Physikalische, chemische und biologische Charakterisierung von menschlichem Choriongonadotropin

Purification of commercially available HCG preparations with DEAE Sephadex A 50 and Sephadex G 100 column chromatography gave homogeneous fractions having specific biological activities four fold those of the starting materials. The purified HCG has ICSH characteristics and, in high doses, a definite FSH effect is present.

Chemical analysis of HCG showed it to contain 29% carbohydrates and 69% peptides. The C-terminal amino acid of the peptide chain was found to be serine, but the N-terminal amino acid could not be determined with normal methods. A molecular weight of 22000 — 27000 daltons was obtained by quantitative end group analysis. Ultracentrifugation experiments in 4 m guanidine hydrochloride gave a molecular weight of 27200 daltons, but in neutral saline solutions at HCG concentrations above 2 mg/ml the apparent molecular weight was higher and indicated dimer formation. A dissociation constant of 10-5 mol/l was estimated for the monomer-dimer equilibrium. Since biological activity is found with 0.1 to 0.5 µg, it was concluded that the HCG monomer is the active entity.

The purified HCG is stable from pH 4.5 to pH 10 for 6 hours at 37 °C. At pH 2.5 only 5 to 10% of the original activity is retained. HCG is rapidly inactivated at 100 °C, but a residual activity of 6 — 10% remained after 30 minutes at 80 °C. No activity was lost after 30 minutes incubation at 60 °C.

Reoxydation der Disulfidbrücken des menschlichen Choriongonadotropins (HCG)

After alkylation of human chorionic gonadotropin (HCG) with iodoacetate in 4 M guanidine-HCl and in 8 M urea, 1.6 and 0.6 mole equivalents of carboxymethylcysteine were found, respectively. The biological activity of these preparations was 25% of the original specific activity.

Slow reoxidation of completely reduced HCG with oxygen yields products having 15 - 25% of the original specific activity, while fast reoxidation results in complete loss of biological activity and immunological specificity.

Immunological specificity and 25% of the original biological activity can be recovered if the disulfide bonds of the inactive sample are reequilibrated in the presence of β-mercaptoethanol.

Modern pharmaceutical biotechnology. Situation worldwide and in Germany 1995

A variety of new diagnostics and drugs have been developed with the aid of modern biotechnology which has opened up new medical possibilities and will yield novel solutions in the future. The remarkable dynamics of the innovation process in the pharmaceutical sector is reflected by the number of drugs under development. In 1995, 771 projects were known to be in development worldwide. The leadership of North America in research and development of drugs from modern biotechnology is clearly demonstrated. Whereas the number of development recombinant DNA products remained practically constant in the triade (North America, Europe, Japan), the number of preclinical and clinical somatic gene therapy projects increased considerably in 1995 compared to 1994 in the United States and in Europe; Japan is virtually absent in this new emerging research field. In Europe, the vast majority of drugs from modern biotechnology, are developed in Great Britain, Germany, Switzerland, France, the Netherlands, and Italy. The number of gene therapy projects show a remarkable growth of more than 60% in 1995 compared with 1994; at the same time, the absolute and relative share of recombinant DNA products decreased distinctly. In Germany, about two thirds of the development of biotechnological drugs are conducted in cooperation with a foreign partner, mostly hightech companies from the United States. A variety of drugs manufactured with modern biotechnology, however, has not only provided significant medical progress and has closed therapeutic gaps but has also demonstrated considerable economic success. In 2000, further significant growth is expected especially for growth factors and cytokines.

A method for the quantitation of interleukin-2 activity

A bioassay for the determination of interleukin-2 activity is described. We have compared the traditional method of data processing, which involves probit analysis and curve fitting, with a simpler method based on the so-called AUC (area under the curve). The latter method is readily applicable to spreadsheet software and can handle large amounts of data.

Inhibition of HIV and virus replication by polysulphated polyxylan: HOE/BAY 946, a new antiviral compound

Xylanpoly-(hydrogen sulphate) disodium salt with a molecular weight of about 6000 daltons (HOE/BAY 946) completely inhibited syncytium formation induced by the infection of T lymphocytes with HIV as well as viral replication at concentrations above 25 micrograms/ml. This dose was found to be inhibitory for several strains of HIV-1 and HIV-2. Low molecular weight fractions of the compound were less active against HIV, and high molecular derivatives were as active as HOE/BAY 946. A direct influence of the drug on the infectivity of the virus could not be demonstrated. The drug inhibited the reverse transcriptase of HIV. Treatment of permanently HIV-infected U937 cells resulted in a drastic reduction of virus particles released into the supernatant and points to an additional mode of action. A therapeutic effect of HOE/BAY 946 against retroviruses in vivo could be demonstrated in Friend leukaemia virus-infected mice. A clinical pilot study with the compound was started recently in Germany with AIDS patients who did not tolerate or refused to take zidovudine and with asymptomatic virus carriers.

