Recommendations for the management of the vascular involvement in Behçet's disease by the Japanese National Research Committee for Behçet's disease-secondary publication.

OBJECTIVES: This study aimed to develop clinical guidelines for the management of vascular Behçet's disease (BD) by the Behçet's Disease Research Committee of the Ministry of Health, Labour and Welfare of the Japanese Government. METHODS: A task force proposed clinical questions (CQs) concerning vascular BD based on a literature search. After screening, draft recommendations were developed for each CQ and brushed up in three blinded Delphi rounds, leading to the final recommendations. RESULTS: This study provides recommendations for 17 CQs concerning diagnosis and differential diagnoses, assessment of disease activity, and treatment. The guidelines recommend immunosuppressive treatments, for both arterial and venous involvement with active inflammation. Anticoagulation is also recommended for deep vein thrombosis except in high-risk patients. Surgical and endovascular therapies can be optional, particularly in patients with urgent arterial lesions undergoing immunosuppression. In addition, two sets of algorithms for diagnosis and treatment are shown for arterial and venous involvement. CONCLUSIONS: These recommendations are expected to serve as useful tools in the daily clinical practice of BD. This content has already been published in Japanese in the Guideline for the Management of Behçet's Disease 2020 and is submitted with permission from both the primary and secondary publishers.

Continuous Intraoperative Neuromonitoring Study Using Pigs for the Prevention of Mechanical Recurrent Laryngeal Nerve Injury in Esophageal Surgery.

PURPOSES: During esophageal surgery, clamping injury and injury associated with the use of energy devices are common mechanisms underlying intraoperative recurrent laryngeal nerve (RLN) damage. Recently, intraoperative neuromonitoring (IONM) has been applied to prevent RLN injury. This study was aimed at investigating the changes in the EMG signals associated with clamping injury of the RLN caused by picking up of the nerve with tweezers in domestic pigs. METHODS: Six domestic pigs (12 RLNs) underwent continuous IONM (CIONM) by our original automated periodic vagal nerve stimulation method. RESULTS: Our system can be used safely and accurately. The signals showed a decrease of the amplitude when the RLN was picked up and closed slowly by the double-action Maryland with jaw covers. If the clamp was released before the signal amplitude decreased to 50% of the baseline, the signal showed gradual recovery to the baseline in 12 ± 3 minutes. CONCLUSION: Although there were limitations in our study using domestic pig, including the small sample size, our results are expected to contribute to a decrease in the incidence of RLN damage during esophageal surgery.

Treadmill exercise induces murine cardiac allograft survival and generates regulatory T cell.

Exercise therapy has been associated with improvement in functional capacity and quality of life. The role of exercise therapy in heart transplant recipients is of great interest for the transplant society, although concerning the effect of exercise therapy, there is little knowledge at present. We analyzed the effects of exercise on alloimmune responses in murine cardiac allograft transplantation. CBA mice (H2(k) ) underwent transplantation of C57Bl/6 (H2(b) ) hearts and exercised on a treadmill. Untreated CBA recipients rejected C57Bl/6 cardiac grafts acutely (median survival time [MST], 7 days). CBA recipients treated with treadmill for 1 week after transplantation, and for 1 week both before and after transplantation prolonged allograft survivals (MSTs, 35 and 18 days, respectively). However, treadmill exercise recipients for 1 week before transplantation were not effective to allograft survival (MST, 8 days). Adoptive transfer of whole splenocytes and CD4(+) cells from treadmill exercise recipients significantly prolonged allograft survival in naive secondary recipients (MSTs, 30 and 52 days, respectively), suggesting that regulatory cells was generated after treadmill exercise. Moreover, flow cytometry studies showed that CD4(+) CD25(+) Foxp3(+) cell population increased in treadmill exercise recipients. Therefore, postoperative but not pre-operative exercise could induce prolongation of survival of fully allogeneic cardiac allografts and generate CD4(+) CD25(+) Foxp3(+) regulatory T cells.

Effects of Japanese herbal medicine Sairei-to on murine experimental autoimmune uveitis.

