结直肠癌患者外周血中CD4+CD45RA+ T和CD4+CD45RO+ T细胞的变化及其意义

目的 探讨外周血中CD4 CD45RA T细胞和CD4 CD45RO T细胞在结直肠癌中的变化及其临床意义。方法 采用流式细胞术检测60例结直肠癌患者手术前、术后1个月和3个月时,外周血的CD4 T细胞、CD4 CD45RA T细胞和CD4 CD45RO T细胞的比例。选取健康查体人群10例作为对照。结果 结直肠癌患者的CD4 T细胞与健康人群相比无差异。CD4 CD45RO T细胞比例明显增高,术后有显著下降,DukesA、B期患者尤其明显;而CD4 CD45RA T细胞比例正好相反。结论 CD4 CD45RA T细胞和CD4 CD45RO T细胞在肿瘤免疫中起重要作用,其表达同结直肠癌的分期和预后有密切关系。     

外周T细胞淋巴瘤患者中PD-1的表达对CD45RA+、CD45RO+T细胞的影响

目的:探讨外周T细胞淋巴瘤(PTCL)患者淋巴瘤组织中PD-1的表达与外周血中初始和记忆T细胞水平的关系.方法:20例PTCL患者采用免疫组化法检测淋巴瘤组织中PD-1的表达,采用流式细胞术检测CHOP方案化疗前后外周血中CD4+CD45RA+、CD4+CD45RO+、CD8+CD45RA+和CD8+CD45RO+T细胞的比例,分析PD-1的表达与T细胞亚群的关系.结果:PD-1、PD-L1蛋白在PTCL患者中表达升高,PD-1阳性患者疗效较差.PD-1阳性患者中CD4+T细胞、CD8+T细胞明显低于PD-1阴性患者;PD-1阴性组患者CD4+CD45RO+、CD8+CD45RA+、 CD8+CD45RO+T细胞明显高于PD-1阳性患者,差异有统计学意义.结论:PTCL患者中存在PD-1/PD-L1蛋白的表达异常,PD-1阳性患者存在更明显的T细胞免疫功能缺陷.     

Absolute number of circulating CD34+ cells is abnormally low in refractory anemias and extremely high in RAEB and RAEB-t; novel pathologic features of myelodysplastic syndromes identified by highly sensitive flow cytometry

We scored absolute numbers of circulating CD34+ cells by a highly sensitive triple-color flow cytometric analysis using CD45 monoclonal antibody, CD34 monoclonal antibody and propidium iodide. Forty-one patients with MDS (RA: 27, RARS: 1, RAEB: 6, RAEB-t: 3,CMML: 4), 12 patients with aplastic anemia (AA) and 36 age-adjusted normal subjects were studied. RA had significantly decreased numbers of cells expressing CD34 (0.21 +/- 0.29 x 10(6)/l) compared with normal subjects (0.81 +/- 0.36 x 10(6)/l)(P < 0.001). This low number of CD34+ cells in RA resembles the case of AA (0.39 +/- 0.73 x 10(6)/l). In light-scatter analysis, the CD34+ cells of RA patients were distributed mainly in low forward scatter (FSC) (lymphocyte region). In contrast, the CD34+ cell counts were extremely high in patients with RAEB (46.54 +/- 71.37 x 10(6)/l) and RAEB-t (57.00 +/- 52.36 x 10(6)/l) (P < 0.001) and the CD34+ cells were observed in high FSC (blast region).CMML patients showed moderately increased numbers of CD34+ cells (3.69 +/- 4.64 x 10(6)/l). Thus, there was a distinct difference in cell size and number of circulating CD34+ cells between RA and RAEB/RAEB-t. In univariate and multivariate analysis, a high CD34+ cell count (> or = 1.0 x 10(6)/l) was a poor prognostic factor. This method allows one to distinguish RA from other MDS subtypes more reliably than by morphology alone and provides early signs of progression to acute leukemia.     

