Lymphocyte subsets in patients with aplastic anemia.

Lymphocyte subsets were enumerated in a group of 31 patients with aplastic anemia. Abnormal numbers of immunoregulatory T-cells were found in some patients: 26% of them showed a reversed helper/suppressor ratio. Seven of 18 patients showed significantly decreased proliferation in response to PWM; this hyporesponsiveness was present in 75% of patients with a reversed helper/suppressor ratio and in 10% of those with a normal helper/suppressor ratio (R = 0.

Development of monoclonal antibodies to proteins separated by two-dimensional gel electrophoresis.

We have developed techniques for the production of monoclonal antibodies using Coomassie blue-stained protein spots cut from high resolution 2-dimensional polyacrylamide gels. The gel spots were homogenized with Freund's adjuvant and injected sub-cutaneously into a mouse, at several places along the flank. After boosting twice the spleen cells were hybridized by standard methods.

Acquired immunodeficiency syndrome associated with blood-product transfusions.

A 53-year-old white man had fever, malaise, and dyspnea on exertion. His chest roentgenogram was normal, but pulmonary function tests showed impaired diffusion capacity and a gallium scan showed marked uptake in the lungs. Results of an open-lung biopsy documented Pneumocystis carinii pneumonia.

Functional studies of Willebrand factor using monoclonal antibodies.

Previously described monoclonal antibodies to porcine Willebrand factor were used to study various functional assays of Willebrand factor. These antibodies comprise at least five separate specificities as determined by differential reactivity in three distinct binding assays. The antibodies were tested for their effect on the in vivo bleeding time, in vitro bleeding time, and ristocetin cofactor activity.

Monoclonal antibodies to human coagulation factor V and factor Va.

BALB/c mice were immunized with human factor V. The immunogen was a mixture of procofactor (factor V) and thrombin-activated cofactor (factor Va). Spleen cells were obtained from an immunized animal and fused with NS-1 murine myeloma cells.

Monoclonal antibodies selective for activated Factor V. Immunochemical probes for structural transitions occurring during the thrombin-catalyzed activation of the procofactor.

Monoclonal antibodies have been used to probe for structural transitions which potentially occur during the activation of bovine Factor V by thrombin. One of these antibodies (alpha 2D) is reactive with an epitope on the NH2-terminal segment of Factor V (i.e.

A monoclonal antibody which inhibits the factor Va:factor Xa interaction.

An immunoprecipitation technique has been used to determine the subunit specificity of two of the monoclonal antibodies to bovine Factor V(Va) developed by this laboratory. One of the antibodies is specific for the 74,000-dalton subunit (the E chain) of Factor Va, and the other antibody is specific for the 94,000-dalton subunit (the D chain). The binding of Factor Va to phospholipid was studied by light scattering, and the interaction of Factor Xa with phospholipid-bound Factor Va was examined using 5-dimethylaminonaphthalene-1-sulfonyl-glutamyl-glycyl-arginyl-Xa (Dns-EGR-Xa).

Monoclonal antibodies selective for the functional states of bovine factor V and factor Va.

Hybridoma technology has been used for the production of murine monoclonal antibodies to bovine coagulation Factor V and its thrombin-activated product, Factor Va. Hybrid cell cultures were assayed for the production of anti-Factor V and anti-Factor Va antibodies by a solid-phase radioimmunoassay. Antibody-producing cell lines were selected, cloned and grown as ascites tumors.

Beta 2-microglobulin determined by radioimmunoassay with monoclonal antibody.

In this sensitive radioimmunoassay for beta 2-microglobulin (beta 2-M) involving a commercially available monoclonal antibody, we used a second monoclonal antibody, produced in our laboratory, for affinity-chromatographic purification of beta 2-M. Both monoclonal antibodies bound to all of the charge isomers of beta 2-M identified by two-dimensional gel electrophoresis. Polyethylene glycol was used to separate the phases after incubation for 3 h at room temperature.

Monoclonal antibodies to porcine factor VIII coagulant and their use in the isolation of active coagulant protein.

Partially purified preparations of porcine factor VIII:C were used to immunize mice and spleen cells from the immunized animals were fused to NS-1 mouse myeloma cells. The ability of hybrid culture fluids to bind factor VIII:C was detected with a radiolabelled, affinity-purified, human antihuman VIII:C inhibitor. Three cloned hybrid lines have been obtained that preferentially bind to VIII:C when compared to von Willebrand factor binding.

The clinical aspects of biclonal gammopathies. Review of 57 cases.

Between 1966 and 1979, biclonal gammopathy was recognized in 57 patients. Clinical and laboratory features differentiated three groups: biclonal gammopathy of undetermined significance, 37 cases (65 percent); multiple myeloma, nine cases (16 percent); and lymphoproliferative disease--including lymphoma, macroglobulinemia, chronic lymphocytic leukemia and unclassified lymphoproliferative disorders--11 cases (19 percent). With biclonal gammopathy of undetermined significance, symptomatic multiple myeloma developed after two years in one patient; the others remained stable.

Monoclonal antibodies to von Willebrand's factor: reactivity with porcine and human antigens.

Monoclonal antibodies to porcine von Willebrand's factor (vWf) were obtained from hybridomas derived from the fusion of NS-1 plasmacytoma cells and spleen cells from immunized BALB/c mice. Twenty hybrids were positive in a radioimmunoassay based on the ability of immobilized hybridoma antibodies to bind porcine vWf as detected by the subsequent binding of 125I-polyclonal rabbit anti-vWf. Growth of the hybridomas as ascitic tumors yielded fluids having titers in this assay ranging from 8 x 10(7) to 8 x 10(11).

Isolation of functional human coagulation factor V by using a hybridoma antibody.

Spleen cells obtained from mice immunized with partially purified human coagulation Factor V were fused with NS-1 mouse myeloma cells, and hybrids were selected. Culture media were screened for anti-Factor V activity, and an antibody-positive clone was obtained and passaged as an ascites tumor in mice. The ascitic fluid from the hybridoma-bearing mouse could be diluted 1:10(6) before losing reactivity in an anti-Factor V radioimmunoassay.

Myeloma-induced immunosuppression: a multistep mechanism.

Hosts of plasma cell tumors have a depressed primary antibody response. We have investigated the ability of cell homogenates and culture fluids from short-term cultures of spleen cells and tumor cells of mice bearing the MOPC-315 plasmacytoma to suppress the in vivo primary antibody response to sheep red blood cells. The homogenates and culture fluids of both MOPC-315 spleen cells and tumor cells suppress the antibody response in a dose-dependent manner.

Role of intracisternal A-particles and of RNA molecules in plasmacytoma-associated immunodeficiency.

A subcellular fraction from murine plasmacytoma cells was shown to suppress the primary antibody response when injected into normal mice. The active subcellular fraction copurified with intracisternal A-particles. The RNA extracted from subcellular fractions enriched in A-particles was also immunosuppressive.