pre-mRNA splicing, occur in up to 11% of MDS patients. While we reported that mice expressing mutant U2AF1(S34F) have altered hematopoiesis and RNA splicing, similar to mutant MDS patients, the role of wild-type U2AF1 in normal hematopoiesis has not been studied. U2AF1mutations are always heterozygous and the wild-type allele is expressed, suggesting that mutant cells require the residual wild-type (WT) allele for survival. A complete understanding of the role of wild-type U2AF1 on hematopoiesis and RNA splicing will enhance our understanding of how mutant U2AF1 contributes to abnormal hematopoiesis and splicing in MDS. In order to understand the role of wild-type U2af1 in normal hematopoiesis, we created a conditional U2af1 knock-out (KO) mouse (U2af1flox/flox). Homozygous embryonic deletion of U2af1using Vav1-Cre was embryonic lethal and led to reduction in fetal liver hematopoietic stem and progenitor cells (KLS and KLS-SLAM, p ≤ 0.05) at embryonic day 15, suggesting that U2af1 is essential for hematopoiesis during embryonic development. To study the hematopoietic cell-intrinsic effects of U2af1 deletion in adult mice, we performed a non-competitive bone marrow transplant of bone marrow cells from Mx1-Cre/U2af1flox/flox, Mx1-Cre/U2af1flox/wtor Mx1-Cre/U2af1wt/wtmice into lethally irradiated congenic recipient mice. Following poly I:C-induced U2af1deletion, homozygous U2af1 KOmice, but not other genotypes (including heterozygous KO mice), became moribund. Analysis of peripheral blood up to 11 days post poly I:C treatment revealed anemia (hemoglobin decrease >1.7 fold) and multilineage cytopenias in homozygous U2af1 KOmice compared to all other genotypes(p ≤ 0.001, n=5 each).Deletion of U2af1 alsoled to rapid bone marrow failure and a reduction in the absolute number of bone marrow neutrophils (p ≤ 0.001), monocytes (p ≤ 0.001), and B-cells (p ≤ 0.05), as well as a depletion of hematopoietic progenitor cells (KL, and KLS cells, p ≤ 0.001, n=5 each). Next, we created mixed bone marrow chimeras (i.e., we mixed equal numbers of homozygous KO and wild-type congenic competitor bone marrow cells and transplanted them into lethally irradiated congenic recipient mice) to study the effects of U2af1 deletion on hematopoietic stem cell (HSC) function. As early as 10 days following Mx1-Cre-induction, we observed a complete loss of peripheral blood neutrophil and monocyte chimerism of the U2af1 KOcells, but not U2af1 heterozygous KO cells, and at 10 months there was a complete loss of homozygous U2af1 KObone marrow hematopoietic stem cells (SLAM, ST-HSCs, and LT-HSCs), neutrophils, and monocytes, as well as a severe reduction in B-cells and T-cells (p ≤ 0.001, n=3-4 for HSCs. p ≤ 0.001, n=9-10 for all other comparisons). The data indicate that normal hematopoiesis is dependent on wild-type U2af1expression, and that U2af1 heterozygous KO cells that retain one U2af1 allele are normal. Next, we tested whether mutant U2AF1(S34F) hematopoietic cells require expression of wild-type U2AF1 for survival. To test this, we used doxycycline-inducible U2AF1(S34F) or U2AF1(WT) transgenic mice. We generated ERT2-Cre/U2af1flox/flox/TgU2AF1-S34F/rtTA(S34F/KO), and ERT2-Cre/U2af1flox/flox/TgU2AF1-WT/rtTA,(WT/KO) mice, as well as all other single genotype control mice. We then created 1:1 mixed bone marrow chimeras with S34F/KO or WT/KO test bone marrow cells and wild-type competitor congenic bone marrow cells and transplanted them into lethally irradiated congenic recipient mice. Following stable engraftment, we induced U2AF1(S34F) (or WT) transgene expression with doxycycline followed by deletion of endogenous mouse U2af1 using tamoxifen. As early as 2 weeks post-deletion of U2af1, S34F/KO neutrophil chimerism dropped to 5.4% indicating loss of mutant cells, while WT/KO neutrophil chimerism remained elevated at 31.6% (p = 0.01, n=6-8). The data suggest that mutant U2AF1(S34F) hematopoietic cells are dependent on expression of wild-type U2af1 for survival. Since U2AF1mutant cells are vulnerable to loss of the residual wild-type U2AF1allele, and heterozygous U2af1KO cells are viable, selectively targeting the wild-type U2AF1allele in heterozygous mutant cells could be a novel therapeutic strategy. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Author(s):  
Zengzi Zhou ◽  
Qi Tian ◽  
Luying Wang ◽  
Xin Sun ◽  
Nu Zhang ◽  
...  