PURPOSE: It has been suggested thatSairei-to (TJ114), a traditional Japanese herbal medicine, has immunomodulatory activities. To evaluate the effects of TJ114 on uveitis, we examined the effectiveness of oral administration in a murine model of experimental autoimmune uveitis (EAU). METHODS: Murine EAU was induced by subcutaneous injection of human inter-photoreceptor retinoid-binding protein (IRBP) peptide mixed with complete Freund's adjuvant. In the TJ114-treated group, 2 g/kg was administrated orally from 0 to 20 days after immunization. Clinical scoring, histopathological scoring of EAU, cell proliferation, cytokine assessment, and adoptive transfer experiment of splenic T cells into naïve mice were performed. RESULTS: EAU development occurred in 32 of 38 mice (86 %) in the untreated group and 12 of 33 (36 %) in the TJ114-treated group. The clinical scores for EAU in the vehicle-treated and TJ114-treated groups were 1.56 ± 1.65 and 0.59 ± 0.63 respectively, at 14 days after immunization (p < 0.01, Mann-Whitney U-test), and 2.26 ± 1.56 and 0.75 ± 1.31 respectively at 21 days (p < 0.001, Mann-Whitney U-test), while the histopathological scores at 21 days were 1.47 ± 1.42 and 0.54 ± 0.84 respectively (p < 0.01, Mann-Whitney U-test). Interferon (IFN)-γ and tumor necrosis factor (TNF)-α production by cervical lymph node cells obtained from the TJ114-treated group were significantly reduced as compared with those from the vehicle-treated group (p < 0.01, Student's unpaired t-test). Moreover, the levels of C-C motif chemokine 2 (CCL2) and IFN-γ were significantly reduced in splenocytes of TJ114-treated mice as compared with the vehicle-treated group (p < 0.01, Student's unpaired t-test). Mice that received adoptive transfer of splenic T cells from TJ114-treated EAU mice caused significantly lower severity of EAU compared to those that received from vehicle-treated EAU mice. CONCLUSION: Oral administration of TJ114 has an inhibitory effect on a murine model of EAU, possibly via reduction in cytokine production by helper type-1 T cells.

Danazol induces prolonged survival of fully allogeneic cardiac grafts and maintains the generation of regulatory CD4(+) cells in mice.

Danazol, a derivative of testosterone, is useful for treatment of endometriosis as well as pretreatment for in vitro fertilization and embryo transfer, although its mechanisms of action are unclear. The aim of this study was to investigate the effect of danazol on alloimmune responses in murine heart transplantation. CBA male mice (H2(k) ) underwent transplantation of C57BL/6 male (H2(b) ) hearts and received a single dose of danazol (0.4, 1.2 or 4mg/kg/day) by intraperitoneal injection on the day of transplantation and for 6days thereafter. An adoptive transfer study was performed to determine whether regulatory cells were generated. The median survival time (MST) of allografts in danazol-treated (1.2 and 4mg/kg/day) mice was 28 and 63days, respectively, compared with 7days in untreated mice. Moreover, secondary CBA recipients given whole splenocytes or CD4(+) cells from primary danazol-treated (4mg/kg/day) CBA recipients 30days after transplantation had prolonged allograft survival (MSTs, 29 and 60days, respectively). Cell proliferation, interleukin (IL)-2 and interferon-γ were suppressed in danazol-treated mice, whereas IL-4 and IL-10 were up-regulated. Moreover, danazol directly suppressed allo-proliferation in a mixed leukocyte culture. Flow cytometry showed an increased CD4(+) CD25(+) Foxp3(+) cell population in splenocytes from danazol-treated mice. Danazol prolongs cardiac allograft survival and generates regulatory CD4(+) cells.

Inchingorei-san (TJ-117) and Artemisiae Capillaris Herba Induced Prolonged Survival of Fully Mismatched Cardiac Allografts and Generated Regulatory Cells in Mice.

