bluuebunny/crossref_metadata_2025 huggingface dataset:
CYTODYNAMICS OF THE IMMUNE RESPONSE IN TWO LINES OF MICE GENETICALLY SELECTED FOR "HIGH" AND "LOW" ANTIBODY SYNTHESIS
Authors: Biozzi G. , Stiffel C. , Mouton D. , Bouthillier Y. , Decreusefond C.
Published: June 2004

Two lines of mice have been separated by selective breeding for the character "agglutinin production to heterologous erythrocytes." Around the 18th generation of selection the two lines could be considered as homozygous for the character investigated. This trait is under the control of a group of additive genes. The interline difference in the production of anti-SE agglutinins was verified for the range of antigen doses from subimmunogenic to maximal. After intravenous immunization with an optimal dose of SE, the duration of the exponential rise in serum antibody was 4–5 days in both lines. At this time most of the interline difference in responsiveness is already expressed. A cytodynamic study carried out in terms of plaque-forming cells (PFC) and rosette-forming cells (RFC) in the spleen during the exponential phase showed that the principal interline difference is found in the doubling time of cells engaged in the immune response.

More precise cytodynamic analysis made in terms of RFC showed that the doubling time of RFC is 9 hr in high responder and 16 hr in low responder mice. The duration of the exponential rise and the number of target cells stimulated by antigen is the same in both lines. The interline difference at the end of the exponential rise (4 days postimmunization) is larger in terms of serum antibody (30–40-fold) than in terms of PFC or RFC (20- and 11-fold, respectively).

A morphological study of RFC in nonimmunized mice showed that about 90% of rosettes were formed by small lymphocytes in both lines. The remainder were medium-sized lymphocytes. At the peak of the cellular response the RFC have differentiated into large lymphocytes, blast cells, and plasma cells. The contribution of plasma cells to RFC is much greater in the high than in the low line. The cytodynamic and morphologic results presented in this article are compatible with the hypothesis that the group of genes segregated in each line during the selective breeding control and regulate the rate of multiplication and differentiation of the antibody-producing cells.
GENETIC CONTROL OF THYMUS-DERIVED CELL FUNCTION
Authors: Williams R. Michael , Benacerraf Baruj
Published: June 2004

Concanavalin A- or phytohemagglutinin-stimulated DNA synthetic responses of 1 million normal mouse spleen cells in vitro were significantly different among various inbred strains. BALB/cJ (H-2d) responded better than C57BL/6J (H-2b) spleen cells, and the responses of C3H/HeJ or AKR/J (both H-2k) cells were intermediate. These responses, measured as the increment in thymidine-3H incorporation of mitogen-stimulated compared with unstimulated cultures, varied according to the number of cells cultured or the mitogen concentration. BALB/c spleens had the highest proportion of θ-positive cells, but no direct relationship between the proportion of θ-positive cells and the DNA synthetic response was observed. (BALB/cJ x C57BL/6)F1 spleen cells responsed as well as BALB/c cells. Responses of spleen cells from (F1 x C57BL/6) backcross littermates varied over a range equal to, or greater than, that of BALB/c and C57BL/6 cells. There was no correlation between H-2 specificity (H-2bd or H-2bb) or sex and the mitogen-stimulated DNA synthetic response of backcross animals. Con A- and PHA-stimulated responses of individual backcross animals were positively correlated with the level of thymidine-8H incorporation by unstimulated spleen cells. These results are consistent with autosomal dominant, non-H-2-linked, polygenic control of the mitogen-stimulated in vitro DNA synthetic response of mouse spleen cells.
SUPPRESSION OF IDIOTYPIC SPECIFICITIES IN ADULT MICE BY ADMINISTRATION OF ANTIIDIOTYPIC ANTIBODY
Authors: Hart David A. , Wang Ai-Lan , Pawlak Laura L. , Nisonoff Alfred
Published: June 2004

It has previously been shown that there are extensive idiotypic cross-reactions among antiphenylarsonate antibodies of A/J mice. The present work indicates that administration, into normal, adult A/J mice, of rabbit antiidiotypic antibody directed to A/J antiphenylarsonate antibody suppresses almost completely the subsequent production of antibody of the corresponding idiotype. No effect was noted on the formation of antibodies to the protein carrier or of antiphenylarsonate antibody of a different idiotype. The data are consistent with central suppression of production of the idiotypic antibody mediated through interaction with immunoglobulin receptors on lymphocytes.
CONNECTIVE TISSUE SYNTHESIS BY SCLERODERMA SKIN FIBROBLASTS IN CELL CULTURE
Authors: Leroy E. Carwile
Published: June 2004

Skin fibroblasts from subjects with scleroderma and control subjects were grown in tissue culture to compare the characteristics of connective tissue metabolism. A striking increase in soluble collagen (media hydroxyproline) was observed in eight of nine scleroderma cultures when they were compared with identically handled control cultures matched for the age and sex of the donor and the anatomic site of the donor skin. Glycoprotein content as estimated by hexosamine and sialic acid was also significantly increased in the scleroderma cultures. Estimations of protein-polysaccharide content by uronic acid determinations were low in all cultures and not significantly increased in scleroderma cultures.

