Functional characteristics of cord blood T lymphocytes after lectin and anti-CD3 stimulation. Differences in the way T cells express activation molecules and proliferate

A single administration of human umbilical cord blood T cells produces long-lasting effects in the aging hippocampus

Neurogenesis occurs throughout life but significantly decreases with age. Human umbilical cord blood mononuclear cells (HUCB MNCs) have been shown to increase the proliferation of neural stem cells (NSCs) in the dentate gyrus (DG) of the hippocampus and the subgranular zone of aging rats (Bachstetter et al., BMC Neurosci 9:22, 2008), but it is unclear which fraction or combination of the HUCB MNCs are responsible for neurogenesis. To address this issue, we examined the ability of HUCB MNCs, CD4+, CD8+, CD3+, CD14+, and CD133+ subpopulations to increase proliferation of NSCs both in vitro and in vivo. NSCs were first grown in conditioned media generated from HUCB cultures, and survival and proliferation of NSC were determined with the fluorescein diacetate/propidium iodide and 5-bromo-2'-deoxyuridine incorporation assays, respectively. In a second study, we injected HUCB cells intravenously in young and aged Fisher 344 rats and examined proliferation in the DG at 1 week (study 2.1) and 2 weeks (study 2.2) postinjection. The effects of the HUCB MNC fractions on dendritic spine density and microglial activation were also assessed. HUCB T cells (CD3+, CD4+, and CD8+ cells) induced proliferation of NSCs (p < 0.001) and increased cell survival. In vivo, HUCB-derived CD4+ cells increased NSC proliferation at both 1 and 2 weeks while also enhancing the density of dendritic spines at 1 week and decreasing inflammation at 2 weeks postinjection. Collectively, these data indicate that a single injection of HUCB-derived T cells induces long-lasting effects and may therefore have tremendous potential to improve aging neurogenesis.

T lymphocytes derived from human cord blood provide effective antitumor immunotherapy against a human tumor

Background

Although the graft-versus-tumor (GVT) effect of donor-derived T cells after allogeneic hematopoietic stem cell transplantation has been used as an effective adoptive immunotherapy, the antitumor effects of cord blood (CB) transplantation have not been well studied.

Methods

We established the animal model by transplantation of CB mononuclear cells and/or tumor cells into NOD/SCID mice. The presence of CB derived T cells in NOD/SCID mice or tumor tissues were determined by flow cytometric and immunohistochemical analysis. The anti-tumor effects of CB derived T cells against tumor was determined by tumor size and weight, and by the cytotoxicity assay and ELISPOT assay of T cells.

Results

We found dramatic tumor remission following transfer of CB mononuclear cells into NOD/SCID mice with human cervical tumors with a high infiltration of CD3⁺ T cells in tumors. NOD/SCID mice that receive neonatal CB transplants have reconstituted T cells with significant antitumor effects against human cervical and lung tumors, with a high infiltration of CD3⁺ T cells showing dramatic induction of apoptotic cell death. We also confirmed that T cells showed tumor specific antigen cytotoxicity in vitro. In adoptive transfer of CD3⁺ T cells into mice with pre-established tumors, we observed much higher antitumor effects of HPV-specific T cells by ELISPOT assays.

Conclusions

Our results show that CB derived T lymphocytes will be useful for novel immunotherapeutic candidate cells for therapy of several tumors in clinic.

Phenotype Analysis of Tumour-infiltrating Lymphocytes and Lymphocytes in Peripheral Blood in Patients with Renal Carcinoma

