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J Lisowski

Publications and source records attributed to J Lisowski.

At least 55 records · Page 3Linked to original sources
PubMed1983

Immunologically active nonapeptide fragment of a proline-rich polypeptide from ovine colostrum: amino acid sequence and immunoregulatory properties.

It has been previously found that a proline-rich polypeptide (PRP) isolated from ovine colostrum has a regulatory effect on the immune response. To study the relationship between the structure of PRP and its immunomodulatory properties, the polypeptide was digested by chymotrypsin. Products of the proteolysis were separated by gel filtration and three fractions were obtained: PRP-1, PRP-2 and PRP-3. The activity of the fractions was compared with the activity of the untreated PRP. It was found that PRP-1 was inactive, whereas PRP-2 and PRP-3 showed an activity in the regulation of the immune response assayed by measurement of PFC, and by studying effects on delayed hypersensitivity, formation of autologous rosette-forming cell, and sensitivity of thymocytes to hydrocortisone. The activity of PRP-2 and PRP-3 was comparable to the activity of PRP. The PRP-3 fraction of low mol. wt was further purified and a pure nonapeptide of mol. wt 1000 (PRP-3b) was isolated. The amino acid sequence of PRP-3b was: Val--Glu--Ser--Tyr--Val--Pro--Leu--Phe--Pro. The nonapeptide showed the full spectrum of biological activities of PRP. Comparison of terminal amino acid suggested that PRP-3b was neither the NH2- nor the COOH-terminal fragment of PRP. The amino acid sequence of the nonapeptide indicated that PRP-3b is different from other known immunomodulators.

Amino Acid Sequence↗
PubMed1983

The inhibitory activity of a proline-rich polypeptide (PRP) on the immune response to polyvinylpyrrolidone (PVP).

The effect of PRP on the humoral immune response to PVP was studied. It was found that PRP administered before immunization with PVP360 inhibits the immune response to this antigen. The studies revealed that PRP caused the increase of the activity of an "intrinsic" suppressor cells probably by enlarging the pool of these cells. PRP also increases generation of precursor cells for the "induced" suppressor category. The precursor cells are the targets for PVP25 giving rise to the antigen-specific, "induced" suppressor cells. The mechanism of the inhibitory action of PRP on the immune response to PVP is discussed.

Animals↗
PubMed1983

Effect of PRP on autologous rosette formation in mice.

It was demonstrated that PRP changes the number of autologous rosette forming cells (ARFC) among thymocytes and splenocytes in mice. Majority of ARFC was found in cortisone-resistant (CR) thymocytes and among glass adherent cells. Treatment of lymphocytes with PRP in vivo and in vitro causes significant reduction in the ARFC formation. It was revealed that PRP acts on two cell subpopulations belongings to both CS and CR thymocytes. PRP affecting cortisone-resistant glass adherent lymphocytes (CR GAL), accounting for the majority of ARFC within the thymus, causes a significant decrease of ARFC number, whereas, it elevates the number of ARFC in cortisonesensitive nonadherent lymphocytes (CS NAL). This phenomenon was the result of the parallel alteration in cortisone-sensitivity and the cell function by respective thymocyte subpopulations.

Animals↗
PubMed1982

Human placental membrane receptor for IgG. Purification of the receptor and its subunit structure.

The method of purification of the human placental Fc receptor to an active form is described. The FcR was purified from the glycoprotein fraction of the placental membranes by immunoprecipitation and chromatography on DEAE-cellulose. The purified FcR corresponded to 1.5-2% of the protein present in the crude glycoprotein fraction (PGP) and showed the tendency to aggregate. In the presence of 1% SDS, 4 M urea or 5 M guanidine- HCl the placental FcR dissociated into subunits of molecular weight of 60,000-65,000. The 60,000-65,000 dalton glycoprotein subunits regarded as monomers of FcR are composed of two chains of molecular weight 25,000-30,000, linked by disulphide bonds. The subunits, after removal of dissociating agents, displayed IgG binding activity.

Chromatography, DEAE-Cellulose↗
PubMed1982

Effect of proline-rich polypeptide on donor cells in graft-versus-host reaction.