This report demonstrates the feasibility of using fibroblast cell cultures to study chronic rheumatic and connective tissue disorders. The initial results suggest a net increase in collagen and glycoprotein synthesis in scleroderma fibroblast cultures. The implications of an abnormality of connective tissue metabolism by skin fibroblasts propagated in vitro in the acquired disorder scleroderma are discussed.
SEPARATION OF STAGES IN THE DEVELOPMENT OF THE "T" CELLS INVOLVED IN CELL-MEDIATED IMMUNITY
Authors: Shortman K. , Brunner K. T. , Cerottini J.-C.
Published: June 2004

Density distribution analysis in continuous gradients of albumin has been used to study the development of cytotoxic lymphocytes (CL), to separate and characterize the progenitors of CL, and to determine their relationship to subpopulations of T cells.

CL progenitors in the thymus were a homogeneous, medium-density population, distinct from the typical, dense, thymus small-lymphocyte. Activity seemed to be associated with one minor subpopulation of cells with surface antigenic properties characteristic of peripheral T cells (high levels of H-2 antigen, low levels of θ-antigen). CL progenitors in the spleen differed from those in the thymus and normally had the high buoyant density of typical small T lymphocytes. In states of antigenic stimulation, some lighter-density CL progenitors were found in the spleen.

The buoyant density of the CL population developing in the spleens of immunized animals showed progressive changes with time. Early, "immature" CL had the light-density characteristics of large, activated lymphocytes. As the response developed, the density of the CL population increased, and finally approached that of CL progenitors and of typical small lymphocytes.

The data suggest that density subpopulations of T cells represent stages in the development of immunocompetent cells. Possible differentiation pathways of T lymphocytes in the thymus and in the spleen are discussed.
CELL SURFACE IMMUNOGLOBULIN
Authors: Sherr Charles J. , Baur Sonia , Grundke Inge , Zeligs Joseph , Zeligs Barbara , Uhr Jonathan W.
Published: June 2004

Cells from an established line of Burkitt lymphoma (Daudi) were enzymatically radioiodinated, and labeled Ig from the cell surface was isolated and studied. Subcellular fractionation of labeled cells confirmed that intracellular proteins from the cytoplasm are not iodinated by this method. Radioactive Ig was identified as monomeric (8S) IgM, and an average of 105 Ig molecules was found per cell. Ig molecules could be released from the plasma membrane by detergent lysis under nonreducing conditions indicating that attachment of Ig to the plasma membrane occurs via noncovalent interactions. The ratio of µ/L radioactivity in surface Ig was the same as that of total cellular Ig radioiodinated in solution suggesting that a large portion of the Fc fragment is not buried within the membrane. In contrast to the results obtained with cell surface Ig, most intracellular Ig was found as "free" µ- and L chains regardless of whether lysates were labeled with 125I or cells were labeled with leucine-3H. The results indicate that only a small percentage of the total Ig of Daudi cells is associated with the cell surface and suggest that covalent assembly of Ig occurs at or near the time that the molecule becomes part of the plasma membrane. Similarities between cell surface Ig on normal splenic lymphocytes and Daudi cells suggest that the latter is a neoplasm of bone marrow-derived lymphocytes.
LEAD AND METHYL MERCURY: EFFECTS OF ACUTE EXPOSURE ON CYTOCHROME P-450 AND THE MIXED FUNCTION OXIDASE SYSTEM IN THE LIVER
Authors: Alvares Alvito P. , Leigh Susan , Cohn Jonathan , Kappas Attallah
Published: June 2004

The rat liver mixed function oxidase system which is responsible for the metabolism of endogenous and exogenous compounds has been shown to be affected by lead and methyl mercury. Administration of these environmental pollutants to rats results in a decrease in cytochrome P-450 content and inhibition of in vitro N-demethylase and hydroxylase activities. The in vitro enzyme-inhibiting effects of the metals found pharmacological expression in the whole animal by prolongation of hexobarbital-induced sleeping times.
INTERACTION OF AGGREGATED γ-GLOBULIN WITH B LYMPHOCYTES
Authors: Dickler H. B. , Kunkel H. G.
Published: June 2004

Specific binding of aggregated γ-globulin to a subpopulation of lymphocytes was demonstrated. This subpopulation was identified as the Ig-staining or B lymphocytes. The binding was irreversible and independent of complement, pH, temperature, protein content of the medium, and divalent cations. Aggregates of large size were needed for optimal visualization. Evidence was obtained that the site on the lymphocyte membrane responsible for binding aggregates was distinct from surface Ig.
CELL INTERACTIONS IN THE IMMUNE RESPONSE IN VITRO
Authors: Feldmann Marc , Basten Antony
Published: June 2004

Tissue cultures with two compartments, separated by a cell impermeable nuclepore membrane (1 µ pore size), were used to investigate the mechanism of T-B lymphocyte cooperation. It was found that collaboration was as effective when the T and B lymphocyte populations were separated by the membrane as when they were mixed together. Critical tests were performed to verify that the membranes used were in fact cell impermeable. The specificity of the augmentation of the B cell response by various T cell populations was investigated. Only the response of B cells reactive to determinants on the same molecule as recognized by the T cells was augmented markedly. Specific activation of thymocytes by antigen was necessary for efficient collaboration across the membrane. The response of both unprimed and hapten-primed spleen cells was augmented by the T cell "factor" although, as expected, hapten-primed cells yielded greater responses. The T cell factor acted as efficiently if T cells were present or absent in the lower chamber. Thus the site of action of the T cell factor was not on other T cells, but was either on macrophages or the B cells themselves.

