Alan L. Epstein

Identification of a nuclear protein component of interchromatin granules using a monoclonal antibody and immunogold electron microscopy

A monoclonal antibody, designated 780-3, has been generated which preferentially recognizes an antigenic component of interchromatin granules in human cells. By indirect immunofluorescence procedures, monoclonal antibody 780-3 produces a cell cycle-specific speckled nuclear staining pattern in adult human fibroblasts which is dramatically altered during metaphase. In contrast, transformed cells appear to express this antigen throughout the cell cycle in increased quantities. Immunogold electron microscopy revealed that the nuclear antigen is intimately associated with interchromatin granules in human cells. Analysis by immunoblot procedures showed that monoclonal antibody 780-3 recognizes two polypeptides of 105 and 41 kD. From these data, a possible nucleolar derivation of interchromatin granules is discussed. These studies demonstrate for the first time that monoclonal antibodies may be used in combination with immunogold electron microscopy to identify the ultrastructural location of nuclear antigens.

Monoclonal antibodies reactive with B-lymphocytes and histiocytes in paraffin sections

Representative sections of normal lymph nodes, cases of reactive lymphadenopathy, and Hodgkins disease were examined using two monoclonal antibodies reactive in paraffin sections using an immunoperoxidase technique. Antibody LN‐1 recognizes B‐lymphocytes in follicles; antibody LN‐2 recognizes a broader spectrum of B‐cells, and also shows positivity with some monocytes/histiocytes. The pattern of immunostaining with these antibodies is described with particular reference to Hodgkin and Reed‐Sternberg cells. Some of the implications are discussed.

Histiocytic lymphoma cell lines: Immunologic and cytogenetic studies

Cell lines were established from 15 patients with diffuse histiocytic lymphoma (DHL) of the intermediate grade, diffuse large cell (class G), and high-grade, large cell immunoblastic (class H) types. Immunologic studies indicated that 11 of the 15 DHL cell lines were B cell in origin, 2 were histiocytic, and 2 were null cell. Cytogenetic studies revealed 1 hypodiploid, 11 hyperdiploid, and 3 near-tetraploid cell lines. Chromosome #7 was trisomic in 3 lines, chromosomes #12 in 4 lines, and chromosome #13 in 3 lines. Chromosome #2 was monosomic in 3 lines, chromosome #8 was monosomic in 5 lines, chromosome #14 in 4 lines, and chromosome #22 in 6 cell lines. This is of special interest, as chromosomes #2, #8, #14, and #22 are clearly concerned with rearrangements in Burkitts lymphoma and immunoglobulin expression. The most common rearrangement in the DHL cell lines involved chromosome #14 at band 14q32. However, in contrast to Burkitts lymphoma, the pattern of translocation in DHL is between chromosome #14 and usually chromosome #11 or chromosome #18. The 14;18 translocation is not restricted to patients with low-grade follicular, small cleaved cell lymphomas, as has been reported. The 14q+ chromosome is characteristic of lymphoid malignancies in general. It is due, invariably, to a translocation with the breakpoint in band 14q32, which is the locus of the immunoglobulin heavy chain genes. We propose that in each translocation, for example, chromosomes #11 or #18, an oncogene may be transposed onto chromosome #14, and that each 14q+ translocation in DHL represents an event that transposes an oncogene from another chromosome to chromosome #14.

Immunohistologic identification of phenotypic antigens associated with Hodgkin and reed‐sternberg cells. A paraffin section study

A combination of two monoclonal antibodies, designated LN‐1 and LN‐2, were used in an attempt to identify the corresponding antigens in Hodgkin and Reed‐Sternberg cells. The LN‐1 antibody has been shown in previous studies in our laboratories to identify follicular center cells, whereas LN‐2 marks certain B‐cell subpopulations as well as interfollicular histiocytes. Utilizing the perioxidase‐antiperioxidase (PAP) technique, paraffin‐embedded sections were examined representing 39 cases of various histologic subgroups of Hodgkins lymphoma following immunostaining with LN‐1, LN‐2, and the antibody to S‐100. Of these 39 cases, the LN‐2 antibody was found to consistently mark the majority of Hodgkin and Reed‐Sternberg cells. LN‐1 was found to identify Hodgkin and Reed‐Sternberg cells in a smaller number of cases. In no instance were Hodgkin or Reed‐Sternberg cells found to mark for the S‐100 protein. The use of LN‐1 and LN‐2 antibodies facilitated the identification of Hodgkin and Reed‐Sternberg cells and produced additional information regarding the phentotypic nature of these cells.

Position effect in translocation (2;8) in acute lymphocytic leukemia with kappa light chain immunoglobulin expression☆

We report a correlation between t(2;8) translocation in acute lymphocytic leukemia and kappa light chain immunoglobulin production. Since the kappa chain genes are on chromosome #2, this, as well as data on Burkitt lymphoma, points to the possibility of position effect on the level of gene action. Chromosome #2 in the translocation together with chromosome #8 is concerned with malignancy, while the normal homologous chromosome #2 transcribes kappa chains. This model applies to B cell leukemias and lymphomas with changes in chromosome #2 which will predictably express kappa chains. The model also applies to B-cell malignancies with changes in chromosome #22 which will predictably express lambda chains.

Immunohistologic Techniques: Their Impact in Tumor Diagnosis with Particular Reference to Lymphomas

The diagnosis and classification of lymphoma and leukemia continues to depend upon examination of a cell sample or tissue biopsy. The morphological criteria employed in attaining a diagnosis are based upon clinicopathological correlations compiled by successive generations of pathologists. Although many attempts have been made to define these criteria strictly, they, nonetheless, remain subjective. Their application by different pathologists is greatly influenced by personal bias, educational prejudice, and such circumstantial evidence as the age of the patient, associated signs and symptoms, and the location of the lesion.