Introduction: When checking tumour growth, a number of observations indicate that the immune system plays a significant role in patients with renal cell carcinoma (RCC). Infiltration by lymphocytes (tumour infiltrating lymphocytes, TILs) is more prevalent in RCC than any other tumours. T lymphocytes are the dominant population of TIL cells. Views concerning the role of T lymphocytic subpopulations, B lymphocytes and NK cells in an anti-tumour response are not established. Aim: The aim is to determine the phenotype and activation of T and B lymphocytic subpopulations and NK cells and to compare their representation in tumour stroma and peripheral blood lymphocytes (PBL) in patients with RCC. Material and methods: Samples of peripheral blood taken from the cubital and renal veins and tumour stroma cells were obtained from 44 patients in the course of their surgeries carried out due to primary RCC. TILs were isolated from mechanically disintegrated tumour tissue. Immunophenotype multiparametric analysis of PBL and TILs was carried out. Their surface and activation characteristics were determined by means of flow cytometer. Results: CD3+ T lymphocytes (69.7 %) were the main population of TILs. The number of CD3+/CD8+ T lymphocytes was significantly higher in TILs, 42.6 % (p< 0.01), while CD4+ T lymphocytes were the majority population in peripheral blood, 41.35 % (p < 0.001). The representation of CD3+/69+ T lymphocytes was significantly higher in TILs, 32.9 %, compared to PBL (p<0.001). On the contrary, the numbers of CD3+/CD25+, CD8+/57+ and CD4+/RA+ (naive CD4+ T lymphocytes) were higher in PBL (p<0.001). The differences in representation of (CD3-/16+56+) NK cells and CD3+/DR+ T cells in TILs and PBL were not significant. Conclusion: The above-mentioned results prove that the characteristics and intensity of anti-tumour responses are different in compared compartments (tumour/PBL). CD3+/CD8+ T lymphocytes are the dominant lymphocytic population of TILs. The knowledge of the phenotype and functions of effector cells, which are responsible for anti-tumour response, are the basic precondition for understanding the anti-tumour immune response and the cause of its failure.

CD4+ CD25+ FOXP3+ regulatory T cells from human thymus and cord blood suppress antigen-specific T cell responses

Activation of self-reactive T cells in healthy adults is prevented by the presence of autoantigen-specific CD4+CD25+ regulatory T cells (CD25+ Treg). To explore the functional development of autoantigen-reactive CD25+ Treg in humans we investigated if thymic CD25+ Treg from children aged 2 months to 11 years and cord blood CD25+ Treg are able to suppress proliferation and cytokine production induced by specific antigens. While CD4+CD25- thymocytes proliferated in response to myelin oligodendrocyte glycoprotein (MOG), tetanus toxoid and beta-lactoglobulin, suppression of proliferation was not detected after the addition of thymic CD25+ Treg. However, CD25+ Treg inhibited interferon (IFN)-gamma production induced by MOG, which indicates that MOG-reactive CD25+ Treg are present in the thymus. In contrast, cord blood CD25+ Treg suppressed both proliferation and cytokine production induced by MOG. Both cord blood and thymic CD25+ Treg expressed FOXP3 mRNA. However, FOXP3 expression was lower in cord blood than in thymic CD25+ T cells. Further characterization of cord blood CD25+ T cells revealed that FOXP3 was highly expressed by CD25+CD45RA+ cells while CD25+CD45RA- cells contained twofold less FOXP3, which may explain the lower expression level of FOXP3 in cord blood CD25+ T cells compared to thymic CD25+ T cells. In conclusion, our data demonstrate that low numbers of MOG-reactive functional CD25+ Treg are present in normal thymus, but that the suppressive ability of the cells is broader in cord blood. This suggests that the CD25+ Treg may be further matured in the periphery after being exported from the thymus.

Early Immune Reaction after Reduced-Intensity Cord-Blood Transplantation for Adult Patients

BACKGROUND

To investigate immune reactions after reduced-intensity cord-blood transplantation (RI-CBT).

MATERIALS AND METHODS

We reviewed medical records of 57 adult RI-CBT recipients. Preparative regimen comprised fludarabine, total-body irradiation, and either melphalan (n=51) or busulfan (n=6). Graft-versus-host disease (GvHD) prophylaxis was cyclosporine. PostRI-CBT immune reactions were classified according to time course: pre-engraftment immune reactions (PIR), engraftment syndrome (ES), and GvHD.

