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Biomedical subjects

H Kirchner

Publications and source records attributed to H Kirchner.

At least 325 records · Page 18Linked to original sources
PubMed1986

Local interferon induction by bacterial lipopolysaccharide in mice after pretreatment with Corynebacterium parvum.

C57BL/6 mice were injected intraperitoneally (i.p.) with Corynebacterium parvum and subsequently, after an interval of 7-10 days, i.p. with lipopolysaccharide (LPS). The peritoneal wash-fluid was recovered at various times after injection of LPS. Marked interferon (IFN) titers were observed between 2 and 10 h after injection of LPS, whereas no IFN was detected in mice injected with either C. parvum or LPS alone. Very low doses of LPS (0.1 microgram/mouse) were sufficient to cause IFN production in the double-stimulation protocol. The IFN produced was neutralized by an antibody against IFN-alpha/beta. In additional experiments, mice were treated by C. parvum alone; the peritoneal exudate cells (PEC) were recovered and stimulated in vitro by LPS. Again substantial titers of IFN were induced by small concentrations of LPS, whereas untreated PEC did not produce IFN. The cell producing IFN in these cultures was not a T lymphocyte, as experiments with a monoclonal anti-thy 1.2 antibody showed.

Animals↗
PubMed1986

Human cytomegalovirus replicates in primary human bone marrow cells.

As an attempt to elucidate further the pathogenesis of human cytomegalovirus (HCMV) infection the replication of HCMV in primary human bone marrow cells (BMC) has been investigated. It was found that BMC held in culture in general were susceptible to HCMV infection. Compared to human embryonic lung cells, however, the replicative cycle of HCMV AD169 in BMC as determined by the analysis of viral protein and DNA synthesis was delayed and productive virus infection was restricted to a subset of BMC not exceeding 21% of the total cell population. Both of these phenomena may explain the short-term persistence of HCMV in BMC cultures which was observed over 3 months. By experiments with specifically enriched and depleted cell populations and by indirect double immunofluorescence experiments we found that both bone marrow fibroblasts and a subset of bone marrow stem cells supported productive virus infection. The finding that HCMV replicates in early stem cells of the human bone marrow may explain important aspects of the pathogenesis of HCMV infection including the presence of HCMV in peripheral blood leukocytes.

Bone Marrow↗
PubMed1986

Enhancement by carprofen or indomethacin of interferon induction by 10-carboxymethyl-9-acridanone in murine cell cultures.

Non-steroidal anti-inflammatory drugs such as carprofen or indomethacin enhanced interferon (IFN) production induced by suboptimal concentrations of 10-carboxymethyl-9-acridanone (CMA) in murine cell cultures. This effect was observed in fibroblasts and in different populations of leukocytes as in peritoneal exudate and spleen cells, and was most pronounced in bone marrow-derived macrophages. Carprofen was the most effective compound causing an up to 500-fold increase of CMA-induced IFN production in pure bone marrow-derived macrophages. In these macrophage cultures the potentiating effect on CMA-induced IFN production by carprofen and indomethacin did not depend on inhibition of cyclooxygenase.

Acridines↗
PubMed1986

Production of interferon-beta by murine T-cell lines induced by 10-carboxymethyl-9-acridanone.

Besides the established T-cell property of producing gamma interferon (IFN-gamma), murine T cells additionally possess the ability to produce IFN-alpha and IFN-beta when appropriate inducers such as 10-carboxymethyl-9-acridanone (CMA) or Newcastle disease virus (NDV) are used. Interleukin 2 (IL-2)-dependent murine T-cell lines, but not purified resting splenic T cells, responded to CMA and NDV with production of IFN-alpha, beta. The IFN production by these T cells was not restricted to a special subset, since T cells expressing the Lyt 1+2- and the Lyt 1-2+ phenotype responded to these inducers with IFN production. After prolonged passaging of the T-cell lines in IL-2-containing medium, the ability to respond to CMA with production of antiviral activity was sustained longer than the ability for concanavalin A-induced IFN-gamma production. Whereas the NDV-induced T-cell supernates contained both IFN-alpha and IFN-beta, the induction with CMA resulted exclusively in the synthesis of IFN-beta by the T-cell lines.