The T cell-specific immunizing factor did not pass through dialysis membranes. The experiments reported here help rule out some of the possible theories of T-B cell collaboration. Clearly T-B cell contact was not necessary for successful cooperation to occur in this system. Possible theoretical interpretations of the results and their bearing on the detailed mechanism of T-B lymphocyte cooperation are discussed.
THE MECHANISM OF ANTIGENIC STIMULATION OF PRIMARY AND SECONDARY CLONAL PRECURSOR CELLS
Authors: Klinman Norman R.
Published: June 2004

Cell transfers to carrier-immunized irradiated mice have permitted an analysis of the in vitro stimulation of clonal precursors of anti-2,4-dinitrophenyl (DNP) antibody-producing cells derived from both immune and nonimmune mice. The results indicate that: (a) carrier-specific enhancement is obligatory for stimulation of primary precursor cells and increases both the size and number of detectable foci derived from secondary precursors. (b) This carrier-specific enhancement is most apparent in the stimulation of precursors of high-affinity antibody producer cells. (c) The antibody produced by primary foci, like that of secondary foci, appears homogeneous. (d) The frequency of clonal precursors in normal spleens is 38% that in spleens from mice 4–8 months after immunization, and the number of such precursors in normal spleens can be reduced fivefold by specific suppression of donor mice with soluble antigen. (e) The average of association constants of primary monofocal antibodies, like that of primary serum antibody produced in carrier-primed mice, is less than 10-fold lower than that of secondary clonal or serum antibody. (f) The affinity of primary monofocal antibodies shows a slight dependence on stimulating antigen concentration; however, a minimum threshold affinity consonant with stimulation is apparent. (g) Free hapten inhibits antigenic stimulation of primary precursor cells at a much lower concentration than is required for the inhibition of secondary precursors.

These results are interpreted as indicating that (a) primary stimulation, like secondary stimulation, results from the selective stimulation by antigen of a population of cells differing from one another in their potential antibody product but each having only a single such product; (b) the antigen receptors of primary cells interact with antigen as if they are monovalent while receptors of secondary cells evidence multivalence; (c) antigenic stimulation appears to require both a relatively high affinity of receptors for bound antigen and an interlinking of receptors through such antigen; stimulation is thus seen as resulting from a stabilization of receptors within antigen-receptor aggregates to the cell surface; (d) T-cells appear to serve both in cross-linking antigens and in amplifying the size of stimulated clones.
CELL-MEDIATED IMMUNE RESPONSE IN VITRO
Authors: Wagner Hermann , Feldmann Marc , Boyle W. , Schrader J. W.
Published: June 2004

All efficient cell separation procedure and specific anti-macrophage serum were used to investigate the requirement of macrophages in the in vitro allograft response of mouse lymphoid cells. The efficiency of the macrophage-depletion procedure used and the undiminished capacity of the purified lymphocytes to respond were verified by also testing the antibody responses to sheep red cells (SRC) and dinitrophenylated polymeric flagellin (DNP POL) as well as the proliferative response to allogeneic cells. It was found that the generation of cytotoxic lymphocytes were diminished after macrophage depletion by surface adherence. The combination of anti-macrophage serum and column purification resulted in the total abolition of cytotoxic activity. The cell-mediated immune response was restored completely by addition of peritoneal macrophages, with as few as 1 macrophage to 600 lymphocytes permitting a significant restoration. Macrophages were not involved in the cytotoxic effector phase, but were essential in immune induction. A subcellular H-2 alloantigen preparation was only immunogenic in the presence of macrophages, indicating that a mere reduction in the size of the antigen from cell-bound alloantigens to membrane fragments was not the sole function of macrophages. The results suggest that macrophages collaborate with T cells in the initiation of an allograft response in vitro.
EVIDENCE FOR A BLOOD-THYMUS BARRIER USING ELECTRON-OPAQUE TRACERS
Authors: Raviola Elio , Karnovsky Morris J.
Published: June 2004

In order to verify the existence of a blood-thymus barrier to circulating macromolecules, the permeability of the vessels of the thymus was analyzed in young adult mice using electron opaque tracers of different molecular dimensions (horseradish peroxidase, cytochrome c, catalase, ferritin, colloidal lanthanum). Results show that although blood-borne macromolecules do penetrate the thymus, their parenchyma] distribution is limited to the medulla of the lobe by several factors: (a) the differential permeability of the various segments of the vascular tree; (b) the spatial segregation of these segments within the lobe; (c) the strategic location of parenchymal macrophages along the vessels.

The cortex is exclusively supplied by capillaries, which have impermeable endothelial junctions. Although a small amount of tracer is transported by plasmalemmal vesicles through the capillary endothelium, this tracer is promptly sequestrated by macrophages stretched out in a continuous row along the cortical capillaries and it does not reach the intercellular clefts between cortical lymphocytes and reticular cells.

The medulla contains all the leaky vessels, namely postcapillary venules and arterioles. Across the walls of the venules, large quantities of all injected tracers escape through the clefts between migrating lymphocytes and endothelial cells; also the arterioles have a small number of endothelial junctions which are permeable to peroxidase, but do not allow passage of tracers of higher molecular weight. The tracers released by the leaky vessels penetrate the intercellular clefts of the medulla, but they never reach the cortical parenchyma, even at long time intervals after the injection.

