Naturally evolving antibodies attain elevated affinity in germinal centers (GCs).[1] In these dynamic open micro-structures, competition between B cell clones and their somatic mutants drives an increase average across individual populations of up to a few thousand cells. Such evolutionary learning the antigenic target (known as maturation), however, eventually saturates. Most notably, saturati...

1. The alcohol-soluble extract of heterogenetic antigen, which possesses the specific chemical structure of the entire antigen, has a detectable but generally very slight power to increase the amount of heterogenetic antibodies, when injected into rabbits. 2. This substance can be transformed into an efficient antigen by mixing it with protein solutions such as diluted normal serum. 3. Such mix...

AIMS To determine whether the monoclonal antibody (MoAb) 83D4, previously shown to be highly specific for carcinoma cells, can be used as an immunocytological marker to discriminate between benign and malignant cells in serous effusions; and to test for a correlation between expression of the antigen reacting with MoAb 83D4 on effusion cells and the amount of soluble 83D4 antigen in effusion fl...

A mouse melanoma (B16) antigen was investigated at a cellular level by three blocking experiments using monoclonal antimelanoma antibodies, soluble melanoma antigen, and enzyme-treated B16 melanoma cells as inhibitors. The activity of antimelanoma cytotoxic T-lymphocytes (CTL) was specifically reduced by addition of the mixture of two monoclonal antimelanoma antibodies, one (M2590) recognizing ...

Soluble precipitating antigens of Brucella suis have been, in various degrees, purified by filtration on Sephadex gels. The most useful gels employed were Sephadex G-150, Sephadex G-200, and Sepharose 4B. Although not all fractions proved to be immunologically pure, some crude molecular-size estimates of most of the 13 soluble antigens of the Brucella cell could be given. In addition, monospeci...

A soluble wall-associated common protein (WAP) has been isolated from cell wall-extracted antigens of exponentially growing cells of Streptococcus sanguis OMZ9, two serotypes (a and e), of Streptococcus mutans and Actinomyces viscosus OMZ104. The WAP antigens from the different strains were obtained by chromatography on an anti-rabbit immunoglobulin column of sodium dodecyl sulfate-dissociated ...

Cross-presentation is a critical process by which antigen is displayed to CD8 T cells to induce tolerance. It is believed that CD8 dendritic cells (DCs) are responsible for cross-presentation, suggesting that the CD8 DC population is capable of inducing both cross-priming and cross-tolerance to antigen. We found that cross-tolerance against intestinal soluble antigen was abrogated in C57BL/6 mi...

A mouse melanoma (B16) antigen was investigated at a cellular level by three blocking experiments using monoclonal antimelanoma antibod ies, soluble melanoma antigen, and enzyme-treated B16 melanoma cells as inhibitors. The activity of antimelanoma cytotoxic I -lymphocytes (CTL) was specifically reduced by addition of the mixture of two mono clonal antimelanoma antibodies, one (M2590) recognizi...

A cross-reaction between Acinetobacter calcoaceticus and chlamydiae is described. A water-soluble, heat stable, non-dialyzable antigen was extracted from Acinetobacter species by boiling. This antigen fixed complement in the presence of homologous hyperimmune sera from rabbits or guinea pigs and in the presence of heterologous human or hyperimmunized animal sera containing chlamydial antibodies...

delayed-type hypersensitivity reaction measured by skin testing, is an important tool for evaluation of cellular immune response in leishmaniasis and has been used recently as an indication of exposure to infection. skin testing in leishmania infection needs a standard reagent with high specificity, sen sitivity, and potency. in the present work, a soluble leishmanin, and three whole parasite p...