Recipient Lymphocytes Research Articles

Psychoneuroimmunomodulating effect of lymphocytes with ortho-fluoro-benzonal modulated activity in syngeneic long-term alcoholized recipients

IntroductionLymphocytes are dysfunctional during long-term ethanol consumption and may contribute the progression from healthy to problem drinking. GABAA receptors are molecular targets of ethanol on lymphocytes, potentiating the effects of alcohol.ObjectivesWe first demonstrated that original compound ortho-fluoro-benzonal, artificial GABA receptor ligand, has immunostimulating properties and is able to restored long-term alcoholized mice lymphocytes activity in vitro through GABAA receptors. Based on the previous results we investigated effects of the ex vivo ortho-fluoro-benzonal modulated lymphocytes in recipients with experimental alcoholism.MethodsMale (CBAxC57Bl/6)F1 mice with 6-month 10% ethanol exposure were undergoing the transplantation of syngeneic long-term alcoholized mice lymphocytes, pretreated in vitro with ortho-fluoro-benzonal. Recipient’s ethanol consumption, parameters of the nervous and immune systems functional activities were estimated.ResultsIt was shown that lymphocytes modulated ex vivo with ortho-fluoro-benzonal after intravenous injection caused in syngeneic long-term alcoholized recipients ethanol consumption decrease and stimulation of behavioral activity in the “open field” test against the background of changes in the level of a number of cytokines in pathogenetically significant brain structures. Stimulation of humoral immune response, estimated by the relative number of antibody-forming spleen cells was also detected in recipients after lymphocytes transplantation. The injected immune cells were recorded in the parenchyma of the spleen and brain of recipients, which suggests, in particular, their direct influence on these functions.ConclusionsResults demonstrated that transplantation of ortho-fluoro-benzonal-modulated lymphocytes caused positive psychoneuroimmunomodulating effect in long-term alcoholized recipients, which makes it possible to consider adoptive immunotherapy as a promising method in the treatment of alcoholism.Disclosure of InterestNone Declared

Immunogenicity and tolerance induction in vascularized composite allotransplantation.

Vascularized composite allotransplantation (VCA) is the transplantation of multiple tissues such as skin, muscle, bone, nerve, and vessels, as a functional unit (i.e., hand or face) to patients suffering from major tissue trauma and functional deficits. Though the surgical feasibility has been optimized, issues regarding graft rejection remains. VCA rejection involves a diverse population of cells but is primarily driven by both donor and recipient lymphocytes, antigen-presenting cells, macrophages, and other immune as well as donor-derived cells. In addition, it is commonly understood that different tissues within VCA, such as the skin, elicits a stronger rejection response. Currently, VCA recipients are required to follow potent and lifelong immunosuppressing regimens to maximize graft survival. This puts patients at risk for malignancies, opportunistic infections, and cancers, thereby posing a need for less perilous methods of inducing graft tolerance. This review will provide an overview of cell populations and mechanisms, specific tissue involved in VCA rejection, as well as an updated scope of current methods of tolerance induction.

A strategy to reconstitute immunity without GVHD via adoptive allogeneic Tscm therapy.

Adoption of allogeneic T cells directly supplements the number of T cells and rapidly induces T-cell immunity, which has good efficacy for treating some tumors and immunodeficiency diseases. However, poor adoptive T-cell engraftment and graft-versus-host disease (GVHD) limit the application of these methods. Alloreactive T-cell clones were eliminated from the donor T-cell repertoire, and the remaining T-cell clones were prepared as Tscm for T-cell adoptive treatment to reconstruct recipient T-cell immunity without GVHD. The subjects in this study included three different strains of mice. Lymphocytes from mice (C57BL/6) were used as the donor T-cell repertoire, from which the Tscm allo-reactive T cell clone was depleted (ATD-Tscm). This was confirmed by showing that the Tscm was not responsive to the alloantigen of the recipient (BALB/c). To prepare ATD-Tscm cells, we used recipient lymphocytes as a simulator, and coculture of mouse and recipient lymphocytes was carried out for 7 days. Sorting of non-proliferative cells ensured that the prepared Tscm cells were nonresponsive. The sorted lymphocytes underwent further expansion by treatment with TWS119 and cytokines for an additional 10 days, after which the number of ATD-Tscm cells increased. The prepared Tscm cells were transferred into recipient mice to observe immune reconstitution and GVHD incidence. Our protocol began with the use of 1×107 donor lymphocytes and resulted in 1 ×107 ATD-Tscm cells after 17 days of preparation. The prepared ATD-Tscm cells exhibited a nonresponse upon restimulation of the recipient lymphocytes. Importantly, the prepared ATD-Tscm cells were able to bind long and reconstitute other T-cell subsets in vivo, effectively recognizing and answering the "foreign" antigen without causing GVHD after they were transferred into the recipients. Our strategy was succeeded to prepare ATD-Tscm cells from the donor T-cell repertoire. The prepared ATD-Tscm cells were able to reconstitute the immune system and prevent GVHD after transferred to the recipients. This study provides a good reference for generating ATD-Tscm for T-cell adoptive immunotherapy.

