Histocompatibility Leukocyte Antigen-A2-restricted and Tumor-specific Cytotoxic T Lymphocytes from Tumor-infiltrating Lymphocytes of a Patient with Testicular Embryonal Cancer

T lymphocytes play an important role in tumor rejection. To understand T cell-mediated specific immunity at the tumor site of testicular embryonal cancer, we investigated whether interleukin-2 (IL-2)-activated tumor-infiltrating lymphocytes (TIL) of a patient with testicular embryonal cancer show histocompatibility leukocyte antigen (HLA)-class I-restricted and tumor-specific cytotoxicity. We established a CD3⁺CD4^-CD8⁺ cytotoxic T lymphocyte (CTL) line from the IL-2-activated TIL of a 37-year-old patient with testicular embryonal cancer. A 6 h ⁵¹Cr-release assay was performed to measure the cytotoxicity of the CTL. The CD3⁺CD4^-CD8⁺ CTL line showed cytotoxicity against HLA-A2⁺ tumor cells, including freshly isolated autologous tumor cells, adenocarcinoma cell lines from various organs (lung, breast, pancreas, colon and kidney) and squamous cell carcinomas (esophagus and oral cavity). No other cell lines examined, including an autologous tumor cell line and HLA-A2" tumor cell lines, were lysed by this CTL line. These results suggest the existence of HLA-A2-restricted and tumor-specific CTL at the tumor site of testicular embryonal cancer.     

Murine Asialo GM1+CD8+ T Cells as Novel Interleukin-12-responsive Killer T Cell Precursors

Freshly isolated CD8⁺ T cells, but not CD4⁺ T cells, contained 20–30% of asialo GM1⁺ (ASGM1⁺) T cells which were distinct from ASGM1⁺NK1.1⁺ natural killer cells. This novel ASGM1⁺CD8⁺ T cell subpopulation showed a strong proliferative response to interlenkin-12 (IL-12) in the presence of IL-2. Culture of ASGM1⁺CD8⁺ T cells with IL-12 plus IL-2 allowed the generation of anomalous killer T cells concomitantly with the accumulation of cytolytic molecules. Moreover, ASGM1⁺CD8⁺ T cells produced high levels of interferon-γ (IFN-γ), but not IL-4, upon stimulation with IL-12 plus IL-2. Such immune responses were not observed in ASGM1⁻ CD8⁺ T cell snbpopulations constituting the majority of CD8⁺ T cells. These results demonstrated that ASGM1⁺CD8⁺ T cells are a novel subpopulation of IL-12-responsive and IFN-γ-producing killer T cell precursors.     

Induction Mechanism of Human Blood CD8+ T Cell Proliferation and Cytotoxicity by Natural Killer Cell Stimulatory Factor (Interleukin-12)

Natural killer cell stimulatory factor (NKSF J IL-12) has been found to induce cytotoxic activity of human blood T cells. In the present study, the effect of NKSF on induction of cytotoxic CD8⁺ T cells in the presence or absence of monocytes was examined. Highly purified lymphocytes (>99%) and monocytes (>90%) were isolated hy centrifugal elutriation from peripheral blood of normal donors. Then, CD8⁺ cells were isolated with antibody-bound magnetic beads from purified lymphocytes. The cytotoxicity of CD8⁺ cells was measured by ⁵¹Cr release assay for 4 h. NKSF enhanced the proliferative response of CD8⁺ cells stimulated with suboptimal concentrations of interleukin-2 (IL-2), but rather inhibited their proliferative and cytotoxic responses on stimulation with an optimal concentration of IL-2. NKSF stimulated CD8⁺ cells to produce interferon 7 (IFNγ) irrespective of the presence of added IL-2, and this effect was augmented by co-cultivation with monocytes. Blood monocytes upregulated induction of cytotoxic CD8⁺ cells stimulated with NKSF alone, and this effect was abolished by addition of antibody against IFNγ, but not of antibody against tumor necrosis factor a. Induction of NKSF-inducible cytotoxic CD8⁺ cells was inhibited by addition of transforming growth factor β, but not of IL-4. These observations suggest that in situ induction of NKSF-stimulated cytotoxic CD8⁺ cells may be regulated by complex cytokine networks, depending on the participation of monocytes.     