Therefore, a blood-thymus barrier to circulating macromolecules does exist, but is limited to the cortex. Medullary lymphocytes are freely exposed to blood-borne substances.
IN VITRO ADHERENCE OF SOLUBLE IMMUNE COMPLEXES TO MACROPHAGES
Authors: Arend William P. , Mannik Mart
Published: June 2004

The adherence of soluble immune complexes to stimulated alveolar macrophages was studied in vitro using HSA-anti-HSA complexes prepared in antigen excess. Those complexes containing more than two molecules of antibody preferentially adhered to macrophages in the absence of complement. Free γG in less than physiological concentrations inhibited the adherence of complexes, and the presence of complement did not significantly alter this inhibition. Complexes prepared with reduced and alkylated antibodies showed a decreased adherence. The strength of binding of soluble complexes to macrophages and their efficiency in fixing complement were greater than seen with small aggregates of homologous γG. These differences in biological properties were observed even though the immune complexes and aggregates contained comparable numbers of γG molecules. The γG receptor on rabbit macrophages exhibited species specificity. Pretreatment of macrophages with proteolytic enzymes led to adherence of larger amounts of soluble complexes.

These observations suggest that the strength of binding of soluble immune complexes to macrophages and their efficiency in fixing complement are not determined solely by a random summation of individual binding sites. It is proposed that conformational changes in the γG antibodies or a specific molecular arrangement in the lattice work of complexes containing large protein antigens may influence the biological properties of the soluble complexes.
IMMUNOLOGICAL RELEASE OF HISTAMINE AND SLOW REACTING SUBSTANCE OF ANAPHYLAXIS FROM HUMAN LUNG
Authors: Kaliner Michael , Orange Robert P. , Austen K. Frank
Published: June 2004

The immunologic release of histamine and slow reacting substance of anaphylaxis (SRS-A) from human lung tissue can be enhanced by stimulation with either alpha adrenergic agents (phenylephrine or norepinephrine in the presence of propranolol) or cholinergic agents (acetylcholine or Carbachol). The finding that atropine prevents cholinergic but not comparable alpha adrenergic enhancement is consistent with the view that cholinergic and alpha adrenergic agonists interact with separate receptor sites on the target cells involved in the immunologic release of chemical mediators. The consistent qualitative relationship between the antigen-induced release of mediators and the level of cyclic adenosine monophosphate (cyclic AMP) as measured by the isolation of 14C-labeled cyclic AMP after incorporation of adenine-14C into the tissues or by the cyclic AMP binding protein assay suggests that changes in the level of this cyclic nucleotide mediate adrenergic modulation of the release of histamine and SRS-A. The addition of 8-bromo-cyclic guanosine monophosphate (cyclic GMP) produces an enhancement of the immunologic release of mediators while dibutyryl cyclic AMP is inhibitory. As cholinergic-induced enhancement was not associated with a measurable change in the levels of cyclic AMP, the possibility is suggested that cyclic GMP may be the intracellular mediator of cholinergic-induced enhancement of the immunologic release of histamine and SRS-A.
THYMUS-DERIVED CELL (T CELL) ACTIVATION BY HETEROLOGOUS ANTIGENS AS A REPLACEMENT OF SPECIFIC IMMUNE T CELLS IN THE TRANSFER OF THE SECONDARY RESPONSE TO SHEEP ERYTHROCYTES
Authors: Mond J. J. , Takahashi T. , Thorbecke G. J.
Published: June 2004

Spleen cells from LAF1 mice hyperimmune to sheep erythrocytes (SE) lost their ability to transfer a secondary response to irradiated recipients after incubation with anti-θ and rabbit complement in vitro. Small numbers of specific immune cells even when taken 3 days after a primary SE injection reconstituted the direct and indirect plaque-forming cell responses.

Larger numbers of cells sensitized to B. abortus (or keyhole limpet hemocyanin), and given together with the corresponding antigen, also partially reconstituted the ability to respond to SE. This property was mediated by θ-bearing cells and was interpreted as due to a nonspecific humoral factor liberated by specifically activated T cells and acting on B cell proliferation or maturation.
CELL INTERACTIONS IN THE IMMUNE RESPONSE IN VITRO
Authors: Feldmann Marc
Published: June 2004

The mechanism of interaction of T and B lymphocytes was investigated in an in vitro hapten carrier system using culture chambers with two compartments separated by a cell impermeable nucleopore membrane. Because specific cell interaction occurred efficiently across this membrane, contact of T and B lymphocytes was not essential for cooperation which must have been mediated by a subcellular component or "factor." By using different lymphoid cell populations in the lower culture chamber and activated thymus cells in the upper chamber (with antigen present in both), it was found that the antigen-specific mediator acted indirectly on B cells, through the agency of macrophages. Macrophages which had been cultured in the presence of activated T cells and antigen acquired the capacity to specifically induce antibody responses in B cell-containing lymphoid populations. Trypsinization of these macrophages inhibited their capacity to induce immune responses, indicating that the mediator of cell cooperation is membrane bound. By using antisera to both the haptenic and carrier determinants of the antigen as blocking reagents, it was demonstrated that the whole antigen molecule was present on the surface of macrophages which had been exposed to activated T cells and antigen. Because specifically activated T cells were essential a component of the antigen-specific mediator must be derived from these cells. By using anti-immunoglobulin sera as inhibitors of the binding of the mediator to macrophages, the T cell component was indeed found to contain both κ- and µ-chains and was thus presumably a T cell-derived immunoglobulin.

