Nonadherent Peripheral Blood Mononuclear Cells Research Articles

Human autologous dendritic cell-glioma fusions: feasibility and capacity to stimulate T cells with proliferative and cytolytic activity.

Gliomas are the most common primary neoplasm of the central nervous system. The failure of conventional treatment modalities to improve outcome over the last two decades has led to interest in alternative treatment modalities. Dendritic cell (DC)-based immunotherapy has utilized DC pulsed with tumor lysate or peptide to induce an antitumor immune response mediated largely by CD8 T cells. While this has been effective in preclinical studies, clinical efficacy remains unproven. Recently, hybrid cells produced by fusions of tumor and autologous DC have demonstrated remarkable efficacy for stimulating an anti-tumor immune response in both preclinical and clinical studies of extra-cranial neoplasms. The advantage of generating such hybrid cells is that the entire cellular material of the tumor is processed and presented in both endogenous and exogenous pathways. This leads to activation of both MHC class I restricted CD8 cells as well as MHC class II restricted CD4 T cells. Here, we examined in vitro T cell stimulatory capacity of autologous human DC-glioma fusion in comparison to DC loaded with apoptotic glioma. DC fused with autologous tumor or loaded with apoptotic tumor cells (DC/apo) were first used to stimulate autologous non-adherent peripheral blood mononuclear cells (PBMC), in vitro. The PBMC were then examined for phenotype (CD3, CD4, CD8) and intracellular IFN-gamma using flow cytometry. Lymphocyte proliferation and cytolytic responses were also assessed. Lymphocytes stimulated in vitro with fusion or DC/apo cells showed significantly enhanced cytotoxicity and proliferation against autologous tumor cells compared with PBMC stimulated with tumor cells or DC alone. Both strategies had similar efficacy. Tumor-cytolytic responses were enhanced by the addition of CD40 ligand (CD40L), and partially blocked by anti-MHC class I antibody. Flow cytometric analysis detected CD3+ CD8+ T cells, which also stained positive for intracellular IFN-gamma. The study suggests that DC/glioma fusion and DC/apo have comparable efficacy for stimulation of CTL with cytolytic and proliferative activity against human malignant gliomas. These findings may have implications for future studies of DC-based immunotherapy in malignant gliomas.

Physiological and pathological relevance of extracellular NM23/NDP kinases.

The NM23 gene is overexpressed in many hematological malignancies and other neoplasms. Some tumor cell lines that overexpress NM23 secrete this protein into extracellular environment. In this study, we found that the serum concentration of NM23-H1 protein was significantly higher in patients with various hematological malignancies. The serum level of NM23-H1 protein was clinically useful as a prognostic factor in malignant lymphoma and acute myelogeneous leukemia (AML). The level of NM23-H1 protein in all of the normal serum samples examined was lower than 10 ng/mL, while those in the tumors varied from about 0 to 1000 ng/mL. Exogenously added NM23-H1 protein did not affect the growth or survival of various leukemia and lymphoma cell lines. However, NM23-H1 protein inhibited the survival of adherent normal peripheral blood mononuclear cells (PBMNC) at 100-1000 ng/mL, and slightly stimulated the survival of nonadherent PBMNC. These results suggest that the effect of NM23-H1 protein on normal PBMNC may be associated with a poor prognosis in hematological malignancies.

Circulating soluble factor-inhibiting natural killer (NK) activity of fresh peripheral blood mononuclear cells (PBMC) from inflammatory bowel disease (IBD) patients.

