T-helper cell responses in liver transplant recipients: correlation with cytomegalovirus and other major infections

Mitogen concanavalin A (ConA) response and cytomegalovirus (CMV)-specific memory response were assessed in 24 liver transplant recipients and compared with healthy subjects. Transplant recipients as compared to healthy subjects had a lower CMV memory response at 2 weeks (P=0.023), and at 1 month (P=0.06), but a comparable response at 3 months. CMV recipient+/donor+(R+/D+) patients had the greatest increase in CMV-specific memory response at 2-3 months as compared to all other groups. Within this R+/D+ group, CMV-specific memory response was significantly more robust in patients who never had CMV infection as compared to those who developed CMV infection (P=0.035). ConA response at 2 weeks was significantly lower in patients with major infections as compared to those without them (SI 5.4 vs. 38.1, P=0.039). Thus, reconstitution of CMV-specific T-helper cell response was distinct for subsets of liver transplant recipients based on the recipient and donor CMV serostatus. Impairment in proliferative response to ConA identified a subgroup of patients with major infections after liver transplantation.     

Artificial antigen-presenting cells plus IL-15 and IL-21 efficiently induce melanoma-specific cytotoxic CD8+ CD28+ T lymphocyte responses

ObjectiveTo develop a novel artificial antigen-presenting system for efficiently inducing melanoma-specific CD8⁺ CD28⁺ cytotoxic T lymphocyte (CTL) responses.MethodsCell-sized Dynabeads® M-450 Epoxy beads coated with H-2K^b: Ig-TRP2_180-188and anti-CD28 antibody were used as artificial antigen-presenting cells (aAPCs) to induce melanoma-specific CD8⁺CD28⁺ CTL responses with the help of IL-21 and IL-15. Dimer staining, proliferation, ELISPOT, and cytotoxicity experiments were conducted to evaluate the frequency and activity of induced CTLs.ResultsDimer staining demonstrated that the new artificial antigen-presenting system efficiently induced melanoma TRP2-specific CD8⁺CD28⁺CTLs. Proliferation and ELISPOT assays indicated that the induced CTLs rapidly proliferate and produce increased IFN- γ under the stimulation of H-2K^b: Ig-TRP2-aAPCs, IL-15, and IL-21. In addition, cytotoxicity experiments showed that induced CTLs have specific killing activity of target cells.ConclusionsThe new artificial antigen-presenting system including aAPCs plus IL-21 and IL-15 can induce a large number of antigen-specific CD8⁺ CD28⁺ CTLs against the melanoma. Our study provides evidence for a novel adoptive immunotherapy against tumors.     

CD8+ cytotoxic T lymphocyte responses to lytic proteins of human herpes virus 8 in human immunodeficiency virus type 1-infected and -uninfected individuals

T cell immunity to lytic proteins of herpesviruses is important in host control of infection. We have characterized the cytotoxic T lymphocyte (CTL) response to 5 human herpesvirus 8 (HHV-8) homologues of lytic proteins in HHV-8-seropositive individuals. HLA class I-restricted, CD8(+) CTL responses to >/=1 HHV-8 lytic protein were detected in all 14 HHV-8-seropositive study subjects tested, with or without human immunodeficiency virus type 1 (HIV-1) infection, but not in any of 5 HHV-8-seronegative individuals. Seven of these study subjects with both HHV-8 and HIV-1 infection had greater anti-CTL reactivity to glycoprotein H (open-reading frame 22) than did the 7 study subjects infected only with HHV-8. Moreover, there was a strong, inverse correlation between HIV-1 load and glycoprotein H-specific CTL lysis in the study subjects infected with both viruses. CTL reactivity to HHV-8 lytic proteins may be involved in host control of HHV-8-related diseases, such as Kaposi's sarcoma.     