We investigated Inchingorei-san (TJ-117), a 6-component Japanese herbal medicine, on alloimmune responses in murine cardiac allograft transplantation. CBA mice underwent transplantation of a C57BL/6 (B6) heart and received oral administration of TJ-117 or each component of TJ-117 from the day of transplantation until 7 days afterward. Naive CBA mice rejected B6 cardiac grafts acutely (median survival time (MST), 7 days). CBA recipients given 1 g/kg/day of TJ-117 had prolonged B6 allograft survival (MST, 37 days). Moreover, given 1 g/kg/day of Artemisiae Capillaris Herba (ACH), one component of TJ-117, indefinitely prolonged B6 allograft survival (MST, >100 days). However, other five components of TJ-117 were less effective than TJ-117 and ACH. Secondary CBA recipients given whole splenocytes, CD4(+), and CD4(+)CD25(+) cells from primary ACH-treated CBA recipients with B6 cardiac allografts 30 days after grafting had prolonged survival of B6 hearts (MSTs, 57, >100, and >100 days, resp.). Flow cytometry studies showed that the CD4(+)CD25(+)Foxp3(+) regulatory cell population was increased in transplant recipients given ACH. Cell proliferation, interleukin-2, and interferon-γ were suppressed in ACH-treated mice, whereas interleukin-4 and interleukin-10 were upregulated. In conclusion, ACH, one component of TJ-117, as well as TJ-117 induced hyporesponsiveness to fully allogeneic cardiac allografts and may generate CD4(+)CD25(+)Foxp3(+) regulatory cells.

[Kampo Medicine for Intractable Brain and Neurological Diseases].

In Japan, 147 types of oral Kampo extract products are covered by the public insurance system; however, to the best of our knowledge, there are no large-scale randomized clinical trials. Therefore, the level of evidence or these products is low compared with that for medicines that have been introduced as insurance reimbursement drugs through randomized clinical trials. However, when conventional western medical treatments have not been effective or when patients desire a more effective therapy, Kampo extract products are one of the treatment options. Kampo extract products involve the adding of crude drugs and comprise a multi-component system. Therefore, it may be effective for various symptoms. I recommend that specialists use these products as complementary alternative medicines. I also introduce the "Huaier extract granule," which is an orally bioavailable traditional Chinese medicine composed of granules containing an aqueous extract of Trametes robiniophila Murr (Huaier), a mushroom found on hardwood tree trunks, with potential immune-regulating activity. Huaier has immunity enhancement activity, such as antineoplastic property, as well as immunity regulating activity against diseases, such as asthma, psoriasis, and immunoglobulin A nephritis. Therefore, for some intractable diseases, especially when the disease is thought to involve an immune disorder, Huaier can be an additional treatment option.

Administration of donor splenocytes via the respiratory tract generates CD8α+ regulatory dendritic cells and induces hyporesponsiveness to fully allogeneic cardiac grafts.

BACKGROUND: We previously showed that pretreatment with intratracheal delivery (ITD) of alloantigen induced prolonged cardiac allograft survival and generated regulatory T cells (Tregs) in mice. In this study, we examined the role of splenic dendritic cells (DCs) in the ITD model. METHODS: CBA mice were treated with ITD from C57BL/10 splenocytes and 7 days later received transplantation of C57BL/10 hearts. In adoptive transfer studies, splenic DCs from ITD-treated mice were transferred into naïve CBA recipients that received C57BL/10 hearts immediately after the transfer. In addition, to determine the role of splenic DCs isolated from ITD-treated mice, the cells were incubated under stimulation with lipopolysaccharide (LPS). RESULTS: ITD-treated CBA recipients had markedly prolonged allograft survival (median survival time [MST], 67 days) while naïve recipients rejected allografts acutely (MST, 8 days). In adoptive transfer studies, CBA recipients of the transfer of splenic DCs from ITD-treated mice had prolonged allograft survival (MST, 85 days), while CBA recipients of the transfer of splenic DCs from naïve mice did not have prolonged allograft survival (MST, 8 days). In another transfer study, CBA recipients of the transfer of splenic CD8α+ DCs from ITD-treated mice had prolonged allograft survival (MST, 79 days), while those receiving splenic CD8α- DCs from ITD-treated mice did not have prolonged allograft survival (MST, 8 days). In vitro studies showed that ITD-treated splenic DCs produced more IL-10 and less IL-12 than naïve splenic DCs under stimulation with LPS. CONCLUSIONS: ITD pretreatment induces regulatory DCs, which produce high amounts of IL-10 resulting in the prolongation of graft survival in our model.

