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J C Jensenius

Publications and source records attributed to J C Jensenius.

At least 145 records · Page 8Linked to original sources
PubMed1981

B-L antigens (Ia-like antigens) of the chicken major histocompatibility complex.

This paper reviews the present knowledge of B-L antigens encoded by the chicken B complex as regards to the following aspects: (1) identification and cellular expression, (2) structural studies, (3) evidence for two distinct populations of B-L antigens, (4) mapping of B-L loci of the B complex, (5) B-L and immune response, and (6) the role of the B-L antigens for the control of mixed lymphocyte reactions (MLR) and graft-versus-host (GVH) reactions. It is concluded that B-L antigens of the chicken exhibit extensive homology with mammalian Ia antigens. A genetic map of the B complex is presented.

Animals↗
PubMed1981

The still elusive T cell receptor: on the possibility of a common V-gene pool for B- and T-cell-antigen receptor molecules.

The contention that VH constitutes a part of T-cell receptors for antigens was probed by purifying rabbit T cells and analysing these cells for non-immunoglobulin VH, i.e. VH not associated with L chain. A number of anti-VH antisera were employed for this purpose, the most important being goat antiserum, reacting with common a1 allotype determinants (allotype determinants expressed on free VH and H chain as well as on intact immunoglobulins), rat antibody against common non-allotype VH determinants (VH framework determinants expressed on VH and H chain as well as on intact immunoglobulins) and chicken antibody against unmasked non-allotype determinants (VH determinants accessible only in the absence of L chain). VH and L chain was quantified by radioimmunoassays on extracts and supernatants from unstimulated T cells as well as from T cells stimulated by concanavalin A and by allogeneic cells. Absolute depletion of Ig-containing and -producing cells was not achieved but in no case was an excess of VH over L chain observed. This indicated that all detected VH originated from cells of the B lineage. The cells were also cultured in the presence of labelled amino acids followed by analysis of detergent extracts and supernatants by immunoadsorption and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) fluorography. Again, no evidence for T-cell VH could be found. Affinity purified anit-VH antibody was used to label viable rabbit T cells through the use of secondary fluorescence-labelled anti-immunoglobulin antibody. No VH-specific labelling of T cells could be observed. Mixed lymphocyte cultures were carried out in the presence of affinity-purified anti-VH antibodies. No inhibition of the reaction could be discerned. The failure to detect T-cell VH is in agreement with the recent finding that the VH-genome in T cells is not rearranged in a functional manner similar to that in B cells.

Animals↗
PubMed1979

Quantification of the pregnancy-specific beta1-glycoprotein (SP1) by immunoprecipitation techniques: the influence of a cross-reacting high molecular weight alpha2-protein.

Two serum proteins with SP1 determinants were separated by means of size chromatography and preparative zone electrophoresis. One of the proteins had beta1 electrophoretic mobility and an estimated molecular weight of 90,000, and the other had alpha2-mobility and a molecular weight around 400,000. When available antibody preparations to SP1 were used, the high molecular weight protein formed immunoprecipitates only when polyethyleneglycol (PEG) was added to the agarose. It is shown that the high molecular weight protein has a pronounced effect on quantification of SP1 by rocket immunoelectrophoresis, whereas the effect was less pronounced but still considerable when quantification was performed by radial immunodiffusion.

Antigens↗
PubMed1978

Antibody against rabbit immunoglobulin VH and L chain allotype determinants in heterologous anti-Ig antisera.

Heterologous anti-rabbit IgG antisera have been examined by radioimmunoassay for the occurrence of anti-VH antibody. Most of the sera contained antibody specific for VH allotype determinants (Aal). The antisera contained as much or more anti-al antibody as estimated in conventional alloantisera. It has further been shown that the anti-L chain antibody in all these sera was specific for L chain allotype determinants. Antibody against H chain-dependent L chain conformational determinants or cross-reacting determinants in CHlgamma and CHlalpha could not be demonstrated.

Animals↗
PubMed1977

VH and L-chain allotype determinants of rabbit IgG and IgA estimated by a semi-automatic, modified Farr-type radioimmunoassay;.

A sensitive radioimmunoassay for rabbit immunoglobulin allotypes has been developed. Separation of antibody-bound and free antigen was accomplished by salt precipitation with ammonium sulfate, followed by collection and wash on glass fiber filters by means of a semi-automatic cell harvester. The efficiency of the collection was increased by the addition of nonionic detergent which was salted out together with the precipitated reagents. The presentation of the a 1 allotype, located in the VH region, was found to be different on IgG and IgA molecules.

Animals↗
PubMed1977

Estimation by radioimmunoassay of VH determinants (Aa1) associated with rabbit T lymphocytes.

A radioimmunoassay with specificity for the a1 allotype determinant of rabbit immunoglobulin (Ig) heavy chains was used for the quantitation of VH in detergent extracts of lymph node cells from a1a1/b4b4 rabbits. B cell-derived Ig in the same extracts was estimated with a radioimmunoassay specific for L-chain. About 2 X 10(5) molecules/cell was found by both assays when assuming a molecular weight of 1.5 X 10(5) dalton. Extracts prepared from lymphocytes depleted of B cells (surface Ig+ cells) were also found to contain corresponding amounts of a1 and L-chain, with values varying from about 10(3) to 10(4) molecules/cellmthe estimates were not influenced by the presence of inhibitors of proteolytic enzymes. Supernatants, obtained after keeping the lymphocytes in culture for 16 h, were analyzed by the same methods. Again, matching amounts of a1 and L-chain were found in supernatants from nonfractionated as well as from B cell-depleted populations. The results obtained indicate that T cells do not carry or produce an excess of a1 compared to L-chain, as would have been expected if the T cell antigen receptor carried the same variable region as the Ig heavy chain while being otherwise composed of nonimmunoglobulin-like structures.

