IL-4 prevents the blockade of dendritic cell differentiation induced by tumor cells

Malignant cells may escape from the immune response in vivo because of a defective differentiation of professional antigen-presenting cells (APCs), i.e., dendritic cells (DCs). We recently reported that tumor cells release interleukin (IL)-6 and macrophage colony stimulating factor (M-CSF), which inhibit the differentiation of CD34+ cells into DCs and promote their commitment toward monocytic lineage with a poor APC function. The results presented here show that both IL-4 and IL-13 reverse the inhibitory effects of renal cell carcinoma conditioned media (RCC CM) or IL-6+M-CSF on the phenotypic and functional differentiation of CD34+ into DCs. IL-4 was found to act through a rapid blockade of the expression of M-CSF and the IL-6 receptor-transducing chain (gp130), along with a decrease of the secondary production of M-CSF, thereby preventing the loss of granulocyte macrophage colony stimulating factor (GM-CSF) receptor alpha chain expression on differentiating CD34+ cells. Consistent with these observations, the differentiation of DCs from monocytes cultured with GM-CSF and IL-4 was also impaired by RCC CM, but the minimal inhibitory concentrations of RCC CM were 10-fold higher than for CD34+ cells. In these conditions, monocytes cultured with GM-CSF and IL-4 also exhibited profound phenotypic changes (CD14+ D32+ CD86+ HLA-DR+ CD115(low) CD23(low) CD1a-) and a poor APC function. These alterations were overcome in a dose-dependent manner by IL-4 (5-500 IU/ml), although not beyond a 40% final concentration of RCC CM. The capacity of RCC CM to block DC differentiation from monocytes strongly correlated with IL-6 and M-CSF concentrations in medium. Taken together, these results demonstrate that IL-4 and IL-13 reverse the inhibitory effect of tumor cells on DC differentiation.     

Human tumor-released microvesicles promote the differentiation of myeloid cells with transforming growth factor-beta-mediated suppressive activity on T lymphocytes

Human tumors constitutively release endosome-derived microvesicles, transporting a broad array of biologically active molecules with potential modulatory effects on different immune cells. Here, we report the first evidence that tumor-released microvesicles alter myeloid cell function by impairing monocyte differentiation into dendritic cells and promoting the generation of a myeloid immunosuppressive cell subset. CD14+ monocytes isolated from healthy donors and differentiated with interleukin (IL)-4 and granulocyte macrophage colony-stimulating factor in the presence of tumor-derived microvesicles turned into HLA-DR(-/low) cells, retaining CD14 expression and failing to up-regulate costimulatory molecules, such as CD80 and CD86. These phenotypic changes were paralleled by a significant release of different cytokines, including IL-6, tumor necrosis factor-alpha, and transforming growth factor-beta (TGF-beta), and a dose-dependent suppressive activity on activated T-cell-proliferation and cytolytic functions, which could be reversed by anti-TGF-beta-neutralizing antibodies. Microvesicles isolated from plasma of advanced melanoma patients, but not from healthy donors, mediated comparable effects on CD14+ monocytes, skewing their differentiation toward CD14+HLA-DR-/low cells with TGF-beta-mediated suppressive activity on T-cell-functions. Interestingly, a subset of TGF-beta-secreting CD14+HLA-DR- cells mediating suppressive activity on T lymphocytes was found to be significantly expanded in peripheral blood of melanoma patients compared with healthy donors. These data suggest the development in cancer patients of an immunosuppressive circuit by which tumors promote the generation of suppressive myeloid cells through the release of circulating microvesicles and without the need for cell-to-cell contact. Therapeutic interventions on the crucial steps of this pathway may contribute to restore tumor/immune system interactions favoring T-cell-mediated control of tumor growth in cancer patients.     

