Biomedical subjects

L Rönnblom

Publications and source records attributed to L Rönnblom.

32 records · Page 2Linked to original sources

PubMed1992

Treatment with alpha-interferon versus alpha-interferon in combination with streptozocin and doxorubicin in patients with malignant carcinoid tumors: a randomized trial.

An open randomized trial was performed to compare the effect of recombinant interferon-alpha 2a (rIFN-alpha 2a) (group A, n = 12) versus rIFN-alpha 2a in combination with chemotherapy (group B, n = 11) in patients with malignant carcinoid tumors. Both groups received rIFN-alpha 2a at a dose of 3 MU/m2 s.c. three times weekly during the first 6 months. IFN was discontinued every third week in group B, followed by an i.v. injection of 2 g streptozocin and 40 mg/m2 doxorubicin. After 6 months group A showed one complete biochemical response (CR), 9 patients with stable disease (SD) and 2 who progressed (PD). Two patients had a partial reduction (PR) of tumor size, 9 showed SD and one PD. All patients in group B demonstrated SD. Chemotherapy was withdrawn after 6 months and all patients continued with rIFN-alpha 2a at an increased dose of 3 MU/m2 five days/week for a further 6 months. After 12 months 6 patients showed PR, 12 SD and one PD biochemically. Tumor size showed SD in 18 patients and PD in one. One patient died from cardiomyopathy, probably induced by doxorubicin. Antibodies against rIFN-alpha 2a developed in 41% of the patients. In conclusion, we detected no difference in response rates between the two treatment groups. Adverse reactions from the combination were considerable. The frequent development of IFN antibodies might have interfered with the therapeutic results.

Aged↗

PubMed1988

Determination of herpes simplex virus-induced alpha interferon-secreting human blood leucocytes by a filter immuno-plaque assay.

A filter immuno-plaque assay was developed which detects alpha interferon (INF-alpha)-secreting human peripheral blood leucocytes (PBL). Polyclonal anti-IFN-alpha antibodies were fixed to the nitrocellulose membrane bottoms of 96-well Millititer plates, which also contained monolayers of glutaraldehyde-fixed human WISH amnion cells infected by Herpes simplex virus type 1 (HSV). Such cells are potent IFN inducers and during a 16 h cocultivation with PBL, IFN-alpha was absorbed by the membrane-bound polyclonal antibodies around IFN-alpha-secreting cells. This IFN-alpha was detected with murine monoclonal antibodies against IFN-alpha and peroxidase-labelled antibodies against murine immunoglobulin, using diaminobenzidine as substrate. Distinctly stained plaques were seen, the frequency of which gave a minimal estimate of approximately 10 IFN-alpha-producing cells in 10(4) PBL (range in 12 blood donors 2.95-25.1). Fewer plaques than expected were seen at low PBL numbers per culture, one explanation being that cell interactions then limit the IFN-alpha response. The immuno-plaque assay should be useful in further studies of the cellular basis of the IFN-alpha response.

Enzyme-Linked Immunosorbent Assay↗

PubMed1988

Phenotypes of peripheral blood leukocytes in Melkersson-Rosenthal syndrome.

Peripheral blood leukocytes from 5 patients with Melkersson-Rosenthal syndrome (MRS) were characterized with an immunoenzymatic staining technique utilizing ten different mouse monoclonal antibodies to cell surface antigens. No gross abnormalities could be found in the various T and B cell subpopulations. However, the proportion of cells expressing the IL-2 receptor was slightly increased, indicating the occurrence of activated lymphocytes in the circulation. Furthermore, in all 5 patients a large proportion of a non-phagocytic, Leu-M1-expressing, granulocyte-like cells of low density was found, probably reflecting the presence of activated granulocytes in the blood in MRS patients. The findings suggest that activation of both the lymphocyte and the granulocyte systems may be of importance in the pathogenesis of MRS.

Antibodies, Monoclonal↗

PubMed1986

Intralesional T lymphocyte phenotypes and HLA-DR expression in Melkersson-Rosenthal syndrome.

An immunohistochemical double-staining technique was used to characterize the infiltrating mononuclear lymphocytes in frozen sections from 3 patients with Melkersson-Rosenthal syndrome. The in situ expression of HLA-DR antigens on different cell types was also investigated. The majority of mononuclear cells could be classified as T-lymphocytes because of their Leu 4 antigen expression. Most of the T-lymphocytes were confined to the helper/inducer lymphocyte subset since they reacted with Leu 3a antibodies. However, big infiltrates of suppressor/cytotoxic lymphocytes with the Leu 2a phenotype were noted in some specimens. These cells were situated between the ducts of the salivary glands. Virtually all mononuclear infiltrating cells carried HLA-DR antigens. HLA-DR expressing keratinocytes were found in the biopsy from one patient. The present study indicates that a local immune response may be important in the pathogenesis of the oro-facial lesions in Melkersson-Rosenthal syndrome.