Chlamydia trachomatis is a leading infectious cause of infertility in women due to its induction of lasting pathology such as hydrosalpinx. Chlamydia muridarum induces mouse hydrosalpinx because C. muridarum can both invade tubal epithelia directly (as a 1 st hit) and induce lymphocytes to promote hydrosalpinx indirectly (as a 2 nd hit). In the current study, a critical role of CD8 + T cells in chlamydial induction of hydrosalpinx was validated in both wild type C57BL/6J and OT1 transgenic mice. OT1 mice failed to develop hydrosalpinx partially due to the failure of their lymphocytes to recognize chlamydial antigens. CD8 + T cells from naïve C57BL/6J rescued the recipient OT1 mice to develop hydrosalpinx when naïve CD8 + T cells were transferred at the time of infection with Chlamydia . However, when the transfer was delayed for 2 weeks or longer after the chlamydial infection, naïve CD8 + T cells no longer promoted hydrosalpinx. Nevertheless, Chlamydia -immunized CD8 + T cells still promoted significant hydrosalpinx in the recipient OT1 mice even when the transfer was delayed for 3 weeks. Thus, CD8 + T cells must be primed within 2 weeks after chlamydial infection to be pathogenic but once primed, they can promote hydrosalpinx for >3 weeks. However, Chlamydia -primed CD4 + T cells failed to promote chlamydial induction of pathology in OT1 mice. This study has optimized an OT1 mouse-based model for revealing the pathogenic mechanisms of Chlamydia -specific CD8 + T cells.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 729-729
Author(s):  
Alan M. Hanash ◽  
Lucy W. Kappel ◽  
Nury L. Yim ◽  
Rebecca A. Nejat ◽  
Gabrielle L. Goldberg ◽  
...  

Abstract Abstract 729 Allogeneic hematopoietic transplantation is frequently the only curative therapy available to patients with hematopoietic malignancies, however transplant success continues to be limited by complications including graft vs. host disease (GVHD) and disease relapse. Separation of GVHD from graft vs. leukemia/lymphoma (GVL) responses continues to be a major goal of experimental and clinical transplantation, and better understanding of T cell immunobiology may lead to novel strategies to accomplish this goal. Interleukin 21 (IL-21) is a pro-inflammatory cytokine produced by Th17 helper T cells, and abrogation of IL-21 signaling has recently been demonstrated to reduce GVHD while retaining GVL. However, the mechanisms by which IL-21 may lead to a separation of GVHD and GVL are incompletely understood. In order to characterize the effect of IL-21 on GVH and GVL T cell responses, we compared wild type and IL-21 receptor knockout (IL-21R KO) donor T cells in a C57BL/6 into BALB/c murine MHC-mismatched bone marrow transplant (BMT) model. Lethally irradiated BMT recipients of IL-21R KO T cells demonstrated decreased GVHD-related morbidity (p<.05) and mortality (p<.01), and decreased histopathologic evidence of GVHD within the small intestine (p<.05). While this reduction in IL-21R KO T cell-mediated GVHD was associated with increased donor regulatory T cells two to three weeks post-BMT (p<.001), IL-21 signaling in both donor CD4 and donor CD8 T cells was found to contribute to GVHD mortality (p<.01 for CD4, p<.05 for CD8). Analysis of IL-21R expression by wild type T cells demonstrated receptor upregulation upon polyclonal activation in vitro and upon alloactivation in vivo (p<.01). However, this IL-21R upregulation was not required for in vivo alloactivation, as IL-21R KO and wild type donor T cells demonstrated equivalently greater proliferation in allogeneic vs. syngeneic recipients (p<.001), equivalent upregulation of CD25 (p<.001), and equivalent downregulation of CD62L (p<.01 for CD8 T cells). Despite this equivalent alloactivation, IL-21R KO T cells demonstrated decreased infiltration within the