An Analysis of Circulating CD4 Lymphocyte Subpopulations in B-Cell Chronic Lymphocytic Leukaemia

The distribution of circulating CD4 lymphocyte subpopulations determined by reactivity with monoclonal antibodies anti-2H4 (CD45RA), anti-UCHL1 (CD45RO), anti-4B4 (CD29) and anti-Leu8, and analysed by dual colour immunofluorescence flow cytometry is described in a series of patients with B-CLL and in age-matched control subjects. The percentages and absolute numbers of CD4 cells reactive with anti-CD45RA, anti-CD45RO and anti-CD29 reagents were similar in the patient and control groups. In contrast, CD4+ Leu8+ cells (percentages and absolute numbers) were significantly reduced in B-CLL patients resulting in an inversion of the normal CD4+ Leu8+ :CD4+Leu8- ratio. The patients' clinical or therapeutic status did not appear to influence the levels of the respective CD4 subpopulations; nor was evidence of hypogammaglobulinaemia associated with specific numerical alterations in any of the CD4 subpopulations studied. It is proposed that, in B-CLL, the alterations in the CD4Leu8 subpopulations are associated with the disease process, whereas the distributions of CD4+CD45RA+, CD4+ CD45RO+ and CD4+ CD29+ cells reflect the normal physiological levels of these subpopulations in elderly subjects.     

Effector CD8+CD45RO-CD27-T cells have signalling defects in patients with squamous cell carcinoma of the head and neck

A subset of circulating T cells (CD8(+)CD45RO(-)CD27(-)) with a na?ve phenotype, but mediating effector function, is considered to play an important role in host antitumour defence. To investigate the attributes of these effector T cells in patients with squamous cell carcinoma (SCC) of the head and neck cancer, venous blood was obtained from 39 individuals with cancer and 45 normal controls (NC). Peripheral blood mononuclear cells were isolated, stained with labelled monoclonal antibodies specific for CD8, CD45RO, CD45RA, CD62L, CD27, TCR-zeta as well as isotype controls and examined by multicolour flow cytometry. Annexin V binding to CD8(+) T cells and PMA/ionomycin-induced IFN-gamma expression were also evaluated in patients and NC. The proportions of CD45RA(+)CD45RO(-) (na?ve) and CD45RA(-)CD45RO(+) (memory) cells were found to be comparable within the CD8(+) T-cell subset. However, relative to NC, the frequency of effector CD8(+)CD45RO(-)CD27(-) cells was strikingly increased in all SCC patients regardless of the disease status (P=0.0003). The proportion of these cells was found to increase with age in both patients and NC. In NC, stimulated IFN-gamma expression was largely restricted to CD8(+)CD45RO(-)CD27(+) cells, while in patients CD8(+)CD45RO(-)CD27(-) expressed IFN-gamma after ex vivo stimulation. Expression of the TCR-associated zeta chain was decreased or absent in freshly isolated CD8(+)CD45RO(-)CD27(-) T cells in patients (P<0.0001). Annexin V was found to bind to a higher proportion of circulating CD8(+) T cells in patients than NC (P<0.006), and significantly more Annexin V(+) T cells were present in the effector (P<0.0059) than the na?ve subset within the CD8(+)CD45RO(-) compartment. The data indicate that the expanded CD8(+)CD45RO(-)CD27(-) T cells, which contain precursors of IFN-gamma-producing T cells, are zeta-negative and sensitive to apoptosis in the circulation of patients with HNC.     

High frequencies of circulating melanoma-reactive CD8+ T cells in patients with advanced melanoma

To determine whether circulating tumor-reactive T cells are present in melanoma patients, unstimulated T cells from peripheral blood were tested for recognition of HLA-A2- or HLA-A1-matched melanoma cell lines using the ELISPOT assay. Eleven out of 19 patients with metastatic melanoma had a T-cell response with up to 0.81%, 0.78%, 0. 53%, 0.12%, 0.10%, 0.09%, 0.07%, 0.06%, 0.06%, 0.04%, and 0.04% of peripheral blood mononuclear cells (PBMC) secreting IFNgamma upon exposure to various HLA-A2- or HLA-A1-matched melanoma cell lines. These T-cell responses were mediated by CD8+ T cells and could specifically be blocked by an anti-HLA-A2 antibody in HLA-A2-positive patients. Separation experiments performed in one melanoma patient showed tumor-reactive T cells in both the CD8+ effector T cell (CD45RA+/IFNgamma+) as well as the CD8+ memory T-cell compartment (CD45RO+/IFNgamma+). In 3 out of 5 patients, in whom autologous cell lines were available, similar frequencies of T cells in response to HLA-A1- or HLA-A2-matched allogeneic and autologous tumor cells were observed, while 2 patients had a T-cell response restricted to either the autologous or the allogeneic cell lines. These results give evidence for the presence of tumor-reactive CD8+ T cells in more than half of melanoma patients tested. Although some of these patients have clinical evidence for an immunological-mediated tumor control, several patients have growing tumors suggesting presence of escape mechanisms.     

