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Biomedical subjects

F Indiveri

Publications and source records attributed to F Indiveri.

At least 127 records · Page 7Linked to original sources

Isolation of human T lymphocytes: comparison between nylon wool filtration and rosetting with neuraminidase (VCN) and 2-aminoethylisothiouronium bromide (AET)-treated sheep red blood cells (SRBC).

Isolation of human T lymphocytes by rosetting with SRBC, centrifugation on Ficoll-Hypaque gradients and lysis of SRBC, which reportedly affects the functional activities of lymphocytes, was compared to isolation of T lymphocytes by filtration through a nylon wool column. The two methods were similar in yields and purity of T lymphocytes. No selective loss of T cell subpopulations was found in T lymphocytes isolated by filtration through a nylon wool column as judged by the percentage of T gamma and T micron and the suppressor and helper activity in functional assays. Therefore, filtration through a nylon wool column is a useful method to purify T lymphocytes and has the advantage of being comparatively simple and quick to perform and of avoiding manipulations which may affect the functional activity of T lymphocytes.

Animals↗

Serological, functional, and immunochemical characterization of a monoclonal antibody (MoAb Q2/70) to human Ia-like antigens.

Serological and immunochemical studies showed that monoclonal antibody Q2/70 (MoAb Q2/70), produced by the hybridoma technique, is specific for human Ia-like antigens. This antibody recognizes an antigenic determinant which is different from those defining the serologic polymorphism of Ia-like antigens, and is expressed on subsets of human Ia-like molecules and on lymphoid cells from other species. MoAb Q2/70 inhibits unidirectional MLRs* between allogenic human lymphocytes, but not between murine and human lymphocytes. In ADCC* assays. MoAb Q2/70 mediates lysis of cultured human B lymphoid cells RPMI 4098, effected by murine splenocytes. The antibody is suitable to isolate immunologically functional B lymphocytes from human peripheral blood.

Animals↗

Lack of association of serologically detectable human melanoma-associated antigens with beta 2 microglobulin: serologic and immunochemical evidence.

Serologic and immunochemical assays showed that human melanoma-associated antigens (MAA) identified with operationally specific xenoantisera were neither spatially nor structurally associated with beta 2-microglobulin (beta 2-mu), the light chain of the HLA-A,B antigen molecular complex; i.e., cultured melanoma cells coated with a specific anti-beta 2-mu xenoantiserum maintained their reactivity with anti-MAA xenoantisera. Furthermore, soluble MAA were not bound by a beta 2-mu immunoadsorbent. Finally, MAA were shed into the culture medium of melanoma cells and then were immunoprecipitated with specific anti-MAA xenoantisera, analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, they appeared as two distinct structures with molecular weights of 240,000 and 94,000 but comprised no structure with the characteristic 12,000 molecular weight of beta 2-mu. Conversely immunoprecipitates obtained by the reaction of spent culture medium of [3H]valine-labeled melanoma cells with anti-beta 2-mu xenoantiserum had the 12,000-molecular-weight component but no structures with the molecular weights established for MAA. Thus the data refute the contention that serologically detectable MAA have a molecular structure similar to that of HLA antigens.

Antibodies, Neoplasm↗

DR (Ia-like) antigens on human melanoma cells. Serological detection and immunochemical characterization.

11 cultured human melanoma cell lines were tested for the expression of DR antigens by using specific allo- and xenoantisera in an indirect rosette microassay. Four of these melanoma cell lines expressed DR antigens, but in lower amounts than expressed on cultured human B-lymphoid cells. Rabbits injected with the DR-positive melanoma cells produced antibodies that were serologically and immunochemically reactive with B-cell-derived DR antigens. Immunochemical studies indicate that melanoma cell-derived DR antigens have a two-chain structure with 34,000 and 27,000 mol wt components. The melanoma cell-derived DR beta-chain at 27,000 mol wt is slightly smaller than that of the Victor cell DR beta-chain whose mol wt is 29,000.

Antigens, Neoplasm↗

Rosetting of human T lymphocytes with goat red blood cells: effect of treatment with 2-aminoethylisothiouronium bromide (AET) and comparison with AET treated sheep red blood cells.

In vitro treatment of goat red blood cells (GRBCs) with the sulphydryl compound 2-aminoethylisothiouronium bromide (AET) increases their specific reactivity with human T lymphocytes without affecting the specificity of the reaction. AET-GRBCs bind to only part of T lymphocytes rosetting with AET-sheep red blood cells (SRBCs): the receptors for both types of RBCs are very simular if not identical, but display higher affinity for AET-SRBCs than for AET-GRBCs. Rosetting of T lymphocytes with AET-GRBCs may be useful to enumerate T lymphocyte subsets in patients with abnormality of the immune system and to fractionate T lymphocyte subpopulations.

Animals↗

Detection of human histocompatibility (HLA) antigens with an indirect rosette microassay.

An indirect rosette assay which utilizes erythrocytes coupled with purified antiimmunoglobulin (Ig) antibodies was modified into a microassay for detecting HLA allo-and xenoantibodies. The test, which is performed in microtiter plates, is specific, reproducible and can handle large numbers of samples. As an inhibition assay the test can detect HLA antibodies even if mixed with antibodies to other cell surface structures. The rosette microassay is at least 10 times more sensitive than the complement-dependent microcytotoxic test and can use target cells which exhibit low viability or abnormal susceptibility to lysis.

Animals↗

Production and characterization of DR xenoantisera: use for detection of serum DR antigens.

Immunoadsorbents consisting of rabbit anti-DR antibodies bound to Staphylococcus aureus were used to bind DR antigens from NP40 cellular extracts of cultured B lymphoid cells. When injected into rabbits, these DR antibody absorbents elicited the production of antibodies that were shown by both serologic and immunochemical techniques to react specifically with the DR antigen molecule. A rosette inhibition assay with B lymphoid cells and anti-DR xenoantisera was used to detect DR antigens in human serum. DR serum antigens could be found in an enriched preparation of serum lipoproteins obtained by centrifugation in KBr. In addition, sera from some patients with neoplastic diseases contained higher levels of DR serum antigens than those found in normal individuals.

Animals↗