Graft protective effect and induction of CD4+Foxp3+ cell by Thrombomodulin on allograft arteriosclerosis in mice.

BACKGROUND: Thrombomodulin (TM) is a promising therapeutic natural anti-coagulant, which exerts the effects to control disseminated intravascular coagulation. However, little is known whether TM on micro-vessels could play an important role in the regulation of intimal hyperplasia. We investigated the vessel-protective effect of TM in the survival of fully major histocompatibility complex (MHC)-mismatched murine cardiac allograft transplantation. METHODS: CBA recipients transplanted with a C57BL/6 heart received intraperitoneal administration of normal saline or 0.2, 2.0, and 20.0 µg/day of TM for 7 days (n = 5, 7, 11, and 11, respectively). Immunohistochemical and fluorescent staining studies were performed to determine whether CD4+Foxp3+ regulatory T cell were generated at 2 and 4 weeks after grafting. Morphometric analysis for neointimal formation in the coronary arteries of the transplanted allograft was conducted at 2 and 4 weeks after grafting. RESULTS: Untreated CBA recipients rejected C57BL/6 cardiac grafts acutely (median survival time [MST], 7 days). CBA recipients exposed with the above doses had significantly prolonged allograft survival (MSTs, 17, 24 and 50 days, respectively). Morphometric assessment showed that intimal hyperplasia was clearly suppressed in the left and right coronary arteries or allografts from TM-exposed recipients 2 and 4 weeks. Immunohistochemical studies at 2 weeks showed more CD4+Foxp3+ cells and lower myocardial damage in the allografts from TM-exposed recipients. Notably, fluorescent staining studies demonstrated that TM-exposed recipients 4 weeks post-engraftment had strong aggregation of CD4+Foxp3+ cells in the intima of the coronary arteries of the cardiac allografts. CONCLUSIONS: TM may prolong the survival of fully MHC-mismatched cardiac allografts through suppressing intimal hyperplasia and inducing the accumulation of regulatory CD4+Foxp3+ cells within coronary arteries.

Prolongation of survival of fully allogeneic cardiac grafts and generation of regulatory cells by a histamine receptor 2 antagonist.

BACKGROUND: The effects of histamine on immunologic responses via the histamine receptor 2 (HR2) have been studied, but few investigations explored the immunomodulatory role of histamine in vivo. We examined whether the HR2 antagonist ranitidine affects the alloimmune response in a murine model of cardiac transplantation. METHODS: CBA (H-2k) recipients were given no treatment or one intravenous injection of ranitidine on the day of transplantation of a heart from C57BL/10 (H-2b) donors. Survival of the allografts was recorded. The effect of the ranitidine treatment on cell proliferation and cytokine production was assessed by mixed leukocyte culture and enzyme-linked immunosorbent assays. An adoptive transfer study was conducted to determine whether regulatory cells were generated. The effect on graft survival of adding FK506 to the ranitidine treatment was also examined. RESULTS: CBA recipients given ranitidine (60 mg/kg) had prolonged graft survival (median survival time [MST], 87 days). Ranitidine treatment also suppressed the proliferation of splenocytes and production of interleukin (IL)-2 and up-regulated IL-10 production. Adoptive transfer of splenocytes and CD4 cells from ranitidine-treated allograft recipients induced significant prolongation of allograft survival in naive secondary recipients (MST, 71 and >100 days, respectively). CBA recipients given both ranitidine and FK506 (0.1 mg/kg/day for 14 days) had indefinite survival of cardiac allografts (MST, >100 days). CBA recipients treated with FK506 alone rejected the allografts (MST, 27 days). CONCLUSION: In our model, ranitidine treatment induced significantly prolonged survival of fully allogeneic cardiac grafts, generated CD4 regulatory cells, and indefinite survival when combined with FK506 (0.1 mg/kg/day).

Induction of indefinite survival of fully mismatched cardiac allografts and generation of regulatory cells by sarpogrelate hydrochloride.