Evaluation of the relationship between de-novo DSA development and CXCR5+PD-1+CD8+ T cells and PD-1/PD-L1 mRNA expression in kidney transplant recipients.

The relationship between the Follicular Cytotoxic T cell subgroup and expression levels of PD1/PD-L1 genes and the development of donor specific antibody (DSA) is unknown. In this study, we aimed to examine CD8+CXCR5+PD-1+ follicular cytotoxic T cell levels and expression levels of PD1/PD-L1 genes in peripheral blood lymphocytes in de-novo DSA positive and negative kidney transplant recipients (KTR). In our study, expression of PD-1/ PD-L1 genes by Real-Time Quantitative PCR method and CD8+CXCR5+PD-1+ T cell expression levels by flow cytometric method were obtained from peripheral blood samples. 63 participants were included in the study (de-novo DSA positive recipients (n=22, group 1), de-novo DSA negative recipients (n=20, group 2) and healthy control (n=21, group 3). All patients had negative PRA before kidney transplantation. Expression (%) levels of target cells were evaluated by flow cytometry method. IBM SPSS Statistics for Windows Version 22 and R.3.3.2 software were used to evaluate the data. The demographic data of the groups were similar. PD-1 mRNA expression was higher in de-novo DSA positive KTR than negative (respectively, 1.03±.29/.82±.15, p: .001). CD8+CXCR5+PD-1+ T cell expression levels were found to be higher in the de-novo DSA positive group than in the negative group and similar to the healthy group (respectively, 3.06±1.98/.52±.40, p:.001, 3.06±1.98/2.78±.59, p:.62). The percentage of CD8+CXCR5+PD-1+ expressing T cells was significantly lower in the HLA-Class II+ group than other groups (HLA CI/II/ I+II, respectively, 3.63±2.72/1.65±.50/3.68±1.67, p: .04). In our study, a significant relationship was found between DSA formation and PD-1 mRNA level and CD8+CXCR5+PD-1+ follicular cytotoxic T cell in KTR.

Feasibility of Flow Cytometry Analysis of Gastrointestinal Tract-Residing Lymphocytes in Hematopoietic Stem Cell Transplant Recipients.

The feasibility of lymphocyte isolation and flow cytometry using a single endoscopic biopsy specimen from the gastrointestinal tract of patients who have undergone hematopoietic stem cell transplantation has not been investigated. We acquired 51 endoscopic biopsy specimens from the gastrointestinal tract of 35 patients. We divided the flow cytometry samples into two groups: group A, successful lymphocyte isolation (n=24), and group B, incomplete isolation (n=27). We compared the backgrounds of the samples between the groups to reveal crucial elements in the successful isolation of lymphocytes residing in the gastrointestinal tract. Comparison between the groups revealed lymphocyte isolation success rates differed between biopsy sites. Isolation was most successful in samples from the duodenum (8/9, 88.9%), followed by the ileum (4/8, 50.0%), large intestine (4/11, 36.4%), and stomach (8/23, 34.8%). Tacrolimus was used more frequently in group B (92.6%) than in group A (62.5%) (p=0.015). Logistic regression analysis revealed that isolation from the duodenum or ileum was a significant factor for successful isolation, while tacrolimus use was not statistically significant. In conclusion, the duodenum and ileum are more suitable sites than the stomach and colorectum for acquiring samples for flow cytometry.

Impact of the Recipient's Pre-Treatment Blood Lymphocyte Count on Intended and Unintended Effects of Anti-T-Lymphocyte Globulin in Allogeneic Hematopoietic Stem Cell Transplantation.

