Effects of interleukin-6 and leukemia inhibitory factor on the acute phase response and DNA synthesis in cultured rat hepatocytes

Human recombinant interleukin-6 (IL-6) and human recombinant leukemia inhibitory factor (LIF) similarly stimulate synthesis of typical acute-phase proteins in the primary rat hepatocyte cultures. LIF is, however, less effective in increasing uptake of alpha-aminoisobutyric acid than IL-6. Antiserum to human IL-6 abolishes induced protein synthesis and amino acid uptake elicited by hrIL-6 but has no effect on the acute-phase response of rat liver cells stimulated by LIF. Both IL-6 and LIF inhibit basal and epidermal growth factor-induced DNA synthesis in rat hepatocytes.

Decreased inhibition of immune precipitation by sera with the C2 B allotype

Complement-mediated precipitation inhibiting (CMPI) activity of sera of 5 individuals homozygous for C2 B was compared to that of sera of 20 individuals carrying the common C2 C allotype. Sera with the rare C2 B allotype had a depressed CMPI capacity in both the early (5 min) and the late (60 min) stages of the reaction. We have also compared the CMPI activity of seven homozygous C4A deficient (C4A*Q0) and eight C4B deficient (C4B*Q0) serum samples and did not find significant differences from the controls (no C4 null alleles) in any stage of the reaction. These results indicate that C2 is the critical component in the CMPI reaction of the two constituents of the classical pathway C3 convertase and that C2 B is less active than C2 C.

Postadsorptive transitions in fibrinogen adsorbed to biomer: changes in baboon platelet adhesion, antibody binding, and sodium dodecyl sulfate elutability

Residence-time-dependent changes in fibrinogen after its adsorption to Biomer were examined by measuring platelet adhesion and antibody binding to the adsorbed protein, and the amount of adsorbed fibrinogen which could be eluted by sodium dodecyl sulfate (SDS). Baboon fibrinogen was first adsorbed (from either pure solution or dilute plasma) to Biomer, which was then stored in either buffer or buffered albumin solution prior to testing. Subsequently, the adherent protein layer was either probed for fibrinogen capable of mediating platelet adhesion using 111In radiolabeled, washed platelet suspensions under both static and shearing conditions, or for fibrinogen capable of binding antibody using a direct enzyme linked immunosorbent assay (ELISA). Alternatively, the surface with the adsorbed protein layer was soaked in a 3% SDS solution, and the amount of 125I radiolabeled fibrinogen retained was measured. Decreases in platelet and antibody binding, and in the SDS elutability of the adsorbed fibrinogen after it was stored in buffer were detected, although different rates of decrease were observed for each method. When the protein-coated surfaces were stored in buffered albumin solution rather than buffer, the decrease in the reactivity of fibrinogen was prevented. While each of the three assays measures a different property of adsorbed fibrinogen, this study suggests that the adherent protein undergoes time dependent conformational changes which render it less reactive toward platelets and antibodies, and more resistant to elution by SDS.

Quinine-induced immune thrombocytopenia associated with hemolytic uremic syndrome: a new clinical entity

Three patients are described who developed severe thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure after ingestion of quinine. In one patient, the same clinical findings recurred several months later after another exposure to quinine. Serum from one patient contained quinine-dependent IgG antibodies reactive with the platelet glycoprotein (GP) Ib/IX complex. In the second and third cases, serum contained IgG and IgM antibodies reactive with both the GP Ib/IX and IIb/IIIa complexes in the presence of quinine. Quinine appears to have induced both immune thrombocytopenia and the hemolytic uremic syndrome (HUS) in these individuals. Findings made in these cases may have implications for the pathogenesis of some forms of HUS.

Enumeration of antigen sites on cells by flow cytometry

We evaluated a cytofluorometric method for determining the number of antigens expressed on the cell surface of human lymphocytes. Using beads that have a known number of binding sites for mouse immunoglobulin and monoclonal antibodies specific for various antigens on human lymphocytes, we found that this system is quite reproducible, reliable and technically easy to perform. The greatest source of variation in expression of cell surface antigens is interdonor variability.

[Effect of pharmacologic blocking of the antigen-antibody reaction in adult respiratory distress syndrome (ARDS)]

In the experimental model of ARDS in rats there was investigated the influence of Intal (Fisons, GB) on the changes in the rat's lungs. Intal was inhaled through the respiratory system. Morphological examinations were carried out by hematoxylin and eosin staining. The results of experiment show that Intal seems to be a protective remedy in ARDS.