Acridines↗
PubMed1986

Biochemical characterization of the T-cell mitogen derived from Mycoplasma arthritidis.

A biochemical procedure is described to purify the T-cell mitogen in the supernatant of cultured Mycoplasma arthritidis organisms. The mitogenic material was bound on an affigel blue column. The eluate of this column was then acylated at 0 degrees C for 1.5 h and subsequently chromatography on a Sepharose Cl 6B and a Superose 12HR column were performed. SDS-PAGE showed a major band at MW 26,000 and some minor bands at 50,000. With this material biological tests were performed, including induction of lymphoproliferation and interferon induction in murine spleen cell cultures. Purified Mycoplasma arthritidis supernatant (MAS) vigorously stimulated spleen cell cultures of A/J, CBA, C3H/He, and DBA/2 mice, whereas a low-grade but definitive response was observed in C57BL/6 spleen cells. Cultures of Balb/c nu/nu mice, in contrast to those of their euthymic littermates, were non-reactive. When induction of interferon was tested, a marked response to purified MAS was observed in CBA and C3H/HeJ spleen cell cultures, whereas C57BL/6 spleen cells were non-reactive.

Animals↗
PubMed1986

Lymphocyte activation and induction of interferon gamma in human leucocyte cultures by the mitogen in Mycoplasma arthritidis supernatant (MAS).

This report succinctly summarizes a number of experiments in which human leucocytes were activated by the mitogen in the supernatant of cultured Mycoplasma arthritidis (MAS). Lymphocytes from a large number of donors were found to be reactive when the two parameters of lymphoproliferation and of production of gamma interferon were analysed. Lymphocytes of cord blood origin were also reactive in lymphoproliferation. Their interferon production was low, but this has been established previously for mitogens in general. During the course of the studies, different batches of MAS were tested, including most recently a purified preparation. All of these were active. Removal of accessory cells adherent to nylon wool column abolished MAS reactivity, whereas it has little effect on lymphoproliferation induced by phytohaemagglutinin (PHA). MAS reactivity was also strongly reduced when monoclonal anti-HLA-DR antibodies were added to the leucocyte cultures.

Bacterial Proteins↗
PubMed1986

Studies of cellular immunity, serum interferon titers, and natural killer cell activity in schizophrenic patients.

In one of the hypotheses on the causes of schizophrenia it is proposed that viruses may play a role in the etiology and pathogenesis of at least some forms of schizophrenia. In our study, 30 healthy adults and 30 schizophrenic patients were investigated for humoral and cellular immunity against herpes simplex virus (HSV) and cytomegalovirus (CMV). A whole blood test system with several advantages over commonly used procedures was used to study cell-mediated immunity to CMV and HSV. Our data showed no difference between serum antibody levels or cellular immunity of the schizophrenic patients and control individuals as far as HSV and CMV were tested. Serum interferon may be indicative for the presence of a yet unidentified virus. Therefore, we tested interferon levels in the serum of patients. No interferon was detected in any of the samples tested. Further, we tested the activity of natural killer (NK) cells in the blood of schizophrenic patients and controls. NK-activity of the patients' blood cells was not different from that of normal donors.

Antibodies, Viral↗
PubMed1986

Effect of interferon on replication of herpes simplex virus types 1 and 2 in human macrophages.

Macrophages derived from human peripheral blood and cultured for 1 week were permissive for the replication of herpes simplex virus (HSV) types 1 and 2. Low titers of interferon (IFN) were produced after virus infection. The yield of infectious virions was reduced by pretreatment of cells with natural and recombinant IFN-alpha and natural IFN-beta. Recombinant and natural IFN-gamma exhibited very low antiviral activity. Treatment of cells with IFN-gamma mixed with IFN-alpha or with IFN-beta did not result in a synergistic inhibition of virus yield. We studied the synthesis of HSV type 1- and HSV type 2-coded proteins in macrophages treated with IFN-beta. Induction of the HSV beta-protein DNA polymerase was strongly inhibited in IFN-treated cells in a dose-dependent manner. As shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, other beta- and gamma-proteins of HSV were inhibited as well. Immunofluorescence studies revealed a strong inhibition of the expression of immediate early alpha-protein ICP4. The results indicate that IFN acts early during the viral replication cycle to inhibit the synthesis of HSV alpha- and beta-proteins.

