Zeitschrift für Immunit?tsforschung: Immunobiology最新文献

Rabbit type-specific opsonic antibodies to type 1 and type 12 streptococci were isolated by affinity chromatography on immobilized phage-enzyme extract. They were tested by precipitation in gel, bactericidal test and radioimmunoassay. Only type-specific activities were demonstrated. These activities were distributed homogeneously according to avidity. No suggestion of opsonizing and precipitating activities being separable from each other was found.

These highly purified rabbit antibodies were marked by radioiodination and used to titrate human anti-M antibodies by competition. These marked antibodies were also used for the study of type-specific antigenic determinants on streptococcal antigens.

We developed a new procedure for the rapid and gentle isolation of the human complement component C6 comparable to that described previously for C9. The procedure is based on affinity chromatography. As a first step, C6 is immunoabsorbed on insolubilized anti-C6 antibodies. These antibodies were derived from C6-defective rabbits (Freiburg strain). C6 was eluted with 3 M thiocyanate, pH 7.2, with a recovery of 15-23% of its hemolytic activity and a more than 270-fold purification. Impurities were removed in a second step by an «anti impurity» column. The final product yielded a 12% recovery of the hemolytic activity and the purification factor was higher than 1300. The final product was homogeneous in SDS polyacrylamide and immunoelectrophoresis.

Three cytotoxic systems, NK, ADCC and the seemingly indiscriminative cytotoxiciry of in vitro activated lymphocytes (cultivated with K 562) were found to require Ca++ and did not function in Mg^{+ +}. The optimum concentration of Ca^{+ +} was identical for the three systems and for various lymphocyte subsets.

15 minutes after initiation of the interaction cell damage had already occurred in all three systems.

If crossreacting antibodies between varicella-zoster virus 01ZV) and herpes simplex virus (HSV) exist, one would expect more positive reactions with VZV in a group of HSV positive patients than in a group of HSV negative patients. This statement can only apply to a group of individuals where positive and negative reactions with respect to HSV and VZV are evenly distributed. Such a distribution can only be found among children. Therefore, the relationship between HSV -1 and VZV was the only one which was considered in this investigation, since the incidence of HSV-2 antibodies in children is very rare.

The sera from 197 children were examined using the neutralization test (NT), the complement fixation test (CFT) and the indirect immunofluorescent assay (1FT) and could be classified as either HSV positive (80) or HSV negative (117). The children's ages were similar in both groups. Approximately the same proportion of VZV positive sera was found in both groups when examined using 1FT (53% in the HSV positive and 47% in the HSV negative group). However, when the CFTwas applied the proportion of VZV positive sera in the two groups differed markedly (22% of the HSV positive sera and 38% of the HSV negative sera).

These findings suggest that crossreactivity observed between HSV and VZV in acute HSV and VZV infections is evidently not dependent on crossreacting antibodies but is apparently confined to the cellular level of the immune response.

Mice were primed in vivo by injection of fetal calf serum (FCS) and their spleen cells were incubated in vitro for 5 days in medium containing 10% FCS. This resulted in the development of cytolytic activity, which was most probably due to «T» cells, since effector cells 1) were sensitive to anti-Thy 1 antiserum or monoclonal antibodies in the presence of complement, 2) were not retained on Ig-anti Ig columns, 3) did not develop from «nude» spleen cells. Further arguments for the T cell nature of these effector cells came from their specificity. Blocking experiments using unlabeled competitor cells demonstrated that FCS-induced cytolysis was polyclonal, with clones recognizing allogeneic or syngeneic determinants possibly related to allo or self H-2. In keeping with polyclonality, cytolysis tested on any given target cell was greatly increased by adding Concanavalin A during the cytolysis test. Experiments were made to investigate whether in particular the anti-self cytolytic activity was directed against FCS determinants. We feel that this possibility, although not formally excluded, was made unlikely.

The polyclonal specificity at the effector stage stood in sharp contrast to the serum specificity at the induction stage (reported elsewhere). We demonstrated that these two sets of specificities corresponded to two sets of specific cells. A first population of FCS-primed cells had promoter .. activity, in the sense that it could trigger a second population of «precursor» cells to differentiate into polyclonally cytolytic T cells.

A human lymphoblastoid cell line, secreting specific antibody against Group A carbohydrate (A-CHO) was established by pre-selection of antigen binding normal human lymphocytes, followed by Epstein-Barr virus (EBV) induced immortalization. Culture supernatants were assayed for anti A-CHO antibodies by radioimmunoassay, N-acetyl-glucosaminecoupled T₄-phage plaque inhibition tests and passive hemagglutination. As a rule, the supernatants contained about 10 I-lg/ml anti-A-CHO antibodies of the μgM-kappa type. The antibody was fractionated and partially purified on an N-acetyl glucosamine Sepharose 4B column with a recovery of about 3 μg/ml of supernatant.

Wheat-germ agglutinin agglutinates all strains of group A and group C streptococci, a part of the strains tested of groups Band E and some strains of other streptococcal groups. It also agglutinates peptidoglycan of several streptococcal groups and precipitates some group specific carbohydrates of streptococcal cell walls as well as some teichoic acid extracts.

The basis for agglutination and precipitation of streptococci and streptococcal cell wall polymers appears to be the interaction of the combining sites of the agglutinin with N-acetyl D-glucosamine residues present in the cell wall polymers, either in terminal or in internal positions respectively.

A methylcholanthrene induced tumor of BALBc (H-2^d) origin had a high rate of spontaneous regression when transplanted into syngeneic animals. The tumor induced in BALB/c mice iso-antibodies with high anti-tumor cytotoxic activity. A specificity analysis of such BALB/c anti MCG4 sera revealed that the antibodies were directed against a tumor antigen which is very similar to H-2-aIIoantigens (e.g. H-2.5) expressed on normal cens of certain foreign mouse strains. The sera also reacted with nine out of ten B10.W congenic strains bearing H-2^wi haplotypes derived from wild mice.

Whether the tumor antigen is identical with foreign H-2 antigens or only cross-reactive cannot be decided at present.

T helper cell factors (HF) have been preparated against protein and synthetic antigens by restimulating in vitro induced helper cells with small amounts of antigen. HF when tested in vitro are antigen specific and capable of replacing T cells, initiating a thymus dependent IgM response. In the in vivo adoptive transfer assay HF is capable of replacing T helper cells and is active at very high dilution, inducing both IgM and IgG responses. When tested on unirradiated DNP primed animals the HF was able to initiate a thymus dependent anti-hapten response, comparable to that seen with helper T cells, of both IgM and IgG class. It was also shown that HF acts on anti-Thy 1 treated spleen cells. The results indicate that antigen specific helper factors may be one of the physiologic mediators of T -B interactions in intact animals.