This study was performed in order to assess the cytotoxic activity, both natural (NK) and antibody-dependent (ADCC), of PBMC from 38 IBD patients and correlate it with their clinical features. Cytotoxicity assays were performed using sensitive target cells for NK and ADCC activities. In some experiments, highly purified NK cells, obtained both by Percoll density gradient and by co-culturing non-adherent PBMC with RPMI 8866 feeder cells, were used as effector cells. Furthermore, we evaluated NK cell parameters such as number, surface expression of adhesion molecules (CD11a/CD18, CD49d and CD54) and response to different stimuli. We observed a decreased NK cytotoxicity of PBMC from IBD patients, both in ulcerative colitis (UC) and Crohn's disease (CD), independently of the clinical activity of disease. In contrast, the ADCC lytic activity was within normal range. The lower NK cytotoxic activity observed in our IBD patients cannot be related to a decreased number of NK cells, surface expression of adhesion molecules, defective response to IL-2 and maturative defect. Decreased NK activity was induced in PBMC of controls when serum of patients was added and this was unrelated to monocyte-derived modulating factor(s). Our data show a decreased natural killing by fresh PBMC from IBD patients. This lower activity seems to be unrelated to a primary NK cell defect, since purified NK cells exhibited normal levels of killing. It might be hypothesized that serum factors, possibly derived from lymphocytes, with inhibitory properties on NK activity, might be functionally active in the blood of IBD patients, thus modulating NK activity.

Detection of Chlamydia pneumoniae DNA in CD3+ lymphocytes from healthy blood donors and patients with coronary artery disease.

Chlamydia pneumoniae is an intracellular bacterium responsible for respiratory tract infections. Recent studies have implicated this organism in the pathogenesis of atherosclerosis. To address how the organism is transported from lungs to cardiac vessels, we characterized the cell population within peripheral blood mononuclear cells (PBMCs) that harbor C pneumoniae DNA. Adherent and nonadherent PBMCs from 28 patients with coronary artery disease (CAD) and 19 healthy blood donors were evaluated for the presence of C pneumoniae DNA by touchdown nested polymerase chain reaction (nPCR). Of the 28 patients, 10 (36%) had detectable PCR product in their nonadherent and 3 (10%) in their adherent PBMC population. C pneumoniae-specific PCR results were positive for 5 of 19 (26%) healthy blood donors. PCR positivity was detected only in the nonadherent cell population among this group of individuals. Fractionation of nonadherent PBMCs identified C pneumoniae-specific PCR signal among the CD3+ T-cell population exclusively. Of the 18 PCR-positive subjects (13 patients and 5 healthy control subjects), 67% (8 patients and 4 healthy blood donors) tested positive for C pneumoniae-specific IgG serology. Interestingly, 2 patients became PCR negative on a repeated blood draw 5 months after initial detection of C pneumoniae DNA despite retaining C pneumoniae-specific antibodies. Our results demonstrate marginally significant prevalence of C pneumoniae DNA in patients with CAD compared with healthy subjects (P=0.082). In contrast, the prevalence of IgG seropositivity among the 2 groups did not reach statistical significance (P=0.306). We also provide unequivocal evidence for the presence of C pneumoniae DNA predominantly among the circulating CD3+ T-cell population.

Secretion of CXC chemokine IP-10 by peripheral blood mononuclear cells from healthy donors and breast cancer patients stimulated with HER-2 peptides.

CXC chemokines play an important role in recruitment of T cells to the site of activation and regulation of angiogenesis. CXC chemokines are secreted by T cells stimulated with cytokines or by established cytotoxic T lymphocyte (CTL) lines at recognition of conventional antigen (Ag), but the activation requirements and the relationship of interferon-gamma (IFN-gamma) inducible protein (IP-10) secretion with IFN-gamma induction in lymphocytes are still unclear. We studied the induction of IP-10 from nonadherent peripheral blood mononuclear cells (PBMC) by IFN-gamma, interleukin-12 (IL-12), and the HER-2 peptide E75, which forms a CTL-defined antigen. We found that IFN-gamma alone was a weak inducer of IP-10 in these cells, whereas IL-12 was a significantly stronger inducer of IP-10. In the presence of IL-12, the tumor peptide E75 (HER-2, 369-377) was a stronger inducer of IP-10 than was IL-12 alone. E75 and its variants mutated at position 5 could also induce IP-10 in the absence of exogenous IL-12 or IFN-gamma. IP-10 induction by E75 required HLA-A2 presentation and B7-CD28 interactions and was partially inhibited by blocking of CD40-CD40L interactions. These results indicate that presentation of tumor peptides to peripheral T cells can induce a fast chemokine response, which in its early phase may be higher than the IFN-gamma response. This shows that the IP-10 response was independent of any early-phase IFN-gamma response in peripheral T cells. This may be important for understanding the regulation of the balance between chemoattractant chemokines (CC) and CXC chemokines by tumor Ag and may have implications for understanding the mechanisms of polarization of T cells and conditioning of antigen-presenting cells (APC) by tumor antigens.