It was proposed that cell cooperation is mediated by complexes of T cell IgM and antigen, bound to the surface of macrophage-like cells, forming a lattice of appropriately spaced antigenic determinants. B cells become immunized by interacting with this surface. With this mechanism of cell cooperation, the actual pattern of antigen-B cell receptor interactions in immunization would be the same with both thymus-dependent and independent antigens. An essential feature of the proposed mechanism of cell cooperation is that macrophage-B cell interaction must occur at an early stage of the antibody response, a concept which is supported by many lines of evidence. Furthermore this mechanism of cell interaction can be elaborated to explain certain phenomena such as the highly immunogenic macrophage-bound antigen, antigenic competition, the distinction between immunity and tolerance in B lymphocytes, and the possible mediation of tolerance by T lymphocytes.
ONTOGENY OF BURSAL FUNCTION IN CHICKEN
Authors: Toivanen Paavo , Toivanen Auli , Good Robert A.
Published: June 2004

To study the occurrence of immunocompetent cells directly responsible for antibody production, cells from yolk sac, embryonic liver, bursa of Fabricius, bone marrow, spleen, or thymus were injected together with SRBC and Brucella abortus into 4-day old cyclophosphamide-treated chicks. A second stimulation was given 4 days later, and samples taken 4 days thereafter were used for antibody titrations.

During ontogeny, immunocompetent cells appeared in significant numbers first in the spleen for anti-SRBC responses, but in the bursa for anti-Brucella responses. Later these cells were also found in thymus and bone marrow. In the bursa, cells immunocompetent for anti-SRBC response were not encountered in significant numbers. The slight response to SRBC by transferred bursa cells reflects the presence of stem cells and their immediate descendents in the bursa at different stages of development.

These findings are compared with the development and maturation of the stem cell responsible for humoral immunity. In the bursa, development of the stem cell population precedes that of immunocompetent cells. The opposite relationship was found in bone marrow, spleen, and thymus where immunocompetent cells were always present some weeks before the appearance of cells capable of achieving a long-lasting reconstitution of bursa-dependent functions. These observations reveal that the bursa seeds out immunocompetent cells during its entire postembryonic development, but does not release the lymphoid stem cell population before this population has matured sufficiently and before the bursa itself, after fulfilling its function, starts to involute.
CELLULAR RECEPTORS: BINDING OF RADIOACTIVELY LABELED ANTI-ALLOANTISERUM
Authors: Binz Hans , Lindenmann Jean
Published: June 2004

Rat alloantisera of the following specificities were obtained after single skin graft rejection: DA anti-BN, BN anti-DA, DA anti-Lewis, and Lewis anti-DA. Anti-alloantibodies were raised by injecting the first two alloantisera into (DA x BN)F1 hosts and the last two alloantisera into (DA x Lewis)F1 hosts. In this manner, four anti-alloantisera were raised: anti-(DA anti-BN), anti-(BN anti-DA), anti-(DA anti-Lewis), and anti-(Lewis anti-DA). From each anti-alloantiserum a gamma globulin fraction was prepared and trace labeled with 125I.

The labeled anti-alloantibodies could be shown to be fixed preferentially by red cells coated with the alloantibody used to induce them. They were also preferentially fixed by normal rat lymphoid cells presumed to carry recognition structures similar to alloantibody. For instance, anti-(DA anti-BN) was fixed by BN red cells coated with DA anti-BN and by normal DA lymphoid cells presumed to carry RS(BN). Conversely, anti-(BN anti-DA) was fixed by DA red cells coated with BN anti-DA and by normal BN lymphoid cells, carrying RS(DA).

Absorption and inhibition experiments showed that alloantibodies and normal lymphoid cells compete for the same labeled anti-alloantibodies. We conclude that cellular receptors and circulating alloantibody are antigenically similar: They have the same aliotype.
LIGAND-INDUCED MOVEMENT OF LYMPHOCYTE MEMBRANE MACROMOLECULES
Authors: Unanue Emil R. , Perkins William D. , Karnovsky Morris J.
Published: June 2004

The fate of different complexes on the membrane of thymocytes and spleen lymphocytes was studied with the use of both immunofluorescence and ultrastructural radioautography. The complexes of anti-immunoglobulin (Ig) with the surface Ig of B lymphocytes were present all around the membrane at 4°C; an increase in temperature produced a rapid aggregation of the complex into a cap which was readily interiorized in vesicles. Ultrastructural details of this process were given. The movement of the complexes depended upon the amount of anti-Ig and the temperature.

The complexes of anti-lymphocyte antibody with surface antigen(s) did not result in formation of a single large aggregate (or cap) unless an anti-antibody was brought into the reaction. The caps formed by this trilayered complex were not interiorized. Concanavalin A (Con A) bound to cell surface carbohydrate moieties and the complexes of Con A readily formed a cap and were interiorized. Finally, antibodies to H-2 determinants did not form in most instances a single cap aggregate even when anti-antibodies were used. With time the H-2 complexes tended to form several large aggregates with some endocytosis.
GENETIC CONTROL OF THE ANTIBODY RESPONSE TO TYPE III PNEUMOCOCCAL POLYSACCHARIDE IN MICE
Authors: Amsbaugh Diana F. , Hansen Carl T. , Prescott Benjamin , Stashak Philip W. , Barthold David R. , Baker Phillip J.
Published: June 2004