Antibodies, Monoclonal↗

PubMed1985

Human peripheral blood null lymphocytes stimulated by Staphylococcus aureus Cowan I produce atypical acid-labile interferon in vitro.

Peripheral blood mononuclear leucocytes (PBLs) stimulated in vitro by heat-killed formaldehyde-fixed Staphylococcus aureus Cowan I (SACoI) produced acid-labile alpha interferon (IFN-alpha) and, to various extents, also IFN-gamma. The IFN producers resided in nylon wool-nonadherent cells, and monocytes suppressed SACoI-induced IFN responses. Further separation of nonadherent PBLs in accordance with expression of surface antigenic markers was performed with a 'panning' technique. The SACoI induced production of IFN in cells that carried neither surface immunoglobulins nor OKT3-defined antigens. These cells were also characterized as OKM1- and OKT10-negative. In contrast, cells with natural killer (NK) activity against K562 erythroleukaemia cells were located in both OKM1- and OKT10-positive and -negative cells. At centrifugation on Percoll density gradients, cells with NK activity and IFN response against SACoI were recovered from light gradient fractions that contained mainly large granular lymphocytes (LGL). Furthermore, the IFN producers were enriched by removal of sheep erythrocyte-rosetting T cells from the Percoll fractions. These SACoI-induced IFN-producing PBLs are LGL but lack certain antigens that are frequently found on NK cells.

Antibodies, Monoclonal↗

PubMed1984

Antiviral activity appearing in serum of renal transplant recipients. Its possible relation to immunological rejection.

Sera collected from a majority (15/16) of recipients of renal transplants occasionally contained low, but significant, levels of antiviral activity, maximally corresponding to 25-50 units of interferon-alpha per milliliter of serum in a bioassay. The exception was the only transplanted patient with a known cytomegalovirus infection, who demonstrated persistent high levels of antiviral activity corresponding to 200-400 interferon units/ml. Only the latter antiviral activity was sufficiently high for a partial characterization. It was pH 2 labile, did not have antigenic properties of interferon-alpha or beta, and may correspond to the lymphokine interferon-gamma. In consecutive serum samples from individual patients, the peaks of the antiviral activity occurred preponderantly in connection with clinical signs and consequent treatment of graft rejections. Interferon may, therefore, be a useful marker (at the serum level) of incipient graft rejection, and of certain viral infections, at least, provided that a more rapid sensitive and precise assay of this lymphokine is developed.

Antibodies, Viral↗

PubMed1983

Properties of human natural interferon-producing cells stimulated by tumor cell lines.

Human peripheral blood mononuclear leukocytes cocultured with WISH human amnion cells or K562 tumor cells rapidly produce interferon-alpha (IFN). In the present report we characterize the IFN-producing cells (IPC) in this system by cell separation procedures, including panning with different monoclonal antibodies. Two types of cells which were responsible for the IFN production could be identified. The first IPC was classified as monocyte/macrophage because it was present in plastic-adherent cells and apparently carried the OKM1 antigenic marker. T and B lymphocytes were not involved in the IFN production. The second type of IPC was nylon wool-nonadherent, sheep erythrocyte rosette-negative, at least partly Fc receptor-negative and resided in light Percoll density gradient fractions. The natural killer activity and IFN-producing capacity was studied in such cells fractionated by the panning technique, utilizing HNK-1, OKT10 and OKM1 antibodies. When WISH and K562 were used as IFN inducers, HNK-1+ and OKT10+ cells with lytic activity against K562 produced little or no IFN. The IPC were instead confined to HNK-1- and OKT10- cells. With cells fractionated with respect to the OKM1 antigen, natural killer activity against K562 and WISH cells and IFN production stimulated by K562 cells resided in the OKM1+ cells. In marked contrast, cells producing IFN in response to WISH cells were OKM1-. The results therefore demonstrate a dissociation between natural killer cells against tumor cells and IPC stimulated by the same targets, suggesting that for at least certain targets/inducers they may represent distinct entities.

Antibodies, Monoclonal↗

PubMed1983

Plasmodium falciparum parasites induce interferon production in human peripheral blood 'null' cells in vitro.