Background: In allogeneic hematopoietic stem cell transplantation (HSCT), Anti-T-Lymphocyte Globulin (ATLG) may be used for the prevention of severe graft-versus-host disease (GVHD). ATLG targets both the recipient's lymphocytes and those transferred with the graft. Assuming an inverse relation between the recipient's absolute lymphocyte count (ALC) and exposure of remaining ATLG to the graft, we aim to evaluate the impact of the recipient's ALC before the first ATLG administration on the benefits (prevention of GVHD and GVHD-associated mortality) and potential risks (increased relapse incidence) associated with ATLG. Methods: In recipients of HLA-matched, ATLG-based HSCT (n = 311), we assessed the incidence of acute GVHD, GVHD-related mortality and relapse, as well as other transplant-related outcomes, in relation to the respective ALC (divided into tertiles) before ATLG. Results: The top-tertile ALC group had a significantly increased risk of aGVHD (subhazard ratio (sHR) 1.81; [CI 95%; 1.14-2.88]; p = 0.01) and aGVHD-associated mortality (sHR 1.81; [CI 95%; 1.03-3.19]; p = 0.04). At the highest ATLG dose level (≥45 mg/kg), recipients with lowest-tertile ALC had a trend towards increased relapse incidence (sHR 4.19; [CI 95%; 0.99-17.7]; p = 0.05, n = 32). Conclusions: ATLG dosing based on the recipient's ALC may be required for an optimal balance between GVHD suppression and relapse prevention.

#2938 DE NOVO DSA IS ASSOCIATED WITH HUMAN PERIPHERAL BLOOD CXCR5+PD-1+CD8+ T CELLS AND PD-1 PD-L1 MRNA EXPRESSION IN KIDNEY TRANSPLANT PATIENTS

Abstract Background and Aims Donor-specific antibody (DSA) development is mainly responsible for chronic antibody-mediated rejection. The immunological events that cause the development of DSA is not fully elucidated. The relationship between the Follicular Cytotoxic T cell subgroup and the development of DSA is unknown. In this study we aimed to examine CD8+CXCR5+PD-1+ follicular cytotoxic T cell levels and expression levels of PD1/PD-L1 genes in peripheral blood lymphocytes in recipients who de-novo DSA positive or negative after kidney transplantation (KTX). Method In this study, the expression levels of PD-1, PD-L1 genes were determined using the Real-Time Quantitative PCR method from peripheral blood samples of 22 KTX patients with de-novo DSA positive, 20 KTX patients with DSA negative and 21 healthy control (Table 1). Our patient groups were PRA negative before transplantation. Expression (%) levels of target cells were evaluated by flow cytometry method. IBM SPSS Statistics for Windows Version 22 and R.3.3.2 software were used to evaluate the data. Results PD-1 expression level was higher in the KTX patients with de-novo DSA positive compared to the KTX patients with DSA negative group (p:0.006 CT: 0,84±0,23). According to the results of flow cytometry, CD8+CXCR5+PD-1+ cell expression (%) levels were found to be significantly higher in patients (3,06±1,98) compared to the transplant control group (0,52±0,40) (p: 0.001) (Figure 1). Conclusion It shows that there may be a direct correlation between DSA and PD-1 / PDL-1 mRNA level and CXCR5+PD1+CD8+ follicular cytotoxic T cell in transplant patients after kidney transplantation.

Effects of BAMBI deficiency in the development of Systemic Lupus Erythematosus

Abstract Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies and immune complexes deposition in various organs. Follicular CD4+ T cells play a crucial role in this autoimmune syndrome by activating autoreactive germinal center B cells. The transforming growth factor β (TGBβ) inhibitor BAMBI (Bone Morphogenetic Protein and Activin Membrane-Bound Inhibitor) is known to control the differentiation of CD4+ T lymphocytes into either tolerogenic Tregs or pathogenic Th17 cells. BAMBI absence in mutant mice or its pharmacological inhibition with the B101.37 monoclonal antibody promotes an increase in Treg differentiation and activity and at the same time, a reduction in Th17 cell differentiation, resulting in the inhibition of autoimmune disease development. Based on these findings, in the present study we have analysed the effects of BAMBI deficiency in the development of SLE. We have employed the chronic graft-versus-host disease lupus model induced after the transference of 40–60 × 106 lymphocytes from B6 or B6-BAMBI-KO mice into either Bm12 or Bm12-BAMBI-KO recipients. As reported previously, Bm12 mice receiving lymphocytes from B6 mice produce high levels of circulating IgG anti-DNA and anti-nucleosomal autoantibodies and exhibit linear glomerular IgG deposits in their kidneys. In contrast, both Bm12 mice injected with allogeneic B6-BAMBI-KO lymphocytes and Bm12-BAMBI-KO recipients receiving lymphocytes from B6 donors do not produce significant levels of circulating autoantibodies and do not reveal immune complexes deposits. Taken together, these results indicate that the absence of BAMBI in either donor or recipient lymphocytes protects mice against the development of SLE.