Recombinant alpha-2b-interferon may restore natural-killer activity in patients with B-chronic lymphocytic leukemia.

In nine patients with CLL treated with chlorambucil followed by alpha-2b-interferon (alpha 2b-IFN), T, B and natural killer (NK) cells and NK activity were studied before entering the study, after chlorambucil treatment, and after administration of alpha 2b-IFN. When considered as a whole, basal NK activity was lower in CLL patients than in controls (21.0% +/- 10.9 versus 40.2% +/- 17.4, p less than 0.001); however, when considered individually, four out of nine patients had normal NK activity at diagnosis. Chlorambucil did not increase global NK activity (21.7% +/- 7.1), whereas alpha 2b-IFN did so (44.3% +/- 19.1). After alpha 2b-IFN only one of seven patients studied had low NK activity. Previously increased absolute counts of CD2+, CD4+, CD8+, CD16+, CD57+ lymphocytes were reversed with chlorambucil treatment to normal levels, while after this therapy CD11b+ and CD19+ cells decreased without reaching normal values. During alpha 2b-IFN therapy, an increase up to normal levels in the percentage of CD16+ (2.7% +/- 3.4 versus 7.7% +/- 6.5, p = 0.04) and CD57+ (3.0% +/- 3.0 versus 8.1% +/- 6.2, p = 0.020) lymphocytes was observed whereas the absolute number of CD19+ B-cells further decreased (5.2 x 10(9)/l +/- 2.5 vs 3.8 x 10(9)/l +/- 2.3), albeit not significantly.     

Five years follow-up after 2-chloro deoxyadenosine treatment in thirty patients with hairy cell leukemia: evaluation of minimal residual disease and CD4+ lymphocytopenia after treatment

Between March 1992 and August 1993, thirty patients with hairy cell leukemia (HCL) were treated in a single institution with 2-chlorodeoxyadenosine (2-CdA) for one course (N=27) or two courses at six month interval (N=3). Sixteen patients were previously untreated, 14 had been treated with alpha interferon (alpha IFN) (N=5), alpha IFN and splenectomy (N=8) and splenectomy, alpha IFN and Deoxycoformycin (N=1). Overall results in 29 evaluable patients were: 25 CR (86%), 3 PR (10%), one failure. The three PR patients relapsed after 18, 24 months and five years. Two were retreated successfully. Two CR patients relapsed after five years. Careful clinical survey, sequential bone marrow biopsies (BMB) with DBA44 immunostaining for assessment of response and detection of residual disease and serially evaluation of lymphocyte subsets counts were performed. Results of bone marrow biopsies study show 1) a progressive reduction in hairy cell infiltration during the first six months after therapy and not after that indicating that the best moment for the evaluation of response may be the sixth month, 2) the persistence of a very small number of DBA44+ cells (80% of BMB). There was a correlation between the presence of > 5% DBA44 positive cells on 6th month BMB and relapse. 60% had an absolute CD4+ lymphocyte count less than 0.2 10(9)/l at least on one examination after treatment. CD4+ lymphocyte level persisted less than baseline level in 8/18 patients tested after four and/or five years. Lymphopenia was less marked in splenectomized patients: 7/7 splenectomized patients tested have recovered a CD4+ lymphocyte count equal to pretherapy level compared to 3/11 non splenectomized patients (p: 0.004). Three opportunistic infections were observed early (first 6 months) after 2CdA therapy: pneumocystis pneumonia, retinitis due to toxoplasma in the patient who failed and legionella pneumonia in a patient retreated after relapse. Two patients developed a second carcinoma 6 and 12 months after therapy. Five patients died, three from a cause unrelated to HCL, one from HCL and one from infection while in second CR. At five years, overall survival is 83% and progression free survival is 66%. Our study shows 1) long-lasting response in the majority of patients after 2-CdA, 2) a correlation between persistent minimal residual disease detected with DBA44 immunostaining and occurrence of relapse and 3) a profound and persistent CD4+ lymphopenia more marked in non splenectomized patients.     

