Localization of human T lymphocytes in tissue sections by a rosetting technique

A technique for the formation of sheep erythrocyte (E) rosettes in frozen human tissue sections is reported. The labile nature of the receptor for E rosettes on lymphocytes requires the use of controlled conditions for tissue processing and the reaction with indicator cells. The distribution of E rosettes in sections of normal human thymus, lymph nodes, tonsils, and spleens was comparable to that of the T marker-positive cells identified by immunofluorescence with the specific anti-human T cell serum. There with no overlap with areas positive for 19S EAC and 7S EA rosettes. Erythrocytes treated with a sulfhydryl reagent, 2-aminoethylisothiuronium bromide (AET), and with neuraminidase formed better rosettes in sections than did untreated erythrocytes. E rosettes in tissue sections can determine changes in the distribution of T cells in different lymphoproliferative and infiltrating disorders.

The effects of tissue processing on markers for T and B cells from solid tissues

Suspensions of lymphoid cells from tissues have been used for the determination of the quantitative relationship between the T and B cell populations. The distribution of the lymphocytes within a given tissue, however, cannot be demonstrated once such a suspension has been prepared. Various methods of characterizing lymphocytes within tissues were evaluated. The method of tissue preparation can alter the capability of detecting the lymphocyte markers. Fluorescein-labeled anti-immunoglobulin sera reacted equally well with lymphocytes in tissue regardless of the method of tissue preparation. Complement-coated sheep erythrocytes were less effective in detecting lymphocyte markers in tissue sections than in cell suspensions. Quantitative assays of lymphocytes could be done in suspensions only. Unaltered sheep erythrocytes did not bind to T lymphocytes in tissue. T lymphocytes could be identified in tissue sections, however, by the use of anti-human T cell serum.

Immunologic characterization of chronic lymphocytic leukemia cells

Immunologic characterization of the neoplastic cells in the circulation of patients with CLL suggests these cells show significant differences in membrane characteristics from normal B lymphocytes. Although the leukemic cells bear a homogenous membrane-associated immunoglobulin, they also react with an anti-human T cell serum. In all patients studied, 60-90% of the cells, were stained by this antiserum. This suggests that the leukemic cells share antigenic determinants with T lymphocytes. CLL cells, unlike normal B cells, showed a marked increase in mouse-complement receptors. No increase in receptors for guinea pig complement was observed in the leukemic cells. The population of SIg-bearing lymphocytes was significantly greater than that of complement-receptor bearing lymphocytes. The total number of E-rosetting cells was increased in all CLL patients. Mitogenic responses of the leukemic cells were depressed and delayed. These results suggest that neoplastic lymphocytes cannot be classified as T- or B-derived on the basis of criteria used to define normal lymphocytes.

Metabolically dependent and independent cell surface antigens

In contrast to metabolically dependent tissue-specific cell surface antigens (MDA) which are available for reactions with antibodies only on surfaces of metabolically active cells, the availability of the universally distributed blood group A or Forssman-type antigens on cell surfaces was found to be independent of the metabolic activity of cultured cells. In case of the MDA, cytotoxic reactions were induced by antibodies alone, resulting in a disorganization of the cellular sheet without a significant release of radioactive label. Radioactive release in this cytotoxic reaction was increased by the addition of complement without additionally affecting the degree of cell sheet disorganization. In case of Forssman and blood group A antigens, such morphologically demonstrable cytotoxicity required complement, and the resulting pathology was always accompanied by extensive release of cellular contents. The ability of anti-MDA antibodies to induce cytotoxic reactions in the absence of complement may be related to a vital role of MDA in cellular function.

Reactivity of anti-human brain serum with human lymphocytes

Specific anti-human T-cell serum was prepared in rabbits by multiple subcutaneous injections of human brain homogenates in incomplete Freund's adjuvant. The serum was exhaustively absorbed with human RBCs, lyophilized human liver, lyophilized normal human serum, and peripheral blood lymphocytes from patients with chronic lymphocytic leukemia (CLL). Specificity of the antiserum for human T lymphocytes was tested by indirect immunofluorescence. It stained 70 to 80% of lymphocytes in circulation, 95% of thymus, 27 to 35% of spleen, 5 to 10% of tonsil lymphocytes, and over 90% of phytohemagglutinin-stimulated lymphocytes in vitro. Only T-dependent areas of cryostat-sectioned human lymph nodes stained with the antiserum. It did not stain circulating lymphocytes which formed HEAC rosettes, plasma cells in marrows of multiple myeloma patients or macrophages. After removal of HEAC rosettes by centrifugation in Ficoll-Hypaque, 75% of interface cells formed E rosettes and 65 to 75% stained with the antiserum. The antiserum was used in studies of lymphocytes in chronic and acute lymphocytic leukemias, lymphomas, and other lymphoproliferative diseases. Numbers and distribution in the circulation, spleen and nodes of lymphocytes bearing the T marker were significantly altered in patients with these disorders.