HLA-restricted CD8+ cytotoxic T lymphocyte, interferon-gamma, and interleukin-4 responses to respiratory syncytial virus infection in infants and children

CD8+ cytotoxic T lymphocyte (CTL) activity, interferon (IFN)-gamma, and interleukin (IL)-4 production were evaluated in a blinded manner among respiratory syncytial virus (RSV)-infected newborns and their mothers for 3 epidemic seasons. Most mothers (80%) exhibited RSV-specific CD8+ CTL activity. Twenty (80%) of the 26 infants exhibited significant RSV-specific CTL activity during or after their first RSV season. CTL frequency increased with RSV infection rate, reaching 75% by the end of the third season. Most infants who shed virus (75%) had a medically attended lower respiratory tract disease (LRD). In the first year, RSV-infected infants (virus culture and antibody increase) were more likely to develop CTL activity (10 of 13) than were uninfected infants (1 of 5; P=.02). Infants with CTL activity in the first year were less likely to have an LRD in the second year. CD8+ CTL levels correlated positively with IFN-gamma (P<.001) and inversely with IL-4 (P=.03). Contribution of CD8+ CTL and IFN-gamma in the control of RSV disease in infants and children is implicated.     

High CD8+ lymphocyte dose in the autograft predicts early absolute lymphocyte count recovery after peripheral hematopoietic stem cell transplantation

Early lymphocyte recovery (ELR) after autologous peripheral hematopoietic stem cell transplantation (ASCT) is an independent predictor for survival in patients with hematological and non‐hematological cancers. Sixty‐five ASCT for hematological cancers were retrospectively analyzed to identify the factors associated with ELR and to assess the impact of different mobilization regimens on the pre‐collection absolute lymphocyte count (ALC). The CD8+ lymphocyte dose in the autograft and the pre‐mobilization ALC were independently associated with ELR (P < 0.001 and P = 0.008, respectively). CD8+ lymphocyte doses higher than 0.1 × 10⁹/kg were strongly associated with ELR [P < 0.001, odds ratio 25.22, 95% confidence interval (CI) 4.98–127.69] and this cutoff may be used to predict ELR (P = 0.001, area under the curve 0.75, 95% CI 0.62–0.88). Mobilization with granulocyte colony‐stimulating factor (G‐CSF) alone, the pre‐collection ALC and the number of apheresis sessions were independently associated with the CD8+ lymphocyte dose (P = 0.04, P = 0.001, and P < 0.001, respectively). The number of aphereses was the variable with the strongest correlation to the CD8+ lymphocyte dose (r_s = 0.68, P < 0.001). Median pre‐mobilization ALC was higher than pre‐collection ALC in the subgroup of patients without ELR mobilized with chemotherapy followed by G‐CSF (1090 vs. 758 lymphocytes/μL; P < 0.001). This reduction was not significant in the subgroup with ELR mobilized with chemotherapy plus G‐CSF (1920 vs. 1539/μL, respectively; P = 0.23). These results suggest that the CD8+ lymphocyte dose in the autograft is critical for ELR after ASCT and also demonstrates that mobilization with chemotherapy followed by G‐CSF significantly decreases the pre‐collection ALC, especially in patients with low pre‐mobilization ALC. Am. J. Hematol, 2009. © 2008 Wiley‐Liss, Inc.     