Circulating and tumor-infiltrating myeloid cell subsets in patients with bladder cancer

Both cancer-related inflammation and tumor-induced immune suppression are associated with expansion of myeloid cell subsets including myeloid-derived suppressor cells. However, little known regarding characteristics of myeloid cells in patients with bladder cancer. In this study, we analyzed myeloid cells from peripheral blood (PBMC) and tumor tissue that were collected from patients with superficial noninvasive and invasive urothelial carcinomas. Our results demonstrate that PBMC from bladder cancer patients contain two major CD11b myeloid cell subsets: granulocyte-type CD15(high) CD33(low) cells and monocyte-type CD15(low) CD33(high) cells. The number of circulating granulocytic but not monocytic myeloid cells in cancer patients was markedly increased when compared to healthy individuals. Both myeloid cell subsets from cancer patients were highly activated and produced substantial amounts of proinflammatory chemokines/cytokines including CCL2, CCL3, CCL4, G-CSF, IL-8 and IL-6. Granulocytic myeloid cells were able to inhibit in vitro T cell proliferation through induction of CD4(+) Foxp3(+) T regulatory cells. Analysis of bladder cancer tissues revealed that tumors were infiltrated with monocyte-macrophage CD11b(+) HLA-DR(+) and granulocytic CD11b(+) CD15(+) HLA-DR(-) myeloid cells. Collectively, this study identifies myeloid cell subsets in patients with bladder cancer. We demonstrate that these highly activated inflammatory myeloid cells represent a source of multiple chemokines/cytokines and may contribute to inflammation and immune dysfunction in bladder cancer.     

A novel natural killer cell line (KHYG-1) from a patient with aggressive natural killer cell leukemia carrying a p53 point mutation.

We present the establishment of a natural killer (NK) leukemia cell line, designated KHYG-1, from the blood of a patient with aggressive NK leukemia, which both possessed the same p53 point mutation. The immunophenotype of the primary leukemia cells was CD2+, surface CD3-, cytoplasmic CD3epsilon+, CD7+, CD8alphaalpha+, CD16+, CD56+, CD57+ and HLA-DR+. A new cell line (KHYG-1) was established by culturing peripheral leukemia cells with 100 units of recombinant interleukin (IL)-2. The KHYG-1 cells showed LGL morphology with a large nucleus, coarse chromatin, conspicuous nucleoli, and abundant basophilic cytoplasm with many azurophilic granules. The immunophenotype of KHYG-1 cells was CD1-, CD2+, surface CD3-, cytoplasmic CD3epsilon+, CD7+, CD8alphaalpha+, CD16-, CD25-, CD33+, CD34-, CD56+, CD57-, CD122+, CD132+, and TdT-. Southern blot analysis of these cells revealed a normal germline configuration for the beta, delta, and gamma chains of the T cell receptor and the immunoglobulin heavy-chain genes. Moreover, the KHYG-1 cells displayed NK cell activity and IL-2-dependent proliferation in vitro, suggesting that they are of NK cell origin. Epstein-Barr virus (EBV) DNA was not detected in KHYG-1 cells by Southern blot analysis with a terminal repeat probe from an EBV genome. A point mutation in exon 7 of the p53 gene was detected in the KHYG-1 cells by PCR/SSCP analysis, and direct sequencing revealed the conversion of C to T at nucleotide 877 in codon 248. The primary leukemia cells also carried the same point mutation. Although the precise role of the p53 point mutation in leukemogenesis remains to be clarified, the establishment of an NK leukemia cell line with a p53 point mutation could be valuable in the study of leukemogenesis.     

In vitro responsiveness to interleukins and theophylline of CD16+, CD56- natural killer cells in a patient with chronic granular lymphocyte disorder.

We report here the case of a 55-year-old patient with chronic granular lymphocyte disorder associated with moderate neutropenia. The majority of peripheral blood lymphocytes displayed a CD3-, CD8-, CD16+, CD56(NKH1)- phenotype. The patient's cells showed high spontaneous cytotoxic activity against K562 targets and developed the ability to kill the natural killer (NK)-resistant target Daudi following activation with interleukin 2 (IL-2). Simultaneously, IL-2 induced proliferation of these cells, albeit to a low level. The effects of IL-2 are likely to be mediated through the IL-2R beta chain (p70) which is expressed on these cells in the absence of the IL-2R alpha chain (p55, Tac). IL-4 was demonstrated to be inhibitory of both the cytotoxic and proliferative effects of IL-2. Thus, despite an unusual CD56- phenotype, the expanded lymphocyte population in this patient display functional and phenotypic properties of normal, non-activated NK cells. These cells probably represent the counterpart of a minor NK cell subpopulation, present in normal individuals at a low frequency, and which has never been fully characterized functionally. In addition, we show that the cytolytic activity of this NK cell population can be blocked in vitro in the presence of a cAMP analog or of theophylline, possibly providing new means of investigating the role of NK cell cytotoxicity on the pathogenesis of associated symptoms in such patients.     