BACKGROUND: At initiation of the immunologic response, platelets rapidly release chemical mediators such as serotonin (5-hydroxytryptamine, [5-HT]) and cytokines. Sarpogrelate hydrochloride (SH), a selective 5-HT2-receptor antagonist, is used to treat patients with peripheral arterial disease. We investigated the effect of SH on the alloimmune response in a murine cardiac transplantation model. METHODS: CBA mice underwent transplantation of a C57BL/10 heart and received a short course of SH treatment. Survival of the allograft was recorded. An adoptive transfer study was performed to determine whether regulatory cells were generated. Immunohistochemistry studies of intercellular adhesion molecule 1 (ICAM-1), histological, cell-proliferation, and cytokine assessments were performed. RESULTS: Untreated CBA mice rejected C57BL/10 cardiac grafts acutely (median survival time [MST], 8 days). In mice given 10 mg/kg of SH, all allografts survived indefinitely (MST, >100 days); these mice also had significantly prolonged survival of donor-specific skin grafts but acute rejection of third-party skin grafts. Secondary CBA recipients given not only whole but also CD4 splenocytes from primary SH-treated CBA recipients with C57BL/10 cardiac allograft had indefinite survival of C57BL/10 hearts (MST, >100 days). SH inhibited upregulation of ICAM-1 on endothelial cells in the allografts. Graft acceptance and hyporesponsiveness were confirmed by the histological and cell-proliferation studies, respectively. Production of interleukin-4 and interleukin-10 from splenocytes of SH-treated transplant recipients increased compared to that from splenocytes of untreated recipients. CONCLUSION: SH induced indefinite survival of fully allogeneic cardiac allografts, generated CD4 regulatory cells, inhibited ICAM-1 expression in the allografts, and upregulated IL-4 and IL-10 production.

Prevalence of Isolated Asymptomatic Deep Vein Thrombosis in Varicose Vein Patients with Superficial Thrombophlebitis: A Single Center Experience in Japan.

OBJECTIVE: Prevalence of asymptomatic deep vein thrombosis (DVT) in patients with primary varicose veins remains unclear. MATERIALS AND METHODS: Here, we conducted a retrospective study to clarify the incidence of asymptomatic DVT in patients with varicose veins, especially focusing on those with superficial thrombophlebitis (STP). RESULTS: Among 431 patients with primary varicose veins with saphenous vein incompetence, 20 (4.64%) had asymptomatic DVT. The presence of STP was a significant risk factor for asymptomatic DVT as 10 of the 24 (41.7%) patients with STP had asymptomatic DVT, and all cases having calf muscle vein thrombosis. In contrast, of the patients with primary varicose veins without STP only 2.46% had asymptomatic DVT. CONCLUSIONS: In patients with primary varicose veins with STP, significant risk factors for DVT were being over C3 on the clinical, etiological, anatomical, and pathophysiological (CEAP) classification. (This article is a translation of Jpn J Phlebol 2014; 25: 13-19.).

Effects of immunosuppressants on induction of regulatory cells after intratracheal delivery of alloantigen.

BACKGROUND: We previously reported that intratracheal delivery (ITD) of alloantigen generated regulatory cells in mice. Here, we examined the effect of various doses of conventional immunosuppressants (FK506, cyclosporine A, azathioprine, mycophenolate mofetil, and rapamycin) on inducing regulatory cells in our model. METHODS: CBA mice (primary recipients) were given C57BL/6 splenocytes by ITD and either no additional treatment or various doses of an immunosuppressant. Seven days later, splenocytes from these mice were adoptively transferred into naive secondary CBA recipients that underwent C57BL/6 cardiac grafting the same day. RESULTS: Adoptive transfer from primary recipients given ITD of splenocytes alone induced prolonged allograft survival in secondary recipients (median survival time [MST], 50 days), suggesting that regulatory cells were generated. When ITD of alloantigen was combined with daily administration of 0.1 mg/kg FK506 or 0.2 mg/kg rapamycin, graft survival was similarly prolonged (MST 55 and 50 days, respectively). When combined with 20 or 40 mg/kg MMF or 0.4 mg/kg rapamycin, the majority of recipients demonstrated indefinite survival (MST, >100 days in all groups). When ITD of alloantigen was combined with 0.3, 0.5, or 1.0 mg/kg FK506; 5, 10, or 25 mg/kg cyclosporine A; or 1.0 or 2.0 mg/kg azathioprine, allografts were rejected acutely (MST 7-13 days). CONCLUSION: Generation of regulatory cells by ITD of alloantigen was facilitated by mycophenolate mofetil and high doses of rapamycin but abrogated by cyclosporine A, azathioprine, and high doses of FK506. Low doses of rapamycin and of FK506 did not interfere with generation of regulatory cells.