Animals↗
PubMed1977

Interaction between a synthetic polypeptide, TIGAL, and Fc receptors on non-bursa-derived chicken lymphoid cells.

Autoradiographic studies have shown that radioiodinated TIGAL binds in vitro to a small but varying fraction of lymphoid cells from bursectomized, agammaglobulinemic chickens, whereas no binding of radioiodinated TGAL or a variety of other radioiodinated antigens can be observed. The binding of [125I]TIGAL is inhibited by antigen-antibody complexes. Radioiodinated antigen-antibody complexes are bound to a similar proportion of the lymphoid cells from bursectomized chickens, and this binding is inhibited by preincubation of the cells with unlabeled TIGAL but not with TGAL. These results indicate a cross-reaction at the level of Fc receptors between determinants on TIGAL and on IgG.

Albumins↗
PubMed1976

A haemolytic spot test for the estimation of alloantibody against antigens of the major histocompatibility complex.

A haemolytic technique for the assay of alloantibody has been developed. Titration of alloantiserum was accomplished by placing microdroplets of serum dilutions on agarose layers containing the appropriate erythrocytes. Complement-mediated lysis was procured after the addition of rabbit serum. The assay appeared specific for products of the major histocompatibility gene complex in the rat and in the mouse.

Animals↗
PubMed1976

Evidence against T-cell immunoglobulin from radioimmunoassay on serum and cells from bursectomized chickens.

A radioimmunoassay with a sensitivity of about 50 pg of chicken immunoglobulin (Ig) was developed and employed for the estimation of Ig in the serum and in extracts of cells from hormonally bursectomized chickens. Chickens, which were judged agammaglobulinaemic by rocket immunoelectrophoresis, had at 12 weeks of age 5-100 ng of Ig/ml of serum. The Ig concentration was decreasing with a half life of 5 days. Thymus and spleen cells from such hypogammaglobulinaemic chickens were extracted with non-ionic detergents, acid urea, or combinations of urea and detergent, and the extracts were analysed for Ig by the inhibition assay. The amount of Ig found in extracts from thymocytes corresponded to less than a hundred molecules of 7S Ig/cell with a lower value of less than five molecules/cell, while extracts of spleen cells contained Ig corresponding to 60-300 molecules of Ig/cell. The inclusion in the media of a number of protease inhibitors did not increase the recovery. Extracts of thymus and spleen cells from untreated chickens contained Ig corresponding to 10-20 X 10(3) and 50-150 X 10(3) molecules of Ig/cell respectively. The results demonstrate the profound hypogammaglobulinaemia of bursectomized chickens and question the concept of an active production of receptor Ig by bursa-independent T cells.

Animals↗
PubMed1969

Antithrombin 3. Protection against death after injection of thromboplastin.

Intravenous injection of autologous lipoprotein (thromboplastin) or thrombin produced a lethal, hemorrhagic syndrome in chicken embryos. The embryos could be protected from this fatal result by injection of antithrombin III, an alpha(2)-globulin (molecular weight 60,000 to 80,000) purified from human, bovine, and guinea pig blood. Heparin also protected the embryos, but other inhibitors were less protective.

Alpha-Globulins↗
PubMedDate not supplied

Human conglutinin-like protein.

The presence in human plasma of a molecule homologous to bovine conglutinin is indicated by the results of biological and immunochemical analysis. The human conglutinin-like protein shows calcium-dependent binding to complement-treated solid phase IgG and immunological cross-reaction with chicken anti-bovine conglutinin. The binding of the human protein to complement-treated IgG was inhibited by N-acetyl-D-glucosamine but not by other sugars. Analysis by SDS-PAGE and Western blotting showed reaction of anti-conglutinin with molecules of similar mobility to the monomer and hexamer of bovine conglutinin.

Animals↗
PubMedDate not supplied

Isolation of a pentraxin-like protein from rainbow trout serum.

Serum amyloid P-component (SAP) is a glycoprotein consisting of five or ten noncovalently associated identical subunits of molecular weight 19,000-30,000. Herein we report the isolation and partial characterization of a SAP-like protein from rainbow trout serum. The protein was isolated by calcium-dependent binding to Sepharose followed by ion-exchange and size-exclusion chromatography. Rabbit antibody against human SAP reacted with the trout protein and the NH2-terminal sequence of 16 amino acids showed 60% identity with the first 15 residues of human SAP. SDS-PAGE and endoglycosidase treatment indicated that the trout protein is a glycoprotein in which five or six subunits are linked by disulphide bonds. The subunits have a molecular weight of 37,000 of which approximately 13% is due to carbohydrate. We propose to name the trout protein sulphide linked SAP (SL-SAP).

Alpha-Globulins↗