Antibiotic prophylaxis: a chance to reduce infections during childhood leukemia treatment

Introduction: In the course of allogeneic hematopoietic cell transplantation (allo-HCT) the donor’s hematopoietic progenitor cells are exposed to immense proliferative stress to reconstitute in the recipient the functional hematopoiesis. Moreover, recipients who develop infections or chronic graft-versus-host disease (GvHD) are subjected to further proliferative stress, especially in the lymphocyte subset. We hypothesized that allo-HCT may induce changes in proinflammatory cytokines profile and immunophenotype in the allo-HCT recipients, especially in patients with a chronic GvHD history. Material and methods: We compared the cytokine profile [interleukin (IL)-6, IL-10, and tumor necrosis factor α (TNF-α)] between long-term allo-HCT recipients and their respective donors and we analyzed cytokine profiles and the immunophenotype of lymphocytes in long-term recipients grouped according to their infection and GvHD history. Results: We found no differences in the proinflammatory cytokines between allo-HCT recipients and their respective donors, or between recipients grouped according to their infectious risk status. Immunophenotyping of recipients grouped according to their GvHD status revealed an increased percentage of B-cell presenting programmed death-1 in recipients without a history of GvHD. Conclusions: A lack of differences in proinflammatory cytokines concentrations between recipients and donors of allo-HCT would suggest that allo-HCT does not induce acceleration of the ‘inflammaging’-resembling phenomenon. No differences in the cytokine profile and immunophenotype between recipients grouped according to infectious risk status suggest that infectious risk is not reflected by the immunophenotype and cytokine profile. Furthermore, the lack of significant differences in immunophenotype of the recipients grouped according to a history of GvHD may suggest that in long-term survivors the immune system tends to stabilize with time.

Long-term allogeneic hematopoietic cells transplantation survivors proinflammatory cytokine profile compared to their respective donors and immunophenotype differences depending on GvHD history and infection status

Background In the course of allogeneic hematopoietic cell transplantation (allo-HCT) the donor’s hematopoietic progenitor cells are exposed to immense proliferative stress to reconstitute in the recipient the functional hematopoiesis. Moreover, recipients who develop infections or chronic GvHD are subjected to further proliferative stress, especially in the lymphocyte subset. We hypothesized that allo-HCT may induce changes in proinflammatory cytokines profile and immunophenotype in the allo-HCT recipients, especially in patients with cGVHD history. We compared the cytokine profile (Il-6, Il-10, and TNF-) between long-term allo-HCT recipients and their respective donors and we analyzed cytokines profile and the immunophenotype of lymphocytes in long-term recipients grouped according to the infection and GvHD history. Results We have found no differences in the proinflammatory cytokines between allo-HCT recipients and their respective donors, as well as between recipients grouped according to infectious risk status. Immunophenotyping of recipients grouped according to GvHD status revealed an increased percentage of B-cell presenting PD-1 in recipients without a history of GvHD. Conclusions Lack of differences in proinflammatory cytokines concentrations between recipients and donors of allo-HCT would suggest that allo-HCT does not induce acceleration of the inflammageing-resembling phenomenon. No differences in the cytokine profile and immunophenotype between recipients grouped according to infectious risk status suggest that infectious risk is not reflected by the immunophenotype and cytokine profile. Furthermore, the lack of significant differences in immunophenotype of the recipients grouped according to the history of GvHD may suggest that in long-term survivors the immune system tends to stabilize with time.

Pre-Transplant Total Lymphocyte Count Determines Anti-Thymocyte Globulin Exposure, Modifying Graft-versus-Host Disease Incidence and Post-Transplant Thymic Restoration: A Single-Center Retrospective Study.