Immunomodulatory dendritic cells generated from nonfractionated bulk peripheral blood mononuclear cell cultures induce growth of cytotoxic T cells against renal cell carcinoma.

Dendritic cells (DCs) loaded with tumor antigens have the potential to become a powerful tool for clinical cancer treatment. Recently, the authors showed that a tumor-specific immune response can be elicited in culture via stimulation with autologous renal tumor lysate (Tuly)-loaded DCs that were generated from cytokine-cultured adherent peripheral blood mononuclear cells (PBMCs). Here, the authors show that immunomodulatory DCs can be generated directly from nonfractionated bulk PBMC cultures. Kinetic studies of DC differentiation and maturation in PBMC cultures were performed by monitoring the acquisition of DC-associated molecules using fluorescence-activated cell sorting analysis to determine the percentage of positive immunostained cells and the mean relative linear fluorescence intensity (MRLFI). Compared with conventional adherent CD14+ cultures, which have mostly natural killer, T, and B cells removed before cytokine culture, bulk PBMC cultures exhibited an early loss of CD14+ cells (day 0 = 78.8%, day 2 = 29.6% versus day 0 = 74%, day 2 = 75%) with an increase in yield of mature DCs (DC19- CD83+) (day 5 = 17%, day 6 = 21%, day 7 = 22% versus day 5 = 11%, day 6 = 15%, day 7 = 23%). Although a comparable percentage of DCs expressing CD86+ (B7-2), CD40+, and HLA-DR+ were detected in both cultures, higher expression levels were detected in DCs derived from bulk culture (CD86 = MRLFI 3665.1 versus 2662.1 on day 6; CD40 = MRLFI 1786 versus 681.2 on day 6; HLA-DR = MRLFI 6018.2 versus 3444.9 on day 2). Cytokines involved in DC maturation were determined by polymerase chain reaction demonstrating interleukin-6 (IL-6), IL-12, interferon-gamma, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-alpha mRNA expression by bulk culture cells during the entire 9-day culture period. This same cytokine mRNA profile was not found in the conventional adherent DC culture. Autologous renal Tuly (30 micrograms protein/10(7) PBMCs) enhanced human leukocyte antigen expression by DCs (class I = 7367.6 versus 4085.4 MRFLI; class II = 8277.2 versus 6175.7 MRFLI) and upregulated cytokine mRNAs levels. Concurrently, CD3+ CD56-, CD3+ CD25+, and CD3+ TCR+ cell populations increased and cytotoxicity against autologous renal cell carcinoma tumor target was induced. Specific cytotoxicity was augmented when cultures were boosted continuously with IL-2 (20 U/mL biological response modifier program) plus Tuly stimulation. These results suggest that nonadherent PBMCs may participate in enhancing DC maturation. Besides the simplicity of this culture technique, bulk DC cultures potentially may be used with the same efficiency as conventional purified DCs. Furthermore, bulk culture-derived DCs may be used directly in vivo as a tumor vaccine, or for further ex vivo expansion of co-cultured cytotoxic T cells to be used for adoptive immunotherapy.

Constitutive Activation of STATs Upon In Vivo Human Immunodeficiency Virus Infection

AbstractInfection by the human immunodeficiency virus (HIV) either upregulates or downregulates the expression of several cytokines and interferons (IFNs) that use the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway for signal transduction. However, very little is known on the state of activation of the JAK/STAT pathway after HIV infection either in vivo or in vitro. In this regard, we report here that a constitutive activation of a C-terminal truncated STAT5 (STAT5▵) and of STAT1α occurs in the majority (∼75%) of individuals with progressive HIV disease. We have further demonstrated that, among peripheral blood mononuclear cells (PBMCs), STAT5▵ is activated preferentially in CD4+ T cells. In contrast to a published report, expression of STATs from PBMCs of infected individuals was comparable with that of seronegative donors. In addition, in vitro infection of mitogen-activated PBMCs with a panel of laboratory-adapted and primary HIV strains characterized by differential usage of chemokine coreceptors did not affect STAT protein levels. However, enhanced activation of STAT was observed after in vitro infection of resting PBMCs and nonadherent PBMCs by different viral strains. Thus, constitutive STAT activation in CD4+T lymphocytes represents a novel finding of interest also as a potential new marker of immunological reconstitution of HIV-infected individuals.