Surface immunoglobulin on activated human peripheral blood thymus-derived cells

Human peripheral blood lymphocytes grown in vitro were stimulated with nonspecific mitogens and in mixed lymphocyte culture. The presence of IgM and thymus (T) surface markers on large and small lymphocytes was investigated by immunofluorescence and correlated with spontaneous rosette formation. All stimulated large lymphocytes formed spontaneous rosettes and all except pokeweed mitogen (PWM)-stimulated large lymphocytes had IgM and T markers. IgG, IgA, and light chain determinants were only detected on PWM-induced large lymphocytes. Thus, surface markers expressed on activated human lymphocytes may differ for different mitogens. IgM was always present on large cells which had the T markers, and it cannot be used to identify a lymphocyte as a bone marrow-derived (B) cell. Due to the overlap of surface markers, the classification into B and thymus-derived (T) cells ought to be restricted to functional phenomena of antibody-production or cell-mediated immunity.

Mesosomes: membranous bacterial organelles

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The presence of IgE on the surface of lymphocytes in nasal polyps

The presence of IgE-bearing lymphocytes in nasal polyps was correlated with the patients' atopic status. Following surgical removal, the polyp tissue was treated with hyaluronidase and a single-cell suspension was obtained. Lymphocytes were isolated by gradient centrifugation, and the fluorescent antibody technique was used to study the presence of various immunoglobulin markers on the surface of lymphocytes. The presence of IgE-bearing cells was correlated with serum IgE levels, history of allergy, and skin test reactions. Patients with a positive atopic history had intermediate to high serum IgE levels. There was no correlation between IgE level and skin reactivity in these patients. Good correlation was obtained between the number of IgE-bearing cells in nasal polyps and serum IgE levels in atopic patients. The IgE-bearing cells represented 10 to 40 per cent of total immunoglobulin-bearing lymphocytes. No IgE-bearing cells were detected in five of six patients with a negative atopic history and negative skin tests. Thus IgE may be synthesized within nasal polyps of atopic patients, and the polyps in atopic patients may have a different etiology from those in nonatopic patients.

Quantitation of human peripheral blood T and B lymphocytes

Centrifugation of heparinized peripheral blood on Ficoll-Hypaque under defined conditions is a most common method of lymphocyte purification in clinical studies. A loss of 25-30% of lymphocytes may occur during this procedure due to incomplete recovery of lymphocytes from the plasma layer after the gradient centrifugation and/or to poor recovery during the washing process. The loss is not selective since T and B cells are lost in the same proportions as determied by several different methods for T and B cell identification. Quantitation of T and B lymphocytes in terms of total number/mm-3 of peripheral blood is necessary in order to determine deficiencies in either of these two cell populations. The percentage values are inadequate in clinical evaluations. Thus, patients with chronic lymphocytic leukemia show elevated absolute number of T cells absolute numbers of T and B cells as well as percentages ought to be reported in all clinical studies.

Studies on the cytotoxic immune reaction. III. Localization of metabolically dependent cell surface antigens

Fluorescein-tagged duck anti-rabbit cornea serum was used to demonstrate changes in the localization of metabolically dependent antigens (MDA) on surfaces of resting versus activated corneal endothelial cells. Actively growing cells in culture exhibited uniform membrane staining which was most pronounced at the periphery of the tissue cultures. In the metabolically less-active center, spotty rather than continuous fluorescence was seen. Cells with a very low metabolic activity, e.g., those kept at 4 °C, did not stain at all. This inhibition was reversible, as the cells transferred back to 37 °C were able to bind the antibodies. Cultured cells dispersed with pronase or trypsin reacted with the tagged antiserum and demonstrated membrane fluorescence. However, dispersed cells from excised normal cornea did not stain. The MDA, although not detectable on normal-cell surfaces, were present in these cells, for the isolated cell membrane fraction was capable of absorbing out antibodies to the MDA. The antigenic determinants involved in the reaction with fluorescein-tagged anti-tissue antibodies are thus present but masked in cell membranes of normal tissues <i>in vivo</i> and can be unmasked by an increase in cellular metabolism and/or cell division but not by treatment with proteolytic enzymes.