Interleukin-10 but not transforming growth factor-beta is essential for generation and suppressor function of regulatory cells induced by intratracheal delivery of alloantigen.

BACKGROUND: We previously reported that intratracheal delivery of alloantigen-induced regulatory cells in mouse heart-transplantation model. Here, we investigated roles of interleukin (IL)-10 and transforming growth factor (TGF)-beta in induction and effector phases of the regulatory cells. METHODS: CBA mice were pretreated with intratracheal delivery of C57BL/10 splenocytes and administration of neutralizing anti-IL-10 or anti-TGF-beta monoclonal antibody (mAb). Seven days after the pretreatment, naive CBA mice (secondary recipients) were given adoptive transfer of splenocytes from the pretreated mice and underwent heart grafting from C57BL/10 mice. To determine roles of these cytokines in the effector phase of the regulatory cells, anti-IL-10 or anti-TGF-beta mAb was administered weekly into the secondary recipients after the adoptive transfer. RESULTS: Adoptive transfer of splenocytes from CBA mice that had been pretreated with intratracheal delivery of C57BL/10 splenocytes significantly prolonged the survival of C57BL/10 allograft (median survival time [MST] 68 days) as compared with adoptive transfer from untreated CBA mice (MST 12 days). In the induction phase, anti-IL-10 mAb abrogated development of the regulatory cells that afforded prolonged allograft survival in the secondary recipients (MST 20 days), whereas anti-TGF-beta mAb did not abrogate it (MST 88 days). In the effector phase, anti-IL-10 mAb abrogated prolonged allograft survival afforded by adoptive transfer of the regulatory cells in the secondary recipients (MST 27 days), whereas anti-TGF-beta mAb did not abrogate suppressor function of the regulatory cells (MST 53 days). CONCLUSION: IL-10 but not TGF-beta was required for generation and suppressor function of the regulatory cells induced by intratracheal delivery of alloantigen.

Induction of operational tolerance and generation of regulatory cells after intratracheal delivery of alloantigen combined with nondepleting anti-CD4 monoclonal antibody.

BACKGROUND: We previously showed that intratracheal delivery of alloantigen induced prolonged survival of fully allogeneic cardiac grafts in mice. Here, this treatment protocol was combined with nondepleting anti-CD4 monoclonal antibody (mAb) to induce operational tolerance. METHODS: CBA (H-2k) mice were pretreated with intratracheal delivery of whole splenocytes from C57BL/10 (H-2b) mice or a 15-mer Kb peptide, with or without intraperitoneal administration of nondepleting anti-CD4 mAb (YTS177). Seven days later, C57BL/10 hearts were transplanted into the pretreated CBA mice. In addition, some naive CBA mice underwent adoptive transfer of splenocytes from pretreated CBA mice and transplantation of a C57BL/10 heart on the same day. RESULTS: Untreated CBA mice rejected C57BL/10 cardiac grafts acutely (median survival time, 12 days). Mice given intratracheal delivery of whole splenocytes or Kb peptide demonstrated prolonged graft survival (median survival time, 84 and 76 days, respectively). Concurrent administration of YTS177 and intratracheal delivery of splenocytes or Kb peptide resulted in indefinite graft survival. Mice with long-surviving C57BL/10 cardiac grafts showed acceptance of skin grafts from C57BL/10 mice but not BALB/c mice, demonstrating that operational tolerance had been induced. Adoptive transfer of splenocytes from mice pretreated with intratracheal delivery of splenocytes or Kb peptide plus YTS177 induced indefinite survival of cardiac grafts in secondary recipients, indicating that regulatory cells had been generated. CONCLUSION: In a murine model, intratracheal delivery of donor splenocytes or Kb peptide combined with YTS177 induced operational tolerance and generated regulatory cells.

Programmed death-1-programmed death-L1 interaction is essential for induction of regulatory cells by intratracheal delivery of alloantigen.