Impact of topotecan-based chemotherapy on the immune system of advanced ovarian cancer patients: an immunophenotypic study

The effects of topotecan-based chemotherapy (CT) on peripheral blood lymphocyte (PBL) subsets were evaluated in ovarian cancer patients. Fourteen patients with epithelial ovarian cancer, at the diagnosis or relapsed after platinum-based CT, were treated with: a) topotecan in association with carboplatin and taxanes as first line CT; b) topotecan alone or c) topotecan in association with carboplatin both as second line of treatment after platinum. The phenotype of PBL was determined before starting treatment and immediately before each CT course by flow cytometric analysis. Before starting CT, the absolute number of lymphocytes and the CD2+, CD3+, CD4+ subsets were significantly lower in pre-treated patients and not significantly altered in CT-naive patients with respect to a cohort of 20 healthy donors utilized as control. Lymphocytes co-expressing CD4+/CD8+ were significantly higher in both subgroups of patients than in normal donors. CD4+/CD45RA+ and CD4+/CD45RO+ subsets were significantly decreased in pre-treated patients and normal in CT-naive patients. CD3+/HLA-DR+ T cell population significantly increased in CT-naive patients at baseline. During CT and after its discontinuation, no relevant changes were recorded for both subgroups of patients with respect to the baseline in lymphocyte absolute count, CD2+, CD3+, CD4+, CD4+/CD45RO+ subsets, while CD4+/CD45RA+ subpopulation was significantly decreased in CT-naive patients. CD8+, CD19+, CD20+, CD16+, CD56+, CD2+/CD25+ subsets did not differ statistically comparing to normal donors both at baseline and during CT. The treatment was well tolerated and no patient developed non-neutropenic infection. Topotecan-based therapy does not have a negative impact on PBL in either CT-naive or in pretreated ovarian cancer patients. This information should be considered when utilizing topotecan with other anticancer drugs in the adjuvant setting as well as when dose-intensification of topotecan with stem cell support is planned.     

Rapid engraftment after allogeneic transplantation of density-enriched peripheral blood CD34+ cells in patients with advanced hematologic malignancies.

BACKGROUND: Acute graft versus host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. Preclinical studies have suggested that a T-cell subset with a CD4-/CD8- double-negative (DN) T-cell phenotype is capable of suppressing GVHD. Double-negative T cells can be mobilized into the peripheral blood with granulocyte colony-stimulating factor (G-CSF) and enriched by density centrifugation. The current study was performed to study the feasibility and safety of applying a density gradient separation technique for enrichment of CD34+ and DN T cells, while depleting CD4+ and CD8+ single-positive (SP) T cells from peripheral blood progenitor cells (PBPCs) for the purpose of allogeneic transplantation. METHODS: Twenty-five patients with advanced hematologic malignancies were treated with a myeloablative preparative regimen consisting of fractionated total body irradiation, etoposide, and cyclophosphamide. Human leukocyte antigen identical donors were mobilized with G-CSF PBPC collected by apheresis. The apheresis product was applied to a single-step density gradient, and the low-density cell population was collected. The low-density cell population was infused as the sole source of allogeneic cells after myeloablative therapy. Graft versus host disease prophylaxis consisted of cyclosporine with or without prednisone. RESULTS: CD34 cell recovery was efficient with a median 72% yield, providing for a median CD34+ cell dose of 6.5 x 10(6)/kg (range,1.0- 13.9 x 10(6)/kg). CD3+CD4+ or CD3+CD8+ SP T cells were depleted by a median of 94.4% (range, 58.8- 99.2%), and the ratio of CD34+:SP T cells increased 10-fold. Double-negative T cells were depleted by 92% (range, 18.8- 99.4%), thus the ratio of DN:SP T cells increased less than 2-fold in 71% of apheresis samples tested. Hematopoietic engraftment was rapid, and there was no occurrence of graft failure in examinable patients. Median time to absolute neutrophil count greater than 0.5 x 10(9)/L and platelet count greater than 20 x 10(9)/L was 10.5 and 12 days, respectively. The incidence of Grade 2-4 acute GVHD was 26% (95% confidence interval [CI], 6-45%), although not all patients were examinable due to an unexpectedly high nonrecurrence mortality that at Day 180 was 62% (95% CI, 40-83%). CONCLUSIONS: These data suggest that T-cell subset manipulation via density gradient separation is a safe procedure and allowed rapid hematopoietic recovery. Selective enrichment of a donor DN T-cell subset was observed in only a few and was not associated with a reduced incidence of GVHD. However, the low-density selected cells still resulted in GVHD, and there was a high treatment-related mortality.     