Immunologic, morphologic and chromosomal characterization of a cell line (TC78) established from a child with acute lymphoblastic leukemia

We characterized a cell line established from bone marrow cells from a child with acute lymphoblastic leukemia. This cell line, TC78, had lymphoblastic morphology and was cytoplasmic peroxidase and esterase negative. The cells did not have T- or B-cell properties such as E- or EAC-rosette forming ability, reactivity with monoclonal T-cell or B2 antibodies, or immunoglobulin synthesis. We concluded that TC78 was a pre-pre B-cell line based on the following monoclonal antibody staining pattern: BA-I⁺, BA-2⁺, cALLa⁺, Ia⁺, 2H7⁺ and OKB2⁺. Growth in ‘Dickie’ culture and reactivity with 1G10 myeloid antibody suggested coexpression of lymphoid and myeloid characteristics. However, 1G10 expression proved dependent on culture conditions, illustrating one caveat in application of monoclonal antibodies in lineage determination.     

Interleukin-12 Augments the Generation of Autologous Tumor-reactive CD8+ Cytotoxic T Lymphocytes from Tumor-infiltrating Lymphocytes

Human tumor-infiltrating lymphocytes (TIL) were obtained from breast cancer, renal cancer or neuroblastoma to investigate the generation of autologous tumor-reactive CD8⁺ cytotoxic T lymphocytes (CTL). When TIL were cultured with interleukin (IL)-2 (100 U/ml), the growth of TIL peaked around 8–10 days after the initiation of culture. In contrast, the proliferation of TIL cultured with IL-2 plus IL-12 peaked around 4–5 days after culture and tumor cells rapidly disappeared from the culture. To determine the generation of autologous tumor-reactive CD8⁺ CTL, TIL-derived CD8⁺ T cells were separated by FACStar. Both IL-2-activated and IL-2 plus IL-12-activated TIL-CD8⁺ T cells showed the same level of lymphokine-activated killer activity against a variety of tumor cells. However, TIL-CD8⁺ T cells activated with IL-2 plus IL-12 revealed greatly augmented cytotoxicity against autologous tumor cells compared with that induced by IL-2 alone. The autologous tumor cell-killing activity of TIL-CD8⁺ CTL was significantly inhibited by the addition of F(ab)₂ anti-CD3 monoclonal antibody, indicating that these CTL recognize autologous tumor antigen through T cell receptor. These results imply that IL-12 is a novel cytokine which facilitates the generation of autologous tumor-reactive CD8⁺ CTL from TIL.     

Effects of interleukins 1–7 on the proliferation of T-lineage acute lymphoblastic leukemia cells

We investigated the proliferative effects of interleukins 1–7 (IL-1 to -7) on leukemic cells from 10 patients with T-lineage acute lymphoblastic leukemia (T-ALL). Five patients had CD7⁺4⁻8⁻ acute leukemia, one had CD5⁺ acute leukemia, and four had CD1⁺ acute leukemia. To examine the proliferative effect of each interleukin, ³H-TdR incorporation method was used. In the presence of IL-1, no increase in ³H-TdR incorporation was observed for any of the T-ALL cells. With IL−2, ³H-TdR incorporation increased in cells from 5 out of 10 T-ALL patients, including those with CD7⁺4⁻8⁻, CD5⁺, and CD1⁺ acute leukemia. In the presence of IL−3 or IL−6, ³H-TdR incorporation increased in cells from 2 out of 5 patients with CD7⁺4⁻8⁻ acute leukemia. However, CD5⁺ or CD1⁺ acute leukemia cells were not stimulated by IL−3 or IL−6. With IL−4, ³H-TdR incorporation was increased in the cells from 2 out of 5 patients with CD7⁺4⁻8⁻ acute leukemia and in the cells of 2 of those with CD1⁺ acute leukemia. IL-5 increased the ³H-TdR incorporation by cells from 2 out of 5 patients with CD7⁺4⁻8⁻ acute leukemia and 1 patient with CD1⁺ acute leukemia. IL-7 increased ³H-TdR incorporation in cells from all five CD7⁺4⁻8⁻ acute leukemia and 2 of those with CD5⁺ or CD1⁺ leukemia. No synergistic effect was found when IL-7 and other cytokines were added to cells from the 3 patients with CD7⁺4⁻8⁻ acute leukemia who were tested.     

