Zeitschrift für Immunit?tsforschung: Immunobiology最新文献

Molecular weight determinations of immunoglobulin D suggest the presence of an extra region in the δ chain. In an attempt to locate this region, an IgDλ myeloma protein (Gur), was digested with trypsin for 4 min at 56 ° and the Fc fragment isolated by ion exchange chromatography. N-terminal analysis of this fragment showed a heterogeneity in the site of splitting by trypsin. The Fc was digested with pepsin and trypsin and the cysteine containing peptides isolated by a two dimensional paper high voltage electrophoresis (diagonal map) at pH 3.5. Further purification of these peptides was carried out by HVE at pH 6.5 and 2.1 and their amino acid composition and partial sequence were determined.

Only five cysteic acid peptides were obtained, one corresponding to the inter heavy-heavy bridge and the other four, to intra chain bridges. This finding would exclude the possibility of an extra « classical domain » in this region. The position of these peptides in the δ chain has been arranged based on homology with the other classes of immunoglobulins.

A rapid test for detection of circulating immune complexes in a small serum sample was developed to facilitate clinical diagnosis of immune complex disorders. The test is based on a selective precipitation of soluble circulating complexes of antigen-antibody in 3.75% concentration of high-molecular polyethylene glycol. Precipitation is followed photometrically at 450 nm, 1 cm cuv. after 1 h incubation at room temperature. Comparison of E⁴⁵⁰ values in groups of patients with immune complex disorders, such as rheumatoid arthritis, systemic lupus erythematosus and glomerulonephritis, with healthy controls or patients with non-immunological disorders revealed highly significant differences. Sera of all patients with high clinical activity of disease exhibited positive reaction. In 121 human sera the results of this examination were compared with the results of C l q binding test. There was 73.5% agreement between the results of both methods. Our test is more rapid, suited for routine clinical use.

Roles of T cells in the responses of B cells and B memory cells in chickens were studied using hapten-conjugated carrier antigens. The secondary anti-DNP antibody response to DNP-BSA was generated not only in chickens primed with DNP-BSA but also in those primed with the same hapten on a heterologous carrier such as DNP-BGG and DNP-KLH. Similarly, the secondary anti-DNP response to DNP-BGG occurred in chickens primed with DNP-BSA as well as in those primed with DNP-BGG. Passive administration of anti-DNP antibody did not enhance anti-DNP response to DNP on a heterologous carrier. It is likely, therefore, that carrier-primed cells are not necessary for elicitation of the secondary anti-DNP response, indicating that the carrier effect is not seen in chickens. When chickens primed with DNP-BGG were challenged by DNP-BSA, it was found that DNP-specific memory was generated within a week after priming and maintained longer than for 4 weeks. Moreover, the primary and secondary anti-DNP antibody responses to DNP-BSA of chickens were suppressed markedly by injection of BSA alone. The carrier-induced suppression of anti-hapten response was carrier-specific. The suppressive effect of BSA could be seen in the wide range of doses injected (0.1 to 1 000 mg) and was found to have no relation to immunological tolerance to BSA. The suppressive effect of BSA was exhibited when BSA was injected in the period of from 3 weeks before to 2 days after the challenge by DNP-BSA. Passive administration of anti-BSA antibody could not substitute for the stimulation by BSA in suppressing anti-DNP response to DNP-BSA. It is suggested therefore that the formation of the carrier-specific suppressor cells (T cell) can be activated by injection of carrier alone and results in suppression of anti-hapten response to the hapten on the homologous carrier. From the present study, it has been concluded that helper T memory cells do not seem to play significant roles in generation of the secondary anti-hapten response, and that stimulation by carrier alone is capable of generating the carrier-specific suppressor T cells which act to suppress antihapten response to the hapten on the homologous carrier.

A study was undertaken to establish markers for HBV replication in relation to HBeAg and anti-HBe. HBsAg carriers with serum HBeAg had DNA polymerase activity in the serum and HBcAg in the liver nuclei. Anti-HBe positive and anti-HBe/HBeAg negative sera lacked these markers. For anti-HBc the following geometrical mean titers were calculated: 1 : 12,000 for HBeAg positive, 1 : 9,100 for anti-HBe and anti-HBc positive, and 1 : 2,800 for anti-HBc positive anti-HBe/HBeAg negative asymptomatic HBsAg carriers. Follow up studies revealed mostly unchanged anti-HBc titers in all three groups over an observation period of ten to twenty months. Our data argue for a prolonged HBV replication in all HBsAg carrier subgroups compared to individuals with an uncomplicated acute virus-B-hepatitis. This study gives no final answer whether HBeAg negative HBsAg carriers have a continuous HBV replication.

