Peptide cytokines in CNS and the immune system.

This study describes the effects of cytokine peptides released into the supernatant during an early allogeneic reaction (AR) of mouse spleen lymphocytes or brain cortex cells which differ in their major histocompatibility complex (MHC). The peptides were isolated by ultrafiltration, liquid chromatography and HPLC. We found that both peptides stimulated the cell surface Na+,K+-ATPase and Ca2+-ATPase activities of quiescent spleen lymphocytes in vitro and mimicked early allogeneic cell interactions. Both brain and spleen AR peptides inhibited Concanavalin A-stimulated spleen lymphocyte proliferation, whereas 3H-TdR incorporation into DNA of the E7 neuroblastoma cell line was stimulated by these peptides. The peptide isolated from the supernatant of the allogeneic brain cell reaction inhibited phagocytosis in phorbol myristate-stimulated LA5-9/8 mouse macrophage cell line. Immunosuppressive activity of spleen AR peptide is supported by inhibition of spontaneous E rosette formation by lymphocytes. The immunosuppressive effect of isolated peptide cytokines on lectin-activated lymphocytes was comparable with the serum thymic factor (FTS, Lenfant et al. 1983). These changes demonstrate the pleiotropic cytokine actions mediated by plasma membrane of immune system and brain cells.

Computer program for planning and evaluating microplate experiments.

A microcomputer program is described for planning and statistically evaluating microplate and other similar experiments. This program is written in BASIC and can be run on any PC XT/AT compatible computer under DOS. The first part of the program writes the protocol of the experiment into a disk file and sends it to a printer and also prints specifications for the addition of ingredients. The second part of the program calculates means and standard deviations of the values measured for all groups of samples. It is also possible for the program to calculate activation coefficients, coefficients of modulation and percentages of suppression for special groups. Inputting the required data can be performed manually from the keyboard or automatically from disk files.

Expression of MHC class II antigens is modulated by ouabain.

Ouabain enhances a modulation effect of lipopolysaccharide (LPS) on the expression of MHC class II antigens. A similar but lesser effect than that of ouabain, which increases intracellular concentration of sodium ions, has been observed when treating cells with ionophores quercetin which increases [Ca2+]i or valinomycin which increases [K+]i. These findings confirm the role of ion flux in cellular activation and differentiation. Optimal concentration of ouabain is 10(-7) M with 10 micrograms of LPS/ml for human and pig peripheral blood cells. The increase in radioactivity of mononuclear human blood cells after the binding of 125I-anti-MHC class II monoclonal antibody is at the fourth hour of cultivation with LPS and ouabain, the number of immunofluorescently positive cells rises at the twelfth hour. A similar modulation has been observed on pig kidney cell line. It can be concluded that the expression of class II antigens on the plasma membrane can be induced by cumulative effect of LPS and agents alterating ion transport.

Alpha-fetoprotein and phagocytosis in athymic nude mice.

Alpha-fetoprotein (AFP) was found to suppress the phagocytic activity of the blood monocytes and neutrophils in vitro. The amounts of AFP detectable by immunofluorescence in the livers of nu/nu, nu/+ and +/+ mice were quite comparable, and thus could not have been responsible for the alterations in phagocytosis found in leukocytes of athymic nude mice during their ontogenetic development.

Monoclonal antibodies against pig transferrin. Blocking and binding activity.

Monoclonal mouse anti-pig transferrin antibodies PTF-01, PTF-02 and PTF-03 and anti-human transferrin antibody HTF-14 detect transferrin coupled with Sepharose particles in an indirect immunofluorescence test. Only the PTF-03 antibody can be used for immunofluorescence detection of pig transferrin bound to specific receptors on the plasma membrane. The binding of iodinated pig transferrin to PK cells was studied. It could be blocked by non-labelled transferrin in excess, by pig serum or by anti-pig transferrin monoclonal antibodies. PTF-03 expressed the lowest blocking activity among the antibodies tested.

Localization of the antigen and antibodies in the placenta of immunized sheep.

Placentomata of sheep immunized with human serum albumin (HSA) were examined. Both HSA and immunoglobulins were found in the maternal part and maternofetal border of the placenta using FITC labelled antisera on paraffin sections. Radiolabelled HSA was also detected in the fetal blood. The ultrastructure of placentomata revealed immunopathological process.