Cells, Cultured↗
PubMed1986

Characterization of interferon induced in murine macrophage cultures by 10-carboxymethyl-9-acridanone.

Pure murine macrophages were induced by 10-carboxymethyl-9-acridanone to produce interferon. The supernatants were partially purified by a three-column procedure including a DEAE-Biogel A, a CM-Biogel A, and a CH-Sepharose 4B column. The specific activity achieved was about 10(5) IU/mg. Two different activities were detected after the third step and designated activity 1 and activity 2. The determination of the molecular weight was in the range of 24,000-27,000 dalton for activity 1 and in the range of 32,000-34,000 dalton for activity 2. Both were neutralized by antibodies against mouse interferon-beta, indicating that two different moieties were produced both representing interferon-beta. When macrophages were induced in the presence of tunicamycin, only one activity of a molecular weight of about 19,000 dalton was found which again was neutralized by anti-interferon-beta.

Acridines↗
PubMed1986

Induction of natural killer cell activity in mice by injection of indomethacin.

The natural killer (NK) cell system of mice in the peritoneal cavity is of very low to undetectable activity, and testing peritoneal NK cells is a useful model to study the influence of activating substances upon local injection. Injection of indomethacin at doses of 100-400 micrograms/mouse caused a marked activation of NK cell activity which was maximal at 3 days and lasted for a total of 6 days. A similar albeit less marked effect was observed with other cyclooxygenase inhibitors such as aspirin. Prostaglandin E2 reversed the activation of NK cells induced by injection of indomethacin. The cellular count of the peritoneal population was 2-fold elevated after indomethacin injection but the percentage of macrophages in the washed-out cell population was decreased from 60% (controls) to around 20%. The NK cell nature of the effector cells activated by indomethacin was substantiated by the finding that previous injection of anti-asialo GM1 antibody prevented activation. Interferon could not be detected in the peritoneal wash fluid after injection of indomethacin, suggesting interferon-independent activation. However, the possibility of small interferon quantities being locally produced could not be excluded. In further experiments we found after intraperitoneal injection of indomethacin not only cells that killed YAC-1 targets in a 4-hour assay but also killer cells that were insensitive to anti-asialo GM1 and killed P815 cells in an 18-hour assay. We assumed that these were macrophages and have done further experiments with in vitro grown bone-marrow-derived macrophages. These could be activated for killing of P815 targets by the addition of indomethacin, but (to a lesser degree) also for killing of YAC-1 lymphoma cells.

Animals↗
PubMed1985

A whole-blood lymphoproliferation assay for measuring cellular immunity against herpes viruses.

A whole blood test system was established to study cell-mediated immunity to cytomegalovirus (CMV) and herpes simplex virus (HSV) in a large number of healthy blood donors. Cellular immunity was measured by the in vitro proliferative response (LP) of peripheral lymphocytes. These responded vigorously to several mitogens. Lymphocytes of most individuals responded to HSV, but only a limited number were reactive towards CMV. In parallel, antibodies against CMV and HSV were measured by an ELISA technique. For HSV, good correlation was observed between serological and lymphocyte proliferation results. For CMV, no clear correlation was obtained, only 21 of 40 donors positive in the antibody test being positive in the LP test. The majority of seronegatives were negative in the LP test. Use of virions purified by sucrose gradient centrifugation, or an additional strain of CMV (strain Davis) did not increase the number of donors positive in the LP test. One explanation might be that individuals possessing antibodies against CMV as measured by ELISA but no capacity to react in the LP test had suffered from a CMV infection a long time before, and now showed waning cellular immunity, but antibody still detectable. Use of the whole blood technique on 108 individuals showed that this very simple test works well with various mitogens and at least some antigens.