BACKGROUND: Programmed death (PD)-1 has been implicated in peripheral tolerance. The authors investigated the roles of PD-1 and its ligands, PD-L1 and PD-L2, in the induction of regulatory cells by intratracheal delivery of alloantigen. METHODS: CBA (H-2k) mice were pretreated with intratracheal delivery of C57BL/10 (H-2b) splenocytes and administration of monoclonal antibody (mAb) specific for PD-1, PD-L1, or PD-L2. Seven days later, C57BL/10 hearts were transplanted into the pretreated CBA mice. Some naive CBA mice underwent adoptive transfer of splenocytes from the pretreated CBA mice and transplantation of C57BL/10 heart. RESULTS: Untreated CBA mice rejected C57BL/10 cardiac grafts acutely (median survival time [MST], 7 days). Pretreatment with intratracheal delivery of C57BL/10 splenocytes prolonged graft survival significantly (MST, 65 days). Administration of control immunoglobulin (Ig) G or anti-PD-L2 mAb did not significantly affect the prolongation (MST, 72 and 68 days, respectively). In contrast, anti-PD-1 or anti-PD-L1 mAb abrogated the prolongation (MST, 18 and 17 days, respectively). Adoptive transfer from mice pretreated with intratracheal delivery of alloantigen plus control IgG or anti-PD-L2 mAb prolonged survival of C57BL/10 grafts in secondary CBA recipients (MST, 72 and 56 days, respectively). However, concurrent administration of anti-PD-1 or anti-PD-L1 mAb abrogated prolonged survival after the adoptive transfer (MST, 14 and 20 days, respectively). CONCLUSIONS: PD-1-PD-L1 interaction was essential for induction of regulatory cells by intratracheal delivery of alloantigen.

Induction of indefinite survival of fully allogeneic cardiac grafts and generation of regulatory cells by intratracheal delivery of alloantigens under blockade of the CD40 pathway.

BACKGROUND: The authors previously showed that intratracheal delivery (ITD) of donor splenocytes induced prolonged survival of fully allogeneic cardiac grafts in mice. In this study, this treatment protocol was combined with blockade of the CD40 pathway in an attempt to induce operational tolerance. METHODS: CBA mice were given donor splenocytes (1x107) or Kb peptide (100 microg) by ITD with or without antibody specific for mouse CD40 ligand (MR1, 200 microg) 7 days before transplantation of a C57BL/10 heart. Also, splenocyte (5 x 107) from primary recipient CBA mice given ITD of donor splenocytes or Kb peptide plus MR1 were adoptively transferred into naive CBA secondary recipients 7 days after the pretreatment and C57BL/10 hearts were transplanted into those recipients the same day. RESULTS: ITD of donor splenocytes and Kb peptide induced prolonged survival of cardiac grafts (median survival time [MST], 74 and 56 days, respectively), whereas naive control mice and mice pretreated with syngeneic splenocytes had acute graft rejection (MST in both groups, 7 days). When MR1 was included, all grafts survived indefinitely (>200 days), but mice pretreated with MR1 alone had graft rejection (MST, 54 days). Mice bearing cardiac grafts had acceptance of skin grafts from C57BL/10 but not BALB/c mice, demonstrating that operational tolerance was induced. Secondary recipients given adoptive transfer of splenocytes from primary recipients of the combined treatment had acceptance of C57BL/10 grafts, suggesting that regulatory cells were generated within 7 days of pretreatment. CONCLUSIONS: ITD of donor splenocytes or Kb peptide under blockade of the CD40 pathway induced operational tolerance and generated regulatory cells.

High dose of antithrombin III induces indefinite survival of fully allogeneic cardiac grafts and generates regulatory cells.

BACKGROUND: The authors investigated whether antithrombin III (AT-III) could induce unresponsiveness to alloantigens. METHODS: CBA mice were given intravenous injection of 50 or 500 U/kg AT-III or control plasma the same day as transplantation of a heart from a C57BL/6 mouse. An adoptive transfer study and mixed leukocyte culture analysis were also performed. RESULTS: Naive CBA mice rejected C57BL/6 cardiac grafts acutely (median survival time [MST], 9 days). The 50-U/kg dose of AT-III induced a moderate increase in graft survival (MST, 25 days), whereas control mice rejected their graft acutely (MST, 7 days). With the 500-U/kg dose of AT-III, all grafts survived indefinitely (>100 days) and regulatory cells were generated. In vitro, AT-III suppressed proliferation of mixed leukocyte responses and generation of interleukin-2. CONCLUSION: AT-III can be not only an antithrombotic agent but also a strong immunomodulating agent when used at high dose.