Effects of Interleukin-12 on the Induction of Cytotoxic T Lymphocytes from the Regional Lymph Node Lymphocytes of Patients with Lung Adenocarcinoma

Lung cancer-specific cytotoxic T lymphocytes (CTL) were induced by repeated stimulations of regional lymph node lymphocytes (RLNL) in lung cancer patients with either autologous or HLA-A-locus-matched tumor cells. To investigate the effect of interleukin-12 (IL-12), IL-12 was added during the stimulation of RLNL from HLA A24 / adenocarcinoma patients with either autologous tumor cells or HLA A24-positive adenocarcinoma cells (PC-9) in combination with, or instead of interleukin-2 (IL-2), and then the cytotoxic activity, cytokine production and populations of the lymphocyte subsets were examined. The addition of IL-12, or the substitution of IL-2 by IL-12 was found to enhance the cytotoxic activity and the cytokine production (IFN-γ, GM-CSF) of the CTL as compared with IL-2 alone. The cytotoxic activity and cytokine production were both partially inhibited by anti-MHC-class I monoclonal antibody. The CTL thus induced by IL-12 had a higher proportion of CD3⁺/CD56⁺ cells than the CTL induced with IL-2 alone. The positively selected CD8⁺/CD56^– lymphocytes showed PC-9-specific cytotoxic activity, because the population did not show any cytotoxicity to K562 or A549 (HLA-A26/A30). However, the CD3⁺/CD56⁺ lymphocytes were cytotoxic to both PC-9 and K562. In conclusion, IL-12 is considered to be a useful cytokine for both the induction of lung-cancer specific CTL and the augmentation of non-MHC-restricted cytotoxicity against tumor cells, and may be applicable for adoptive immunotherapy using CTL.     

Direct Activation of Human CD8+ Cytotoxic T Lymphocytes by Interleukin-18

Direct activation of human cytotoxic T lymphocytes (CTL) by interleukin (IL)-18 was observed in a system in which CTL effective against autologous tumor cells were generated. Peripheral blood mononuclear cells (PBMC) from tumor-bearing patients, after removal of natural killer (NK) cells, were cultured in a medium containing IL-1, -2, -4, and -6, with or without IL-18, and stimulated with autologous tumor cells. IL-18 increased the activity of the CTL and the proportion of autologous CD8⁺ T cells present after 28 days in the induction culture. When purified CD8⁺ T cells were cultured in the presence of IL-18 and IL-2 for 7 days, the CTL showed enhanced cytotoxic activity against autologous tumor cells. Moreover, a purified CD8⁺ T cell population, which did not exhibit any apparent cytotoxic activity against autologous tumor cells, displayed cytotoxic activity after 7-day incubation with IL-18. These results suggest that IL-18 may be useful to generate autologous CTL in humans and may thereby contribute to adoptive immunotherapy for tumors.     