Regulation of the expression of CD45 isoforms in the Farage human B cell lymphoma line and its 10.6.1 subline

Different B-cell neoplasias vary in the expression of CD45 isoforms. In the present study two sublines of a human B cell lymphoma- the original Farage line (Farage OL) and the Farage 10.6.1 subline were used to analyze the regulation of the expression of CD45 cell surface determinants. Cells of the Farage OL line constitutively expressed both CD45RO and CD45RA determinants on their cell surface. In contrast, the majority of the cells of the Farage 10.6.1 subline expressed CD45RA, and only few cells were CD45RO+. The low molecular spliced CD45 mRNA, characteristic for CD45RO was found in Farage OL cells, but was almost undetectable in Farage 10.6.1 cells. Following exposure to interleukin-4 (IL-4) a large proportion of the Farage 10.6.1 cells expressed CD45RO while in Farage OL cells the proportion of CD45RO+ was slightly reduced. The low molecular, spliced mRNA characteristic for CD45RO, was increased in Farage 10.6.1 cells following IL4 stimulation, but was slightly reduced in Farage OL cells. The molecular weight of CD45RA molecules produced by Farage cells varied from 185 kDa to 220 kDa while that of CD45RO molecules was 175 kDa. Preliminary attempts were made to determine a possible correlation between the expression of CD45RO and apoptosis in Farage cells. In both the Farage OL and Farage 10.6.1 cells the proportion of Bcl-2+ cells was lower among CD45RO+ cells than among CD45RO- cells. The present study indicates that IL4 has different effects on the alternative splicing of CD45 mRNA in two closely related B cell lymphoma lines. Thus, factors produced by the B lymphoma cells themselves may endow the cells with different patterns of responsiveness to a single stimulatory agent.     

Regulation of the Expression of CD45 Isoforms in the Farage Human B Cell Lymphoma Line and Its 10.6.1 Subline

Different B-cell neoplasias vary in the expression of CD45 isoforms. In the present study two sublines of a human B cell lymphoma-the original Farage line (Farage OL) and the Farage 10.6.1 subline were used to analyze the regulation of the expression of CD45 cell surface determinants. Cells of the Farage OL line constitutively expressed both CD45RO and CD45RA determinants on their cell surface. In contrast, the majority of the cells of the Farage 10.6.1 subline expressed CD45RA, and only few cells were CD45RO+. The low molecular spliced CD45 mRNA, characteristic for CD45RO was found in Farage OL cells, but was almost undetectable in Farage 10.6.1 cells. Following exposure to interleukin-4 (IL-4) a large proportion of the Farage 10.6.1 cells expressed CD45RO while in Farage OL cells the proportion of CD45RO+ was slightly reduced. The low molecular, spliced mRNA characteristic for CD45RO, was increased in Farage 10.6.1 cells following IL4 stimulation, but was slightly reduced in Farage OL cells. The molecular weight of CD45RA molecules produced by Farage cells varied from 185 kDa to 220 kDa while that of CD45RO molecules was 175 kDa. Preliminary attempts were made to determine a possible correlation between the expression of CD45RO and apoptosis in Farage cells. In both the Farage OL and Farage 10.6.1 cells the proportion of Bcl-2+ cells was lower among CD45RO+ cells than among CD45RO-cells. The present study indicates that IL4 has different effects on the alternative splicing of CD45 mRNA in two closely related B cell lymphoma lines. Thus, factors produced by the B lymphoma cells themselves may endow the cells with different patterns of responsiveness to a single stimulatory agent.     