Establishment of the T-cell large granular lymphocyte leukemia cell line MOTN-1 carrying natural killer-cell antigens

A novel interleukin-2 (IL-2) dependent leukemia cell line MOTN-1 was established from the peripheral blood of a 63-year-old woman with T-cell large granular lymphocyte (LGL) leukemia in chronic phase. Primary peripheral blood leukemia cells were CD3+, CD5+, CD7+, CD56+, CD94+, CD161+, TcRalphabeta+, and HLA-DR+. The immunoprofile of the established cell line MOTN-1, however, showed CD3-, CD5-, CD7+, CD56+, CD94+, CD159+, CD161+, TcRalphabeta- and HLA-DR+; the MOTN-1 cells were cytoplasmatically positive for CD3varepsilon and the products of the T-cell receptor (TcR) genes beta and gamma. While the TcRbeta and TcRgamma genes were rearranged, the TcRdelta gene was found to be deleted. DNA fingerprinting and chromosome analysis identifying the t(2;6)(q?23;q?21) and t(12;18)(q13;q?22) alterations demonstrated the authenticity and the malignant nature of the cell line. The scientific significance of MOTN-1 lies in (1) the rarity of this type of leukemia cell lines, (2) the co-expression of various T- and natural killer (NK)-cell-associated markers, and (3) its unique chromosomal aberrations.     

Phenotyping of human tumor-infiltrating lymphocytes before and after exposure to different in vitro stimulation conditions.

Tumor-infiltrating lymphocytes (TiL) and autologous peripheral blood lymphocytes (PBL), mainly from breast and kidney tumor patients were cultivated with high- and low-dose rIL-2 under addition of autologous tumor cells or nonmalignant epithelial cells. Tumor cells added to TIL-cultures induced an additional proliferative response. Before cultivation, CD8+ and CD25+ lymphocytes were more frequent in TIL when compared to PBL, while CD16+, CD19+ and CD56+ cells were rare. After culture, lymphocytes of both origins showed an increase of CD2+, CD25+, CD56+ and HLA-DR+ cells and a relative decrease of CD3+ cells. The CD4+/CD8+ ratios and a number of CD56+ cells were rIL-2 dose dependent.     

Identification of a novel CD56- lymphokine-activated killer cell precursor in cancer patients receiving recombinant interleukin 2.

Circulating lymphokine-activated killer (LAK) cell activity in cancer patients receiving recombinant interleukin 2 (rIL-2) therapy is confined to cells expressing the CD56- surface marker. However, CD56- cells from these patients but not normal individuals have been reported to exhibit LAK cytotoxicity only following in vitro activation with rIL-2. Studies were performed to document the existence of CD56- LAK precursor cells and to phenotypically characterize this population in patients receiving rIL-2 therapy using fluorescence-activated cell sorter-purified CD56- cell subsets. Initial studies confirmed that CD56- cells exhibit NK activity [20 +/- 7 (SE) LU/10(6) cells] but not LAK activity (0 +/- 0 LU/10(6) cells) when evaluated directly from peripheral blood of patients receiving rIL-2. CD56- cells from patients but not normal individuals developed significant LAK cytolytic activity against NK-resistant COLO 205 targets (16 +/- 3 LU/10(6) cells) when cultured for 3 days with 1500 units/ml rIL-2. The CD56- LAK precursor activity was confined to cells expressing a CD56-CD16+ phenotype and a large granular lymphocyte morphology; little or no NK or LAK precursor activity was detectable in CD56-CD5+ T-cells from patients. Phenotypic characterization of CD16+CD56- cells revealed that this population is uniformly CD11a+,CD18+, and CD38+ and is heterogeneous in its expression of CD11b, CD11c, and CD16/Leu 11c. These results indicate that rIL-2 administration induces enhanced LAK precursor activity in a novel population of CD5-CD16+CD56- cells.     

