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G A Molinaro

Publications and source records attributed to G A Molinaro.

44 records · Page 3Linked to original sources
PubMed1975

A general method for enumerating single cells secreting antigen: albumin-secreting hepatocytes detected as plaque-forming cells.

Sheep erythrocytes, artificially coated with purified antibody specific for mouse serum albumin (anti-MSA Ab-E) were agglutinated and lysed by mouse serum albumin. Mouse liver cells, plated with anti-MSA Ab-E formed hemolytic plaque in a modified plaque-forming cell (PFC) assay. The same cells tested with anti-MSA Ab-E did not rosette in modified immunocyto-adhesion assay. Thus, liver cells secreted molecules (albumin) which were not detectable on the cell membrane. This PFC assay with Ab-E is probably a general method for enumerating antigen-secreting cell.

Agglutination↗
PubMed1975

Enumerating immunoglobulin-secreting cells among peripheral human lymphocytes. A hemolytic plaque assay for a B cell function.

Cells bearing immunoglobulin (Ig) can be enumerated by current methods, but cells secreting Ig (with unknown antibody specificity) can not. By using a reverse plaque-forming cell assay, we counted the Ig-secreting cells in the blood of nonimmunized individuals. Isolated human lymphocytes were plated in gels together with erythrocytes coated with purified antibody to human Ig. After treatment with anti-Ig antibody and complement, the Ig-secreting cells formed hemolytic plaques. In 10 normal individuals, 1.2 +/- 0.4% of the plated mononuclear cells formed plaques; in an individual tested on 7 different days during 3 months, 1.1 +/- 0.2% of the cells formed plaques. From the number of mononuclear cells in the blood, we calculated 22 +/- 8 Ig-secreting cells per mm3 of blood. Enumerating Ig-secreting cells is a new direct assay for a B cell function and need not correlate with quantitating serum Ig. Thus, this assay should be useful for studying Ig-secretion in normal and altered states.

Animals↗
PubMed1975

Rosetting of antibody-sensitized tumor cells with anti-immunoglobulin antibody-coated erythrocytes by a new method for detecting antigens on cells.

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 2 guinea pigs) bear antigens not present on normal liver cells. We also confirmed that line 1 and line 10 cells bear antigenically different tumor-associated cell surface antigens. This method appears simpler than other serological methods for detecting tumor-associated cell surface antigens on tumor cells. Also, this method may be a general one for detecting and enumerating cells bearing surface antigens.

Animals↗
PubMed1974

Antigen-secreting cells: enumeration of immunoglobulin-allotype-secreting cells in nonimmunized rabbits by means of hybrid-antibody-coated erythrocytes in a reverse hemolytic plaque assay.

A reverse hemolytic plaque-forming cell (PFC) assay for the enumeration of immunoglobulin-(Ig)secreting cells in nonimmunized rabbits was developed by using erythrocytes coated with anti-Ig antibody. These indicator cells lysed after reacting with the secreted Ig antigen and complement. The anti-Ig antibodies used were specific for the b4 or b5 allotypic specificities, which are antigenic determinants on the kappa chain of rabbit Ig and controlled by alleles at the b locus. We coated erythrocytes with anti-b4 or anti-b5 antibody, using hybrid antibody with dual specificity to sheep red blood cells and to the b4 or b5 kappa chain. The coated erythrocytes were plated with cells from various lymphoid organs of nonimmunized rabbits. These lymphoid cells formed allotype-specific plaques, i.e., the cells of b4 homozygous rabbits formed hemolytic plaques with anti-b4 but not with anti-b5-coated erythrocytes and vice versa. In eight nonimmunized rabbits, 0.06-0.3% of the spleen cells (590-2900 PFC per 10(6) cells) secreted the b locus Ig allotypes. In three nonimmunized rabbits, 320-590 PFC per 10(6) cells were counted in the lymph node or bone marrow; 26-40 PFC per 10(6) cells were detected in the thymus. Since the b4 and b5 specificities are present on approximately 90% of the serum Ig, our results indicate that less than 1% of the lymphoid cells in nonimmunized rabbits secrete Ig at any one time. By this reverse PFC assay, Ig-secreting cells were for the first time detected as antigen-secreting cells. This assay can be applied to the detection of cells secreting other antigens.

Animals↗