The rate of appearance, in a population of mouse-human heterokaryons, of cells with intermixed mouse and human surface antigens may be used to estimate the rate of lateral diffusion of the antigens in a single cell. Most heterokaryons appear to restrict diffusion of their surface antigens. These restrictions are altered by exposing either heterokaryons or their parent cells to conditions that c...

Surface antigens of Saccharomyces cerevisiae protoplast were visualized immunocytochemically with protein A-gold or ferritin conjugated antibodies. Ferritin particles were densely distributed at the surface of yeast protoplast after treatment with rabbit anti-protoplast serum and ferritin conjugated antibody against rabbit IgM. Control experiments demonstrated that the binding of these ferritin...

The malaria-induced surface antigens on Plasmodium falciparum-infected erythrocytes from West African patients were characterized by agglutination of infected cells by human sera, surface immunofluorescence of live infected cells, inhibition of cytoadherence to C32 melanoma cells by human sera, immunoelectron microscopy (immunoEM), and immunoprecipitation. In a nonimmune individual, serum antib...

The course of infection of Plasmodium fragile in its natural host, the toque monkey Macaca sinica, consists of a primary peak of parasitemia followed by several distinct, successive peaks of lower parasitemia. In the S+ host, the late intraerythrocytic asexual developmental stages of P. fragile induce the expression of antigens on the surface of infected erythrocytes, which could be detected us...

Using indirect immunofluorescence (IFL) on viable human thyroid cultures, it has been shown that, although adult follicular cells do not express blood group ABH antigens in vivo, they invariably reexpress the corresponding antigens on the cell surface when cultured in monolayers, even for very short periods. The absence of blood group antigens on noncultured thyroid cells was confirmed by negat...

Lactoperoxidase-catalyzed radioiodination of cell-surface proteins was used in the isolation of cell-surface immunoglobulin from thymus-derived thoracic duct lymphocytes activated to histocompatibility-2 antigens. Immunoglobulin was identified by specific precipitation with antiserum to mouse immunoglobulin. Polyacrylamide gel electrophoresis of reduced and alkylated precipitates showed that th...

Tumor cells were treated with rabbit antibody to tumor-associated cell surface antigens and tested with erythrocytes coated with antibody specific for the sensitizing rabbit immunoglobulin. The sensitized tumor cells formed rosettes with the indicator cells. By this method, we confirmed that line 1 and line 10 hepatoma cells (from two tumors independently induced by diethylnitrosamine in strain...

L2C is a transplantable B-cell leukemia of strain 2 guinea pigs. Transplantation protection experiments were performed with L2C sublines expressing or lacking cell surface antigens coded for by the I region of the major histocompatibility complex (Ia). A subline (BZ-L2C) that lacked cell surface Ia antigens was immunogenic but relatively resistant to immunological attack. The data suggest that ...

L2C is a transplantable B-cell leukemia of strain 2 guinea pigs. Transplantation protection experiments were performed with L2C sublines expressing or lacking cell surface antigens coded for by the I region of the major histocompatibility complex (la). A subline (BZ-L2C) that lacked cell surface la antigens was immunogenic but relatively resistant to immunological attack. The data suggest that ...