Fc-binding molecules specific for human IgG1 and IgG3 are present in Echinococcus granulosus protoscoleces.

In this work we describe the presence of Fc-binding activity on the suckers and tegument of E. granulosus protoscoleces. A fraction (PSA-Fc+) from protoscolex somatic antigens was isolated by affinity chromatography on human Fc-gamma1-Sepharose.

T cell activation results in physical modification of the mouse CD8 beta chain.

The T lymphocyte glycoprotein, CD8, is an essential component of the response of class I MHC-restricted T cells to Ag. CD8 is expressed on the surface of class I-restricted T cells as disulfide-bonded heterodimers and higher multimers of two distantly related polypeptides, alpha and beta. The CD8 alpha polypeptide, expressed in transfection studies as homodimers, is able to reproduce both the adhesive and stimulatory properties of CD8, leaving the function of the CD8 beta polypeptide unresolved.

Expression of functional IL 2 receptors by lipopolysaccharide and interferon-gamma stimulated human monocytes.

Human peripheral blood monocytes were stimulated with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) alone or in combination. Stimulated but not resting monocytes displayed the Tac peptide of the interleukin 2 (IL 2) receptor within 24 hr as measured by immunofluorescence staining and [3H] Tac binding. The total number of anti-Tac binding sites on co-stimulated monocytes was 13,700.