Human peripheral blood mononuclear cells were found to produce interferon (IFN) when stimulated by free P. falciparum parasites in vitro. On the other hand parasite-infected, intact erythrocytes were unable to induce IFN synthesis. When the IFN was characterized according to sensitivity to anti-IFN-alpha antibodies and pH 2 treatment it was found to consist of IFN-alpha. Cell fractionation procedures and analysis of each cell fraction with regard to natural killer (NK) cell activity and IFN-producing capacity revealed that both activities were confined to the same cell fraction. The possible relevance of the IFN-NK cell system in malaria is discussed.

Cell Separation↗

PubMed1983

Characterization of interferons induced by bacteria and interferon-producing leukocytes in human peripheral blood.

All of 23 different preparations of formaldehyde-fixed and heat-killed bacteria induced the appearance of high levels of interferon (IFN) in cultures of human peripheral blood mononuclear leukocytes. Some bacteria induced peak IFN titers after 24 h of culture, whereas other bacteria showed maximal titers on culture days 2 to 3. The IFN displayed various properties. One type, which appeared early during the cultures, had characteristics of IFN-alpha, being resistant to pH 2 treatment but neutralized by antibodies to IFN-alpha. A second type, which appeared later, on culture days 2 to 3, resembled IFN-gamma in being sensitive to pH 2 treatment but resistant to anti-IFN-alpha antibodies. A third type, which appeared to be sensitive to both pH 2 and antibody treatment, was interpreted as atypical IFN-alpha. The application of cell fractionation procedures indicated that nonadherent, predominantly Fc receptor-bearing, non-T, non-B cells were producers of IFN-alpha as defined by its antigenic properties. They copurified approximately with cells carrying natural killer activity toward human erythroid leukemia K562 cells. Some bacteria apparently also stimulated T lymphocytes to produce material with properties of IFN-gamma.

Antibodies, Viral↗

PubMed1983

Evaluation of the natural killer cell-interferon system in patients with mid-gut carcinoid tumours treated with leucocyte interferon.

Nine patients with mid-gut carcinoid tumours received leucocyte interferon (IFN) i.m. daily for 90 days. Six patients clearly ameliorated in symptoms typical of the carcinoid syndrome (flushing, diarrhoea, asthma) which correlated with reduced serum levels of tumour related polypeptides and urinary output of 5-hydroxyindole acetic acid (5-HIAA). Before IFN treatment, peripheral blood mononuclear leucocytes (PBLs) from carcinoid patients showed markedly deficient production of pH 2 labile IFN-alpha in response to Staphylococcus aureus Cowan I (SACoI) in vitro. In contrast, IFN-alpha responses to the inducers Sendai virus and beta-haemolytic streptococcus group G and IFN-gamma responses to Lens culinaris lectin and concanavalin A were normal. Also, basal and in vitro IFN enhanced natural killer (NK) cell activity and T cell mitogen-induced cell proliferation were similar in patients and controls. During 90 days of IFN therapy, SACoI-induced IFN responses became entirely undetectable. There were transient declines at 1 and 30 days in IFN responses to the other IFN inducers, of mitogen-induced lymphocyte proliferation and of basal NK activities. The increments of NK cell activities after in vitro IFN exposure were clearly decreased in IFN treated patients, suggesting in vivo activation of these cells. Thus, the results demonstrate one remarkable abnormality in carcinoid patients: a deficient IFN response to SACoI and a clear influence of IFN therapy on several parameters of the IFN-NK system.

Aged↗

PubMed1982

Limiting dilution analysis of human peripheral blood mononuclear leukocytes that react to human amnion cells and protect these against viral challenge.

Human peripheral blood mononuclear leukocytes (PBL) cocultured with WISH human amnion cells rapidly produced alpha-type interferon (IFN-alpha) and in an IFN-dependent manner protected the WISH cells against the cytopathic effects caused by vesicular stomatitis virus. When the number of PBL per WISH cell monolayer culture was diluted out using multiple WISH microtiter plate cultures for each PBL dilution, the protection of the WISH cultures appeared as an all-or-none phenomenon. Thus, at one small mean number of PBL per culture, some cultures were protected against the virus, while others were not. Limiting dilution analysis, with plot of the logarithm of the fraction of nonprotected WISH cell cultures at each PBL dilution against the mean number of PBL per culture, yielded straight lines with an intercept on the ordinate close to 1. This indicated a single-hit event due to the function of a single type of limiting "protecting unit". The frequency of this limiting unit in the PBL population could reproducibly be determined for an individual blood donor. For a limited number of different blood donors it ranged from 1/400 to 1/3000. These minimal frequency estimates were considerably increased (40-300%) after 3 h preincubation of PBL with IFN-alpha. Two major alternatives were considered with regard to the nature of the limiting protecting units. They were either IFN-producing cells operating alone, or they were inducer-type cells that possibly used IFN as a mediator to activate protecting cells present in excess in the coculture system. The second possibility was favored, and the relation of the protecting cell type to the natural killer cell system is discussed herein.