Constitutive Activation of STATs Upon In Vivo Human Immunodeficiency Virus Infection

Infection by the human immunodeficiency virus (HIV) either upregulates or downregulates the expression of several cytokines and interferons (IFNs) that use the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway for signal transduction. However, very little is known on the state of activation of the JAK/STAT pathway after HIV infection either in vivo or in vitro. In this regard, we report here that a constitutive activation of a C-terminal truncated STAT5 (STAT5▵) and of STAT1 occurs in the majority (∼75%) of individuals with progressive HIV disease. We have further demonstrated that, among peripheral blood mononuclear cells (PBMCs), STAT5▵ is activated preferentially in CD4+ T cells. In contrast to a published report, expression of STATs from PBMCs of infected individuals was comparable with that of seronegative donors. In addition, in vitro infection of mitogen-activated PBMCs with a panel of laboratory-adapted and primary HIV strains characterized by differential usage of chemokine coreceptors did not affect STAT protein levels. However, enhanced activation of STAT was observed after in vitro infection of resting PBMCs and nonadherent PBMCs by different viral strains. Thus, constitutive STAT activation in CD4+T lymphocytes represents a novel finding of interest also as a potential new marker of immunological reconstitution of HIV-infected individuals.

Regulation of bovine leukemia virus tax and pol mRNA levels by interleukin-2 and -10.

Recently, particular cytokines have been identified to affect progression of a variety of diseases and retrovirus infections. Previously, we demonstrated that interleukin-2 (IL-2), IL-12, and gamma interferon increased in peripheral blood mononuclear cells (PBMCs) from animals with early disease and decreased in PBMCs from animals with late disease stages of bovine leukemia virus (BLV) infection. In contrast, IL-10 increased with disease progression. To examine the effects of these cytokines on BLV expression, BLV tax and pol mRNA and p24 protein were quantified by competitive PCR and immunoblotting, respectively. IL-10 inhibited BLV tax and pol mRNA levels in BLV-infected PBMCs; however, the inhibitory effect of IL-10 was prevented in PBMCs depleted of monocytes and/or macrophages (monocyte/macrophages). To determine whether these factors were secreted or monocyte/macrophage associated, monocyte/macrophage-depleted PBMCs were cultured with isolated monocyte/macrophages in transwells where contact between monocyte/macrophages and nonadherent PBMCs was blocked. BLV tax and pol mRNA levels increased in transwell cultures similar to cultures containing nonseparated cells, and IL-10 addition inhibited the increase of BLV tax and pol mRNA. These results suggest that monocyte/macrophages secrete soluble factor(s) that increases BLV mRNA levels and that secretion of these soluble factor(s) could be inhibited by IL-10. In contrast, IL-2 increased BLV tax and pol mRNA and p24 protein production. Thus, IL-10 production by BLV-infected animals with late stage disease may serve to control BLV mRNA levels, while IL-2 may increase BLV mRNA in the early disease stage. To determine a correlation between cell proliferation and BLV expression, the effect of IL-2 and IL-10 on PBMC proliferation was tested. As anticipated, IL-2 stimulated while IL-10 suppressed antigen-specific PBMC proliferation. The present study, combined with our previous findings, suggests that increased IL-10 production in late disease stages suppresses BLV mRNA levels, while IL-2-activated immune responses stimulate BLV expression by BLV-infected B cells.