Role of the CTLA4 pathway in hyporesponsiveness induced by intratracheal delivery of alloantigen.

BACKGROUND: The authors previously reported that intratracheal delivery (ITD) of donor alloantigen induced donor-specific hyporesponsiveness to C57BL/10 cardiac allografts in CBA recipients and that blockade of the B7 pathways abrogated that hyporesponsiveness. In this study, the authors used a CD28-deficient model to evaluate which signal, either through CD28 or cytotoxic T-lymphocyte-associated antigen (CTLA4), is involved in the induction of hyporesponsiveness. METHODS: Seven days before transplantation of hearts from C3H/HeJ (H2k) mice into C57BL/6 (H2b) or CD28-deficient (C57BL/6 background) mice, the transplant recipients were given ITD of donor splenocytes (1 x 10(7)), alone or in combination with human CTLA4-immunoglobulin (Ig) (200 microg). RESULTS: ITD of C3H splenocytes induced donor-specific hyporesponsiveness to C3H cardiac grafts in C57BL/6 recipients (graft median survival time [MST], 40 days). Administration of CTLA4-Ig concurrently with ITD abrogated the prolonged allograft survival (MST, 12 days). Interestingly, ITD of C3H splenocytes induced prolonged survival of C3H allografts in CD28-deficient recipients (MST, 55 days). Furthermore, administration of CTLA4-Ig combined with ITD of C3H splenocytes abrogated the prolonged survival of C3H allografts in CD28-deficient recipients (MST, 7 days), whereas recipients given isotype-control antibody in combination with ITD of splenocytes had prolonged survival of C3H allografts (MST, 58 days). CONCLUSIONS: Taken together, the authors' findings indicate that a signal through CTLA4, rather than through CD28, plays an important role in the induction of hyporesponsiveness by ITD of alloantigen in this model.

CD27/CD70, CD134/CD134 ligand, and CD30/CD153 pathways are independently essential for generation of regulatory cells after intratracheal delivery of alloantigen.

BACKGROUND: We investigated whether blockade of tumor necrosis factor receptor-ligand pathways could generate regulatory cells induced by intratracheal delivery of alloantigen. METHODS: CBA (H-2k) mice were pretreated with intratracheal delivery of splenocytes (1x10(7)) from C57BL/10 (H-2b) mice and intraperitoneal administration of monoclonal antibody (mAb) specific for CD70, CD134 ligand (CD134L), CD153, or CD137L. Seven days later, C57BL/10 hearts were transplanted into pretreated CBA mice. Some naive CBA mice underwent adoptive transfer of splenocytes (5x10(7)) from pretreated CBA mice and transplantation of a C57BL/10 heart on the same day. RESULTS: Untreated CBA mice rejected C57BL/10 cardiac grafts acutely (median survival time [MST] 12 days). Pretreatment with intratracheal delivery of C57BL/10 donor splenocytes prolonged graft survival significantly (MST 84 days). Mice given intratracheal delivery of alloantigen plus anti-CD70, anti-CD134L, or anti-CD153 mAb, but not those given intratracheal delivery of alloantigen plus anti-CD137L mAb, rejected their graft acutely (MST 16, 14, 10, and 65 days, respectively). Adoptive transfer of splenocytes from mice pretreated with intratracheal delivery of alloantigen plus anti-CD70, CD134L, or CD153 mAb did not prolong survival of C57BL/10 cardiac grafts in naive secondary CBA recipients (MST 14, 11, and 11 days, respectively), whereas adoptive transfer of splenocytes from mice given intratracheal delivery of alloantigen plus anti-CD137L mAb did (MST 75 days). CONCLUSION: The CD27/CD70, CD134/CD134L, and CD30/CD153 pathways are independently required for generation of regulatory cells in our model.