Phenotypic and genotypic characterization of 14 leukemia and lymphoma cell lines with 11q23 translocations

11q23 translocation is the most popular chromosomal abnormality in infant leukemia. In adults, it is often encountered in non-Hodgkin's lymphoma (NHL). In this study, we analyzed the phenotypic and genotypic characteristics of 9 acute leukemic cell lines with 11q23 translocations and one with deletion of the 11q23 locus, nine of which were established by researchers in this group, together with 4 NHL cell lines with 11q23 translocations. All lines were considered to belong to the B-cell lineage at different stages. All 10 leukemic lines showed clonal rearrangement of the immunoglobulin heavy chain (IgH) gene: two corresponded to the B-precursor stage (CD19⁺, cytoplasmic μ⁻), while the other 8 corresponded to the pre-B stage (cytoplasmic μ⁺). All 4 NHL lines showed rearrangements of both the IgH and Igκ genes with three expressing surface Ig; specifically, mature B-cell phenotype. As for myelocytic-monocytic markers, at least one out of 4 antigens examined were positive in 8 of the 10 leukemic cell lines, while only one of the 4 NHL lines was reactive. There were essentially no clear phenotypic or genotypic differences between t(4;11) and t(11;19) cell lines, supporting the view that both diseases have similar clinicopathological characteristics. These cell lines are also valuable for cloning genes at the chromosomal breakpoints.     

Primary Effusion Lymphoma Cell Lines Harbouring Human Herpesvirus Type-8

Primary effusion lymphoma (PEL) is a novel lymphoma entity consistently infected by HHV-8 that occurs predominantly in immunodeficient patients and is characterized by liquid growth in the serous body cavities. In order to facilitate the understanding of PEL pathogene-sis and histogenesis, we have established three PEL cell lines termed CRO-AP/2, CRO-AP/3 and CRO-AP/5. All cell lines have been derived from HIV positive homosexual men affected by PEL with (in the case of CRO-AP/2 and CRO-AP/5) or without (in the case of CRO-AP/3) a previous history of Kaposi's sarcoma. The cell lines are representative of both virologic variants of PEL, i.e. HHV-8⁺ EBV⁺ PEL (CRO-AP/2 and CRO-AP/5) and HHV-8⁺ EBV^- PEL (CRO-AP/3). Morphologic and phenotypic features of CRO-AP/2, CRO-AP/3 and CRO-AP/5 are typical of PEL, and include morphology bridging immunoblastic and anaplas-tic features as well as an indeterminate (non B- non T-cell) phenotype. The B-cell nature of the cell lines is documented by the presence of rearranged immunoglobulin genes. The detailed analysis of the molecular and phenotypic features of CRO-AP/2, CRO-AP/3 and CRO-AP/5 has allowed the identification of recurrent chromosomal abnormalities of PEL and has contributed to the definition of PEL as a lymphoma of post-germinal center, pre-ter-minally differentiated B-cells.     

Expression of CCL17 and CCL22 by latent membrane protein 1-positive tumor cells in age-related Epstein-Barr virus-associated B-cell lymphoproliferative disorder

Age-related Epstein–Barr virus-positive (EBV⁺) B-cell lymphoproliferative disorder (ALPD) is a disease entity identified from a large-scale re-survey of cases diagnosed as diffuse large B-cell lymphoma. ALPD is a group of EBV⁺ polymorphic B-cell lymphoma typically seen in elderly patients. An age-associated decline in host immunity against EBV might be partly responsible for the pathogenesis of ALPD. Histologically, ALPD is often characterized by a minor proportion of EBV-encoded RNA-positive tumor cells in a background of extensive cellular infiltration, similar to that of classical Hodgkin's lymphoma. In contrast to Hodgkin and Reed–Sternberg cells, ALPD tumor cells are clearly positive for B cell markers CD20 and/or CD79a. Hodgkin and Reed–Sternberg cells produce various chemokines, including CCL17 and CCL22, that attract chemokine receptor CCR4-expressing Th2 cells and regulatory T cells. Previously, we have shown that EBV-immortalized B cells also produce CCL17 and CCL22 through latent membrane protein 1 (LMP1)-mediated activation of nuclear factor κB. Here we examined expression of CCL17 and CCL22 in ALPD. ALPD tumor cells were often heterogeneous in size in accordance with the differential expression of EBV latent genes at the single cell level. LMP1-expressing tumor cells were typically large in size and selectively positive for CCL17 and CCL22. CCR4⁺ cells and forkhead box protein 3⁺ regulatory T cells were abundantly present, and the majority of forkhead box protein 3⁺ cells were CCR4⁺. Collectively, our data show production of CCL17 and CCL22 by LMP1⁺ large-sized tumor cells and accumulation of CCR4-expressing cells including regulatory T cells in ALPD. ( Cancer Sci 2008; 99: 296–302)     