Antigens, Viral↗
PubMed1985

Lack of inhibition of mitogen-induced lymphoproliferation by interferon gamma.

Interferon (IFN) gamma has been shown to have enhancing effects on immunocompetent cells, as for example induction of the expression of I-A antigens. In this report the effect of purified mouse IFN-gamma on mitogen-induced proliferation was studied. In contrast to the situation observed with IFN-alpha or IFN-beta, treatment by IFN-gamma had no suppressive effect on mitogenesis. Enhancing effects on DNA synthesis induced by phytohemagglutinin were observed at low concentrations of IFN-gamma in the early stage of lymphocyte activation. The effects on T cell proliferation, however, were not consistent under all experimental conditions.

Animals↗
PubMed1985

Recombinant interleukin 2 rapidly augments human natural killer cell activity.

Recombinant human interleukin 2 (r-IL-2) rapidly stimulated human natural killer cell activity in vitro. Augmentation of NK activity occurred within 1 hr of preincubation with r-IL-2. Responsive killer cells were typical NK cells as shown by cell fractionation procedures. These included Percoll density gradient separation and depletion of OKT3+ T cells by an indirect rosetting method. Analysis with a panel of polyclonal and monoclonal antibodies against alpha and gamma interferon revealed that this early enhancement of NK activity by r-IL-2 was independent of the production of both types of interferon.

Antibodies↗
PubMed1985

Role of interferon in the resistance of C3H/HeJ mice to infection with herpes simplex virus.

C3H/HeJ mice known to be defective in their responses to bacterial lipopolysaccharides, are more resistant to infection with herpes simplex virus (HSV) than the closely related strain C3HeB/FeJ. The increased resistance is reflected in higher early local interferon titers after HSV infection. However, NK cell activation by HSV is not correlated with resistance, since the NK cell response of C3H/HeJ mice was significantly lower than that of the control strain.

Animals↗
PubMed1985

Interferon inducibility in mice treated with Corynebacterium parvum.

Mice were given single intraperitoneal (i.p.) injections of Corynebacterium parvum, followed, after different time intervals, by i.p. injections of the interferon inducers polyinosinic-polycytidylic acid (poly-I:poly-C), 10-carboxymethyl-9-acridanone (CMA) or herpes simplex virus. With all three inducers production of interferon in the peritoneal cavity was enhanced in C. parvum-pretreated mice. Production of circulating interferon in C. parvum-pretreated mice was enhanced with CMA and depressed with poly-I:poly-C as inducers. This modulation of the interferon response was prominent for at least 10 weeks after C. parvum injection and then gradually reverted. The increased local interferon production seemed to be caused by macrophages still activated several weeks after treatment with C. parvum.

Animals↗
PubMed1985

Attempts to correlate interferon induction and activation of natural killer cells by Corynebacterium parvum.

Intraperitoneal (i.p.) injection of Poly I:Poly C resulted in high interferon titers in the peritoneal wash fluid and in the serum of mice, which was maximal at 4 to 6 h after injection. In contrast, no interferon could be measured in the peritoneal fluid at various times after injection of C. parvum. Also, all attempts to induce serum interferon by C. parvum were unsuccessful. However, both Poly I:Poly C and C. parvum were causing the activation of Natural Killer (NK) cells in the cell population recovered from the peritoneal cavity. From adoptive transfer experiments, there was no indication that C. parvum induced a soluble mediator causing the activation of NK cells. There was also no indication that the interferon activity in the peritoneal cavity of C. parvum-treated mice might have been masked by the presence of an inhibitory molecule interfering with the antiviral effect of interferon in the assay. Our data may suggest activation of NK cells by C. parvum to be independent of interferon induction. Accordingly, we have observed that the injection of anti-interferon did not abolish NK cell activation by C. parvum. Thus, there is the interesting possibility of an interferon-independent mechanism of NK cell activation. However, we have additionally shown that doses of murine alpha/beta interferon as low as 1 IU per mouse caused a significant activation of NK cells in the peritoneal cavity upon i.p. injection. Thus, interferon itself is extremely potent in activating NK cells.

Animals↗