Influence of Monoclonal Antiplatelet Glycoprotein Antibodies on In Vitro Human Megakaryocyte Colony Formation and Proplatelet Formation

The influence of antiplatelet glycoprotein (GP) antibodies on megakaryocytopoiesis in patients with idiopathic or immune thrombocytopenic purpura (ITP) has been well studied. However, the influence of GP antibodies on proplatelet formation is poorly understood. Here we investigated whether in vitro human megakaryocyte colony formation and proplatelet formation are affected by various monoclonal antiplatelet GP antibodies (MoAb). The megakaryocyte colony formation inhibition assay was performed by methylcellulose culture with modifications, using peripheral blood nonadherent mononuclear cells. The proplatelet formation inhibition assay was performed by megakaryocytes derived from CD34(+) cells, stimulated with thrombopoietin + stem cell factor, which were then incubated with antiplatelet GP MoAb for 24 or 48 hours. Anti-GP-Ibalpha MoAb (CD42b; HIP1) slightly inhibited megakaryocyte colony formation (P < .05). and strongly inhibited proplatelet formation (after 24 hours incubation, P < .0002; after 48 hours incubation, P < .0007). Anti-GP-IIb MoAb (CD41; 5B12) inhibited only proplatelet formation (only after 24 hours incubation, P <. 03). Anti-integrin alphavbeta3 MoAb (CD51/CD61; 23C6) only slightly inhibited colony size (P < .05). However, anti-GP-IIIa MoAb (CD61; Y2/51) did not inhibit either colony formation or proplatelet formation. These results suggest that antiplatelet GP MoAbs have differing effects on in vitro megakaryocyte colony formation and proplatelet formation.

Both C3a and C3a(desArg) regulate interleukin-6 synthesis in human peripheral blood mononuclear cells.

Synthesis of complement components is part of the acute-phase response. Interleukin-6 (IL-6) is a critical mediator of the acute-phase response during infections and injuries. Plasma levels of C3a and IL-6 have been proposed as prognostic indicators in sepsis and trauma. The effects of C3a and C3a(des)Arg on IL-6 gene expression and protein production in human peripheral blood mononuclear cells (PBMC) were investigated. Neither C3a nor C3a(des)Arg alone induced detectable IL-6 protein or mRNA levels. However, C3a and C3a(des)Arg affected endotoxin-induced IL-6 synthesis in a dose-dependent manner. In nonadherent PBMC, C3a or C3a(des)Arg suppressed, while in adherent PBMC, C3a or C3a(des)Arg enhanced IL-6 protein and mRNA levels. These results suggest that C3a and C3a(des)Arg may provide a control mechanism of acute-phase responses by enhancing IL-6 synthesis in adherent monocytes at local inflammatory sites and by inhibiting IL-6 synthesis in circulating monocytes.

Enhancement of megakaryocytopoiesis by Campath-1G-treated natural killer cells.

Campath-1G is a CD52 (rat IgG2b) moAb used in bone marrow transplantation (BMT) to prevent graft-versus-host disease (GVHD) by the elimination of T cells via antibody-dependent cell cytotoxicity (ADCC) in vivo. We have previously reported that Campath-1G induces T cell proliferation, activation, and production of cytokines which in turn causes an enhancement of megakaryocytopoiesis in vitro. In view of the fact that recent studies have indicated that natural killer (NK) cells may also be involved in the regulation of megakaryocytopoiesis, we undertook the study of the in vitro effect of Campath-1G-treated NK cells on the regulation of megakaryocytopoiesis. Early burst-forming BFU-MK and late colony-forming CFU-MK were grown from 2 x 10(5) peripheral blood non-adherent mononuclear cells (NAMC) in plasma clots in the presence of aplastic canine plasma (PICS-J) which was used as megakaryocyte colony-stimulating factor (MK-CSF). The first step in elucidating this series of events was to investigate the direct influence of NK cells on megakaryocytopoiesis. Co-culturing NK cells (>85% CD16+) with autologous NAMC at a ratio of 1:1 resulted in a significant increase in the proliferation of CFU-MK and BFU-MK over NAMC cultured alone. This effect was further enhanced upon exposure of NK to Campath-1G (0.1-3 microg/ml). To investigate the possible influence of soluble factors released from NK cells treated with Campath-1G on MK maturation, conditioned medium (CM) derived from Campath-1G-treated-enriched populations of NK cells was found to enhance MK progenitor growth. Our data demonstrate that resting and Campath-1G-treated NK may be involved in the immunomodulation of megakaryocytopoiesis.