CD+8 T细胞激活分子CD38、HLA-DR与HIV-1载量的相关性研究

目的研究HIV/AIDS患者CD8^＋ T细胞表达激活分子CD38、HLA-DR水平与血浆病毒载量（VL）的相关性,以及用CD8CD38、CD8HLA-DR比例替代VL检测的可行性.方法用流式细胞术分析103例接受12个月高效抗逆转录病毒治疗（HAART）患者的CD＋8 T细胞表达CD38和HLA-DR水平;用分支DNA扩增技术检测血浆VL.用敏感性、特异性、准确性等参数分析能有效预测VL＜50拷贝/ml、VL＜500拷贝/ml、VL＞1000拷贝/ml和VL＞10 000拷贝/ml时CD8CD38和CD8HLA-DR的检测范围.结果103例艾滋病患者CD38、HLA-DR和VL在12个月治疗中均呈下降趋势;CD38和VL在HAART治疗前及治疗第1、3、6、9、12个月6个检测点的总相关系数为0.483（P＜0.001）、HLA-DR和VL的总相关系数为0.477（P＜0.001）.用CD8CD38和CD8HLA-DR的水平预测VL值有显著诊断价值：当CD38＜68.5%和＜72.5%时预测VL＜50拷贝/ml和＜500拷贝/ml有较高的灵敏度和特异性;当HLA-DR在＞39.5%和＞46.5%时预测VL＞1000拷贝/ml和＞10 000拷贝/ml有较高的灵敏度和特异性.结论在条件匮乏的艾滋病高发区,可以用CD8CD38和CD8HLA-DR激活亚群的结果来预测血浆VL,作为监测HIV疾病进展和评价抗病毒疗效的参考.     

Comparison of CD8+ T Cell responses to cytomegalovirus between human fetuses and their transmitter mothers

BACKGROUND: The mechanisms responsible for the increased susceptibility of fetuses to cytomegalovirus (CMV) were studied by comparing CD8(+) T cell responses to the virus in susceptible fetuses to those in their comparatively more resistant mothers. METHODS: Included in the study were 16 transmitter mothers who underwent seroconversion during the first trimester of pregnancy as well as their fetuses, who were positive for CMV in amniotic fluid by polymerase chain reaction at 17-19 weeks of gestation. Fetal and maternal blood samples were collected between the 22nd and 39th week of gestation. Cytotoxic T lymphocytes (CTLs) that had activated (HLA-DR(+)), effector/memory (CD28(-)), and memory (CD18(high)) phenotypes; that stained with the HLA-A2/pp65 or the HLA-B7/pp65 multimer; and that secreted interferon (IFN)- gamma were enumerated by flow cytometry. Viral loads were determined simultaneously. RESULTS: The results showed (1) similar levels of activated, effector/memory, and memory CTLs in fetuses and mothers but a smaller pp65-specific CTL pool in fetuses (median, 0.015% vs. 0.99%; P=.003); (2) similar percentages of CTLs secreting IFN- gamma after stimulation with ionomycin/phorbol myristate acetate in fetuses and mothers but lower percentages of CTLs secreting IFN- gamma after stimulation with a CD3 monoclonal antibody in fetuses (median, 1% vs. 14%; P=.01); and (3) higher viral loads (mean, 17,290 vs. <250 genome equivalents/mL) in fetuses. CONCLUSION: Impaired viral clearance might be related to a defective expansion of the pp65-specific CTL pool and/or to the immaturity of IFN- gamma -secreting cells in fetuses.     

Analysis of CD8~+CD28~-T-suppressor cells in living donor liver transplant recipients

BACKGROUND:Human CD8 + CD28 - T-suppressor(Ts) cells have been considered to indicate a reduced need for immunosuppression in pediatric liver-intestine transplant recipients and recipients of deceased heart-kidney transplants.However,in adult-to-adult living donor liver transplantation(A-A LDLT)little information is available and the clinical significance is still unknown. METHODS:Flow cytometry was used to detect the population of CD8+CD28 -Ts cells present in peripheral blood in A-A LDLT recipients(n=31),...     

Increased numbers of CD8+CD11+, CD8+CD11- and CD8+Leu7+ cells in patients with chronic graft-versus-host disease after allogeneic bone marrow transplantation.