RESULTS

Forty-five patients achieved engraftment at a median of day 19. PIR was characterized by high-grade fever and weight gain and developed on a median of day 9 in 35 of the 45 evaluable patients, including 3 who did not achieve engraftment. PIR subsided spontaneously in 12 patients, whereas corticosteroids were required in the other 23. ES and grade I to IV acute GvHD developed in 36 and 29 patients, respectively. GvHD could not be distinguished from preceding PIR or ES in 10 patients. Causes of the 32 nonrelapse mortalities included GvHD (n=5) and PIR (n=1). There were no significant differences in relapse and nonrelapse deaths between patients with PIR and those without it (18% vs. 5%, and 60% vs. 65%, respectively).

CONCLUSIONS

Immune reactions after RI-CBT can be categorized into three distinct subtypes.

Cord blood transplantation in adult patients

Early clinical reports outlining outcomes for primarily pediatric patients undergoing UCB transplantation point to delayed time to hematopoietic recovery and favorable incidence and severity of GvHD. Recently, clinical reports in adult patients identified the feasibility of UCB transplantation for those patients lacking an available histocompatible-related or unrelated adult donor Intensive clinical and laboratory research is ongoing focused on strategies to foster UCB allogeneic donor engraftment thereby allowing wider application of this stem cell source for patients requiring allogeneic transplantation.

Phenotype and function of lymphocytes from the neonatal umbilical cord compared to paired maternal peripheral blood cells isolated during delivery

In the present study, we analyzed the immunological characteristics of mononuclear cells (MNC) isolated from both neonatal umbilical cord blood (UCB) and maternal peripheral blood (MPB) during the delivery. The in vitro proliferative response of UCB T lymphocytes was significantly reduced compared to the maternal response to phytohemagglutinin A, pokeweed mitogen, and alloantigen stimulation, in correlation with the lower percentage of UCB than MPB lymphocytes, but not with that of B cells. The mean cytotoxic activity level of interleukin-2 (IL-2)-activated natural killer (NK) was higher in UCB than in MBP, whereas the percentage of CD56(+) NK cell count was similar. Our results show differences in the immune reactivity of T and B lymphocytes from neonate and adult isolated under similar physiological conditions.

Cord blood serum affects T cells ability to produce and respond to IL-2

The current literature suggests that cord blood (CB) cells are functionally immature. We previously reported that CB sera inhibit T cell proliferation and suggested that the microenvironment in which CB T cells reside may be, in part, responsible for their reduced function. In this study we have tried to explain some of the actions of the CB sera on peripheral blood mononuclear cells (PBMC). We showed that, as expected CB sera decreased the anti-CD3 and anti-CD28-induced proliferative response of PBMC (p < 0.01) but unexpectedly, increased the interleukin-2 (IL-2) specific proliferation of both a human T cell line (p < 0.005) and T cells within a mononuclear cell population (p < 0.05). These findings prompted us to analyse the effect of CB sera on the T cell ability to make and respond to IL-2. Stimulation of T cells in the presence of CB sera increased the frequency of IL-2 producing cells (p < 0.005) (but not the amount of IL-2 secreted) and resulted in a higher expression of CD25 (p < 0.05). Furthermore CB sera (in the presence and absence of IL-2) made the cells apoptose less (p < 0.005) than adult sera. Our results go some way to explaining the effect of the CB microenvironment on CB cellular function.

Increased expression of activation markers in renal cell carcinoma infiltrating lymphocytes

PURPOSE

As manifested by the presence of immune competent cells, failure to control the progression of renal cell carcinoma by a local immune response attests to impaired local cell mediated immunity. To test this hypothesis we compared the expression of T-cell activation markers in renal cell carcinoma infiltrating lymphocytes with the expression of activation markers of peripheral blood lymphocytes in the same patients.

MATERIALS AND METHODS

Tumor infiltrating lymphocytes were harvested from a patient with renal cell carcinoma undergoing radical nephrectomy. Peripheral blood was obtained before surgery. Tumor infiltrating and peripheral blood lymphocytes were incubated with monoclonal antibodies defining specific differentiation and activation markers on the cell surface, and analyzed by flow cytometry. Cell subsets are expressed as a fraction of the total number of mononuclear cells.