Role of adhesion molecules in natural killer cell-induced DNA fragmentation of cytomegalovirus-infected fibroblasts.

We investigated the roles of CD11a, CD11b, CD18, and CD54 adhesion molecules in non-adherent peripheral blood mononuclear cells (NPBMC)-induced DNA fragmentation of cytomegalovirus (CMV)-infected cells. DNA fragmentation in the supernatant from CMV-infected cells and NPBMC was assayed, and cytotoxicity against CMV-infected cells was calculated. Treatment of NPBMC with monoclonal antibodies to CD11a, CD11b, CD18, and CD54 significantly reduced cytotoxicity against CMV-infected cells. A combination of anti-CD11a, anti-CD11b, and anti-CD18 antibodies further inhibited cytotoxicity against CMV-infected cells. Cytotoxicity against CMV-infected cells treated with anti-CD54 antibody was also significantly inhibited. Binding of effector cells to target cells was not affected by treatment of NPBMC or CMV-infected cells with antiadhesion molecule antibodies. These results indicate that LFA-1 (CD11a/CD18), Mac-1 (CD11b/CD18), and ICAM-1 (CD54) adhesion molecules are involved in natural killer (NK) cell-induced DNA fragmentation in CMV-infected cells.

Non-radioactive assay of natural killer cell-mediated cytotoxicity against cytomegalovirus-infected fibroblasts by DNA fragmentation ELISA

Cell-mediated cytotoxicity against cytomegalovirus (CMV)-infected fibroblasts (FS-4 cells) was investigated by a non-radioactive assay, and by DNA fragmentation ELISA and LDH release assay and the assays were compared to the standard chromium release assay. Fragmentation of DNA and LDH activity were detected in the supernatant of CMV-infected FS-4 cells cultured with non-adherent peripheral blood mononuclear cells (PBMC). The DNA fragmentation ELISA was most sensitive to cytotoxicity against CMV-infected FS-4 cells and showed excellent correlation with the standard chromium release assay. DNA fragmentation of CMV-infected FS-4 cells by non-adherent PBMC was reduced markedly by treatment with anti-leu 11b plus complement. Thus, the present DNA fragmentation ELISA is non-radioactive, highly sensitive and a useful method for detecting natural killer cell-mediated cytotoxicity against CMV-infected fibroblasts.

Tumor necrosis factor-α responses are depressed and interleukin-6 responses unaltered in feline immunodeficiency virus infected cats

Feline immunodeficiency virus (FIV), a lentivirus similar to HIV, causes an acquired immunodeficiency syndrome in cats. Similar to human immunodeficiency virus (HIV), the pathogenesis of FIV is associated with dysregulation of the cytokine network. While alterations in tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) expression have been reported in HIV-infected patients, changes attributable to HIV and those caused by cofactors such as secondary infections cannot always be readily distinguished. This study evaluated the effect of FIV infection on TNF-α and IL-6 production in cats not exposed to other potential cofactors such as secondary infections. TNF-α and IL-6 activities were evaluated in bronchoalveolar lavage (BAL) cells from FIV-infected and uninfected specific pathogen free (SPF) cats. Supernatants from lipopolysaccharide (LPS)-stimulated BAL cells from uninfected SPF cats had high levels of TNF-α and IL-6 activity, while stimulated BAL cell supernatants from FIV-infected SPF cats had significantly lower levels of TNF-α but unaltered IL-6 activity. Similarly, Con A/phorbol myristate acetate (PMA) stimulated non-adherent (NA-) peripheral blood mononuclear cells (PBMC) from FIV infected cats synthesized less TNF-α than similarly treated NA-PBMC from uninfected cats. Feline immunodeficiency virus could be recovered from the culture supernatants of BAL cells from infected cats by co-cultivation with susceptible lymphocytes. In situ hybridization identified FIV mRNA in a small fraction of alveolar macrophages in the BAL cell cultures. Considering that these SPF cats have been infected with FIV for up to 3 years, yet remain asymptomatic and have no evidence of secondary infections, the present data suggest that the deficiency in TNF-α production by BAL cells and NA-PBMC is an intrinsic characteristic of the FIV infection.