IL-10 induces the development of immunosuppressive CD14+HLA-DRlow/? monocytes in B-cell non-Hodgkin lymphoma

The biological role of monocytes and macrophages in B-cell non-Hodgkin lymphoma (NHL) is not fully understood. We have previously reported that monocytes from patients with B-cell NHL have an immunosuppressive CD14⁺HLA-DR^low/− phenotype that correlates with a poor prognosis. However, the underlying mechanism by which CD14⁺HLA-DR^low/− monocytes develop in lymphoma is unknown. In the present study, we found that interleukin (IL)-10, which is increased in the serum of patients with B-cell NHL, induced the development of the CD4⁺HLA-DR^low/− population. Using peripheral blood samples from patients with B-cell NHL, we found that absolute numbers of CD14⁺ monocytic cells with an HLA-DR^low/− phenotype were higher than healthy controls and correlated with a higher International Prognostic Index score. IL-10 serum levels were elevated in lymphoma patients compared with controls and were associated with increased peripheral monocyte counts. Treatment of monocytes with IL-10 in vitro significantly decreased HLA-DR expression and resulted in the expansion of CD14⁺HLA-DR^low/− population. We found that lymphoma B cells produce IL-10 and supernatants from cultured lymphoma cells increased the CD14⁺HLA-DR^low/− population. Furthermore, we found that IL-10-induced CD14⁺HLA-DR^low/− monocytes inhibited the activation and proliferation of T cells. Taken together, these results suggest that elevated IL-10 serum levels contribute to increased numbers of immunosuppressive CD14⁺HLA-DR^low/− monocytes in B-cell NHL.     

CD14+ peripheral blood mononuclear cells from chronic myeloid leukemia and normal donors are inhibitory to short- and long-term cultured colony-forming cells

Monocyte-induced cell-cytotoxicity has been implicated in the mechanism of suppression of normal haematopoietic progenitors in chronic myeloid leukemia (CML). We examined here the in vitro effect of CML-derived and normal peripheral blood (PB) monocytes on short- and long-term cultured haematopoietic progenitor cells. Short-term coculture (5 days) of CML or normal monocytes with CML or normal peripheral blood mononuclear cells (PBMNC)/CD34+ cells as targets resulted in a significant inhibition of colony-forming cell (CFC) growth. Coculture conditioned medium (CCM) from 5-days cocultures of normal or CML CD14+ monocytes with CD34+ cells were likewise inhibitory to CFC. In 5-week long-term cocultures of monocytes in direct contact with normal bone marrow (BM) progenitors, CML monocytes reduced the proportion of long-term cultured CFC (LTC-CFC) significantly to 52% of the controls, while normal monocytes had a less pronounced inhibitory effect (89% of the controls) on LTC-CFC. Reduction of LTC-CFC was great when CML monocytes and target cells were separated by a transwell membrane as compared to control cultures in the absence of CD14+ cells (53.5 vs. 9%). CCM from 5-week cocultures of normal or CML CD14+ monocytes with CD34+ progenitors from bone marrow (BM) cells were also inhibitory to CFC. No difference in cytokine levels for TNF-alpha, IFN-gamma, G-CSF, IL-10, IL-6 was detectable between CML CD14+ CCM and control CCM derived from short- and long-term cocultures. Our results suggest that CML monocytes may play a role in the inhibition of normal haematopoiesis through a yet not defined soluble factor supporting the expansion of the malignant clone in CML.     

Effect of blood transfusion during radiotherapy on the immune function of patients with cancer of the uterine cervix: role of interleukin-10

: To analyze prospectively the effects of blood transfusion administered during radiotherapy (RT) on the immune function of patients with locally advanced cervical cancer.

: In a total of 15 patients, 7 transfused and 8 untransfused, lymphocyte populations, including CD3+, CD4+, and CD8+ T-cell subsets, B cells (CD19+), and natural killer (NK) cells (CD56+, CD16+, CD3−) were studied before (i.e., time 0), during (i.e., times 1 and 2), and after (i.e., time 3) therapy. Expression of the early (CD25) and late (HLA-DR) activation markers on CD3+ T cells, the intracellular levels of perforin in CD8+ and CD56+ cells, and interferon (IFN)-γ, interleukin (IL)-2, and IL-4 in CD4+ and CD8+ T cells were also measured. NK cell cytotoxicity against the NK-sensitive target K-562 cells and CD8+ T-cell-directed cytotoxicity against OKT3 hybridoma cells were also assessed. Finally, the plasma levels of the immunoregulatory cytokine IL-10 were analyzed by enzyme-linked immunosorbent assay.