RESULTS

The T-cell subset level was significantly higher in peripheral blood than in renal cell carcinoma tissue of the same patient. However, the level of activated T-cell subset expressing HLA-DR was significantly higher in renal cell carcinoma tissue than in peripheral blood. The levels of interleukin-2 receptor and transferrin receptors expressing T-cell subsets were also significantly higher in carcinoma tissue than in peripheral blood. Natural killer cells were found in significantly higher proportions in renal cell carcinoma than in peripheral blood.

CONCLUSIONS

These results point to significant activation of T, B and natural killer tumor infiltrating lymphocytes. The inability of tumor infiltrating lymphocytes to mount an effective immune response to renal cell carcinoma may be secondary to the presence of suppressive factors in the tumor that prevent tumor infiltrating lymphocytes from transforming into effector cells. These factors may be particularly valuable for the further study of renal cell carcinoma-host interactivity.

Tumour necrosis factor-alpha-induced apoptosis in cord blood T lymphocytes: involvement of both tumour necrosis factor receptor types 1 and 2

Cord blood T cells are much more likely to be induced to apoptosis in vitro than adult T cells. Nevertheless, the expression of Fas is markedly lower on cord blood lymphocytes than on peripheral blood lymphocytes. In the current investigation, we determined the capacity of tumour necrosis factor-alpha (TNF-alpha) to induce apoptosis in human naïve T cells in cord blood, and assessed the roles of two distinct TNF receptors (TNFRs) in mediating death signals. After activation, cord blood T cells were sensitive to TNF-alpha-induced apoptosis, and interleukin 2 (IL-2) could prevent this apoptotic response. Both TNFR1 (p55) and TNFR2 (p75) expressed on activated cord blood T cells were able to transmit apoptotic signals. Moreover, a synergistic effect was observed by a combination of TNFR1- and TNFR2-signals. Additionally, CD4(+) T cells showed higher sensitivity to TNFR-mediated apoptosis than CD8(+) T cells. These data suggest that TNF-alpha probably is a mediator of apoptosis in cord blood T cells in vivo and may contribute to the low incidence of graft-versus-host disease in cord blood transplantation.

Functional analyses of cord blood natural killer cells and T cells: a distinctive interleukin-18 response

OBJECTIVE

To search for the functional property of cord blood (CB) cells, the effects of interleukin-18 (IL-18) on interferon-gamma (IFN-gamma) production of T cells or natural killer (NK) cells were compared between CB and adult peripheral blood (PB).

MATERIALS AND METHODS

T cells, CD45RA(+) T cells, and NK cells were purified from CB and adult PB mononuclear cells using magnetic beads or a cell sorter. After stimulation with or without IL-18 in the presence of IL-12 for 48 hours (NK cells) or 72 hours (T cells or CD45RA(+) T cells), IFN-gamma concentration was measured in each subset. Although IL-18 induced significant IFN-gamma production from both CB and adult PB T cells in the presence of IL-12, the IFN-gamma levels from CB T cells were lower than those from adult PB T cells. However, CD45RA(+) T cells from CB and from adult PB produced similar levels of IFN-gamma after stimulation with IL-18 + IL-12. On the other hand, CB NK cells exhibited higher IFN-gamma production and CD69 expression than adult PB NK cells after stimulation with IL-18 + IL-12. Cytolytic activity of CB NK cells increased to a level comparable to that of adult PB NK cells after the same IL-18/IL-12 stimulation.

CONCLUSIONS

These results suggest that a low response of CB T cells to IL-18 is due to a higher proportion of naive (CD45RA(+)) T cells in CB, which may be one of the factors responsible for the neonatal immaturity of the immune system as well as the low incidence of graft-vs-host disease in patients receiving CB stem cell transplantation. On the other hand, a high response of CB NK cells to IL-18 may contribute to the host defense during the neonatal period and antitumor effects in CB stem cell transplantation.