Monitoring of interleukin-2 receptor (IL-2R) expression in vivo and studies on an IL-2R-directed immunosuppressive therapy of active and adoptive adjuvant-induced arthritis in rats

Recent evidence indicates that adjuvant arthritis (AA) of rats induced by complete Freund's adjuvant (CFA) is an autoimmune disease that is mediated by T cells. This report describes the distribution of activated IL-2 receptor (IL-2R)-bearing cells in spleen, popliteal lymph nodes (PLN) and blood in AA rats and in naive healthy rats using the monoclonal antibody (mAb) ART-18. It was found that in the primary lymph nodes (injected side) two peaks of elevated numbers of IL-2R-positive cells (Day 9/10 with a 40-fold increase; Day 25 with a 75-80-fold increase) occur. The PLN of the non-injected site also show an increase (30-fold) in the number of IL-2R-positive cells on Day 25. This investigation also included the monitoring of soluble IL-2R in the serum of AA rats in comparison to control sera of non-induced rats. The incidence of free IL-2R in the serum of AA rats does not completely correlate with the pattern of the distribution of receptor-bearing cells in PLN; elevated levels of IL-2R were observed at Day 9 and subsequently declined to below control levels. On Day 25, there was no correlation between IL-2R+ cells and soluble IL-2R. ART-18 was not active in suppressing the development of AA, in contrast to the complete inhibition of the passively transferred AA.

Pseudo-allergic reactions to drugs and chemicals

Drugs can interfere with the immune system in two basically different ways: (1) they may interact with the specific recognition mechanisms of the immune system and thus induce an allergic response that is specific for the offending agent; (2) drugs may exert pharmacological effects on the immune systems which result in a response that is independent of its recognition structures or they may activate effector and amplification mechanisms that are normally triggered by specific immune processes. Allergic reactions to drugs are different from reactions that exhibit the same clinical symptoms but lack the specificity of an allergic reaction to the offending agent. It has been suggested that those non-specific reactions which mimic the signs and symptoms of allergic reactions should be classified as pseudo-allergic reactions (PAR). PAR are characterized by the following properties which differentiate them from allergic reactions. (1) The symptoms of PAR are qualitatively different from the pharmacological response of a drug and are not related to adverse reactions connected with its pharmacological and toxicological profile. (2) PAR are not specific with regard to the chemical structure of the triggering agent. (3) PAR lack transferability to other subjects of the same species. (4) In contrast to the allergic reactivity, the pseudo-allergic reactivity is not acquired but genetically predetermined. (5) Pseudo-allergic reactivity is often expressed upon the first contact with an eliciting agent. PAR are thus an expression of a pharmacological interaction of drugs or their metabolites in genetically predisposed individuals.

A new model for investigations of T-cell functions in mice: differential immunosuppressive effects of two monoclonal anti-Thy-1.2 antibodies

Two monoclonal anti-Thy-1.2 antibodies were investigated for their activity in eliminating T cells in vitro and in vivo. Both antibodies exert a complement-dependent cell cytotoxicity in vitro. Antibody B that belongs to the IgM class shows a 100-fold higher complement-dependent cytotoxic activity than antibody C, which is of IgG2a class. However, administration of antibody C into Balb/c mice results in the elimination of T cells as determined by the failure of different T-cell functions. Within 24 hours after administration of antibody C, the reactivity of spleen of lymph-node cells to T-cell mitogens, the antibody response to the T-cell-dependent antigen SRBC and the SRBC-induced delayed-type hypersensitivity are completely abolished. These effects are dose-dependent in a dose range of 0.1-1.0 mg Ig protein per animal and affects only T cells in the peripheral lymphoid organs. The Thy-1.2-bearing cells residing in the thymus are not impaired by the treatment of the animals with this monoclonal antibody and are able to repopulate the peripheral lymphoid organs within 30 to 60 days. Investigations into the mode of action of the removal of peripheral T cells revealed that antibody-C-coated Thy-1.2-bearing cells are rapidly phagocytosed by macrophages, while antibody-B-coated Thy-1.2-bearing cells are not. This might be the reason for the differential in-vivo activities of the two monoclonal antibodies. A model with new qualities for the study of functions and the regeneration of T cells in vivo has been established.