small intestine (p<.05), decreased infiltration in mesenteric lymph nodes (p<.05 for CD8 T cells, p<.001 for CD4 T cells), and decreased inflammatory cytokine-producing CD4 T cells within mesenteric lymph nodes (p<.01 for IFN-g, p<.001 for TNF-a, Figure 1A). Consistent with this, transplanted IL-21R KO donor T cells demonstrated decreased expression of a4b7 integrin (LPAM, p<.05), a molecule known to be involved in homing of GVHD-mediating donor T cells to the gut. However, in contrast to the reduced inflammatory cytokine-producing CD4 T cells observed in mesenteric lymph nodes, IL-21R KO helper T cell cytokine production was maintained in spleen (Figure 1B) and peripheral lymph nodes, and IL-21R KO T cells were able to protect recipient mice from lethality due to A20 lymphoma (p<.001). In summary, abrogation of IL-21 signaling in donor T cells leads to tissue-specific modulation of immunity, such that gastrointestinal GVHD is reduced, but peripheral T cell function and GVL capacity are retained. Targeting IL-21 for therapeutic intervention is an exciting strategy to separate GVHD from GVL, and this novel approach should be considered for clinical investigation to improve transplant outcomes and prevent malignant relapse. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 133-133 ◽  
Author(s):  
Barbara Du Rocher ◽  
Odette M Smith ◽  
Andrew M. Intlekofer ◽  
Jarrod A Dudakov ◽  
Emily Levy ◽  
...  

Abstract Despite increasing insights into its immunobiology, graft vs host disease (GVHD) remains a major obstacle for successful allogeneic hematopoietic stem/progenitor cell transplantation (allo-HCT). Separation of GVHD from graft vs. leukemia/lymphoma (GVL) responses also remains an elusive goal for allo-HSCT. Efforts to delineate the transcriptional networks regulating T cell differentiation post-HCT have suggested that multiple transcription factors may be involved in the regulation of alloreactive helper T (Th) cells and GVHD. However, conflicting data have emerged regarding the role of Th1 and Th17 pathways, and it remains unclear which transcription factors mediate the early activation of alloreactive T cells necessary for subsequent GVHD development. The T-box transcription factor eomesodermin (Eomes) cooperates with T-bet to regulate CD8 T cell cytotoxic function, IFNy production, and memory cell formation. Recently, a role for Eomes in CD4 Th cell polarization has been described as well. In order to evaluate the role of Eomes in T cell function in the context of allo-HCT, we used a MHC-disparate mouse model (C57BL/6 into BALB/c) with T cell depleted donor bone marrow (TCD-BM) and wild-type (WT) or Eomes knock out (KO) donor T cells. Recipients were conditioned with lethal total body irradiation. Eomes deficiency in donor T cells led to a significant reduction in GVHD mortality (Fig 1, p<.001), morbidity (p<.001), and intestinal pathology (p<.05, colon). Notably, Eomes KO T cells exerted significantly less GVHD mortality than T-bet KO T cells (Fig 1, p<.001). Given the reduced gastrointestinal (GI) GVHD observed with Eomes KO T cells, we next analyzed the expression of homing molecules important for T cell migration to the GI tract. Consistent with reduced GI GVHD, we detected reduced expression of α4β7 integrin on Eomes KO donor CD8 T cells one week post-HCT. We also observed an increase in the proportion and absolute numbers of Foxp3+ regulatory T cells, as well as a decrease in expression of T-bet in mesenteric lymph nodes (MLNs). Moreover, we found decreased production of IFNy by Eomes KO donor CD4 T cells two weeks (spleen and MLN, p<.001) and three weeks (spleen, p<.01) post-HCT without a comcomitant increase in IL-17. We also found increased IL-4 production by Eomes KO CD4 T cells two weeks post-HCT (MLN, p<.05), indicating a shift from Th1 to