Peripheral blood lymphocytes from 25 allogeneic bone marrow transplant recipients were studied serially using flow cytometry and two colour analysis. Fourteen patients were transplanted for haematologic malignancies, eight for aplastic anaemia, two for congenital immunodeficiencies and one for Morquio's disease. All patients were alive more than 100 days post-grafting; nine patients had chronic graft-versus-host disease (GVHD). Dual labelling with monoclonal antibodies, CD4/2H4, CD4/4B4, CD8/CD11, CD8/HLA-DR and CD8/Leu 7 was used to analyse the surface phenotypes of lymphocytes. The population of CD4+2H4+ cells was decreased, and CD8+CD11+, CD8+CD11- and CD8+Leu7+ cells were markedly increased in patients with chronic GVHD. The increase of CD8+CD11+, CD8+CD11- and CD8+Leu7+ cells closely correlated with clinical signs of chronic GVHD in each patient. These results suggest that CD8+ cells may play an important role in effector and/or suppressor mechanisms of chronic GVHD and could be used as an indicator of need for and response to treatment.     

Efficacy and safety of once daily tacrolimus compared to twice daily tacrolimus after liver transplantation

BACKGROUNDOnce daily tacrolimus regimen was found to exhibits similar bioavailability, safety and efficacy properties compared to twice-daily tacrolimus in kidney transplantation patients.AIMTo compare the efficacy and safety of once-daily prolonged release tacrolimus compared to twice-daily tacrolimus in liver transplantation patients.METHODSMEDLINE, EMBASE, CENTRAL databases were searched for clinical trials until December 2020. Efficacy outcome measured as the rate of treatment failure indicated by biopsy-proven acute rejection, Serum creatinine, graft loss, or death. Two reviewers independently selected studies, collected data and assessed risk of bias. The results are reported as risk ratio with 95% confidence interval (CI) for dichotomous data.RESULTSSeven studies included with 965 patients. All the included studies were of moderate quality according to the risk of bias assessment using Cochrane Risk of Bias tool. Biopsy-proven acute rejection was reported in four studies, and pooled analysis of those studies indicated similar rejections in both twice daily and once daily tacrolimus groups (risk ratio: 1.06, 95%CI: 0.84-1.34, n = 758, I² = 0%) and also we found no significant difference between both groups for renal outcome (serum creatinine; mean difference, 0.001 mg/dL, 95%CI: -0.042 to 0.043, n = 846, I² = 18.6%). Similarly, there was similar number of adverse events such as hypertension, headache, back pain, blood related disorders, infections and nausea observed in both groups.CONCLUSIONThe analysis findings confirm that both once daily and twice daily tacrolimus formulations are comparable in terms of efficacy and safety outcomes.     

Survey of naturally occurring CD4+ T cell responses against NY-ESO-1 in cancer patients: correlation with antibody responses

NY-ESO-1 is one of the most immunogenic proteins described in human cancers, based on its capacity to elicit simultaneous antibody and CD8+ T cell responses in vivo. Although HLA class II restricted epitopes from NY-ESO-1 have been identified, no broad survey has yet established the status of natural CD4+ T cell responses in cancer patients in relation to CD8+ and antibody responses. We used a recently developed general strategy for monitoring CD4+ responses that overcomes the need for prior knowledge of epitope or HLA restriction to analyze a series of 31 cancer patients and healthy donors for the presence of CD4+ T cells to NY-ESO-1, and related this response to NY-ESO-1 expression in tumor cells and serum antibodies to NY-ESO-1. None of the 18 patients that tested seronegative for NY-ESO-1 had detectable CD4+ T cell responses. On the contrary, 11 of 13 cancer patients with serum antibodies to NY-ESO-1 had polyclonal CD4+ T cell responses directed against various known and previously undescribed NY-ESO-1 epitopes. NY-ESO-1 peptide 80-109 was the most immunogenic, with 10 of 11 patients responding to this peptide. We show here that 12-mer determinants from NY-ESO-1 eliciting a CD4+ T cell response were peptide 87-98 with promiscuous HLA class II presentation, peptide 108-119 restricted by HLA-DP4, and peptides 121-132 and 145-156, both shorter epitopes from previously described HLA-DR4 peptides, also presented by HLA-DR7. This study represents the next step in compiling a comprehensive picture of the adaptive immune response to NY-ESO-1, and provides a general strategy for analyzing the CD4+ T cell response to other tumor antigens eliciting a humoral immune response.     