Polyanions inhibit binding of human autoantibodies to certain cellular proteins

The effect of polyanions on the reactivity of human autoantibodies with cellular proteins was studied. The results of immunoblotting revealed that dextran sulfate (DS), heparin, single-stranded (ss) DNA, and polyinosinic acid (poly I) inhibit interaction between immunoglobulins (Ig) from human autoimmune sera and many polypeptides with various molecular mass. These proteins were suggested to belong to a new subclass of autoantigens, the immunoreactivity of which is sensitive to the presence of polyanions. For some of these antigens, molecular mass, intracellular localization and frequency of appearance of positive sera were determined.

Monoclonal antibodies against antithrombin III and their application in an immunoradiometric assay

Monoclonal antibodies (MAbs) to antithrombin III (AT III) have been produced and characterized, and a two-site immunoradiometric assay (IRMA) developed, using one of the MAbs as a 'catcher' antibody and a radiolabelled affinity-purified rabbit antibody for detection. The IRMA could be performed in one day and the optimum concentration range of AT III was 1-100 ng/ml. Assays on AT III concentrates by the IRMA method showed a good correlation with AT III antigen values measured by the immunoelectrophoresis method (Laurell), the IRMA results averaging 94.3% of the Laurell values. Two of the MAbs (11 and 16) inhibited heparin cofactor but not AT III progressive activity, and the binding of AT III to MAb 11, used for the IRMA, was blocked by heparin. These results indicate that MAb 11 is directed at or near to the heparin binding site, and could therefore be useful in the study of structural aspects of this site in normal and genetically abnormal AT III.

Problems with the measurement of apolipoproteins AI and AII

There is considerable evidence demonstrating that increased levels of low density lipoprotein (LDL) cholesterol and decreased levels of high density lipoprotein (HDL) cholesterol are associated with coronary artery disease (CAD). Yet, these lipoprotein markers are insensitive for identifying risk of CAD. Measurement of subcomponents of HDL may offer more sensitive markers. Investigators have focused on protein components (apolipoproteins) of HDL as a potentially important marker. Unfortunately, because much of the immunoreactivity of apolipoproteins is hidden as a result of an association with lipids, it is difficult to measure them accurately. Detergents and other denaturing agents have been used to expose immunoreactivity. Poor correlations among different methods suggest that some detergents presently used may not be adequate for effective measurement of apolipoprotein (APO) AI. Studies using denaturing agents to probe HDL particles indicate that APO AII immunoreactivity is more resistant to exposure than that of APO AI. Data presented here indicate that the immunoreactivity of APO AII can be increased up to 50 percent by treatment with 4M guanidine provided the concentration of guanidine is diluted to less than 50 mM in the assay system. Previous studies failed to notice this effect because high levels of guanidine inhibited the antibody-antigen reaction in the immunoassay, making it appear that APO AII had not been exposed. It is concluded that with our present state of knowledge, it is unclear which, if any apolipoprotein assays, are adequately designed to achieve optimal exposure of antigenic sites, but that pretreatment with guanidine may be a simple, effective way to optimize APO AI and APO AII assays for clinical purposes.

A monoclonal antibody directed to Tn antigen

A murine monoclonal antibody, MLS 128, that was assigned to an anti-Tn antibody has been established by immunizing mice with human colonic cancer cells (LS 180). MLS 128 bound to mucin glycopeptides from LS 180 cells and their asialo forms to the same extent as well as to ovine submaxillary mucin (OSM) and asialo OSM. Special non-sialylated GalNAc residue(s) attached to a certain peptide region in the antigens seems to be involved in the binding since N-acetylgalactosaminidase treatment of the antigen abolished the binding and pronase digestion diminished the binding markedly.

[Elution of sensitized erythrocytes with chloroquine]

The results of erythrocyte elutions sensitized either in vitro or in vivo with a 15% solution of Chloroquine indicate that at a low degree of sensitization it is possible in more than half of the tested cases to release incomplete antibodies from the red cell surface without causing damage of the group receptors. This makes it possible to assess the phenotypes of the majority of erythrocyte characteristics, although some may be weakened by elution.