A B-CELL LINE HAVING CHROMOSOME 14 ABERRATION AT BREAK BAND qll DERIVED FROM AN ADULT T-CELL LEUKEMIA PATIENT

A B-cell line having translocations of chromosome 14 at break band q11 (the assigned locus of the α-chain gene of the T-cell antigen receptor) and chromosome 3 at break band p25 (the assigned locus of the c- raf -1 oncogene) was established from peripheral blood leukocytes of an adult T-cell leukemia (ATL) patient. The same chromosome 14 aberration at break band q11 and chromosome 3 aberration at break band p25 were also found in fresh T-cell leukemia cells. The B-cell line is surface immunoglobulin (sIg)⁺, immunoglobulin gene rearrangement⁺, ATL-specific antigen (ATLA)⁺, HTLV-1 proviral genome⁺, Epstein-Barr virus (EBV)-associated nuclear antigen (EBNA)⁺ and the EBV DNA genome⁺. The fresh T-leukemic cells were T-cell receptor gene rearrangement⁺, the HTLV-1 proviral genome⁺ and EBV DNA genome⁻.     

Cytokine regulation of constitutive production of interleukin-8 and -6 by human pancreatic cancer cell lines and serum cytokine concentrations in patients with pancreatic cancer

Patients with pancreatic cancer frequently demonstrate symptoms such as weight-loss and muscle wasting and have clinical evidence of a systemic inflammatory response. Such effects may be mediated by pro-inflammatory cytokines derived from tumor cells. The production of interleukin-6 and -8 by pancreatic cancer cell lines and the influence of other cytokines on this production was studied. IL-8 was produced by all cell lines and production was increased following exposure to IL-1 and TNF. Cytokine-stimulated, but not basal IL-8 production was reduced by co-incubation with IL-4 in the MIA PaCa-2 and PANC-1 cell lines. The CFPAC cell line produced IL-6, but this production was not altered by IL-1, TNF or IL-4. In the PANC-1 cell line IL-8 and IL-8 receptors were only detected by PCR in cells which had been stimulated with TNF or IL-1. Serum concentrations of IL-6 and IL-8 were elevated in patients with pancreatic cancer compared with controls. In conclusion, human pancreatic cancer cell lines elaborate pro-inflammatory cytokines which have the potential to mediate elements of the systemic inflammatory response.     

IL-2-dependent ATL cell lines with phenotypes differing from the original leukemia cells

Adult T-cell leukemia (ATL) cells have been shown to express the receptor for IL-2 by studies using anti-CD25 monoclonal antibody, but these cells usually show no or only a weak proliferative response to IL-2. In the present study, we established thirteen IL-2-dependent T-cell lines from four ATL patients. Examination of the clonalities of these cell lines by the rearrangement profiles of the TCR beta-chain gene and the integration sites of the HTLV-I proviral genome, revealed that two cell lines (KK-1 and KK-5) were of real ATL cell origin. The others were of normal T-cell origin and had been established by infection with HTLV-I. The KK-1 and KK-5 cell lines were derived from a single ATL patient (KK). Interestingly, these cells showed different phenotypic features from the majority of original leukemia cells (CD3 +/- CD4+ CD8-). The KK-1 cell line acquired CD8 antigen expression and became double-positive (CD3 +/- CD4+ CD8+), while the KK-5 cell line prominently expressed CD3 antigen (CD3+ CD4+ CD8-). These results indicate that the phenotypic feature of ATL cells are not fixed, but can change in vitro as has occasionally been observed in vivo.     