Th2 polarization in the absence of Eomes. Strikingly, one of the greatest differences we observed between WT and Eomes KO donor T cells was impaired early activation of CD4 T cells; Eomes deficiency was associated with reduced proliferation (p<.001), reduced expression of CD25 (p<.001, spleen; p<.001, MLN), and increased expression of CD62L (p<.01, spleen; p<.001, MLN) in CD4 T cells within the first 72 hours post-HCT (Fig 2). In order to determine if Eomes was important for T cell-mediated GVL responses, we performed allo-HCT in the presence of A20 lymphoma cells. Despite the reduction in GVHD mortality as described above, A20 tumor challenge led to increased mortality in recipients of Eomes KO T cells, indicating that Eomes was also critical for effective GVL function. Given the importance of Eomes in early alloactivation of CD4 T cells, we evaluated if the impaired GVL function was due to an intrinsic CD8 defect or lack of CD4 help. B6 TCD-BM was transplanted into BALB/c recipients along with either WT or Eomes KO CD4 or CD8 T cells. Eomes deficiency in both CD4 and CD8 T cells again led to significant mortality, but HCT with Eomes KO CD4 T cells and WT CD8 T cells led to the greatest survival due to less GVHD and intact GVL (Fig 3), suggesting that Eomes is essential for intrinsic CD8 function during GVL, but not for CD4 help. In summary, we identified distinct requirements for Eomes in CD4 versus CD8 T cells in the context of allo-HCT. Eomes regulated multiple aspects of CD4 T cell function following allo-HCT, including early activation, cytokine production, and gut trafficking. The multifacted functions of Eomes in CD4 T cells likely explain its requirement for GVHD. In contrast, Eomes deficiency in CD8 T cells led to impaired GVL, consistent with its established importance for cytotoxic CD8 T cell differentiation. To our knowledge, this is one of the first descriptions of a transcription factor necessary for effective GVL capacity. Our results suggest that selective manipulation of Eomes function in T cell subsets may be useful for both limiting GVHD and enhancing GVL. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2004 ◽  
Vol 104 (10) ◽  
pp. 3393-3399 ◽  
Author(s):  
Chang-Ki Min ◽  
Yoshinobu Maeda ◽  
Kathleen Lowler ◽  
Chen Liu ◽  
Shawn Clouthier ◽  
...  

Abstract Administration of exogenous interleukin-18 (IL-18) regulates experimental acute graft-versus-host disease (GVHD) in a Fas-dependent manner when donor CD4+ T cells are required for mortality after experimental allogeneic bone marrow transplantation (BMT). However, CD4+ and CD8+ T cells can induce acute GVHD after clinical allogeneic BMT, and the role of IL-18 in CD8+-mediated acute GVHD is unknown. We, therefore, determined the role of IL-18 in GVHD mediated by CD4+ or CD8+ T cells across major histocompatibility complex (MHC) class II- and class I-disparate allogeneic BMT, respectively. Administering IL-18 significantly increased survival in CD4+-mediated GVHD but reduced survival in CD8+-mediated GVHD. This increase in deaths was associated with significantly greater clinical, biochemical, and histopathologic parameters of GVHD damage and was independent of Fas expression on donor T cells. Administering IL-18 significantly enhanced allospecific cytotoxic function and expansion of CD8+ cells. Endogenous IL-18 was critical to GVHD mediated by CD8+ donor T cells because IL-18 receptor-deficient donors caused significantly less GVHD but exacerbated CD4+-mediated, GVHD-related death. Furthermore, administering anti-IL-18 monoclonal antibody significantly reduced CD8+-mediated, GVHD-related death. Together these findings demonstrate that IL-18 has paradoxical effects on CD4+ and CD8+ cell-mediated GVHD. (Blood. 2004;104:3393-3399)


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