Induction of Alzheimer antigens by an uncoupler of oxidative phosphorylation

Since previous studies have suggested that the coupling of oxidation to phosphorylation is impaired in Alzheimer brain and fibroblasts, the effects of carbonyl cyanide m-chlorophenylhydrazone, a hydrazone known to uncouple mitochondrial oxidative phosphorylation, were tested on the development of immunoreactivity with antibodies to "Alzheimer antigens" in cultured fibroblasts from cognitively intact subjects. The fibroblasts were exposed for 10 to 14 days to a medium (DMd) modeled on media that favor neuronal differentiation in fetal brain cultures. The addition of a 10-microns concentration of carbonyl cyanide m-chlorophenylhydrazone to the DMd culture medium increased by more than 10-fold the proportion of cells reacting immunocytochemically with antibodies to paired helical filaments and by 157-fold the proportion of cells reacting with the Alz-50 monoclonal antibody. These observations suggest that the oxidative abnormalities previously described in tissues from patients with Alzheimer's disease may contribute to the accumulation of abnormal cytoskeletal materials in this disorder.

Effects of spaceflight on levels and activity of immune cells

Experiments were carried out on cells from rats that had been flown on Soviet Biosputnik Cosmos 1887 to explore the effects of spaceflight on immune responses. Rat bone marrow cells were examined for their response to colony stimulating factor-M. Rat spleen and bone marrow cells were stained with antibodies directed against cell surface antigenic markers. The results of the studies indicate that bone marrow cells from flown rats showed a decreased response to colony stimulating factor. There was a higher percentage of spleen cells from flown rats staining positively for pan-T-cell, suppressor-T-cell and interleukin-2 receptor cell surface antigens. A small increase in the percentage of cells staining positively for helper-T-cell antigens was also noted. In addition, a higher percentage of cells that appeared to be part of the myelogenous population of bone marrow cells from flown rats stained positively for surface immunoglobulin.

Lytic, agglutinating, and opsonizing effect of alpha 2-macroglobulin on sheep red blood cells

Mouse alpha 2-macroglobulin (alpha 2M) induced agglutination and lysis of sheep red blood cells depending on temperature and time of incubation in vitro. When these erythrocytes (E) were treated with a subagglutinanting dose of alpha 2M, they were adhered to and phagocytosed by thioglycollate-elicited and BCG-activated mouse peritoneal macrophages. Phagocytosis was not observed when resident peritoneal macrophages were tested. alpha 2M also was able to dissociate sheep red blood cells previously aggregated by IgM anti-E.

Does reversed-type anaphylaxis in healthy subjects mimic a real allergic reaction?

Immediate and late cutaneous reactions were induced in healthy and atopic subjects by anti-IgE challenge and a skin-window technique was used in order to verify if the pattern of cells observed at 24 hr was similar in both groups. The study was first performed under basal conditions, and in a second double-blind cross-over step, it was performed again during treatment with cetirizine 10 mg b.i.d. and terfenadine 60 mg b.i.d. Anti-IgE challenge was followed by a significant eosinophil accumulation in atopic subjects only. Cetirizine significantly inhibited this phenomenon while terfenadine showed a mild non-significant inhibitory effect.

The relative affinity of recombinant dihydrolipoamide transacetylase for autoantibodies in primary biliary cirrhosis

In normal individuals there is an adaptive immune response to a foreign antigen in which antibodies of increasing affinity are produced with time. This is not always true of an autoimmune response. However, because only a limited number of autoantigens have been cloned or purified, this issue has not been studied well. In primary biliary cirrhosis the predominant manifestation of autoimmunity is antimitochondrial antibodies that react with dihydrolipoamide transacetylase. The availability of recombinant dihydrolipoamide transacetylase and the development of a rapid and reproducible enzyme-linked immunosorbent assay for autoantibodies has allowed us to address the affinity of autoantibodies using thiocyanate inhibition. Thiocyanate is a chaotropic compound known to inhibit antigen-antibody binding in a concentration-dependent manner. We used this property to inhibit the binding by enzyme-linked immunosorbent assay of human recombinant dihydrolipoamide transacetylase with serum autoantibodies from 55 patients with primary biliary cirrhosis. The relative affinity and serum autoantibody titers were then compared with the histological stage of the liver biopsy sample. Interestingly, we found a considerable heterogeneity of relative affinities. These relative affinities did not correlate with the histological stage or the serum titer of antimitochondrial antibodies. However, the ability of serum autoantibodies to inhibit intact primary biliary cirrhosis enzyme activity was found to correlate highly (R2 = 0.751) with the relative affinity. Thus there are profound differences between patients with respect to qualitative expression of autoantibodies. The significance of this data will be unclear until more is determined regarding the nature of the epitope that drives T cells and leads to B-cell responses.