The use of anti-thymocyte globulin (ATG) as part of conditioning to prevent graft-versus-host disease (GVHD) may severely impair immune reconstitution (IR). We analyzed relationships between ATG exposure, the recipient lymphocyte count, IR, and transplant outcome. We retrospectively reviewed patients aged ≤ 18 years who underwent allogeneic HSCT between April 2005 and April 2020. The outcomes of interest included the incidence of GVHD, overall survival (OS), and IR. IR was analyzed through thymic magnetic resonance imaging (MRI) and by quantifying T CD4+ and recent thymic emigrants (RTEs). The ATG-exposed group was split into a low ATG/lymphocyte ratio subgroup (ratio < 0.01) and a high ATG/lymphocyte ratio subgroup (ratio > 0.01). The low ratio subgroup had a higher incidence of GVHD (29 [59%] vs. 7 [16.6%]) but a better IR in both laboratory and MRI imaging assessments (p < 0.0001). The median thymic volume in the low ratio subgroup was significantly higher (14.7 cm3 vs. 4.5 cm3, p < 0.001). This was associated with a better OS and lower transplant-related mortality (TRM) (80.4% vs. 58.0%, p = 0.031) and (13.1% vs. 33.0%, p = 0.035). An individualized approach to ATG dosing allows for the obtainment of rapid thymic reconstitution and the best transplant-related outcomes.

The long-term perioperative lymphopenia associates with low absolute counts of T lymphocytes in liver transplantation recipients with hepatocellular carcinoma

The long-term perioperative lymphopenia associates with low absolute counts of T lymphocytes in liver transplantation recipients with hepatocellular carcinoma

P2.13: Immunosuppression Monotherapy Does Not Protect Donor Leukocytes From Depletion Post MHC-Mismatched Kidney Transplantation in Mice

Background: The retention of donor tissue-resident leukocytes within a transplanted organ is likely to be important to graft health and survival post-transplantation. We have previously shown that in the absence of immunosuppression, donor tissue-resident leukocytes are depleted following MHC-mismatched transplants, due to infiltrating recipient effector leukocytes. We hypothesised, therefore, that the retention of donor leukocytes described following mismatched transplants in humans is a result of immunosuppressive therapy, which targets recipient effector cells. In this study, we investigated the impact of different immunosuppressive agents as monotherapies on the retention of donor leukocytes after MHC-mismatched transplantation. Methods: We developed immunosuppression regimens using clinically-relevant levels of immunosuppressive medications including tacrolimus and mycophenolate, and treated mice receiving MHC-mismatched kidney transplants. At seven days post-transplant, we compared the donor leukocyte retention and recipient leukocyte responses of mice on immunosuppression to those without. Results: As expected after immunosuppression treatment, the circulating lymphocyte count was decreased. Simultaneously, the absolute number and proliferation of recipient lymphocytes within the graft and peripheral organs were reduced in comparison to immunocompetent controls. Immunosuppression also altered macrophage polarisation within the graft, to a less pro-inflammatory phenotype. Interestingly, our preliminary data showed that despite the decrease in recipient leukocyte infiltration, and a less inflammatory microenvironment within the graft, treatment with a single immunosuppressive agent did not improve donor leukocyte retention post-transplantation. Conclusions: This highlights the requirement for the use of multiple immunosuppressive agents to sufficiently suppress recipient effector leukocyte responses, not only for graft tolerance but for donor leukocyte retention. Hackett Postgraduate Research Scholarship. Australian Government Research Training Program Scholarship. Sir Charles Gairdner and Osborne Park Health Care Group RAC Grant (MRGP21-22_24).

Proportion versus absolute counts of B cell populations in the assessment of immunological profiles of kidney transplant recipients

Immunophenotyping lymphocytes in kidney transplant recipients often raises questions as to whether proportions or absolute counts should be considered, especially for longitudinal assessment. Several studies conclude the pathophysiology of rejection based on proportions of naive and memory B cells. We compared the two analytical methods for B cells sampled from 82 clinically stable, adult kidney transplant recipients. Time post-transplant was analyzed both as a continuous variable and as tertiles (<1.5 years, 1.5–8 years, and > 8 years). B cells were stained for CD38 and IgD and were classified according to mature B cells (Bm) classification. The proportion of cells in the naive Bm2 compartment decreased by more than half in the late versus the early tertile, whereas the percentages of memory early Bm5 tripled and that of memory Bm5 cells doubled. In contrast, we observed a substantial reduction in naive B cell counts, but very stable memory B cell counts. Linear regressions showed that the absolute reduction in the Bm2 cell compartment was independent of age, sex, graft function, immunosuppression scheme, and rejection occurrence. In conclusion, the physiological reservoir of naive cells decreases over time post-transplant in kidney recipients, whereas that of memory B cells remains stable. Peripheral B subset percentages should be interpreted cautiously when analyzing pathophysiological processes.