Analysis of monocyte chemotactic protein-1 production in different major histocompatability complex-restricted antigen presentation systems

In the present study the production of the CC chemokine monocyte chemotactic protein-1 (MCP-1) in several MHC II-restricted antigen presentation systems was investigated in vitro. To assess which type of antigen-presenting cell (APC) influences MCP-1 production during antigen presentation, cultures enriched for different APC populations were prepared and MCP-1 production was determined. Our results showed that APCs that effectively induce a T cell response also produce elevated amounts of MCP-1. The MCP-1 production is highest in the memory-driven secondary response against a single antigen. Despite a massive T cell proliferation, low MCP-1 concentrations are found in Con A-induced cultures. These results suggest that T cell proliferation alone is not sufficient for MCP-1 production and that stimulation of the APC during the process of antigen presentation results in MCP-1 production. Based on our results and the literature, we propose a model for MCP-1 as an enhancer of the adaptive immune response.

Lymphocyte subset reconstitution after HLA-identical placental blood transplantation (PBT) or PBT plus bone marrow transplantation (BMT) in three children with beta-thalassemia major

The kinetics of circulating lymphoid cells were evaluated in three children suffering from beta-thalassemia major after HLA-identical sibling placental blood transplant (PBT) in one patient and placental blood plus bone marrow transplantation (BMT) in two patients. Recovery of the main lymphocyte subsets, as determined by phenotype analysis of circulating PBMCs, was complete within 2 months after transplant. NK (CD56+) cells were the first to appear in peripheral blood, followed by T (CD3+, CD2+, CD7+) and B (CD19+) cells. Of the T lymphocytes, the CD8+ were the first to reconstitute, but recovery of CD4+ cells was also rapid and within 6 months these T cells reached normal values. The expression of CD57 by NK or T cells was slightly delayed. The evaluation of RA and RO isoform expression of the CD45 molecule showed a prevalence of the CD45RA antigen with a ratio of 2-3:1. In the PBT only patient, T cells expressing the CD45RO antigen prevailed in the early post-transplant period. Severe or chronic GVHD was not observed. This experience demonstrates that reconstitution of lymphocyte subsets is successful in genetic hematological diseases after transplantation of HLA-identical placental blood or placental blood plus bone marrow from healthy or heterozygous siblings. Bone Marrow Transplantation (2000) 26, 743-747.

Can cord blood cells support the cytokine storm in GvHD?

Cord blood has a high number of proliferating hematopoietic progenitors and is therefore used as an alternative source of hematopoietic cells for allogeneic transplantation. In addition there is a wider availability of cord blood and a lower cost of procurement compared to bone marrow. However one of the most interesting immunological benefits of a cord blood transplant that has been proposed is the low severity of Graft versus Host Disease (GvHD). This review aims to address some of the immunological reasons why this may be the case by assessing the role of cord blood cytokines in the cytokine storm of GvHD.

A novel sensitive assay to define immune status using short-term peripheral blood derived cell culture and dual-color flow cytometry

In this study we describe a novel and highly sensitive in vitro system to determine the functionality of immune cells based on short term culture of peripheral blood derived mononuclear cells (PBMCs) and subsequent analysis of cellular proliferation and surface marker expression by automated dual-color flow cytometry. The standardized mild stimuli introduced into the culture system by supplemented medium (containing exogenous interleukin-2 (IL-2), and fetal bovine serum (FBS)) allow a more physiological interaction of the different cell subsets contained in PBMCs (including CD14+ accessory cells) than other methods that are based on potent and harsh cell activators, such as phytohemagglutinin (PHA) or anti-CD3 antibodies. Measurement of T-cell proliferation and cell surface marker (CD3, C25, CD26, CD71, HLA-DR) analysis revealed that activation response capacity in our assay depends on both the status of the obtained cells and their ability to interact in culture with CD14+ cells. This in vitro assay proved to be very sensitive in detecting changes in the status of T-cell activation and proliferation capacity, and avoid the use of radioactive reagents.