Immunological communications最新文献

Binding constants for the human IgG-anti human IgG heavy chain were determined from elution profiles obtained by loading human IgG-Sepharose 4B columns with the antibody and eluting it at different NaI concentrations. The agreement between the value obtained at zero NaI concentration and the value determined in solution by equilibrium molecular sieving was good. An application of this column method should be useful for comparison of avidity values of antibody populations of the same specificity.

A naturally occurring heterophile agglutinin directed against human erythrocytes and lymphocytes is present in the serum of the marine mammal, Tursiops truncatus (Bottlenose dolphin). Differential specificity was demonstrated with the use of absorption techniques that showed at least 3 separate specificities directed against erythrocytes, T cells, and B cells, of which the B cell agglutinin was in the highest titer. Isolation techniques employing ion exchange and affinity chromatography have shown these agglutinins to be of the IgM class. Agglutinin activity is lost when lymphocytes are treated with pronase, suggesting that the surface receptor is protein or protein associated.

Out of twenty-nine strains of Acinetobacter calcoaceticus (A. calcoaceticus) only eight adhered to lymphocytes. The percentage of lymphocytes labeled with bacteria varied from 5 to 70%. Most of the labeled lymphocytes had large numbers of bacteria attached to them. The variation in the percentages of lymphocytes labeled in various individuals was minimal.

A single step assay is described which allows detection of IgM and IgG in tissue culture supernatants at concentrations below 100 ng/ml. The assay is based on the agglutination of staphylococcal protein A coated sheep red blood cells (E-spA) in the presence of an enhancing antibody. The assay was designed for the rapid screening of antibody production by hybridoma cultures.

Microspheres of poly(glycidyl methacrylate) and its derivatives have been prepared. The diameter can be varied in the range from 0.5 to 5 micron. Proteins were immobilized on the microspheres by various processes. The maximum amount of covalently immobilized gamma-globulin on the microspheres was found to be about 6 mg/m2. It was shown that dyed microspheres with a diameter of 2-4 micron are applicable to immunological agglutination tests on a microplate as carrier particles substituting for red blood cells.

The magnitude of the primary humoral anti-Thy-1.1 responses was measured by the number of PFC in spleens of B10.S(7R) mice and some of their H-2 heterozygous F1 hybrids immunized with thymocytes of either AKR.TH or B10.S(7R)-Thy-1a strain. These two of the five newly developed strains are non-H-2 incompatible and non-H-2 compatible with B10.S(7R) mice, respectively. The low anti-Thy-1.1 responses of B10.S(7R) mice and their F1 hybrids after immunization with thymocytes from non-H-2 compatible B10.S(7R)-Thy-1a donors indicated that the I-As "allele" of B10.S(7R) mice and the I-A "alleles" of other parental strains tested did not produce a complementary effect that is required for non-H-2 compatible thymocytes to elicit a good anti-Thy-1 response.

We describe a simple and sensitive method for the detection of circulating immune complexes (CIC) in rats and have applied the method to test sera from tumor-bearing rats. CIC were precipitated preferentially with 6% polyethylene glycol, dissolved, and then bound to Staphylococcus aureus that are Protein A (PA) positive. Rabbit-anti-rat IgG (RARG) antibodies were then added and followed by 125I-PA. The RARG sandwich antibody enhanced the sensitivity of detection of CIC in rats at least 5 fold compared to that observed using 125I-PA without RARG.

Two lines of Obese strain (OS) chickens of identical MHC (B) genotype, B5B5, bred over 10 years with different selection parameters, differ in their severity of spontaneous autoimmune thyroiditis. To determine whether alterations in immune responsiveness underly this discrepancy, the two lines were compared for their thyroiditis effector mechanisms. The OS B5B5 chickens, selected for high levels of serum thyroglobulin autoantibody, had correspondingly higher levels of thyroid-specific cytotoxic cells and also antibody dependent cellular cytotoxicity (ADCC) than the equivalent B5B5 line selected solely for the phenotypic trait of hypothyroidism. These results thus emphasize the importance of the non-MHC locus controlling immune responsiveness, in the 3 locus-model for this autoimmune disorder.

The activation level of thioglycolate (TG)-elicited peritoneal macrophages (Mphi) from normal and fibrosarcoma-bearing BALB/c mice was investigated. Lipopolysaccharide was used to distinguish in vitro levels of Mphi activation. The results of cytotoxicity assays, which measured nonspecific killing of P815 tumor cells by activated Mphi, indicated that tumor-bearing host Mphi were primed in situ while normal host Mphi remained in a resting state. This level of Mphi induction may contribute to the resulting tumor-bearing host T cell immune hyporesponsiveness.

Two synthetic peptides corresponding to surface regions of sperm whale myoglobin that are not antigenic in the native molecule were used in their free form (i.e. not coupled to a carrier) to immunize separate groups of Balb/cByJ mice. The synthetic peptides corresponded to regions 1-6 and 121-127. Serum samples obtained from each group of mice contained antibodies that bound specifically to myoglobin and exclusively to the immunizing peptide. Monoclonal antibodies to each of the two surface regions were subsequently obtained by hybridizing Fa/O mouse myeloma cells with spleen cells derived from each group of mice. These monoclonal antibodies were IgM (kappa). They expressed the same isotype as the antigen specific serum antibodies produced by the mice whose spleen cells were used for hybridization. Solid phase radioimmunoassay studies also indicated that each monoclonal antibody, like the immune serum of the parent animals, bound specifically to myoglobin and exclusively to the synthetic peptide used as an immunogen. These results suggested that the hybridoma antibodies expressed submolecular binding specificities that were the result of peptide immunization rather than hybrid selection and that monoclonal antibodies with preselected submolecular binding specificities to non-antigenic surface regions in a protein molecule can be produced by the techniques of somatic cell hybridization when the corresponding free synthetic peptides are used as immunogens.