Interleukin-8 increases vascular endothelial growth factor and neuropilin expression and stimulates ERK activation in human pancreatic cancer

Interleukin-8 (IL-8) is associated with tumorigenesis by promoting angiogenesis and metastasis. Although up-regulation of IL-8 is indicated in many cancers, its function in pancreatic cancer has not been well characterized. In this study we examined the expression of IL-8 on pancreatic cancer cells and clinical tissue specimens, and investigated the effect of exogenous IL-8 on gene expression, and signaling in human pancreatic cancer cells. We found that pancreatic cancer cells expressed higher amount of IL-8 mRNA than normal human pancreatic ductal epithelium cells. IL-8 mRNA was also substantially overexpressed in 11 of 14 (79%) clinical pancreatic-adenocarcinoma samples compared with that in their surrounding normal tissues. Exogenous IL-8 up-regulated the expression of vascular endothelial growth factor₁₆₅, and neuropilin (NRP)-2 in BxPC-3 cells, one of human pancreatic cancer cell lines. IL-8 expression was inducible by hypoxia mimicking reagent cobalt chloride. In addition, IL-8 activated extracellular signal-regulated kinase (ERK)1/2 signaling pathway in BxPC-3 cells. Our studies suggest that IL-8 might be a malignant factor in human pancreatic cancer by induction of vascular endothelial growth factor and NRP-2 expression and ERK activation. Targeting IL-8 along with other antiangiogenesis therapy could be an effective treatment for this malignancy. ( Cancer Sci 2008, 99: 733–737)     

T Cell Response to Embryonal Carcinoma F9 Cells: Induction and Characterization of T Cell Receptor αβ+ Double-negative Cytotoxic T Lymphocytes

We investigated the mechanism of T cell response to marine embryonal carcinoma F9 cells. Thy-1⁺, CD4⁻, CD8⁻ (double-negative) cytotoxic effector cells were induced in spleen cells obtained from immune A.BY mice to F9 cells, and the cytotoxic activity was major histocompatibility complex (MHC)-unrestricted. Furthermore, CD4⁺ T cells were essential for the induction of double-negative cytotoxic T lymphocytes directed to F9 cells. Most of the double-negative cytotoxic T lymphocyte lines obtained by long-term culture of the effector cells had CD3 molecule and T-cell receptor β chain on their cell surface, and the CDS molecule was found to be involved in target cell recognition. The T cell receptor αβ⁺ double-negative cytotoxic T lymphocyte line (2A5) also lysed various tumor cells in a non-MHC-restricted manner, but did not lyse concanavalin A-stimulated blasts of 129 strain, from which F9 cells had originated. These results indicate that T cell receptor αβ⁺ double-negative cytotoxic T lymphocytes induced by F9 cells recognize a common antigen(s) expressed on F9 cells and other tumor cells but not minor histocompatibility antigens.     

Adult T-cell leukemia/lymphoma cells from blood and skin tumors express cytotoxic T lymphocyte-associated antigen-4 and Foxp3 but lack suppressor activity toward autologous CD8+ T cells