Studies on the Cytotoxic Immune Reaction

The occurrence and specificity of metabolically dependent cell surface antigens in various rabbit and chicken tissues were studied <i>in vitro</i> with cytotoxic duck anti-rabbit and rabbit anti-chicken tissue sera. In all tissues investigated, a relationship between the accessibility of cell surface antigens and the metabolic condition of cells was established. Only actively growing rabbit and chicken tissue cultures <i>in vitro</i> were found to be sensitive to cytotoxic anti-tissue antibodies. No cell surface binding of the fluorescein-tagged anti-tissue antibodies and no cytotoxic effects were detected in cultures inhibited by physical (cold) or chemical means. The metabolically dependent accessibility of certain cell surface antigens is thus a universal phenomenon. The metabolically dependent surface antigens (MDA) in tissues of birds and mammals were found to have an ubiquitous distribution. Cross-cytotoxicity involving the MDA was found to be restricted to tissues of common ontogenic origin. The same cross-cytotoxicity tests showed that species-specific antigenic determinants are not involved in the MDA. The common ontogenic antigen or antigens appear to constitute the majority of the metabolically dependent cell surface antigens. However, the occurrence of some metabolically dependent antigens with even more restricted specificity was established in all tissues tested.

Use of antibody to membrane adenosine triphosphatase in the study of bacterial relatioships

An antiserum to Ca(2+)-activated adenosine triphosphatase from membranes of Micrococcus lysodeikticus cross-reacted in agar gels with membrane adenosine triphosphatases from other pigmented micrococci and related species. Species of Micrococcus and Sarcina showed different levels of inhibition of adenosine triphosphatase activities in heterologous reactions with antiserum. Inter- and intraspecific relationships based on the inhibition reaction were compared with an independent parameter, namely the quantitative and qualitative composition of the bacterial membrane phospholipids and fatty acids. The guanine plus cytosine contents in the deoxyribonucleic acid of the species studied correlated well with the serological cross-reactivity of adenosine triphosphatases from their membranes. The types of cross-bridges found in the peptidoglycans of these cocci were also compared with the other properties. The results suggest that an antiserum specific for a major membrane protein may be a reliable and most useful adjunct in studying bacterial serotaxonomy.

Effect of enzymes on the composition and structure of Chromobacterium violaceum cell envelopes

Cell envelopes of Chromobacterium violaceum were isolated and treated under controlled conditions with trypsin, Pronase, lipase, phospholipase C, lysozyme, and a mixture of enzymes produced by a bacteriolytic Pseudomonas sp. After each enzyme treatment, losses in dry weight, protein, lipid, carbohydrate, 2,6-diaminopimelic acid, and total phosphorus were determined. Electron-microscopic examination of the enzyme-treated envelopes indicated complete or partial loss of envelope rigidity or some envelope fragmentation, or both. Each enzyme hydrolyzed at least one envelope component and liberated several others into the supernatant fluid, where they appeared as nondialyzable particulate components, identified by means of electron microscopy. Unlike the other enzymes, the Pseudomonas sp. enzyme mixture partially liberated all major envelope components except phosphorus, heptose, and 2-keto-3-deoxy octonic acid. In spite of these large losses, the envelopes preserved some features of their integrity and elongated shape.

Extracellular enzymes produced by a Pseudomonas sp. and their effect on cell envelopes of Chromobacterium violaceum

A bacterium producing lytic enzymes was isolated from soil on bacterial agar in which heat-killed, Gram-negative cells served as a substrate. On the basis of its morphology, physiological properties, and growth characteristics, the lytic bacterium was identified as a Pseudomonas sp. It produced extracellular enzymes which were recovered from the culture nitrate by fractionation with ammonium sulfate and partially purified by ion-exchange chromatography on DEAE-cellulose. The enzymes which were resolved included a proteinase, at least two lipases, and one enzyme which caused some lysis of cell envelopes but was neither a proteinase nor lipase. Isolated envelopes of a Gram-negative bacterium, Chromobacterium violaceum, were extensively lysed by the enzyme mixture, and resulted in partial liberation of all the major envelope components, except phosphorus, in either a diffusible or non-diffusible form. In spite of large losses of protein, lipid, and polysaccharide, the enzyme-treated envelopes preserved their integrity and their elongated shape. This indicated that little or no hydrolysis of glycosaminopeptide took place.