: The mean absolute number of all lymphocyte subsets compared with pretreatment levels decreased significantly during RT of both transfused and untransfused patients (p >0.001), with no detectable differences between the two groups in terms of total lymphocytes or relative numbers of CD3+ and CD4+ T cells, CD56+ NK cells, or CD19+ B cells. In contrast, concomitant with an inversion of the CD4/CD8 ratio, a significant increase in the number of CD8+ T cells at time 2 and CD3+ T cells, CD8+ T cells, and NK cells at time 3 was found in the transfused patients compared with the untransfused group. The percentages of CD25+/CD3+ T cells and HLA-DR+/CD3+ T cells increased during RT of the untransfused patients, but CD3+ T cells showed decreased CD25 expression and increased HLA-DR expression in the transfused group. An increase of CD8+ IFN-γ+ T cells with a concomitant decrease in CD8+ IL-2+ T cells was found in the transfused vs. untransfused group, and no differences were noted in the percentage of CD4+ IFN-γ+ T cells and CD4+ IL-2+ T cells. The proportion of perforin-positive CD8+ and CD56+ cells was higher in the transfused group than in the untransfused group. However, CD56+ cells and CD8+ T cells from the transfused patients showed markedly diminished cytotoxic function. Finally, IL-10 was detected only in the plasma of the transfused patients.

: Blood transfusion during primary RT for cervical cancer profoundly alters the magnitude and characteristics of radiation-induced immunosuppression. Elevated serum IL-10 in transfused patients may play a role in the disregulation of lymphocyte function, in particular, the depression of NK- and T-cell cytotoxicity. Investigation of alternatives to blood transfusion during RT that do not diminish host immunity is warranted.     

Blood classical monocytes phenotype is not altered in primary non-small cell lung cancer

AIM: To evaluate the M1 and M2 monocyte phenotype in patients with non-small cell lung cancer (NSCLC) compared to controls. Also, to examine the expression of Th1 and Th2 cytokines in plasma of NSCLC vs controls.METHODS: Freshly prepared peripheral blood mononuclear cells samples were obtained from patients with NSCLC (lung adenocarcinoma and squamous cell lung carcinoma) and from non-cancer controls. Flow cytometry was performed to investigate M1 and M2 phenotypes in peripheral monocytes (classical monocytes CD14+, CD45+ and CD16-) using conventional surface markers. Th1 and Th2 cytokine production was also analysed in the plasma using cytometric bead array technique.RESULTS: There were no significant difference in expression of M1 (HLA-DR) and/or M2 markers (CD163 and CD36) markers on classical monocytes in patients with NSCLC compared to non-cancer controls. Expression of CD11b, CD11c, CD71 and CD44 was also shown to be similar in patients with NSCLC compared to non-cancer controls. Th1 and Th2 cytokines [interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-8, IL-10, IL-12 (p70), tumor necrosis factor (TNF)-α, TNF-β, and interferon-γ] analysis revealed no significant difference between patients with NSCLC and non-cancer controls.CONCLUSION: This study shows no alteration in peripheral monocyte phenotype in circulating classical monocytes in patients with NSCLC compared to non-cancer controls. No difference in Th1 and Th2 cytokine levels were noted in the plasma of these patients.     

A novel c-kit positive biphenotypic acute leukemia cell line,TMBL-1, carrying a p53 point mutation

We established and characterized a c-kit positive cell line from the bone marrow of a patient with biphenotypic acute leukemia (BAL). The cell line, designated TMBL-1, carried a His-175 mutant p53. The immunophenotype of the primary leukemia cells at diagnosis was cytoplasmic CD3+, CD7+, CD13+, CD33-, interleukin-7 (IL-7) receptor+ and c-kit -. However, leukemia cells in relapse and TMBL-1 cells were CD33+ and c-kit +. Immunophenotypically, TMBL-1 is a BAL cell line that coexpresses T-lymphoid and myeloid markers which fulfill the criteria of the European Group for the Immunological Characterization of Leukemia. Stem cell factor (SCF), a key regulator of hematopoiesis signaling through c-kit, enhanced the proliferation of TMBL-1 cells. Direct sequencing revealed the conversion at codon 175 of the p53 gene in the TMBL-1 cells. Primary leukemia cells in relapse also carried the same point mutation but not at diagnosis. Moreover, TMBL-1 cells are sensitive to paclitaxel, which could induce p53-independent apoptosis. The biphenotypic features and p53 mutation may be associated with progression to a more malignant type. This cell line may provide new information on the role of SCF in the overlapping area between early T-lymphoid/myeloid cells, and help in the design of new therapies targeted towards p53 mutations.     