Amnion↗

PubMed1982

Lectins as inducers of interferon-gamma production in human lymphocytes: lentil lectin is highly efficient.

Several of many tested plant lectins induced interferon (IFN) production in cultures of human peripheral blood mononuclear leucocytes (PBL). The mannose-binding lectin obtained from Lens culinaris (LCL) was a particularly efficient inducer of trypsin-sensitive antiviral activity, which qualified as IFN-gamma because it was 90-95% destroyed by pH 2 treatment but not neutralized by anti-IFN-gamma antibodies. However, such antibodies neutralized the residual 5-10% pH 2-resistant IFN, which therefore represented IFN-alpha. Further evidence for the IFN-gamma nature of the LCL-induced IFN was that its production in PBL cultures required both T lymphocytes and macrophages and that its induction of antiviral resistance in human amnion cells was significantly delayed compared with IFN-alpha. Under optimal conditions LCL induced titres of IFN-gamma corresponding to more than 20,000 IFN-alpha units/ml medium, higher than observed with other tested, established IFN-gamma inducers. Other desirable properties of this lectin, as discussed, also suggest that it will be of value for efficient large-scale IFN-gamma production.

Humans↗

PubMed1977

Natural cell-mediated immunity to lymphoma cells. I. Characteristics of effector cells in a cytostasis assay in vitro.

Spleen cells from normal, nonimmune, CBA or (CBA X AKR)F1 mice markedly and rapidly inhibited the incorporation of [3H]thymidine by two different T-cell lymphomas in an in vitro cytostasis assay. These were the I-529 lymphoma of spontaneous AKR origin and the Moloney murine leukemia virus-induced YAC lymphoma of A mouse origin. Spleen cells were the most efficient inhibitors for both types of target cells, whereas lymph node cells were much less active and thymus cells showed little or no activity. Granulocytes, as well as conventional T- and B-lymphocytes, were excluded as important contributors to the cytostatic cell population. Spleen cells were separated on nylon wool, Sephadex G-10 columns, or plastic petri dishes and tested for activity in the cytostasis assay or for cytotoxicity against 51Cr-labeled lymphoma target cells. Adherent cells carried almost all cytostatic activity against the AKR lymphoma but also showed significant cytotoxic activity against these target cells. In addition, the cytostatic activity against the YAC lymphoma was mainly due to adherent spleen cells, but nonadherent cells were relatively more active against this target than against I-529 cells. Such nonadherent spleen cells further showed increased cytotoxic activity, compared to the whole spleen cell population.

Animals↗

PubMedDate not supplied

Autoantibodies to alpha-fodrin in primary Sjögren's syndrome and SLE detected by an in vitro transcription and translation assay.

OBJECTIVE: To investigate the prevalence of alpha-fodrin autoantibodies in primary Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE) with and without secondary SS, using an in vitro transcription and translation assay (ITT). METHODS: cDNA encoding JS-1, the amino-terminal portion of alpha-fodrin, was used for ITT. Immunoprecipitation was performed with sera from 56 primary SS patients and 67 SLE patients, 14 with and 53 without secondary SS. Correlations to RF, ANA, anti-dsDNA, anti-SS-A and anti-SS-B antibodies, hypergammaglobulinemia, labial salivary gland biopsy grade, extraglandular manifestations and a modified SLE disease activity index (mSLEDAI) were made. RESULTS: Autoantibodies against alpha-fodrin were detected in 16/56 (29%) of primary SS patients and in 25/53 (47%) of sera from SLE patients without secondary SS. In SLE patients with secondary SS the prevalence was 3/14 (21%). None of the blood donors showed alpha-fodrin reactivity. Correlations were found to RF, ANA, anti-dsDNA antibodies and a positive mSLEDAI score. CONCLUSION: The frequency of alpha-fodrin autoantibodies detected by this method is similar in sera from primary SS patients and SLE patients with or without secondary SS. The presence of alpha-fodrin autoantibodies seems to reflect non-organ-specific autoimmunity in primary SS and SLE and to be of limited discriminating value.

Autoantibodies↗