非小细胞肺癌患者引流区淋巴结中CD4+CD25+调节性T细胞的检测及临床意义

目的分析非小细胞肺癌(NSCLC)患者引流区淋巴结中CD4 CD25 调节性T细胞在淋巴结局部免疫抑制状态的形成以及在肺癌发生发展中的作用。方法手术切除53例NSCLC患者引流区淋巴结,采用双标记的间接免疫荧光法检测CD4 CD25 调节性T细胞数量,实时荧光定量逆转录-聚合酶链反应(RT-PCR)法检测细胞因子TGF-β1、IL-10的表达水平,常规免疫组化方法检测CD8 T细胞的数量。结果NSCLC患者引流区转移淋巴结中,CD4 CD25 调节性T细胞(28.80%±8.06%)明显高于未转移淋巴结(15.48%±4.66%,P<0.01)。随肺癌的进展,引流区淋巴结中CD4 CD25 调节性T细胞数量增多。在转移的纵隔淋巴结(N2)和肺内淋巴结(N1)中,CD4 CD25 调节性T细胞数量分别为32.58%±7.52%和22.76%±4.67%(P<0.01)。在进展期(Ⅲ)和早期(Ⅰ Ⅱ)NSCLC患者引流区淋巴结中,CD4 CD25 调节性T细胞数量分别为30.42%±7.47%和16.22%±4.88%(P< 0.01)。NSCLC患者引流区淋巴结中的CD4 CD25 调节性T细胞数量与其自身的CD8 T细胞的数量呈负相关(r=-0.756,P<0.001)。在NSCLC患者引流区淋巴结中,CD4 CD25 调节性T细胞数量与抑制性细胞因子TGF-β1和IL-10的表达水平呈正相关(TGF-β1:r=0.645,P<0.001;IL-10:r=0.769,P<0.001)。结论NSGLC患者引流区淋巴结的CD4 CD25 调节性T细胞数量与肺癌的发展密切相关。一方面,检测肺癌患者引流区淋巴结的免疫状况为评价NSCLC患者疾病的进展程度和预后提供了一个新的免疫学指标;另一方面,在NSCLC的生物治疗中,控制CD4 CD25 调节性T细胞数量,阻断其发挥免疫抑制作用,具有广阔的临床应用前景。     

Frequency of CD45RO+ subset in CD4+CD25(high) regulatory T cells associated with progression of hepatocellular carcinoma

The purpose of this study was to assess the properties of CD4+CD25(high/low/negative) T cell subsets and analyze their relation with dendritic cells (DCs) in patients with hepatocellular carcinoma (HCC). In HCC patients, the prevalence of CD45RO+ cells in CD4+CD25(high) T cells was increased and associated with higher frequencies of plasmacytoid DCs. Larger proportions of this T cell subset were detected in the patients with larger tumor burdens. These results suggest that increased frequencies of the CD45RO+ subset in CD4+CD25(high) Tregs in HCC patients may establish the immunosuppressive environment cooperatively with tolerogenic plasmacytoid DCs to promote disease progression of liver cancer.     

Peptide-specific CD8+ T-cell evolution in vivo: response to peptide vaccination with Melan-A/MART-1

Monitoring of CD8+ T-cell responses in cancer patients during peptide vaccination is essential to provide useful surrogate markers and to demonstrate vaccine efficacy. We have longitudinally followed CD8+ T-cell responses in 3 melanoma patients who were immunized with peptides derived from Melan-A/MART-1. Recombinant HLA-A2 tetramers loaded with the naturally presented Melan-A/MART-1 nonamer peptide (AAGIGILTV) and the Melan-A/MART-1 analog (ELAGIGILTV) were used in combination with phenotypical analysis for different T-cell subsets including naive T cells, effector T cells, "true memory" T cells and "memory effector" T cells, based on CD45RA/RO and CCR7-expression. At least in a single patient, T cells binding to the AAGIGILTV epitope were detected in naive, precursor (CD45RA+/CCR7+) CD8+ T cells, and CD8+ T cells binding to the analog ELAGIGILTV peptide were identified in the terminally differentiated (CD45RA+/CCR7-) T-cell subset. Molecular and functional analysis of tetramer-binding T cells revealed that the T-cell receptor (TCR) repertoire was oligo/polyclonal in AAGIGILTV-reactive T cells, but different and restricted to a few TCR clonotypes in ELAGIGILTV-reactive T cells prior to vaccination. The TCR repertoire reactive with Melan-A/MART-1 peptide epitopes was broadened during vaccination and exhibited a different profile of cytokine release after specific stimulation: tetramer-binding T cells from 2/3 patients secreted granulocyte/macrophage colony-stimulating factor (GM-CSF) and interferon-gamma but not interleukin-2 (IL-2) in response to Melan-A/MART-1 peptides. In the third patient, tetramer-binding T cells secreted IL-2 exclusively. Our results show that T-cell responses to peptide vaccination consist of different T-cell subsets associated with different effector functions. Complementary analysis for TCR CDR3 and cytokine profiles may be useful to define the most effective CD8+ T-cell population induced by peptide vaccination.     