Distinct granzyme expression in human CD3- CD56+ large granular- and CD3- CD56+ small high density-lymphocytes displaying non-MHC-restricted cytolytic activity.

Cultured natural killer (NK) cells derived from CD3- CD56+ high-density small lymphocytes (HDLs) exhibit similar morphology and high levels of non-major histocompatibility complex-restricted (NK) cytotoxicity equivalent to those of cultured NK cells from CD3- CD56+ low-density large granular lymphocytes (LGLs). To examine the similarities and differences between NK cells from HDLs and NK cells from LGLs, we investigated the expression of three distinct members of the granule serine protease (granzyme) family within cultured CD3- CD56+ LGLs and HDLs. CD3- subpopulations of nonadherent peripheral blood mononuclear cells, LGLs (density < 1.063 g/ml), and HDLs (density > 1.063 g/ml) were stimulated to proliferate in culture. The cultured cells from each population were entirely CD3- CD56+ and were indistinguishable in terms of their increased granularity and size once activated. All cultured CD3- CD56+ LGLs and HDLs displayed cytolytic activity against K562 and immunoglobulin-coated P815. Western analysis detected perforin in both cultured LGL and HDL populations. Cultured HDLs and LGLs both expressed BLT-esterase activity and human granzyme A mRNA. Granzyme B mRNA and protein and Asp-ase activity were detected in unstimulated and cultured LGLs and cultured HDLs. By contrast, unstimulated HDLs did not express significant levels of granzyme B. High levels of Hu-Met-1 granzyme mRNA and Met-ase activity were detected only in cultured LGLs. Thus, despite the development of large granular morphology during proliferation, interleukin-2 cultured CD3- CD56+ HDLs display a different pattern of granzyme expression from CD3- CD56+ LGLs. These data also further suggest an unusually restricted expression of the Hu-Met-1 granzyme in LGLs.

Alveolar macrophage-induced suppression of peripheral blood mononuclear cell responsiveness is reversed by in vitro allergen exposure in bronchial asthma

Little information is available on the specific role of alveolar macrophages (AMs) in modulating local cellular reactions to inhaled allergens in atopic asthma. We investigated the influence of alveolar macrophages obtained by bronchoalveolar lavage (BAL) on the proliferative responses of lavage and peripheral lymphocytes from 12 patients with atopic asthma, 6 nonasthmatic symptomatic atopic subjects, and 6 nonatopic normal volunteers, in the context of in vitro exposure to relevant and nonrelevant allergens. Fresh nonadherent bronchoalveolar lavage cells from atopic asthmatic patients, depleted of alveolar macrophages, proliferated spontaneously more than nonadherent bronchoalveolar lavage cells from normal subjects. Addition of autologous asthmatic alveolar macrophages reduced this endogenous "activation". Asthmatic and normal alveolar macrophages also inhibited phytohaemagglutinin-stimulated proliferation of both autologous and allogeneic nonadherent peripheral blood mononuclear cells (PBMC). In contrast, autologous asthmatic alveolar macrophages induced strong proliferation of peripheral blood mononuclear cells when stimulated with allergen to which the patient was skin test and radio allergosorbent test (RAST) reactive; however, no response was seen with allergens to which the patient was insensitive. No such allergen-specific proliferation was seen with alveolar macrophages from nonasthmatic atopic subjects. These data support the presence of functionally-active alveolar macrophages within the airways of atopic asthmatic patients, that under normal stable conditions suppress the induction of peripheral blood mononuclear cell responses, and which only on contact with specific allergen appear to switch to inducer alveolar macrophages, with consequent peripheral blood mononuclear cell hyperactivation.