Cell-free supernatants from cultures of specifically stimulated toxoplasmaimmune T-cells contain factor (or factors) that can in vitro arm non-immune thioglycollate stimulated mouse peritoneal macrophages (MPM) to exert antitoxoplasma activity (anti-toxoplasma arming factor(s) = ATAF). ATAF was not demonstrated in supernatants from cultures of concanavalin A stimulated spleen lymphocyte cultures or specifically stimulated listeria-immune T-cell cultures, although they contained macrophage migration inhibitory factor (MIF). It was found that toxoplama-immune T-cells incubated together with specific antigen for 16 hrs, but not those incubated for 1 or 6 hrs, yield ATAF containing supernatants. Furthermore, production of ATAF in T-cell supernatants was an active temperature dependent process, since it required glucose for its production and appeared in cultures incubated at 37 °C but not at 4°C. ATAF failed to appear in supernatants of toxoplasma-immune T-cells when cultured with specific antigen in presence of actinomycin D, emetine or puromycin but colchicine had no effect on its production. ATAF activity was found to show no genetic restrictions, in that it could induce anti-toxoplasma activity in MPM from mouse strains genetically unrelated to the strain which donated immune T-cells for obtaining ATAF. ATAF could be absorbed out with normal, but not with trypsinized MPM. Neither normal nor trypsinized lymphocytes could absorb out ATAF from active supernatants. Enzyme treatments revealed that ATAF was resistant to DNase and RNase but was inactivated by exposure to trypsin or heating at 58 °C for 30 min. Apparently, ATAF in crude supernatants could be stored at -70 °C for 4 months without loss of its activity. Experiments using «Diaflo» membranes suggest that molecular size of ATAF in crude supernatants lies in the range 50,000–100,000. The above findings have extended our previous observations and further defined the characteristics of ATAF.

M proteins of type 1 and type 12 Streptococcus pyogenes were extracted by means of phage-associated lysin and purified by ion-exchange chromatography on CM and DEAE cellulose. Molecular weight distributions were studied by gel chromatography on Biogel A 0.5 m in a 6 molar urea solution and by SDS electrophoresis. Serological activities were studied by the complement-fixation reaction and immunodiffusion and were compared with the estimated molecular weights. Type-specific and non-specific activity was found to be located on the same polypeptide chain of a size of 2 × 10⁴ daltons (type 1) and 1.5 × 10⁴ daltons (type 12). These serologically active chains are in preparations purified by Chromatographic methods accompanied by polypeptides of different sizes which are held together by noncovalent bonds thus forming molecules above 4 × 10⁴ daltons.

Antibody response and generation of immunologieal memory in chickens after stimulation by bovine serum albumin (BSA) were investigated. A single intravenous injection of BSA induced a relatively high primary antibody response but failed to generate definite memory for the secondary antibody response. Variation in antigen dosage and the time interval between antigen injections did not affect significantly the levels of the primary and secondary antibody responses. The immunogenicity of deaggregated BSA in chickens was as potent as that of aggregated BSA. Soluble adjuvants such as the capsular polysaccharide of Klebsiella pneumoniae, cell wall lipopolysaccharide of Salmonella enteritidis and cell wall peptidoglycan of Staphylococcus epidermidis exhibited little enhancing effect on antibody response and memory. However, stimulation of chickens by BSA emulsified in Freund's adjuvant enhanced generation of memory. Repeated injections of BSA alone also showed a similar effect. It seems likely therefore that in chickens continuous antigenic stimulation is required for generation of definite memory. From the present results it has been concluded that the characteristics of the immune response of chickens to BSA resemble those of mammals to T-independent antigens.

In a comparative study the presently known eleven allotypes of properdin factor B (Bf) were examined. Bf polymorphism consists of the two common alleles F and S, the two less common alleles F 1 and S 1 and seven further rare alleles. A variant designation has been proposed according to their relative electrophoretic mobility in comparison to the migration difference between the S and F 1 band. Three rare variant alleles were redesignated : F 1.55, SO.45 and SO.7, which previously had been described as F 1.6, S 0.8 and S 1, respectively. Conversion studies did neither reveal variant mobility in the Bb nor in the Ba fragment of factor B in three of the rare alleles. This finding confirms the earlier report on one of the variants, possibly suggesting the existence of a so far unknown third clearing fragment.