Fas ligand expression by neoplastic T lymphocytes mediates elimination of CD8+ cytotoxic T lymphocytes in mycosis fungoides: a potential mechanism of tumor immune escape?

Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma (CTCL) and arises from the accumulation and clonal proliferation of epidermotropic, CD4+/CD45RO+ (helper/memory) T lymphocytes. Loss of CD8+ CTLs within MF lesions is associated with poor prognosis and disease progression. Because T-lymphocyte apoptosis is controlled mainly through the Fas/Fas ligand (FasL) pathway and tumor cells may escape immune surveillance by expressing FasL, triggering apoptosis of tumor-infiltrating T lymphocytes, we studied the role of this system in MF. T-cell subsets, Fas/FasL expression, and apoptosis were evaluated in normal and lesional skin biopsy specimens from 21 patients with all stages of MF and in cultured CTCL cell lines (MJ, HUT78, and HH) using immunohistochemistry, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and Western blotting. MF lesions and paired, clinically "normal," uninvolved skin showed increased numbers of both TUNEL-positive epidermal keratinocytes (n = 13; F = 31.146; P < 0.01, ANOVA) and dermal lymphocyte infiltrates (n = 13; F = 15.825, P < 0.01, ANOVA) compared with the normal control skin. FasL expression was highest in lesional epidermal keratinocytes, in CTCL tumor cell lines, and in dermal tumor lymphocytes in MF lesions compared with uninvolved skin. FasL colocalized with CD45RO+ cells. CD8+ cells in or adjacent to CD45RO+ cells were positively labeled by TUNEL for apoptosis. In addition, CD8+ cell numbers were decreased in areas in which FasL+ tumor cells were abundant (2.01 +/- 0.86%) compared with non-FasL expressing areas (13.53 +/- 3.54%; P < 0.02). These results suggest that a potential mechanism of tumor immune escape in MF is FasL-mediated apoptosis of infiltrating CD8+ CTLs.     

The effect of short-course high-dose methylprednisolone on peripheral blood lymphocyte subsets in children with acute leukemia during remission induction treatment

We have previously demonstrated a favorable effect of high-dose steroid in the treatment of children with acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML). This study was performed to determine the effect of short-course high-dose methylprednisolone (HDMP) treatment on the peripheral blood (PB) T lymphocyte subsets, and blast cells, during remission induction treatment in 23 children with newly diagnosed acute leukemia (16 with ALL, seven with AML). All patients were administered HDMP as a single daily oral dose of 30mg/kg for the first 4 days of induction therapy. The number of PB lymphocyte subsets (CD3, CD4, CD8, CD16+56, CD45RA, and CD45RO) were determined by flow cytometry before and after 4 days of HDMP treatment. While the number of PB blast cells significantly decreased, the absolute number of T lymphocytes expressing CD3, CD4, CD8, CD45RA and the absolute number of CD16+56 (natural killer) cells increased in all patients. We suggest that the beneficial effects of HDMP in the induction treatment of acute leukemia may occur partly due to an increase in the number of PB T lymphocyte subsets. A study randomly assigning patients to treatment with either conventional therapy or HDMP may provide further information.     

Decrease in number of CD16(Leu 11)+CD45RA(2H4)+ cells and defective production of natural killer cytotoxic factor in childhood acute lymphoblastic leukemia.

CD16 or CD45RA is known to be a functional molecule, which provides activation signals in natural killer (NK) cells or T cells, respectively. To dissect the decreased NK activity in childhood acute lymphoblastic leukemia (ALL), the expression of CD16 (Leu 11) or CD45RA (2H4) and the production of natural killer cytotoxic factor (NKCF) were investigated. CD16+ cells or CD45RA+ cells in peripheral blood lymphocytes were not decreased as compared with controls, however, CD16+CD45RA+ cells in ALL (4%) were lower (p less than 0.05) than controls (17%). The production of NKCF in ALL patients (9.2%) was lower (p less than 0.05) than controls (16.5). These data suggest that the decreased NK activity in ALL patients can be attributable at least in part to the functional impairment of NK cells to produce NKCF.     

