Avery and Heidelberger and their associates (1-4) have presented convincing evidence that the virulent pneumococcus cell contains two different types of antigens: (1) a type-specific antigen (SP) which gives rise to a type-specific antibody; (2) a species-specific antigen (p)l which gives rise to a species-specific antibody. The typespecific antigenic complex is contained in the intact cell of ...

Intravenous Ig (IVIg) mediates protection from the effects of immune thrombocytopenic purpura (ITP) as well as numerous other autoimmune states; however, the active antibodies within IVIg are unknown. There is some evidence that antibodies specific for a cell-associated antigen on erythrocytes are responsible, at least in part, for the therapeutic effect of IVIg in ITP. Yet whether an IVIg dire...

The possibility that the antigen-presenting "macrophages" interacting with helper cells either directly or via the intermediary action of a soluble factor consisting of Ia antigen and a fragment of immunogen, termed GRG (genetically related factor), are a site of Ir gene action was investigated by using the synthetic polypeptide antigen (T,G)-A--L. It was found that T cells from (responder x no...

Immunological tolerance to a soluble, partially purified fraction of histocompatibility (H)-2(a) antigen was induced in B10.D2 strain mice. The fraction used was obtained after chromatography on a Sephadex G-150 column. Tolerance of humoral-antibody formation (cytotoxins and hemagglutinins) was observed in mice injected with soluble antigen since birth, but cell-mediated immunity, as measured b...

We used enzyme immunoassay to measure apolipoprotein B concentration in human plasma. Pure lipoprotein B was isolated from serum samples of fasting normolipidemic subjects by sequential preparative ultracentrifugation and coated to a polystyrene tube surface by adsorption. Human serum samples and rabbit antiserum to human apolipoprotein B were incubated with the solid-phase lipoprotein B. Solub...

Human blood Vgamma9Vdelta2 T cells respond to signals from microbes and tumors and subsequently differentiate into professional antigen-presenting cells (gammadelta T-APCs) for induction of CD4(+) and CD8(+) T cell responses. gammadelta T-APCs readily take up and degrade exogenous soluble protein for peptide loading on MHC I, in a process termed antigen cross-presentation. The mechanisms underl...

The thymus leukemia (TL) antigen is a major histocompatibility complex-encoded nonclassical class I molecule. Here we present data demonstrating that expression of the TL antigen, unlike other class I molecules, is completely independent of the function of the transporter associated with antigen processing (TAP). The TL antigen is expressed by transfected TAP-2-deficient RMA-S cells when these ...

A series of immunoglobulin (Ig)-transgenic mice were generated to study the functional capabilities of the IgM and IgD classes of B lymphocyte antigen receptor in regulating both cellular development and responses to specific antigen. B cells from Ig-transgenic mice expressing either hen-egg lysozyme (HEL)-specific IgM or IgD alone were compared with B cells from mice that coexpressed IgM and I...

A method for cloning soluble antigen-specific proliferating human T lymphocytes directly from peripheral blood cells of individuals recently primed with the antigen is described. The soluble antigen was keyhole limpet hemocyanin. After expansion in liquid culture, these cells were shown to be antigen specific and to require HLA-DR-histocompatible presenting cells. Recloning of small numbers of ...

A water-soluble component of membranes of cells from a Burkitt's lymphoma cultured cell line was used to develop an antiserum that detects an antigen(s) on acute leukemia cells. This antiserum did not react with nonlymphoid cultured cell lines except for human embryonic kidney cells infected with the Rauscher murine leukemia virus. Absorption studies demonstrated this antigen to be crossreactiv...