The effect of a proline-rich polypeptide (PRP) isolated from early sheep colostrum on the graft-versus-host (GvH) reaction was studied. Unfractionated thymocytes, treated with PRP in vivo or in vitro, acquired the ability to elicit the GvH reaction. In fact PRP elicited GvH reactivity in cortisone-sensitive thymocytes and cortisone-sensitive thymocytes become cortisone-resistant after incubation with PRP. On the other hand, some of the cortisone-resistant thymocytes become cortisone-sensitive when treated with PRP and the ability to induce the GvH reaction was reduced.

Animals↗
PubMed1981

Chemical and physical characterization of a proline-rich polypeptide from sheep colostrum.

A proline-rich polypeptide isolated from sheep colostrum is described. The molecular weight of the polypeptide determined by gel filtration is 17 200. However, in the presence of guanidinium chloride the molecular weight found is about 6000. The polypeptide contains about 22% of proline, a high proportion of non-polar amino acids, a low percentage of glycine, and no alanine, arginine and cysteine residues. The only N-terminal amino acid found is leucine. C.d. spectra in water and in 50% (v/v) trifluoroethanol suggest the presence of block sequences of proline residues forming helices of polyproline II type. The proline-rich polypeptide is soluble at 4 degrees C but is reversibly precipitated on warming to room temperature. Maximal precipitation is observed at pH 4.6 and at ionic strength above 0.6. The precipitation depends on the concentration of the polypeptide. No effect of other proteins, Ca2+ and Zn2+ ions on the precipitation of the polypeptide was found. The proline-rich polypeptide is not an amphipathic protein. The lack of effect of the polypeptide on proteolytic enzymes ruled out the possibility that it is an inhibitor of proteinases.

Amino Acids↗
PubMed1981

Immunoglobulins of colostrum. V. Localization of structural differences between serum and colostral ovine and bovine IgG1 and IgG2 immunoglobulins.

Studies on localization of structural differences between ovine and bovine serum and colostral IgG immunoglobulins are described. Comparison of heterogeneity, susceptibility to proteolytic enzymes, peptide maps, amino acid compositions, and antigenic properties of immunoglobulins and their Fab and Fc fragments and H and L chains showed that structural differences are localized in the Fc region. The strongest differences were found in case of IgG2. It was also shown that no Fc fragments could be obtained from bovine serm IgG2 and ovine serum and colostral IgG2 due to their susceptibility to papain and trypsin. The results obtained confirmed our suggestion that colostral IgG2 are locally synthesized in mammary glands, whereas colostral IgG1 might be a mixed population of molecules locally synthesized and transferred from the serum.

Amino Acids↗
PubMed1980

Circular dichroism studies of M and N blood group-specific glycoproteins and glycopeptides.

CD spectra of M and N blood group glycoproteins and their NH2-terminal tryptic glycopeptides were compared. The CD spectra of glycoproteins obtained suggest the presence of a low content of alpha-helix. The M glycoprotein contained a higher percentage of a periodical structure. CD spectra of M and N tryptic glycopeptides, both sialoglycopeptides and desialylated preparates, were similar and showed positive ellipticities in the range of 210--240 m. However, the spectra of desialylated glycopeptides were red-shifted in respect to spectra of sialoglycopeptides. The CD spectra of glycopeptides suggest the presence of beta-turns.

Circular Dichroism↗
PubMed1980

Studies on properties of guinea pig peritoneal macrophage Fc receptor.

Properties of guinea pig peritoneal macrophage Fc receptor for IgG are described. It was found that the receptor was binding both monomeric and aggregated rabbit IgG. The values of apparent affinity constants were 2.6 +/- 0.6 x 10(8) M-1 and 3.84 +/- x 10(8) m-1 for IgG monomers and aggregates, respectively. The number of monomeric IgG molecules bound was calculated to be 3.3 +/- 0.2 x 10(5) per cell and of aggregated IgG 3.95 +/- 0.12 x 10(5) per cell. When the homologous system: guinea pig IgG2 and guinea pig macrophages was investigated, the affinity constant found was 1.66 +/- 0.45 x 10(8) M-1 and 2.6 +/- 0.24 x 10(5) molecules of IgG were bound per cell. Both, rabbit IgG and, guinea pig IgG2, interacted wih the same receptor binding sites on macrophages. Treatment of macrophages with 2-mercaptoethanol, formaldehyde, and iodoacetamide was without any effect on the IgG binding properties of cells. Periodate, trypsin, pronase, phospholipase C considerably diminished the number of IgG molecules bound to macrophages. Treatment of macrophages with neuraminidase increased the number of IgG molecules bound per cell. The results obtained suggests that both sugar and protein components are important for the IgG binding activity of guinea pig peritoneal macrophages. Studies on the effect of pH, ionic strength, and temperature on the interaction of macrophages with IgG showed that electrostatic interactions are important for binding of IgG to the macrophage Fc receptor.

