The isolation of the soluble form of the Enterobacteriaceae common antigen from Salmonella montevideo was achieved by a combination of the phenol/water method and the phenol/chloroform/ petroleum ether extraction procedure. A phenol-soluble fraction highly enriched in the antigen was obtained which was further purified by DEAE-cellulose chromatography. A fraction eluted with 0.9 M ammonium acet...

1. T antigens of group A hemolytic streptococci have been obtained in soluble form by digestion of the bacterial cells with pepsin or trypsin. Large quantities of this antigen were readily extracted from type 1 strains, whereas only small amounts could be obtained from strains of other types. 2. The T antigen, prepared in this way from a type 1 strain, was partially purified by chemical precipi...

Soluble foreign antigen usually leads to a transient clonal expansion of antigen-specific T cells followed by the deletion and/or functional inactivation of the cells. As interleukin (IL)-10 is a key immunoregulatory cytokine, we questioned whether neutralization of IL-10 during priming with soluble antigen could prime for a subsequent T helper cell type 1 (Th1) effector recall response. By usi...

This study was performed in order to define the cellular immune response of 12 recovered cutaneous leishmaniasis subjects to different soluble antigens of the amastigote form of Leishmania major. A soluble leishmanial antigen preparation (SLA) derived from highly-purified amastigotes from infected nude mice was fractionated by Mono Q column using Fast Protein Liquid Chromatography (FPLC) s...

Two serogroups (B and E) of Pasteurella multocida associated with hemorrhagic septicemia in cattle were differentiated by a coagglutination test with antibody-coated staphylococci. The group antigen was soluble and heat stable. It was not detectable in unencapsulated cells or their heated extracts. Adsorbed onto human type O erythrocytes, it could be demonstrated by an indirect hemagglutination...

Programmed death-ligand 1 (PD-L1) is a surface protein overexpressed in tumor cells. Recently, targeted therapy using PD-L1 antibodies to reconstitute the antitumor activity of T cells has received considerable attention as cancer treatment. Among several types anti-PD-L1 antibodies, small-sized antibody fragments are useful agents block for experimental and therapeutic purposes owing their hig...

Type 5 adenovirus was purified by fluorocarbon (freon 113) treatment followed by banding in a CsCl equilibrium density gradient. This method permitted separation of virus from normal host cell materials and virus-specific soluble antigens. Virus banded in CsCl with a mean bouyant density of 1.3349 gm/cm(3). The three virus-specific soluble antigens (group- and type-specific antigens and toxin) ...

Peripheral blood monocytes from polar lepromatous leprosy (LL) patients were unable to support Mycobacterium leprae-induced in vitro lymphoproliferation of HLA-D-matched T cells from tuberculoid leprosy subjects, whereas those from responder individuals were able to do so. Monocyte-rich adherent cells from untreated LL patients released de novo soluble factors which inhibited antigen-induced ly...

Evidence is presented which indicates that influenza virus elaborates a soluble antigen. The antigen is considerably smaller than the virus and can be separated from it, but the virus has not been washed free of antigen. The properties of the antigen suggest that it is an unstable protein of relatively large size.

The synthesis and transport of the soluble antigen of influenza A virus were traced by immunofluorescent staining with human convalescent sera during abortive and complete infection of hamster BHK21 ceils and mouse L ceils. Times of synthesis in the nucleus, transport to the cytoplasm and extrusion by the cell were the same in complete and in abortive infection. The product of abortive infectio...