宫颈癌患者外周血树突状细胞的体外扩增和鉴定

 目的 探索体外扩增宫颈癌患者外周血来源的成熟树突状细胞(denelritic cell，DC)的方法，并鉴定DC的形态、结构、表型及生物学活性。方法 淋巴细胞分离液分离宫颈癌患者外周血，得到DC前体细胞(PBMC)，以(3M-CSF、IL-4、TNF-α诱导培养。用光镜和透射电镜观察形态结构，流式细胞仪检测细胞表面特异性分子，MTT法测定DC刺激T细胞增殖的活性。结果 联合应用细胞因子可诱导扩增出源自宫颈癌患者外周血的成熟DC，具有典型形态特征，较高表达HLA-DR、CD1a、CD80，能强烈激发同种异体T细胞增殖反应。结论 宫颈癌患者外周血体外培养可成功获得成熟的DC，为开展宫颈癌临床免疫治疗奠定了基础。     

Myeloid/NK cell precursor acute leukemia lost both CD13 and CD33 at first diagnosis

It has been reported that malignancies of natural killer (NK) cell precursors, which are present in both myeloid and lymphoid antigens, are characterized by immature lymphoblastoid morphology with CD7+, CD33+ and CD56+ phenotype. Here, we report a 18-year-old man who was diagnosed with CD33- and CD13- NK cell precursor acute leukemia at first diagnosis. Following a 3-year remission state, he had a relapse as a testicular tumor and CD33+ myeloid/NK cell precursor acute leukemia after allogenic BMT. This case suggests that myeloid antigens are not necessary for diagnosis of myeloid/NK cell precursor acute leukemia.     

Differentiation and maturation of growth factor expanded human hematopoietic progenitors assessed by multidimensional flow cytometry.

Non-adherent cord blood and bone marrow mononuclear cells were analyzed by multiparameter flow cytometry before and at day 2, 4, 7, and 11 of culture in recombinant interleukin 3 (IL-3) and granulocyte colony-stimulating factor (G-CSF, cord blood) or stem cell factor (SCF), IL3 and granulocyte-macrophage colony-stimulating factor (GM-CSF, BM) to assess the differentiation and maturational pathway of myeloid cells. Before cell culture cord blood contained progenitor cells (CD34+) in various differentiation stages (CD38(-)----CD38bright), mature lymphocytes, monocytes, and neutrophils, but no immature neutrophils and immature monocytes. During cell culture, all CD34+ cells acquired the CD38 antigen between day 2 and 5 of cell culture, the CD34 antigen was lost between day 5 and 11 of cell culture. Differentiation of cells into the myeloid cell lineage was characterized by the acquisition of both CD33 and CD71. The latter is indicative for the active proliferation of these cells. Maturation of the cells into the neutrophilic pathway was indicated by the acquisition of first the CD15 antigen followed by CD11b and CD16 respectively. Whereas maturation of the cells into the monocytic pathway was indicated by the acquisition of first CD11b followed by CD14 and a dim expression of both CD15 and CD16. In normal bone marrow, cells of various maturational stages are already present before cell culture. During cell culture differentiation of cells into the myeloid lineage and maturation of the cells along the monocyte and neutrophilic lineage followed identical pathways as was observed before cell culture. Differentiation and maturational pathways of cord blood and adult bone marrow were identical. The results confirm the surface-antigen-defined pathways of myeloid cell differentiation described previously for non-cultured normal bone marrow aspirates. The detailed assessment of cell maturation and differentiation of cultured cells by multidimensional flow cytometry permits the determination of the specific effects of various recombinant human growth factors on myeloid cells.     

Acute leukemia with natural killer cells antigens in Brazilian children

Malignancies arising from Natural Killer cells (NK) were described mainly comprising disorders related to large granular lymphocyte expansion. Clinical, morphological and immunophenotypic characteristics of myeloid/NK cell precursor acute leukemia (M/NK-AL) have been mainly described in adult patients. We identified nine children with M/NK-AL precursor cells in a series of 264 childhood acute leukemia diagnosed in our laboratory from consecutive referrals before treatment. CD34 +/-, CD13/33 +, CD11b +, a-MPO + and CD56 +, characterized these cases with TcR alphabeta and gammadelta negative cells. The differential diagnosis between subtypes of NK leukemia with those of lymphoid or myeloid origin in childhood raises the question regarding the pathogenesis and therapeutic implications of this rare entity in children.     