CD8+ cell depletion of donor lymphocyte infusions using cd8 monoclonal antibody-coated high-density microparticles (CD8-HDM) after allogeneic hematopoietic stem cell transplantation: a pilot study

A CD8 murine monoclonal antibody-coated high-density microparticle (HDM) has been developed, which allows for the rapid depletion of CD8+ T cells from apheresis products by gravity sedimentation. We conducted a study to determine the efficacy and safety of CD8 depletion of donor lymphocyte infusions (DLI) to treat relapse after stem cell transplantation using the Eligix CD8-HDM Cell Separation System. Patients were targeted to receive 3 x 10(7) CD4+ T cells/kg. Nine patients were enrolled, three with CML, three myeloma, two CLL, and one NHL. A median of 1 x 10(10) mononuclear cells were obtained by apheresis and processed. The median depletion of CD8+ cells was 99.3% (97.8->99.5%). CD8 depletion was highly specific, with a median recovery of CD4+ cells of 75%. A median of 2.9 x 10(7) CD4+ cells/kg was infused. No infusional toxicity was noted. All CML patients achieved a complete molecular remission. A CLL patient demonstrated a complete response. One patient developed GVHD (grade II acute GVHD and subsequently chronic GVHD). The CD8-HDM Cell Separation System appears to be highly selective and effective in depleting CD8+ T cells from DLI apheresis products, and CD8-depleted DLI is capable of mediating a graft-versus-leukemia effect while minimizing GVHD.     

Bone marrow transplant recipients have defective MHC-unrestricted cytotoxic responses against cytomegalovirus in comparison with Epstein-Barr virus: the importance of target cell expression of lymphocyte function-associated antigen 1 (LFA1).

Cytomegalovirus (CMV) remains the most common single infective cause of death following allogeneic bone marrow transplantation (BMT) from major histocompatibility complex (MHC)-identical siblings, whereas Epstein-Barr virus (EBV)-related disease is infrequent. We show here that MHC-unrestricted cytotoxic effector cells in the peripheral blood of BMT recipients are highly effective at killing EBV-infected target cells, but are inactive against CMV-infected target cells. Differential cytotoxicity is associated with disparate target structure expression. Although both EBV- and CMV-infected target cells express viral antigens, it is only those infected with EBV that express the adhesion molecule lymphocyte function-associated antigen 1 (LFA1; CD11a/18). Thus, EBV-infected target cells are able to interact with the principal LFA1 ligand, intercellular adhesion molecule 1 (ICAM1; CD54), which is expressed on posttransplant peripheral blood mononuclear (PBM) effector cells. CMV-infected target cells cannot utilize this ligand. Posttransplant cytotoxicity against EBV-infected target cells is abolished by target and effector cell blockade with monoclonal antibodies (MoAbs) to LFA1 and ICAM1, respectively, demonstrating the functional relevance of this additional ligand interaction. These results provide an illustration both of the importance and of the limitations of MHC-unrestricted cytotoxicity in vivo and may explain the frequency of CMV disease and the relative rarity of EBV-related disease following allogeneic transplantation from MHC-matched siblings. The increased immunosuppression used following MHC-mismatched/matched unrelated-donor BMT may cause this MHC-unrestricted defense mechanism to fail and may contribute to the greatly increased incidence of EBV lymphoproliferative syndrome in these patients.     