Immune Recovery Following Autologous Hematopoietic Stem Cell Transplantation in HIV-Related Lymphoma Patients on the BMT CTN 0803/AMC 071 Trial.

We report a first in-depth comparison of immune reconstitution in patients with HIV-related lymphoma following autologous hematopoietic cell transplant (AHCT) recipients (n=37, lymphoma, BEAM conditioning), HIV(-) AHCT recipients (n=30, myeloma, melphalan conditioning) at 56, 180, and 365 days post-AHCT, and 71 healthy control subjects. Principal component analysis showed that immune cell composition in HIV(+) and HIV(-) AHCT recipients clustered away from healthy controls and from each other at each time point, but approached healthy controls over time. Unsupervised feature importance score analysis identified activated T cells, cytotoxic memory and effector T cells [higher in HIV(+)], and naïve and memory T helper cells [lower HIV(+)] as a having a significant impact on differences between HIV(+) AHCT recipient and healthy control lymphocyte composition (p<0.0033). HIV(+) AHCT recipients also demonstrated lower median absolute numbers of activated B cells and lower NK cell sub-populations, compared to healthy controls (p<0.0033) and HIV(-) AHCT recipients (p<0.006). HIV(+) patient T cells showed robust IFNγ production in response to HIV and EBV recall antigens. Overall, HIV(+) AHCT recipients, but not HIV(-) AHCT recipients, exhibited reconstitution of pro-inflammatory immune profiling that was consistent with that seen in patients with chronic HIV infection treated with antiretroviral regimens. Our results further support the use of AHCT in HIV(+) individuals with relapsed/refractory lymphoma.

Study of prevalence of lymphoceles after kidney transplantation

Introduction: One of the complications of renal transplantation after surgery, which is frequently observed, is the symptomatic accumulation of fluid around the kidney, such as hematoma, lymphocele or lymphuria. Objectives: The incidence of lymphocele after kidney transplantation is widely different, therefore we decided to conduct a study to investigate the prevalence of lymphocytes in transplant recipients. Patients and Methods: The present study was a cross-sectional descriptive-analytical study. The target population in this study was adult and middle-aged men and women with end-stage renal disease (ESRD) who have undergone kidney transplant surgery at the kidney center of Imam Reza hospital in the last 5 years. Results: In all transplant recipients, symptomatic lymphoceles were observed in only 5 patients (3 female and 2 male patients with the mean age of 40.2±17.2 years) who occurred on average 48.4 ± 21.12 days after surgery between 24 days and 78 days. The results showed that 62% (156 cases) of patients were men and 211 patients (84.4%) were male transplant recipients. Also, 198 (79.2%) transplant donors were living donor and 52 (20.8%) were deceased donor/brain death. Conclusion: In the present study, we found the prevalence of lymphocele in transplant recipients in the kidney transplant center of Imam Reza in five years is 5 patients (2%) out of 250 patients with an average annual incidence of 1-2%.

A Prospective, Non-Randomized, Multicenter, Phase II Study to Assess Safety and Efficacy of the Infusion of Peripheral Blood Stem Cells Obtained from HLA-Haploidentical Familial Donors (mHaploSCI) after Standard Chemotherapy in Elderly Patients with Acute Myeloid Leukemia at Intermediate or Adverse Risk

A Prospective, Non-Randomized, Multicenter, Phase II Study to Assess Safety and Efficacy of the Infusion of Peripheral Blood Stem Cells Obtained from HLA-Haploidentical Familial Donors (mHaploSCI) after Standard Chemotherapy in Elderly Patients with Acute Myeloid Leukemia at Intermediate or Adverse Risk

Dynamic changes to tissue-resident immunity after MHC-matched and MHC-mismatched solid organ transplantation.