The IgM antibody response to Type III pneumococcal polysaccharide (SSS-III) was assessed in F1, F2, and backcross progeny derived from high (BALB/cAnN) and extremely low (CBA/HN) responding parental strains of inbred mice. The results of these studies indicated that a major component involved in the antibody response is X-linked, i.e., carried on the X chromosome; this component determines responsiveness to SSS-III in an almost quantal or "all-or-none" manner. Other factors, presumably autosomal genes, regulate the magnitude of the antibody response produced by mice possessing the X-linked gene; these appear to influence independently the number of antibody-producing cells found after immunization and the amount of antibody made by such cells. Strains of inbred mice varied widely in their ability to respond to SSS-III. Responsiveness was not associated with H-2 histocompatibility type. The implications of these findings with respect to the genetic control of the antibody response to SSS-III are discussed.
LASTING BIOLOGICAL EFFECTS OF EARLY ENVIRONMENTAL INFLUENCES
Authors: Lee Chi-Jen , Dubos Rene
Published: June 2004

The effects of neonatal infection, perinatal malnutrition, and crowding on the metabolism of brain catecholamine were studied in specific pathogen-free mice. Metabolic turnover of catecholamine was determined by measuring the incorporation of precursor tyrosine-14C into brain tissue, catabolic activity of norepinephrine-3H at various times after intracisternal injection, and tissue levels of dopamine and norepinephrine.

The rate of tyrosine incorporation was decreased by neonatal infection but was increased by perinatal malnutrition and crowding. There was no difference in catabolic activity of norepinephrine between infected, crowded, and control groups. In the malnourished group, however, the total radioactivity from norepinephrine was significantly higher than in the control group ½ and 2 hr after injection.

The brain contents of dopamine and norepinephrine were depressed in the malnourished group. There was no significant difference in catecholamine levels between infected, crowded, and control groups.

In the malnourished group, treatment of the mothers with growth hormone prevented almost completely weight loss during lactation, and also resulted in higher fetal weight. Hormone treatment restored to normal the levels of brain catecholamine and the enzymatic activity of brain tyrosine hydroxylase in progeny of malnourished mothers.
THE INTERACTION BETWEEN TOXOPLASMA GONDII AND MAMMALIAN CELLS
Authors: Jones Thomas C. , Hirsch James G.
Published: June 2004

Electron microscope methods have been used to study delivery of macrophage primary or secondary lysosomal contents to phagocytic vacuoles containing living or dead toxoplasmas. Secondary lysosomes were labeled by culturing the cells in colloidal thorium dioxide (thorotrast) or in ferritin. Acid phosphatase cytochemistry was employed for detection of primary as well as secondary lysosomal constituents. These various lysosomal labels were present in nearly all vacuoles containing toxoplasmas killed with glutaraldehyde, or in vacuoles containing those parasites undergoing degeneration 1 hr after the uptake of living toxoplasmas. In contrast, at times ranging from 1 to 20 hr after infection, no vacuoles containing morphologically normal, apparently viable toxoplasmas were thorotrast or ferritin positive, and only rarely did these vacuoles react for acid phosphatase. In many instances vacuoles containing viable toxoplasmas and no lysosomal markers were situated in the same cell nearby to vacuoles containing degenerating toxoplasmas and lysosomal constituents, thus indicating that the determinants of lysosomal fusion were operating locally in the immediate vicinity of the phagocytic vacuole, and not operating to influence general cell function. Thus, some toxoplasmas are able to prevent the delivery of lysosomal contents, and apparently the phagocytic vacuole provides for these parasites a sheltered microenvironment ideal for their growth.

Morphologic evidence indicated that living toxoplasmas altered the phagocytic vacuolar membrane in macrophages, fibroblasts, and HeLa cells. Within minutes after phagocytosis, the vacuole became surrounded by closely apposed strips of endoplasmic reticulum and mitochondria; somewhat later, microvillous protrusions of the membrane into the vacuole were seen. These morphologic features of phagocytic vacuoles containing living toxoplasmas may be of importance in relation to the absence of lysosomal fusion, or they may serve some function in protecting the host cell or in nourishing the parasite.
GENETIC CONTROL OF THE IMMUNE RESPONSE
Authors: Ordal John C. , Grumet F. Carl
Published: June 2004

The transfer of parental (H-2k/k) nonresponder lymphoid cells into heterozygous (H-2k/q) nonresponder recipients at the time of primary challenge with aqueous poly-L(Tyr,Glu)-poly-D,L-Ala-poly-L-Lys [(T,G)-A--L] elicited the production of both IgM and IgG anti-(T,G)-A--L antibody. Normally, the production of IgG anti-(T,G)-A--L antibody is restricted to strains possessing the responder Ir-1 allele. The timing and intensity of the graft-versus-host (GVH) reaction required for this effect were found to be critical. Injection of H-2k/k cells into H-2k/q recipients 1 wk before antigen challenge did not elicit IgG anti-(T,G)-A--L antibody production, and markedly suppressed IgM anti-(T,G)-A--L antibody production. The transfer of alloimmune (H-2q-primed) H-2k/k cells at the time of antigen challenge was also associated with no IgG and little IgM anti-(T,G)-A--L antibody production. These data are consistent with the model that nonresponder thymus-derived lymphocytes (T cells) activated in a GVH reaction can substitute for (T,G)-A--L-reactive T cells to induce a shift from IgM to IgG anti-(T,G)-A--L antibody production.
HISTOCOMPATIBILITY-LINKED IMMUNE RESPONSE GENE FUNCTION IN GUINEA PIGS
Authors: Shevach Ethan M. , Paul William E. , Green Ira
Published: June 2004