NATURAL-KILLER-CELL AND ANTIBODY-DEPENDENT CELLULAR CYTOTOXICITY IN GASTRIC-CARCINOMA PATIENTS - MODULATORY EFFECTS OF IL-2 AND 5-FLUOROURACIL

Non-adherent peripheral blood mononuclear cells (PBMC) from 15 patients with carcinoma of the stomach and 6 normal healthy controls were assessed for natural killer cell mediated cytotoxicity (NKCMC) and antibody dependent cellular cytotoxicity (ADCC) in a 4 hour (51)Chromium release assay against target cells, K-562 and sensitized chicken red blood cells (CRBC), respectively. NKCMC and ADCC were significantly reduced in patients with respect to normal controls. However, significant enhancement in NKCMC and ADCC was observed when PBMC from patients were cultured in RPMI-1640 containing 200 IU/ml of Interleukin-2 (IL-2) for 4 days in 5% CO2 atmosphere at 37 degrees C. Augmentation of NKCMC and ADCC was also detected when a follow-up study of the patients was conducted after one month following initial trial of chemotherapy with 5-fluorouracil (5-Fu). Patients, who had undergone clinical trial with 5-Fu were better responders of IL-2 activation as reflected on NK cell and ADCC potential of these patients. Our investigations highlight the synergistic effect of 5-Fu and IL-2 on effecters of natural immunity in patients with carcinoma of the stomach, Judicious modulation of effecters may be beneficial in killing residual cancer cells in vivo.

Synthesis of tumour necrosis factor‐alpha and interferons by mononuclear cells from Theileria annulata‐infected cattle

Bovine macrophage-derived tumour necrosis factor-alpha/cachectin (TNF-alpha) was synthesized when peripheral blood mononuclear cells (PBMC) and purified adherent PBMC from naive and Theileria annulata-infected cattle were incubated in vitro with concanavalin A (Con-A) or bovine recombinant interferon gamma (Bo rIFN-gamma). TNF-alpha production was also induced when adherent PBMC were cultured with T. annulata macroschizont-infected cells. In contrast, non-adherent PBMC from sublethally infected cattle produced interferon (IFN) when incubated with Hu rIL-2, Con-A, phytohaemagglutinin (PHA) or T. annulata macroschizont-infected cells growing as cell lines in vitro. Whilst PBMC from lethally infected cattle spontaneously produced IFN-gamma during advanced stages of infection, the sera of such animals contained type 1 IFN (alpha/beta). IFN was also produced by T. annulata macroschizont-infected cell lines maintained in vitro. This work suggests that cytokines serve as crucial links between proliferating Theileira-infected cells and the characteristic clinical symptoms of tropical theileriosis.

Se´zary syndrome with elevated serum IgE and hypereosinophilia: Role of dysregulated cytokine production

A 62-year-old man presented with a 4-year history of a pruritic erythematous rash. Initial workup was not diagnostic, and the rash was refractory to standard treatment. A complete blood cell count demonstrated a white cell count of 9100 cells/μl with 61% polymorphonuclear neutrophils, 16% eosinophils, and 17% lymphocytes. A serum protein electrophoresis revealed an M spike identified as IgGk. His IgE level was 11,900 IU/ml. A bone marrow biopsy specimen demonstrated “atypical plasma cells” but was not diagnostic for myeloma. Peripheral blood smear was remarkable for highly convoluted lymphoid cells diagnostic for Se´zary T cells. Consistent with this diagnosis, 89% of his peripheral blood CD2 + cells expressed CD4. The eosinophilia, elevated IgE level, and monoclonal gammopathy led to further investigations. Circulating adherent monocytes were 96% positive for presumed low-affinity IgE receptor expression as shown by surface IgE binding. In a 9-day lymphocyte coculture, the patient's T lymphocytes induced IgE production in vitro (1.25 ng/ml) by a normal donor's cultured B cells. A healthy donor's T cells failed to induce IgE production (0 ng/ml) in a similar culture system. In situ hybridization with an Sulfur-35-labeled cDNA probe revealed interleukin-4 mRNA expression by 84% and interleukin-2 mRNA expression by 62% of nonadherent peripheral blood mononuclear cells. Interleukin-5 mRNA was shown by reverse transcription and the polymerase chain reaction. These studies demonstrate a subject with Se´zary T cell leukemia with hypereosinophilia and elevated IgE due to presumed enhanced interleukin-4 and interleukin-5 production by the Se´zary T cells.