The heterogeneous pool of tissue-resident lymphocytes in solid organs mediates infection responses and supports tissue integrity and repair. Their vital functions in normal physiology suggest an important role in solid organ transplantation; however, their detailed examination in this context has not been performed. Here, we report the fate of multiple lymphocyte subsets, including T, B, and innate lymphoid cells, after murine liver and heart transplantation. In major histocompatibility complex (MHC)-matched transplantation, donor lymphocytes are retained in liver grafts and peripheral lymphoid organs of heart and liver transplant recipients. In MHC-mismatched transplantation, increased infiltration of the graft by recipient cells and depletion of donor lymphocytes occur, which can be prevented by removal of recipient T and B cells. Recipient lymphocytes fail to recreate the native organs' phenotypically diverse tissue-resident lymphocyte composition, even in MHC-matched models. These post-transplant changes may leave grafts vulnerable to infection and impair long-term graft function.

Reactivations of Latent Viral Infections Are Associated with an Increased Thr389 p70S6k Phosphorylation in Peripheral Lymphocytes of Renal Transplant Recipients.

Reactivations of BK polyoma virus (BKPyV) and human cytomegalovirus (HCMV) frequently cause life- and graft-threatening complications after renal transplantation. Both viruses are dependent on the mTOR pathway for replication. In this study we investigated the association of viral replication with mTOR activity in peripheral lymphocytes of renal transplant recipients. A flow-cytometry based assay for the measurement of Thr389 p70S6k phosphorylation, a surrogate marker of the mTOR pathway was established. Forty-eight adult renal transplant recipients were recruited to measure p70S6k activity in their peripheral blood mononuclear cells. This data set in conjunction with information concerning previous replication of BKPyV and HCMV was examined for correlations. Episodes of BKPyV replication were significantly associated with increased p70S6k phosphorylation in CD4+ T lymphocytes (p = 0.0002) and CD19+ B lymphocytes (p = 0.0073). HCMV infection of patients with a high-risk HCMV constellation of donor and recipient (D+/R−) was associated with increased p70S6k phosphorylation in CD19+ B lymphocytes (p = 0.0325). These associations were found to be independent of the trough levels of the immunosuppressive drugs. Conclusion: P70S6k phosphorylation in peripheral lymphocytes is associated with BKPyV reactivations and to a lesser extent with HCMV infections in renal transplant recipients.

Up-Regulation of Donor Dendritic Cell PD-L1 Expression Reduced Recipient Lymphocyte Activation and Proliferation In Vitro

ObjectiveTo observe the effects of dendritic cells (DC) in donor C57BL/6 (H-2b) micetransfected with recombinant adenovirus vector Ad-PD-L1 on proliferation and activation of lymphocytes in recipient DBA/2 (H-2d) mice. MethodsThe pSport 1-mSD274 plasmid containing the full-length PD-L1 cDNA of the mouse was digested and subcloned to the shuttle plasmid pShuttle-GFP-CMV(-), and then the adenovirus skeleton plasmid pAdxsi-GFP-CMV-PD-L1 was constructed by enzymolysis and ligation, transformed into DH5α sensitive bacteria, and screened for positive clones. After enzyme digestion, sequencing, and identification, 293 cells were transfected with liposome after linearization for packaging and amplification, and the virus was purified by cesium chloride density gradient centrifugation. DC of donor C57BL/6 mice were isolated, cultured, and divided into the following 3 groups: group A, adenovirus vector Ad-PD-L1 transfection group; group B, empty vector transfection group; and group C, control group. Western blot was used to detect the expression of PD-L1 in each group of cells after transfection. Isolate lymphocytes from recipient DBA/2 mice were labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) and mixed with DC of donor C57BL/6 mice with lymphocytes of recipient DBA/2 mice. Flow cytometry was performed to observe the proliferation of lymphocytes. ResultsDigestion and sequencing confirmed that the recombinant adenovirus vector Ad-PD-L1 containing PD-L1 was successfully constructed. After transfection with DC of donor C57BL/6 mice, the expression of PD-L1 increased by 37% (P < .05), and the PD-L1 transfected DC and recipient DBA/2. Mouse lymphocytes were cocultured. Compared with the control group, the increased expression of PD-L1 significantly inhibited the proliferation and activation of lymphocytes. The lymphocyte proliferation of DBA/2 mice decreased by 41% (P < .01). ConclusionThe recombinant adenovirus vector Ad-PD-L1 containing the mouse PD-L1 gene was successfully constructed. After transfection with dendritic cells of donor C57BL/6 mice, PD-1/PD-L1 inhibited lymphocytes proliferation and activation of recipient DBA/2 mice through costimulatory pathway.