Adult T cell leukemia/lymphoma (ATL) cells share the CD4⁺CD25⁺ phenotype with regulatory T (Treg) cells. However, it is still controversial whether ATL cells are Treg cells. The aim of the present study was to investigate the Treg nature of ATL cells obtained from peripheral blood and skin tumors in terms of their phenotype and function. By flow cytometry and immunohistochemistry, the expression of the Treg-associated molecule cytotoxic T lymphocyte-associated antigen (CTLA)-4 and Foxp3 was examined in freshly isolated circulating and skin-infiltrating tumor cells from 21 ATL patients with skin eruptions. The expression of CTLA-4 on freshly isolated circulating tumor cells was elevated in two of 15 patients, and Foxp3 was expressed intracytoplasmically at high levels in three of nine patients. In five of the patients examined, skin-infiltrating tumor cells bore variously elevated CTLA-4 with high Foxp3 expression. The potentiality of ATL cells as Treg cells was further addressed by stimulating ATL cells with anti-CD3/CD28 monoclonal antibodies and monitoring CTLA-4 expression. With the stimulation, even CTLA-4-low ATL cells expressed higher levels of CTLA-4 than normal CD4⁺CD25⁺ cells. To study function, ATL cells isolated from blood and skin tumors were tested for their ability to suppress the proliferation of autologous CD8⁺ T cells stimulated with allogeneic lymphocytes. Despite the expression of CTLA-4 and Foxp3, these tumors were incapable of suppressing the proliferation of autologous CD8⁺ T cells. ATL cells are phenotypically Treg cells in at least some patients, but lack immunoregulatory functions, at least toward CD8⁺ T cells. ( Cancer Sci 2008; 99: 98–106)     

Stimulatory Effect of Interleukin-1α on Proliferation through a Ca2+/Calmodulindependent Pathway of a Human Thyroid Carcinoma Cell Line, NIM 1

NIM 1 cells, a human thyroid cell line established from a patient with thyroid papillary adenocarcinoma, produce cytokines such as interleukin-1α (IL-1α) and granulocyte-colony stimulating factor. In the present study, we investigated the signal transduction pathway in the proliferation of NIM 1 cells evoked by IL-1α. Incubation of NIM 1 cells with IL-1α for 48 h increased the incorporation of ³H-thymidine (³H-TdR). The stimulatory effect of IL-1α was evident at 0.01 ng/ml and the maximal effect was seen at 10 ng/ml. IL-1α evoked an influx of ⁴⁵Ca into NIM 1 cells within 3 min in a concentration-dependent manner (0.01–1 ng/ml). These stimulatory effects of IL-1α on both ³H-TdR incorporation and ⁴⁵Ca influx were similarly inhibited by nicardipine, an inhibitor of voltage-dependent Ca²⁺ channels, in a concentration-dependent manner (10–1000 nM). The stimulatory effect of IL-1α on ³H-TdR incorporation was inhibited by N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), an antagonist of calmodulin, but not by 1-(5-isoquinoline sulfonyl)-2-methylpiperazine (H-7), an inhibitor of protein kinase C. While the culture medium initially contained 0.75 m M Ca²⁺, inhibition of ³H-TdR incorporation by nicardipine and W-7 under these baseline conditions was also recognized. These results suggest that IL-1α stimulates cell proliferation through a Ca²⁺/calmodulin-dependent pathway in NIM 1 cells.     

Expression of 1D8—A novel non-sialylated B-cell-associated carbohydrate epitope in lymphoproliferative disorders

The expression of a novel B-cell-associated carbohydrate epitope (1 D8) was studied by means of flow cytometry in 153 well defined cases of leukemias and lymphomas and 19 cases of lymphadenopathy used as controls. The 1D8 epitope was detected preferentially in proliferations of mature B-lymphocytes (11/15 CD20⁺ acute lymphoblastic leukemia (ALL), 14/ 16 chronic lymphocytic leukemia (CLL), 4/7 mantle cell non-Hodgkins lymphoma (NHL), 3/8 follicle cell NHL. However its expression did not appear lineage- or differentiation stage-restricted. Intensive expression on in vivo and in vitro-activated lymphocytes as well as in some high grade malignancies indicated a relationship to the functional state of cells. Bearing in mind the enhanced detection of 1D8 upon desialylation, the epitope might be involved in the regulation of adhesion/migration potential of normal leukocytes and their malignant counterparts.