The pathomechanism of acetylsalicylic acid intolerance. A hypothesis

In a number of individuals suffering from chronic asthma or chronic urticaria, acetylsalicylic acid and structurally unrelated non-steroidal anti-inflammatory agents and other compounds, e.g. tartrazine, elicit an intolerance syndrome that mimics the signs and symptoms of an immediate-type allergic (anaphylactic) reaction. An immunological basis for this reaction could be excluded. It is assumed that the eliciting agents activate complement and that the intolerant individuals lack plasma carboxypeptidase B, that normally inactivates C3a and C5a in statu nascendi. The anaphylatoxins, if not immediately inactivated, release the endogenous mediators of the anaphylactic reaction from the tissue mast cells.

Macrophages/monocytes require cell-to-cell contact in order to regulate the growth of a murine lymphoma cell line

The mechanism of the macrophage-regulated proliferation of the murine lymphoma cell line FIO 30 has been further investigated. It appears that the macrophage is alone in its ability to support FIO 30 growth; a macrophage-like cell line, however, is unable to provide the stimulus required by the FIO 30 cells for their proliferation. Investigations into the nature of this stimulus indicate that the serum factor pro-MaSF and a macrophage cell surface component act synergistically to support the growth of the FIO 30 cell, but only when the two cell types are in close promixity. MaSF has also been further characterized and is shown to be closely associated with serum albumin.

[Cell kinetics in experimental rheumatoid lesions and application in antirheumatic drug research (author's transl)]

The kinetics of chronic inflammatory cellular infiltrates in antiglobulin-induced arthritis, peritonitis and subcutaneous fibrin granuloma were investigated. Only small numbers of the mononuclear cells were labeled after 3H-thymidine impulse labeling, whereas a high labeling index results after 3H-thymidine labeling of the bone marrow. It is concluded that in experimental arthritis the inflammatory so-called cellular hyperplasia consists in bone marrow derived mononuclear cells. In experimental peritonitis glucocorticoid treatment decreases the 3H-thymidine labeling indices. By means of such labeling studies the antiproliferative and antiexsudative properties of steroids were demonstrated quantitatively. Therefore we suggest to make use of experimental cell kinetics for the recognition of anti-rheumatic drugs.

Humoral Primary Immune Response in Vitro in a Homologous Mouse System: Replacement of Fetal Calf Serum by a 2-Mercaptoethanol or Macrophage-Activated Fraction of Mouse Serum

The primary immune response in mouse spleen cell cultures against heterologous red cell antigens is dependent on the medium being supplemented with selected batches of fetal calf serum. Mouse serum itself is not able to support this response. The active immune response-supporting component in fetal calf serum seems to be a distinct factor (s), which has been partially purified by Sephadex G-100 filtration and termed MaSF — 2-mercaptoethanol-activated serum factor. In this report it is demonstrated that MaSF is also present in mouse serum. For functional detection, mouse MaSF has to be separated from higher m.w. inhibitors, and has to be activated by 2-ME. After separation and activation mouse MaSF can support the primary immune response in a completely homologous in vitro culture system. Evidence is presented that MaSF can also be activated by macrophages. It is concluded that macrophages and 2-ME have the same mode of action in the primary immune response in vitro, i.e., induction of lymphocyte competence by activation of a serum factor.

Humoral primary immune response in vitro in a homologous mouse system: replacement of fetal calf serum by a 2-mercaptoethanol or macrophage-activated fraction of mouse serum

The primary immune response in mouse spleen cell cultures against heterologous red cell antigens is dependent on the medium being supplemented with selected batches of fetal calf serum. Mouse serum itself is not able to support this response. The active immune response-supporting component in fetal calf serum seems to be a distinct factor (s), which has been partially purified by Sephadex G-100 filtration and termed MaSF-2-mercaptoethanol-activated serum factor. In this report it is demonstrated that MaSF is also present in mouse serum. For functional detection, mouse MaSF has to be separated from higher m.w. inhibitors, and has to be activated by 2-ME. After separation and activation mouse MaSF can support the primary immune response in a completely homologous in vitro culture system. Evidence is presented that MaSF can also be activated by macrophages. It is concluded that macrophages and 2-ME have the same mode of action in the primary immune response in vitro, i.e., induction of lymphocyte competence by activation of a serum factor.