[The effect of the peptide fractions of neutrophilokines on the immune response of mice infected with Staphylococcus aureus]

The influence of immunostimulating and immunosuppressing neutrophilokine fractions on the immune response of mice with staphylococcal infection has been studied. When injected into mice with staphylococcal infection, the immunostimulating fraction of the supernatants of activated neutrophils has been found to restore the activity of the immune system of the infected animals. The secretory products of intact neutrophils do not change or decrease the capacity of the animals for immune response under the conditions of the infectious process.

[The combined action of glucocorticoid hormones and interleukin-1 on the development of an immune response]

The effect of interleukin-I (IL-I) on glucocorticoid-induced inhibition of the immune response and reactions of cyclic nucleotides to antigen was studied on a model with the use of purified IL-I preparation. Hydrocortisone (HC) in the applied dose caused suppression of the immune response and sharp inhibition of antigen-induced reactions--cAMP in 10 minutes and cGMP on the 6th day after immunization. IL-I administered 10 minutes prior to HC and before immunization prevented the immunosuppressive effect of HC completely. Control administration of heated IL-I and in inactive fraction of the preparation failed to produce a similar effect. IL-I injected 10 minutes after HC also inhibited immunosuppression.

The effect of dithiotreitol on thyroid peroxidase and microsomal antigen epitopes recognized by auto and monoclonal antibodies

The effect of disulphide bridges reduction of the microsomal antigen (Mic-Ag) and thyroid peroxidase (TPO) by dithiotreitol (DTT) has been investigated. The reaction of all 67 tested sera from untreated hyperthyroid Graves' and from 22 Hashimoto's patients with high microsomal antibodies (aAb) titer was diminished by 90-95% by DTT, at pH 9.6. The remaining 5-10% of the activity was not destroyed by DTT. The residual Mic-Ag after DTT reduction was able to inhibit the binding of all 45 Graves' and 22 Hashimoto's tested aAb's to the native microsomal antigen by 100% at high concentration. Reaction of affinity purified TPO with two monoclonal antibodies (mAb) were diminished by 80% to 95% by DTT pretreatment, while the reaction of one mAb with TPO was only slightly affected. The reaction of TPO and Mic-Ag with rabbit polyclonal anti-TPO serum (rabbit a TPO) was diminished by 60% by DTT pretreatment. The immunological reactivity of TPO with aAb's was diminished by 65% after DTT pretreatment. The microsomal antigen-aAb's complex was not destroyed by DTT. Results presented in this paper suggest conformational epitope structure of the Mic-Ag recognized by aAb's in patients with thyroid autoimmune disease (AITD).

[Cytochrome P-450 induction and the subsequent induction of an immune response in rats during the chronic administration of xenobiotics]

The long-term administration of xenobiotics carcinogens o-aminoazotoluene (o-AAT) and benz(a)pyrene (BP) to rats was found to cause induction of the liver cytochrome P-450 system which gradually decreases in spite of continued administration of the agents. Induction of microsomal oxygenases under these conditions is followed by induction of the immune response to o-AAT and BP. The data obtained correspond to the conception of the immunochemical functional system of homeostasis implying that the cytochrome-450 system and the immunity system are functionally linked and are elements of the common functional adaptive system of the organism.

Effect of a free sulphydryl group on expression of HLA-B27 specificity

Sequence studies indicate that the alpha-1 domain of the HLA-B27 molecule has a characteristic unpaired cysteine residue at position 67, adjacent, because of secondary structure, to a lysine at position 70. Simple chemical considerations predict that this cysteine should have an exceptionally reactive sulphydryl group. We have shown by ELISA and flow cytometry that the binding of some monoclonal antibodies to B27 on lymphoid cell lines can be inhibited by reagents which react with sulphydryl groups. However this inhibition is never complete: the evidence suggests 2 forms of B27 molecule, one of which is already blocked. We propose that some HLA molecules with oxidised sulphydryls are recognised as different from the reduced forms. Whether they are also recognised as foreign will depend on an individual's history of thymic learning. Oxidation to 'foreign' HLA in the adult is likely to predispose to inflammatory reactions.

