Augmentation of delayed-type hypersensitivity by doses of cyclophosphamide which do not affect antibody responses.

Mice immunized with more SRBC than are required to produce optimal delayed-type hypersensitivity reactions, developed good antibody responses and poor delayed foot pad reactions. Cyclophosphamide treatment in low doses (20 mg/kg) before immunization, augmented the delayed-type hypersensitivity without affecting antibody responses. Cyclophosphamide did not augment delayed responses to optimal doses of SRBC (0.

Cytophilic antibodies in mice contact-sensitized with oxazolone. Immunochemical characterization and preferential binding to a trypsin-sensitive macrophage receptor.

Oxazolone-specific cytophilic antibodies in the sera of non-immune CBA mice and mice contact-sensitized with oxazolone, were studied with a rosette test employing peritoneal exudate macrophages and oxazolone-coupled sheep erythrocytes. Macrophage rosettes, produced by direct or indirect cytophilic antibodies, were found to depend on optimally hapten-coupled erythrocytes. Sera obtained 1 week after contact sensitization with oxazolone contained principally 7S IgG2a cytophilic antibodies.

Cutaneous basophil hypersensitivity in contact-sensitized guinea pigs. I. Transfer with immune serum.

Cutaneous basophil hypersensitivity, an immune inflammatory reaction characterized by infiltrates of basophils and a delayed time-course, was studied in guinea pigs contact sensitized with oxazolone. Routine histological techniques, employing ordinary paraffin sections, were modified to study this reaction. When biopsies of contact lesions were processed by these methods dense infiltrates of basophils could be demonstrated.

Augmented agglutination of erythrocytes in the presence of macrophages; a new assay for antibody.

Normal mouse peritoneal exudate cells (PEC), consisting of 90–95 per cent macrophages, were used to augment haemagglutination in microtrays. Antibody titres were augmented 1000-fold when 10 PEC/ml were mixed with sheep erythrocytes (SRBC) and added to serial dilutions of mouse anti-SRBC sera. This method has certain advantages over conventional antiglobulin augmented haemagglutination.

Contact sensitivity to oxazolone in the mouse. VIII. Demonstration of several classes of antibody in the sera of contact sensitized and unimmunized mice by a simplified antiglobulin assay.

CBA mouse antibodies to oxazolone were assayed by direct and antiglobulin augmented haemagglutination, using oxazolone coupled sheep erythrocytes. The antiglobulin Coombs' test was simplified by eliminating washing the sensitized cells and running the entire assay in a microtitre plate. Oxazolone antibodies of IgM, IgG and IgG classes were found in unimmunized mice, and antibodies of significantly higher titre were found in IgM, IgG, IgG, and IgG classes of contact sensitized mice.