Growth regulation of a murine lymphoma cell line by a 2-mercaptoethanol or macrophage-activated serum factor

A mouse lymphoma cell line has been established that is dependent for growth on the presence of an activated serum component. This growth factor is found in an inactive form in fetal bovine serum (FBS) and can be activated by 2-mercaptoethanol and by macrophages. A factor-containing fraction can be separated from FBS by Sephadex G-100 chromatography and once activated, can be used as a substitute for whole serum in the culture medium without adverse effect on the cell growth. The significance of these findings with respect to the study of the immune response and cancer research is discussed.

Immunogenicity of aryl esters of salicylic or acetylsalicylic acid in guinea pigs

A variety of derivatives of acetylsalicylic and salicylic acid have been investigated for their immunogenic properties in guinea pigs including salicylsalicylic acid (SSA), acetylsalicylsalicylic acid (ASSA), disalicylide (DI), trisalicylide (TRI), acetylsalicylic acid paracetamol ester (ASPE) and acetylsalicylic acid guajacol ester (ASGE). Contact sensitivity could be elicited by the sensitizing agent, however, with acetylsalicylic acid anhydride (ASAN) a more pronounced contact reaction could consistently be observed. Systemic anaphylactic reactions elicited by intravenous injection of N-salicyloyl bovine serum albumin could only be induced by ASAN, DI, TRI and ASSA, whereas SSA, ASPE and ASGE did not induce an anaphylactic state at a comparable dose level. From these results it is anticipated that all aryl esters of acetylsalicylic or salicylic acid are immunogenic when applied intradermally, leading to a N-salicyloyl specific immune response.

The lipid composition of rabies virus

The lipid composition of the Flury HEP strain of rabies virus grown in BHK 21/C 13 cells was determined. The dried purified virus preparation contains 5.5 % neutral and 19.5 % polar lipids. Cholesterol was found to be the major neutral lipid. Phopholipids constitute 11.2 %; and glycolipids represent 4.6 % of the virus mass. The residual 3.7 % of extracted polar lipid material could not be accounted for by any known lipids. Phosphatidylethanolamine, phosphatidylcholine and sphingomyelin are the main constituents of the viral phospholipids. Hema- toside is the only ganglioside and the main glycolipid present in the virus. The glycolipids of the host cell and the virus are identical. The molar ratio of sphingolipids to glycerophospho-lipids is 0.8.

Comparison of the gonadotropin release induced by a hypothalamic factor and by a synthetic decapeptide exhibiting luteinizing hormone releasing activity

A gonadotropin-releasing factor could be extracted from human hypothalamic tissue. Follicle-stimulating hormone (FSH)- and luteinizing hormone (LH)-releasing activities were assayed according to Ramirez and McCann. FSH and LH were testet according to Steelman and Pohley or Parlow. A minimal FSH-releasing activity was caused by 0.01 µg human FSH-releasing factor. The optimal dose was achieved with 0.025 µg. An increase of the dose up to 0.3 µg did not result in a further FSH release. 0.01 µg of the synthetic LH-/FSH-releasing factor showed a significant FSH release. An increase of the dose did not result in an increased FSH release. In contrast, the LH release was dose-dependent. The course of FSH release after application of 0.1 µg human gonadotropin-releasing factor showed the maximum after 30 min and reached the normal level after 2 h. Injection of 0.01 µg synthetic LH-releasing factor produced a maximum after 10 min and a smaller maximum after 60 min. The course of LH release after injection of 0.2 µg human gonadotropin-releasing factor showed a peak maximum 30 min and a second maximum 120 min after application. The synthetic LH-releasing factor showed a peak maximum after 5 min, followed by declines and maximas between 30 and 45 min and 100–120 min. Human gonadotropin-releasing factor and synthetic LH-/FSH-releasing factor showed a different behaviour. Chemical differences may be responsible for these differences.

Infertility of mice induced by antibodies specific for human chorionic gonadotrophin

Injections of rabbit antisera to cross-linked human chorionic gonadotrophin (HCG) into female STu mice made tolerant to rabbit γ-globulin, induced prolonged oestrus lasting for 18–60 days and phases of sterility of 37–130 days duration. When immune-competent mice were treated in a similar manner these effects were very markedly decreased due to the interference of antibodies developed against rabbit serum proteins.

The results are discussed on the basis of cross-reactions with endogenous gonadotrophins.