Animals↗
PubMed1979

Synthetic antigens: IV. Antigen-binding cells to interpolymer of styrene and maleic acid (PSM) in rats immunized with sheep red blood cells.

The results of studies on the effect of a new synthetic antigens: interpolymer of styrene and maleic acid (PSM) on the immunological response in rats to sheep red blood cells, and vice versa are presented. It was found that in rats, in contrast to mice, PSM did not generate antigen-binding cells for sheep red blood cells. However, an opposite effect was observed: sheep red blood cells generated in rats antigen-binding cells to PSM.

Animals↗
PubMed1979

Proline-rich polypeptide from ovine colostrum: its effect on skin permeability and on the immune response.

The effect of a proline-rich polypeptide from ovine colostrum on the humoral immune response in mice against sheep red blood cells (SRBC) was studied. It was shown that the polypeptide had a regulatory activity stimulating or suppressing the immune response. The proline-rich polypeptide also increased the permeability of skin vessels in guinea-pigs. Studies on the mechanism of the effect of the proline-rich polypeptide suggest that prostaglandins are involved in the activity of the polypeptide.

Animals↗
PubMed1979

Immunoglobulins of colostrum. V. Comparative studies of ovine and bovine serum and colostral IgM.

Comparative studies of physiocochemical properties of ovine and bovine serum and colostral IgM are described. Serologic properties, molecular weight, amino acid composition, carbohydrate content, peptide maps, heterogeneity, and ORD and CD spectra were compared. Colostral IgM have additional antigenic determinants, higher carbohydrate content, lower heterogeneity, and higher content of beta-structure. Different amino acid composition and different peptide maps of serum and colostral IgM were shown. The results obtained suggest that ovine and bovine colostral IgM immunoglobulins may be a mixed population of molecules locally synthesized and transferred from the serum.

Animals↗
PubMed1979

Synthetic antigens III. Antigen-binding cells to interpolymer of styrene and maleic acid PSM and sheep red blood cells in mice immunized with PSM.

Studies on the immune response in mice to a new synthetic antigen interpolymer of styrene and maleic acid (PSM) are described. The immune response was measured by determination of antigen binding cells by means of rosette test with PSM-coated SRBC, An unexpected effect was observed--besides rosette-forming cells for PSM, rosette-forming cells and agglutinating antibodies for sheep red cells were found. The results presented in this paper suggest that PSM is acting both as an immunogen and a polyclonal B-cell activator. As a polyclonal B-cell activator, PSM might stimulate the immune response to sheep red blood cells. However, in the case of PSM, in contrast to other polyclonal B-cell activators, this response is suppressed and delayed. The suppression may be caused by suppressor T-cells generated by PSM or by blockade by PSM of antigen-binding cells and antibody-forming cells for sheep red blood cells. The mechanism of the effect observed is discussed.

Animals↗
PubMed1978

Physicochemical properties of a proline-rich polypeptide (PRP) from ovine colostrum.

Properties of a proline-rich polypeptide (PRP) accompanying ovine colostral IgG2 are described. PRP is soluble at 4 degrees C but reversibly precipitates by warming to room temperature. Maximal precipitation is observed at pH = 4.6, temp. 48 degrees C, and ionic strength higher than 0.6. There is a linear dependence of precipitation on concentration of PRP. Molecular weight of PRP is 38,000 daltons. It is not changed in the presence of 6 M guanidine hydrochloride, SH-compounds, and in the presence or absence of metal ions. PRP is built of one polypeptide chain. No difference in proteolysis of IgG2 by pepsin, papain and trypsin in the absence or presence of PRP was found.

Animals↗