A number of autosomal dominant immune response (IR) genes have been identified in both mice and guinea pigs. These IR genes have been shown to be linked to the major histocompatibility antigens of the species and to be functionally expressed primarily in T lymphocytes. In order to more fully understand the relationship between IR genes, histocompatibility antigens, and immune recognition, the effect of specific alloantisera on lymphocyte stimulation induced by antigens under control of IR genes was examined. Using lymphocytes from strain 2 or strain 13 animals, the in vitro proliferative responses both to antigens which are known to be under genetic control (DNP-GL in strain 2 guinea pigs and GT in strain 13 guinea pigs) and to an antigen which is not known to be under genetic control (PPD) were inhibited to a similar degree and to a much greater extent than the response to phytohemagglutinin. However, when cells from F1 (2 x 13) animals are used, the alloantisera markedly inhibit only the response which is linked to the histocompatibility antigens against which the serum is directed. Thus, the anti-2 serum inhibited the response to DNP-GL but not to GT; the anti-13 serum inhibited the response to GT but did not affect DNP-GL response. The inhibitory activity of the alloantisera could not be removed by absorption with gamma globulin of the opposite strain. It can be concluded from these observations that immune response genes produce a cell surface-associated product and that this product plays a role in the mechanism of antigen recognition by the T lymphocyte. The mechanisms by which alloantisera block this process of antigenic recognition is not resolved nor is the relationship between the IR gene product and the antigen-binding receptor of the T lymphocyte. The approach described here offers a powerful tool for the resolution of these problems.
STUDIES ON GONOCOCCUS INFECTION
Authors: Swanson John
Published: June 2004

Gonococci have been studied by electron microscopy after freeze-cleavage, freeze-etching and the findings correlated with those obtainable through thin sectioning and negative staining. The outer membrane of the cell wall is composed of round to hexagonal subunits 80 A in diameter. This membrane is also punctuated by 80-A holes visible on the exterior of the organism and extending into the substance or through the outer membrane. Pili coursing over the surface of the organisms appear to maintain a close anatomical relationship with the cell wall. In some instances, the surfaces of the organisms are virtually covered by a layer of pili.
OYSTER CILIARY INHIBITION BY CYSTIC FIBROSIS CULTURE MEDIUM
Authors: Danes B. Shannon , Bearn Alexander G.
Published: June 2004

Using the oyster ciliary test, sera and fibroblast culture fluid from certain homozygotes and heterozygotes for cystic fibrosis can be shown to contain an inhibitory factor. The tissue culture fluid derived from the metachromatic fibroblast cultures (cystic fibrosis classes I and II) show ciliary inhibition. The fluid derived from the ametachromatic fibroblast cultures (cystic fibrosis class III), thus far studied, cannot be invariably distinguished from the normal noncarriers. Similarly sera from classes I and II show marked ciliary inhibition, whereas sera from class III individuals do not consistently. These experiments support the notion of genetic heterogeneity in cystic fibrosis. The nature of the inhibitory factor in tissue culture fluid and its relationship to the serum factor remain to be explored.
MOUSE THYMUS-INDEPENDENT AND THYMUS-DERIVED LYMPHOID CELLS
Authors: Lamelin J.-P. , Lisowska-Bernstein B. , Matter A. , Ryser J. E. , Vassalli P.
Published: June 2004

The simultaneous use on mouse lymphoid suspensions of heterologous antisera directed against thymus-derived (T) cell mouse-specific lymphocyte antigen and brain-associated theta antigen (MSLA and BAθ) or thymus-independent (B) cell mouse-specific bone marrow-derived lymphocyte antigen (MBLA) surface antigens allowed direct proof of the different specificity of these antisera by double immunofluorescence (IF) staining with selective visualization of fluorochromes. These antisera and antisera against mouse Ig and its different types of chains were then used with technique of either double IF staining or IF combined with radioautography, allowing the following conclusions:

(a) Surface Ig (sIg) was found exclusively on B cells and never on T cells, but not all B cells had sIg. Cells containing detectable amounts of Ig were MBLA+, but had less sIg than other B cells or none at all. There was evidence for the existence of a significant number of MBLA+ lymphocytes, neither bearing nor containing detectable Ig.

(b) µ-Chains were the most frequent but not the only heavy chains found on spleen cells; however, it could not be decided with the technique used, if a single cell can bear more than one type of heavy chain. No cell containing γ-chains was found to bear surface µ-chains, although a very few cells containing both µ- and γ-chains were observed.

(c) The antigen-binding cells detected after immunization with bacteriophage T4, bovine serum albumin, Maia squinado hemocyanin, and sheep erythrocytes were analyzed for MSLA, MBLA or sIg using double IF, a combination of IF and radioautography, or inhibition of "rosette" formation. Practically all the antigen-binding cells detected were MSLA-, MBLA+, sIg+.

(d) More B cells than T cells were found among short-lived lymphoid cells labeled by repeated in vivo injections of tritiated thymidine, but the results did not support a simplified concept equating T cells to long-lived and B cells to short-lived lymphocytes.

(e) Cells dividing rapidly in the lymph nodes draining the sites of immunization with various antigens were predominantly T cells 2 days after immunization and in majority B cells a few days later.

