Richard D. Moore

CYTOPLASMIC INTERACTION BETWEEN MACROPHAGES AND LYMPHOCYTIC CELLS IN ANTIBODY SYNTHESIS.

A direct cytoplasmic connection between macrophages and potential antibody-producing cells has been demonstrated in lymph nodes and spleen. This was observed in the tissues from both immunized and nonimmunized rabbits.

Optical microscopy of ultrathin tissue sections.

A method of staining ultrathin tissue sections in the range of 500–1500 A for observation with the optical microscope is presented. The procedure is based upon, (1) the choice of dyes with high molar absorptivities and, (2) the charge of the dye and substrate.

THE STRUCTURE OF THE SPLEEN AND ITS FUNCTIONAL IMPLICATIONS.

Abstract Spleens from normal albino rabbits were studied with optical and electron microscopy. There were openings in the walls of the capillaries of the white pulp, in the walls of the large parafollicular sinusoids, and the sinusoids of the red pulp. All types of cells and platelets were seen within the intersinusoidal tissue and also crossing the walls of the sinusoids. The lining of the parafollicular sinusoids was actually formed in part by the cells of the marginal zone. Most of the material that had been phagocytized was in the cells of the intersinusoidal tissue rather than in the cells lining the sinusoids. Erythrocytes and leucocytes in various stages of degeneration comprised the major part of the material that had been phagocytized. The findings are discussed in relation to the route and communications of the circulatory system of the spleen; the sequestration, phagocytosis, and degeneration of erythrocytes; the phagocytosis, distribution, and effect of extracellular materials carried to the spleen by the circulation; the production and interchange of cells between red and white pulp and the general circulation; and the components of the supporting connective tissue of the spleen.

The transport and distribution of colloidal iron and its relation to the ultrastructure of the cell

Rabbits were given saccharated iron oxide intravenously. The iron accumulated in the cytoplasm of a variety of cells, but particularly in the Kupffers cells and the cells lining the sinusoids of the spleen. The distribution of iron-containing particles in the cytoplasm and nucleus is described. Pinocytosis did not appear to be important in the uptake of the colloidal iron. The passage of these particles across the nuclear membranes was not related to the nuclear pores. It is suggested that fairly large molecules may be diffusible from the cytoplasm through the nuclear envelope, and the system of nuclear pores may be limited to the exchange of ribonucleoprotein between the nucleus and cytoplasm.

Proliferation of the reticuloendothelial system and phagocytosis

Abstract The phagocytosis and the cellular and organ distribution of polystyrene latex particles were studied in normal rabbits and rabbits treated with complete Freunds adjuvant. The size of the particles, the amount injected and the number of cells capable of phagocytosis were of importance in determining the clearance of the blood. The clearance curves were analyzed in terms of an equilibrium between phagocytosis and re-entry of particles into the circulation. Despite extensive proliferation of the RES produced by Freunds adjuvant the general nature of the clearance from the circulation was not changed. The implications of these findings in the interpretations of clearance of the blood and the process of phagocytosis were discussed.

Restimulation of antibody synthesis by antigen in cultures of lymphocytes.

THE initiation of a primary immune response seems to depend on the phagocytosis of antigen by the macrophage. The antigen is processed in some way by the macrophage to yield an RNA-antigen complex that stimulates potential immunocompetent lymphocytic cells to synthesize specific antibody1–9. We have examined the requirement of the macrophage in subsequent responses to the same antigen.

Changes in antibody producing cells in the spleen during the primary response

Abstract In rabbits given complete Freunds adjuvant or complete adjuvant and diphtheria toxoid there were two types of cells in the spleen which contained antibody and gamma globulin. Non-phagocytic mononuclear cells containing 19S γ 1M antibody and gamma globulin were associated with the appearance and level of circulating 19S γ 1M globulin antibody. Gamma globulin and 7S γ 2 antibody in the cytoplasm of the plasma cells were associated with the appearance and level of circulating 7S γ 2 globulin antibody. Changes in the basophilia and ultrastructure of the cytoplasm of these cells were consistent with increased protein synthesis. The mononuclear cell was present in the red pulp, and the development of the plasma cell occurred primarily in the non-follicular white pulp.

ORIGIN OF PLASMA CELLS IN SITES OF INFLAMMATION.

THE origin of plasma cells in inflammatory reactions in non-lymphoid tissue is perplexing. They are found in the circulation only in unusual circumstances1 and are not a usual cellular component of normal connective tissue. A possible source of these cells in areas of injury is suggested from investigations of lymphocytic cells in the vascular spaces and alveolar walls of the lung following the intravenous injection of complete Freunds adjuvant. The changes in some of these lymphocytes are similar to those described for white cells of the peripheral blood grown in tissue culture in the presence of a variety of materials. When phytohæmagglutinin, tuberculin, tetanus toxoid, diphtheria toxoid, smallpox vaccine, hæmophilus pertussis antigen, staphylococcal antigen, leukocyte antiserum, pollen extract and various tissue antigens are added to cultures of white cells from the peripheral blood, the small and medium sized lymphocytes enlarge and mitotic division may occur2–13. Tanaka et al.14 have described a developing Golgi apparatus, increased ribosomes and a small amount of endoplasmic reticulum in cultures of lymphocytes from peripheral blood.

Modifications of Antibody Synthesis by Chloramphenicol

When chloramphenicol (CM) is given in sufficient quantity before immunization or early in the inductive phase of antibody synthesis, there is an attenuation of antibody formation. This has been shown in animals and in cultures of lymphoid tissue [1–8]. Despite these studies, there is little information about the cellular aspects of the immune process in the presence of CM.