The generation of interleukin-2-dependent suppressor T-cells from patients with systemic metastasis of gastric carcinoma and the phenotypic characterization of the cells defined by monoclonal antibodies

Suppressor cells, which might be activated in patients with gastric carcinoma, were successfully enriched by the use of interleukin-2 (IL-2) prepared from human tonsils and spleens. That is, peripheral blood lymphocytes cultured for 3 or 4 weeks with IL-2 strongly inhibited the patient's own lymphocyte-proliferative responses to alloantigen or phytohemagglutinin (PHA). Quantitative fluorescence measurement for immunologic analysis of phenotypic characterization of the cells was made on FACS-IV with monoclonal antibodies anti-Leu-1 anti-Leu-2a, anti-Leu-3a, anti-Leu-4, anti Leu-5, anti-Leu-7, and anti-HLA-DR and goat anti-human immunoglobulin (Ig). Functional suppressor T-cells expanded with IL-2 showed the following phenotype: Leu-1+ Leu-2a+, Leu-3a-, Leu-4+, Leu-5+, Leu-7-, HLA-DR+, human Ig-. The IL-2-dependent suppressor T-cells could be obtained only when the cells were derived from patients with systemic metastasis of gastric carcinoma. These findings suggest that generation of IL-2-dependent suppressor T-cells is the result of large tumor burdens; this may exert negative cellular control in the immune responses, thus inducing the status of the lower cell-mediated antitumor immunity, and may promote cancer progression in gastric cancer patients.     

Aggressive natural killer-cell leukemia revisited: large granular lymphocyte leukemia of cytotoxic NK cells.

Aggressive natural killer-cell leukemia (ANKL) is a rare form of large granular lymphocyte leukemia, which is characterized by a systemic proliferation of NK cells. The clinical features of 22 ANKL cases were analyzed. Hepatomegaly (64%), splenomegaly (55%) and lymphadenopathy (41%) were also frequently observed. Leukemic cells were identified as CD1-, CD2+, surface CD3-, CD4-, CD5-, CD7+, CD8+/-, CD10-, CD11b+/-, CD13-, CD16+, CD19-, CD20-, CD25-, CD33(-), CD34-, CD38+, CD56+, CD122+, HLA-DR+ and TCR-. Two of the 16 cases examined for CD57 were positive and three of the seven cases examined for cytoplasmic CD3. Epstein-Barr virus was detected in the tumor cells of 11 of the 13 cases examined. No common cytogenetic abnormalities were identified and 6q anomaly was detected in only one. Three of 13 patients treated with chemotherapy containing anthracycline/anthraquinone attained complete remission, in contrast to none of the eight who were treated with regimens without anthracycline. Although the overall prognosis was poor with a median survival of 58 days, those who attained remission showed better prognosis (P=0.005). These findings suggest that ANKL is an entity of mature cytotoxic NK-cell neoplasms with distinct phenotype and disease presentations. Intensive treatment for ANKL may result in a better prognosis.     

In vitro immunization of patient T cells with autologous bone marrow antigen presenting cells pulsed with tumor lysates

Presentation of cell-associated antigen to T cells is a critical event in the initiation of an anti-tumor immune response but it appears to often be deficient or limiting. Here we report an experimental system for stimulation of human T lymphocytes using autologous antigen presenting cells (APCs) and autologous tumor cells. Two types of APCs were prepared from human bone marrow: MC and DC. MC were produced by using GM-CSF and SCF. DC were obtained with the same cytokines plus IL-4. DC and MC were generated in parallel from the same patients and their phenotypes and capacities to prime T lymphocytes were analyzed and compared. MC were CD14+, CD1a-, CD33+ and HLA-DR+. Two populations of DC were defined: immature DC were uniformly CD1a-; mature DC expressed CD1a, CD80, CD86, HLA-DR, CD54 and CD58 but lacked surface CD14. Stimulation of autologous T lymphocytes was studied by measuring their proliferation and cytotoxic function. In more than 80% of our experiments the proliferation of autologous T lymphocytes cocultured with APC pulsed or not with tumor cell lysates was higher than that of T cells cultured alone. DC were more effective than MC in stimulating proliferation of lymphocytes. The capacity of a patient's autologous bone marrow-derived APC to stimulate T cells when exposed to autologous tumor cell lysates suggest that such antigen-exposed APC may be useful in specific anti-tumor immunotherapy protocols.