Decreased numbers of CD4+ T lymphocytes in peripheral blood after treatment of childhood acute lymphoblastic leukemia

Treatment-related immunosuppression in patients with acute lymphoblastic leukemia (ALL) is associated with increased susceptibility to infectious diseases, also after the treatment. The aim of the present study was the detailed evaluation of T lymphocyte subsets in peripheral blood in children after treatment of ALL. All children were treated according to the BFM 90 protocol. The patients were divided into 5 groups of 30 children in each, depending on the time from cessation of the ALL treatment. A control group consisted of 30 healthy children subjected to elective "1-day" surgery. The children's age ranged from 6 to 18 years. The examinations were performed in FACScan flow cytometer with the use of wide set of monoclonal antibodies: CD3, CD4, CD8, TCRalphabeta, TCRgammadelta, CD19, CD25, CD45RA, CD45RO, CD69, HLA-DR, CD16 and CD56, which particularly allowed detailed analysis of T lymphocytes. The results showed that most parameters in children 1 year after ALL treatment completion were similar to healthy children. However, we observed persistently low CD4+ T cell numbers, both CD45RA+ as well as CD45RO+ subsets as compared to the control group. This might reflect decreased regenerative potential of immunological system in children 1 year after ALL treatment.     

T-Cell Membrane CD45RA (2H4) and CD45RO (UCHL1) Determinants: I, Diverse Patterns of Expression in Mature (Post-Thymic) T-Cell Proliferations

By simultaneous two- and three-colour flow cytometry, this study analysed the expression of membrane CD45RA (2H4) and CD45RO (UCHL1) determinants by normal thymocytes (n = 5) and peripheral blood lymphocyte subpopulations (CD4⁺, n = 21; CD8⁺, n = 12; CD8^dim+, n = 12) and compared these patterns with those of T-cells from representative CD4⁺CD8^- (n = 8), CD4⁺CD8⁺ (n = 2), CD4^-CD8⁺ (n = 10) and CD4^-CD8^- (n = 1) proliferations. These comprised cases of prolymphocytic leukaemia (T-PLL, n = 5), adult T-cell leukaemia-lymphoma (ATLL, n = 2), Sezary Syndrome (SS, n = 4), chronic lymphocytic leukaemia (T-CLL, n = 4), and lymphoproliferative disease of granular lymphocytes (LDGL, n = 5). Normal thymocyte fractions, of which a mean of 85% cells co-expressed membrane CD4 and CD8, were predominantly (mean 89%) 2H4^-UCHL1⁺ with the remaining cells consisting of 2H4^intUCHL1⁺ and 2H4⁺UCHL1^- components. Further analysis showed that virtually all CDla⁺ thymocytes were UCHL1⁺ whereas the CD1a^- fraction comprised similar proportions of both UCHL1^- and UCHL1⁺ subpopulations. Similarly, normal blood CD4⁺, CD8⁺ and CD8^dim+ lymphocytes showed reciprocal CD45RA/CD45RO expression and could be phenotypically grouped into 2H4⁺UCHL1^- 2H4^intUCHL1⁺ and 2H4^-UCHL1⁺ subpopulations. Mean proportions of 48% and 68%, for CD4⁺ and CD8⁺ lymphocytes respectively, showed a composite 2H4⁺UCHL1^- phenotype, whereas the percentage of NK-associated CD8^dim+ cells with this phenotypic pattern was considerably higher (mean, 85%). Normal lymphocyte subpopulations lacking both determinants (2H4^-UCHL1^-) were only rarely noted. Comparing normal patterns of CD45RA/CD45RO expression with those of the T-cell proliferations revealed diverse and abnormal patterns of staining for 3/6 of the CD4⁺CD8^- SS and ATLL, and for 5/5 of the T-PLL (CD4⁺CD8^-, n = 2; CD4⁺CD8⁺, n = 2; and CD4^-CD8⁺, n = 1) cases studied. In contrast, the nine cases of CD4^-CD8⁺ T-CLL and LDGL all showed CD45RA/CD45RO staining patterns similar to that of normal CD8⁺/CD8^dim+ blood lymphocytes (i.e. a predominance of 2H4⁺UCHL1^- cells). Although the variant CD45RA/CD45RO pattern types of the CD4⁺ proliferations did not appear to be related to either the diagnostic category or other phenotypic characteristics, the high proportion of abnormal patterns within this case group suggests that recognition of these abnormalities may be potentially relevant to the differentiation of benign and malignant CD4⁺ proliferations and, in addition, may be of aetiological importance with respect to the diverse acquired defects in immunity commonly seen in patients with such disorders.