Immunomodulating effect of met-enkephalin on different stages of lymphocyte proliferation induced with concanavalin A in vitro.

Met-enkephalin (ME) in the range of concentrations 10(-15) M to 10(-9) M has exhibited an immunomodulating effect on concanavalin A (Con A) induced proliferation of mice lymphocytes from lymph nodes in vitro. The effect of ME was shown to vary with the stage of lymphocyte activation and to depend on the mitogen dose. In the case that ME and Con A were injected simultaneously, at the zero time of proliferation, maximum inhibition was observed on the first and fourth days. In an other set of experiments when ME was added at intervals of 4 hours before measuring the proliferation response value, both inhibition (after 24 hours of proliferation) and stimulation (after 28 and 96 hours) were observed. Opioid ligands of various classes were found to act in the same manner as ME. Naloxone was shown to block the immunomodulating effect of opioids.

[Participation of opioid receptor of the kappa-, mu-, and delta-types in regulating the humoral immune response]. / Uchastie opioidnykh retseptorov kappa-, mu-, i delta-tipov v reguliatsii gumoral'nogo immunnogo otveta.

The alteration of opioid receptor total binding level as well as ae- and mu-, delta-type distribution has been investigated on the every day of primary and secondary immune response on bovine gamma-globulin. It has been shown that a level of opioid binding measured with [3H]naloxone increased by 6 times during the primary, and by 1.5 times during the secondary immune response on the antigen. A maximal value of opioid receptor activity has been observed at the 7-th and the 5-th days correspondingly, i.e. at the peak of the response. Receptor activity has been measured by displacement of [3H]naloxone with corresponding selective opioid ligand. Growth of the quantity of ae-receptors and decrease of that of mu- and delta-receptor types has been found to take place starting with zero time till 7-th and 5-th days of response development. A reverse picture has been detected during the immune response falling down. Selective ae-ligand stimulated the secretion of specific antibodies to bovine gamma-globulin, whereas mu- and delta-ligands suppressed the antibody production. Functional role of different types of opioid peptides taking part in immune regulation is analyzed.

[A comparative study of met-enkephalin effects on the secretion by murine lymphocytes of antibodies to different antigens]. / Sravnitel'noe izuchenie éffektov met-énkefalina na sekretsiiu limfotsitami myshi antitel k razlichnym antigenam.

The influence of met-enkephalin on specific antibody production by lymphocytes from mouse lymph nodes was studied in vitro in productive phase of immune response. It was shown that the peptide did not influence secretion of IgM-antibody to T-independent antigen-trinitrobenzensulfoacidic group, but suppressed secretion of IgG-antibody to T-dependent antigens both during primary and secondary response. The efficiency of superlow concentrations of the peptide (10(-15)-10(-14) M) for the response to ovalbumin, but not for the response to bovine gamma-globulin was shown. All effects of met-enkephalin were naloxone-reversible. The existence of individual distribution in dose-dependences of peptide action on antibody secretion in response to ovalbumin was demonstrated.

[Interaction of (3H)naloxone with immunocompetent murine cells: the effect of mitogenic and antigenic activation]. / Vzaimodeistvie (3H)naloksona s immunokompetentnymi kletkami myshi: vliianie mitogennoi i antigennoi aktivatsii.

The binding of the opioid antagonist [3H]-naloxone to immunocompetent cells of the mouse, F1(CBA x C57B1/6), in medium 199 has been studied. The binding was reversible and reached a maximum during 15-20 min at 37 degrees C. The stereospecificity profile was proven to correspond to mu-type receptors. The binding curve was characterized by high positive cooperativity (nH = 2.3, IC50 = 5 nM). Mitogenic stimulation by Con A, SEA, and ML caused an increase in the number of receptors. Besides, stimulation by an antigen (ovalbumin) changed the binding parameters. The distribution of binding sites for naloxone on various immunocompetent cells was investigated. The maximal number of sites was found on lymphocytes of lymph nodes and bone marrow cells. A conclusion is drawn that both T- and non-T-cells play a role in naloxone binding.

Involvement of opioid receptors in Met-enkephalin modulation of blast-transformation of mouse splenocytes.

The influence of Met-enkephalin on mitogenic stimulation of mouse splenocytes was investigated. Met-enkephalin (ME) was shown to suppress proliferation induced by Concanavalin A and activate proliferation induced by Staphylococcus enterotoxin A. Both effects were revealed at low (down to 10(-14) M) concentration of pentapeptide. Naloxone reversed ME influence on cell activation. The number of receptors for naloxone was shown to increase up to 2.5-fold during mitogenic activation. The difference in expression of various types of opioid receptors at mitogenic stimulation was demonstrated by ligand displacement experiments.

[Interaction of monoclonal antibodies with horseradish peroxidase]. / Vzaimodeistvie monoklonal'nykh antitel s peroksidazoi khrena.

Properties of four types of monoclonal antibodies to horse-radish peroxidase were investigated. The dissociation constants and molecular-weight composition of the immune complexes were determined. The antibodies are shown to be directed to different epitopes on the polypeptide chain. Results of the theoretical prediction of the epitope localisation are presented. The interaction between the antibodies and peroxidase isozymes were studied.