Fresh human T lymphocytes respond proliferatively to soluble antigens, such as PPD, provided the cell donor has been immunized to those antigens in vivo. This proliferative response requires the addition of antigen-presenting cells bearing autologous HLA-D antigens. This report demonstrates that the proliferative response to PPD activates a collaborative response that aids in the activation of ...

A soluble polysaccharide antigen from the cell wall of Rothia dentocariosa ATCC 17931 has been isolated, purified and characterized by serological and chemical procedures. The polysaccharide (RPS) was found to be located at the surface of cells grown under diverse environmental conditions, and could be easily detected on cells in pure culture or in clinical samples from humans and experimentall...

Freezing of the chorioallantoic membrane after brief fixation in formalin preserves antigenicity of cellular components and allows penetration of ferritin-conjugated antibody. Dense aggregates of viral antigen, presumed to be of the soluble type, were found in the nuclei of cells infected with influenza virus. Intracytoplasmic antigen, on the other hand, was widely dispersed. The experimental o...

Soluble and particulate complement-fixing antigens of Rickettsia sennetsu were prepared from spleen suspensions of mice infected with the rickettsia and treated with cyclophosphamide. The medium used during purification of antigens, a solution consisting of equal volumes of phosphate-glutamate-sucrose buffer and veronal-buffered saline, was suitable for obtaining antigens with high titers and n...