Antibody-dependent cytotoxicity mediated by natural killer cells is enhanced by castanospermine-induced alterations of IgG glycosylation

Inhibitors of glycosylation and carbohydrate processing were used to probe the functional consequences of specific, differential alterations in glycosylation of monoclonal IgG secreted by hybridoma clones. Neither the absence of glycosylation nor the presence of atypical oligosaccharides significantly influenced binding of the monoclonal antibody to the cell surface antigen recognized. However, lymphocyte-mediated antibody-dependent cytotoxicity was enhanced significantly, as compared to native (unmodified) IgG-sensitized target cells, when target cells were sensitized with IgG bearing the atypical oligosaccharides induced metabolically by castanospermine, N-methyldeoxynojirimycin, deoxymannojirimycin or monesin, but not by swainsonine. The enhanced cytotoxicity was mediated by natural killer cells but not by monocytes or interferon-activated polymorphonuclear leukocytes. By contrast, antibody-dependent cytotoxicity mediated by activated polymorphonuclear leukocytes against target cells sensitized with the IgG glycosylation phenotypes induced by swainsonine and tunicamycin, but not by castanospermine, was decreased in comparison to cytotoxicity against target cells sensitized with native IgG. The enhanced lymphocyte-mediated cytotoxicity was Fc receptor-dependent. A panel of monoclonal antibodies directed against different human tumor target cells was used to demonstrate that the castanospermine-induced IgG phenotype generally enhanced antibody-dependent tumoricidal activity mediated by natural killer cells. However, differences in lymphocyte response to an alteration in IgG glycosylation were observed.

A comparison of three nucleoside analogs with anti-retroviral activity on immune and hematopoietic functions in mice: in vitro toxicity to precursor cells and microstromal environment

A number of 2'3'-dideoxynucleosides have been reported to markedly inhibit the in vitro growth of HIV, the causative agent of acquired immunodeficiency syndrome (AIDS). Clinical trials have shown that the continued therapeutic use of these nucleoside derivatives can be associated with adverse side effects. Since these side effects include myelotoxicity, as occurs in many patients treated with zidovudine (AZT; 3'-azido'3-deoxythymidine), and AIDS patients already represent an immunologically compromised population, we examined the immunological effects of three nucleoside inhibitors, including zidovudine, 2'3'-dideoxycytidine, and 2'3'-dideoxyadenosine (DDA) in a mouse model. Additional studies were conducted to further determine and characterize the potential toxic effects associated with these drugs on the hematopoietic system. Of the three dideoxynucleosides examined, only DDA altered immune functions following a 30-day subchronic exposure in mice. This was evidenced by a marked suppression of the antibody plaque-forming cell response and a slight alteration in macrophage function. None of the nucleoside derivatives affected bone marrow function following in vivo exposure, although AZT produced a mild macrocytic anemia in vivo and was myelotoxic when added in vitro to bone marrow cell cultures. In vitro studies indicated that AZT was capable of affecting both proliferating stem cells as well as the stromal cell microenvironment, both of which play a role in hematopoiesis. These data indicate that, although the mice may not develop the identical toxicities associated with nucleoside therapy in humans, certain adverse immunological and hematological effects were readily discerned which could have relevance to humans.

In-vivo and in-vitro interference of antibiotics with antigen-specific antibody responses: effect of josamycin

The effects of josamycin on the antigen-specific primary antibody responses of human peripheral blood cells have been studied by the method of haemolytic colonies in soft agar. The tests were performed before and after the oral administration of 1 g of josamycin or by adding the drug directly to cultures of cells from untreated donors. The results demonstrate that josamycin, added in vitro or administered in vivo significantly depresses the primary antibody responses. The mechanism by which josamycin exerts its activity on antibody production has been partially elucidated. The immunodepression depends on the stimulation of hydrogen peroxide production by monocytes and requires the actual presence of josamycin during the immune response. The stimulation of the respiratory burst of the phagocytic cell is a common feature of macrolide antibiotics and suggests the need for more extensive clinical and preclinical trials on antibacterial antibiotics that alter the human immune responses.

Effect of 8-anilino-1-naphthalene sulfonic acid (ANS) on the interaction between thyroid hormone and anti-thyroid hormone antibodies

Effect of 8-anilino-1-naphthalene sulfonic acid (ANS) on the interaction between thyroid hormone and anti-thyroid hormone antibodies was examined. Addition of 5.1 x 10(6) or 6.3 x 10(6) molar excess of ANS, respectively, enhanced the binding of 125I-T3 or 125I-T4 to their respective autoantibodies. However, further increase in ANS concentration resulted in a decrease in binding. These results suggest that the optimum concentration of ANS for the detection of anti-thyroid hormone antibodies is 5 approximately 6 x 10(6) molar excess of ANS to 125I-T3 or 125I-T4. On the other hand, addition of 10(4) molar excess of ANS concentration decreased the binding of 125I-insulin to anti-insulin antibodies. It was therefore suggested that the effect of ANS could be a nonspecific one and likely due to its negative charge.