(f) Incubation of lymphoid cells at 37°C with rabbit anti-mouse Ig or anti-κ chains led to complete disappearance of sIg and to decrease of MBLA ("antigenic modulation"). In the same conditions, anti-MBLA gave partial modulation of MBLA and of sIg; MBLA, however, reappeared much faster than sIg. No modulation of T cell surface antigens by the appropriate antisera was observed. Cell treatment with Pronase could remove MBLA, sIg, MSLA, and BAθ, which reappeared within a few hours. Neuraminidase treatment was without detectable effect on these antigens.
EVIDENCE THAT THE BONE RESORPTION-STIMULATING FACTOR PRODUCED BY MOUSE FIBROSARCOMA CELLS IS PROSTAGLANDIN E2
Authors: Tashjian Armen H. , Voelkel Edward F. , Levine Lawrence , Goldhaber Paul
Published: June 2004

A transplantable mouse fibrosarcoma, HSDM1, produces a potent bone resorption-stimulating factor. The factor can be extracted from the tumor tissue and harvested from the medium of clonal strains of HSDM1 tumor cells growing in monolayer culture. It has several chemical and biological properties of a prostaglandin. Using radioimmunoassay techniques, we have shown that HSDM1 cells synthesize and secrete large quantities of prostaglandin E2 (PGE2). The specific bone resorption-stimulating activity of the HSDM1 factor extracted from the tumor is high and approximately equal to that of PGE2 as measured in a bone tissue culture system in vitro. Indomethacin, a potent inhibitor of PGE2 synthesis in HSDM1 cells, also inhibits production by the cells of the bone resorption-stimulating factor, and has no detectable nonspecific effects on the bone culture assay system. Mice bearing the HSDM1 tumor have higher levels of both calcium and PGE2 in serum than control mice. We conclude that PGE2 is the bone resorption-stimulating factor produced by HSDM1 tumor cells, and that secretion of PGE2 by the tumor in vivo accounts for the relative hypercalcemia observed in tumor-bearing animals. The HSDM1 tumor cell system constitutes a new model for studying the pathogenesis of hypercalcemia associated with certain malignant tumors.
THE FIBRINOLYTIC PATHWAY OF HUMAN PLASMA
Authors: Kaplan Allen P. , Austen K. Frank
Published: June 2004

The conversion of the plasminogen proactivator to plasminogen activator by activated Hageman factor or its fragments has been recognized as an essential step in the conversion of plasminogen to plasmin. The plasminogen proactivator has been completely separated from prekallikrein and pre-PTA, two other proenzyme substrates of activated Hageman factor or its fragments. Plasminogen proactivator, free of any contaminating proteins as assessed by disc gel electrophoresis or isoelectric focusing, revealed a single band with an isoelectric point of 8.9 corresponding in position to the Hageman factor activatable material eluted from replicate unstained gels. After conversion of plasminogen proactivator by Hageman factor fragments to the plasminogen activator, the active site of the plasminogen activator is not inhibited by C1INH and is thus readily distinguished from that of kallikrein or PTA. The plasminogen activator is susceptible to inactivation by DFP while the plasminogen proactivator is not, as has been the case for esterases having a serine in the active site. Its interaction with plasminogen is inhibited by ϵ-aminocaproic acid.
IMMUNOLOGICAL TOLERANCE IN BONE MARROW-DERIVED LYMPHOCYTES
Authors: Katz David H. , Hamaoka Toshiyuki , Benacerraf Baruj
Published: June 2004

Administration of the 2,4-dinitrophenyl (DNP) derivative of the copolymer of D-glutamic acid and D-lysine (D-GL) to inbred mice induces a state of DNP-specific tolerance in such animals irrespective of their immune status at the time of treatment. Taking advantage of the relative ease with which DNP-D-GL can induce tolerance in an animal previously primed with an immunogenic DNP-carrier conjugate, we have established conditions for tolerance induction in an adoptive cell transfer system. Thus, the adoptive secondary anti-DNP antibody response of DNP-keyhole limpet hemocyanin (KLH)-primed spleen cells was completely, or almost completely, abolished by exposure of such cells to DMP-D-GL either in vivo or in vitro. Tolerance induction in vivo occurred irrespective of whether the DNP-primed cells were exposed to DNP-D-GL in the donor animal before adoptive transfer or in recipient mice after transfer. In the latter situation, it was possible to show that tolerance induction in this model occurs very rapidly (1 hr) and with relatively low doses of tolerogen (50 µg). Incubation of DNP-KLH-primed cells with DNP-D-GL in vitro under varying culture conditions also resulted in depression of the adoptive secondary response of such cells, although the kinetics and degree of tolerance induction in this way were slightly different from that obtained by in vivo tolerization.

Utilizing the adoptive transfer tolerance system, it was possible to approach certain questions concerning the mechanism of tolerance induction and fate of tolerant bone marrow-derived (B) lymphocytes in the DNP-D-GL model. The possibility that suppression of anti-DNP antibody from the DNP-D-GL reflects blocking of surface receptor molecules on B lymphocytes has been ruled out by several experimental observations. The most conclusive evidence on this point derives from the failure of enzymatic treatment with trypsin to reverse the tolerant state induced by in vitro exposure of primed cells to DNP-D-GL, whereas trypsinization completely restored the immunocompetence of DNP-KLH-primed cells rendered unresponsive by exposure to DNP-ovalbumin in vitro. The present studies also demonstrate that the tolerant state induced by DNP-D-GL represents a predominantly irreversible inactivation of specific B lymphocytes. This conclusion is derived from experiments in which it was found that tolerance was maintained through as many as two serial adoptive transfers performed over a period of time of at least 24 days from the single exposure of such cells to the tolerogen. Moreover, the possibility that maintenance of tolerance through such serial transfers was due to inadvertent transfer of tolerogenic doses of DNP-D-GL was definitively ruled out. It appears, therefore, that DNP-specific tolerance induced by DNP-D-GL is an example of irreversible inhibition of cell reactivity to antigen reflecting yet-to-be-determined events at the intra- and subcellular levels.