CD8+淋巴细胞表达强度与乙型病毒性肝炎不同肝组织炎症分级的关系

目的探讨CD8 淋巴细胞与乙型肝炎患者肝组织炎症分级的关系和意义。方法应用免疫组织化学技术,检测不同炎症分级的肝组织中CD8 淋巴细胞的表达。结果G0肝组织中CD8 表达弱,随着炎症分级的增强,CD8 表达逐渐增强。G4最为明显,有明显统计学意义。结论CD8 淋巴细胞表达强度与肝组织炎症分级有明显相关性。     

Deficiency of cytomegalovirus (CMV)-specific CD8+ T cells in patients presenting with late-onset CMV disease several years after transplantation

Abstract: Cytomegalovirus (CMV) is a major cause of morbidity and mortality among transplant recipients. The routine use of anti-CMV prophylaxis has modified the epidemiology of post-transplant CMV infection by delaying the onset of clinical disease. While the majority of delayed-onset CMV disease still occurs during the first year after transplant, reports of late-onset CMV disease presenting many years after transplantation are increasing. Here, we describe 2 CMV-seropositive transplant recipients who presented with late-onset CMV disease at 8 and 11 years after transplantation. To determine whether CMV disease occurring at a very late period after transplantation is related to immune competence, we assessed global and CMV-specific cellular immunity by evaluating the activation capability of CD8+ T cells to a mitogenic stimulus and by quantitative and functional analysis (as assessed by intracellular cytokine production and degranulation) of CMV-specific CD8+ T cells. In both patients, we demonstrated the absence or marked deficiency of CMV-specific T-cell immunity despite CMV seropositivity, and in one patient, a partial defect in the immune response to phorbol myristate acetate and ionomycin suggesting impaired global immune competence. Hence, our data suggest that late-onset CMV disease occurring many years after transplantation remains related to defects in the immune competence of patients. Measurement of CMV-specific cellular immune competence may therefore provide an additional tool to screen for patients at high risk of developing late-onset CMV disease. The clinical utility of this assay, however, will need to be evaluated in larger prospective studies.     

Recovery of lymphocyte and dendritic cell subsets after autologous CD34+ cell transplantation

Following high-dose chemotherapy (HDC) and peripheral blood progenitor cell transplantation (PBPCT), there are profound changes in leukocyte homeostasis and the immune system is compromised. Transplantation of purified CD34+ cells may further compromise immune recovery because the grafts are depleted of mature immune cells. However, a detailed monitoring of immune cell reconstitution has not been done. We monitored blood levels of antigen-presenting cells (APC) and of lymphocytes by multi-color flow cytometry at different times post CD34+ PBPCT. We found a rapid normalization of circulating levels of the antigen-presenting CD11c+ dendritic cells (defined as lineage- HLA-DR+ CD11c+ cells). There was a slight over-representation of lin- DR+ CD11c- cells at day 42 post transplantation suggesting that the composition of the APC population might be affected. Normal levels of total T, B and NK lymphocytes were rapidly achieved but the composition of the T cell population was abnormal. Patients had elevated levels of CD8+ T cells at early times and a persistent reduction in levels of naive CD8+ T cells (CD8+ CD4- CD45RA+ CD27+) and of naive CD4+ T cells (CD4+CD3+ CD8- CD45RA+). Thus, we found a rapid recovery of DC after CD34+ PBPCT but the specific numerical defects in naive T cells are likely to be a major cause of immune dysfunction in the patients. Bone Marrow Transplantation (2000) 25, 1249-1255.     

Dynamics of CD4 and CD8 T cell responses to cytomegalovirus in healthy human donors

To study the dynamics of cytomegalovirus (CMV) immunity in healthy immunocompetent hosts, interferon-gamma-producing CD4 and CD8 T cell responses in the presence or absence of CMV antigens were measured from 15 CMV-seropositive donors and 13 CMV-seronegative donors. Cytokine responses in the absence of antigen were significantly higher in CMV-seropositive donors. Also, a disproportionate number of CD69(+) cells isolated ex vivo from CMV-seropositive donors were specific for CMV, suggesting recent reactivation in vivo. To examine changes in cellular responses over time, 10 seropositive donors were tested over a 6-month period. About half of the donors showed significant variability over time, but staphylococcal enterotoxin B responses remained relatively constant. These findings suggest that CMV can present a considerable and recurrent burden to the human immune system. By understanding the normal dynamics of CMV responses over time, it may be possible to better identify aberrant responses to CMV in immunocompromised hosts.