bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antibodies to surface IgM and IgD increase the expression of various class II antigens on human B cells
Authors: Godal Tore , Davies Catharina , Smeland Erlend B. , Heikkilä Reino , Funderud Steinar , Steen Harald B. , Hildrum Kari 
Published: February 2007

AbstractAntibodies to surface IgM and IgD were found to induce increased expression of class I1 antigens on normal and neoplastic human B cells within 24 h of stimulation. Antigens associated with different class II sub‐locus genes (DC, DR and SB) were all found to be increased as determined by monoclonal antibodies (Leu‐10 and B 3/4 for DC, D1/12 for DR and MHM4 for SB‐associated antigens). The increased expression of class 11 antigens was selective as anti‐immunoglobulins failed to increase expression of other surface antigens such as B1 and β2‐microglobulin. The effect of anti‐μ and anti‐μ could be blocked specifically by corresponding myeloma proteins suggesting that antibodies to surface IgM and IgD, respectively, were responsible for the effect observed. Moreover, antibodies to another surface antigen (B1) failed to induce such changes. Increased class II antigen expression appeared to be dependent on protein synthesis, and early changes in ion fluxes, but could not be elicited by membrane depolarization as reported in murine systems.
The action of human C3 in soluble or cross‐linked form with resting and activated murine B lymphocytes
Authors: Erdei Anna , Melchers Fritz , Schulz Thomas , Dierich Manfred 
Published: February 2007

AbstractThe third component of complement C3 has been implied in the stimulation of B lymphocytes to proliferation and maturation for Ig secretion. We have reinvestigated the extent of this activation with either activated or resting murine splenic lymphocytes in serum‐substituted cultures. Human C3 was used in either soluble or cross‐linked form. Soluble as well as Sepharose‐bound or glutaraldehyde‐cross‐linked C3, over a range of concentrations, was inactive with resting splenic lymphocytes of (C57BLW/6J × DBA/2)F1 C3H/HeJ and C57BL/6J nu/nu mice. However, lipopolysac‐charide‐activated spleen cells, enriched for B cell blasts, were stimulated by immobilized and cross‐linked C3, while they did not respond to soluble C3. The extent of restimulation was comparable to that indiced by lipopolysaccharide and resulted in both increased proliferation and maturation to Ig‐secreting cells. The stimulation of the blast cells appears to be C3 specific, since it can be inhibited by free c3.
B cell growth factor activity of immunoaffinity‐purified and recombinant human interleukin 2
Authors: Mingari Maria Cristina , Gerosa Franca , Moretta Alessandro , Zubler Rudolf H. , Moretta Lorenzo 
Published: February 2007

AbstractWe investigated the effect of recombinant and affinity‐purified human interleukin 2 (IL2) on human B cell proliferation. Five × lo4 nonadherent spleen cells that had been depleted twice of T cells were activated by 3‐day culture with formaldehyde‐killed Staphylococcus aureus Cowan strain I (SAC) prior to addition of tested growth factors. Cultures were harvested 72 h later. It was found that both IL 2 preparations led to optimal cell proliferation compared with a control supernatant obtained by 36 h phytohemagglutinin stimulation of spleen mononuclear cells. Moreover, the effect of such spleen supernatant on B cell proliferation correlated with the IL2 activity since its B cell growth factor activity (BCGF) was not greater than that of purified IL2 and no residual BCGF activity could be detected after absorption of all IL 2 activity by the IL2‐dependent cytotoxic T lymphocyte line cells. T cells, enumerated as E‐rosetting cells as well as T3+ cells, represented 0.2 to 2% of the cells recovered at termination of the cultures (day 6) and there were < 1% E‐rosetting cells in freshly purified or SAC‐activated (day 3) B cell populations. Therefore, we conclude that IL2 is a growth factor not only for activated T cells but also for activated human B cells.
B cell activation and adjuvant activities of chemically synthesized analogues of the nonreducing sugar moiety of lipid A
Authors: Kumazawa Yoshio , Matsuura Motohiro , Homma J. Yuzuru , Nakatsuru Yoko , Kiso Makoto , Hasegawa Akira 
Published: February 2007

AbstractImmunological activities of synthetic lipid A analogues (derivatives of 3‐O‐tet‐ radecanoyl D‐glucosamine) were investigated. Compounds possessing a N‐tet‐ radecanoyloxytetradecanoyl group with or without a 4‐O‐phosphoryl group exhibited both mitogenic and polyclonal B cell activating activities. Among these, the phos‐phorylated compound exhibited strong activity. 4‐O‐phosphorylated analogues with a N‐tetradecanoyl group or 6‐O‐tetradecanoyl group in addition to N‐3‐hydroxyacyl groups showed no activity. All the analogues tested showed adjuvant activity, which was determined by augmentation of IgM antibody response against sheep erythrocytes. Relationship between chemical structure and biological activities is also discussed.
Segregation of reactivity to the mitogens lipopolysaccharide, lipoprotein and dextran sulfate in clones of the B cell lymphoma line WEHI 279.1
Authors: Kleine Bernhard , Bessler Wolfgang , Coutinho António 
Published: February 2007

AbstractThe B cell lymphoma line WEH1279.1 (surface IgM+, I‐A+ and I‐E+) was used as a model system to analyze functional reactivity of B lymphocytes to mitogens. Among the mitogens tested, lipopolysaccharide (LPS), lipoprotein (LP), and dextran sulfate (DxS) all induced a strong, dose‐dependent growth inhibition of tumor cells. The analysis of independently derived clones, however, revealed that mitogen sensitivity could be lost in the absence of detectable alterations in the expression of those surface markers. Moreover, reactivity to LPS, LP and DxS segregated independently in these clones, suggesting distinct triggering mechanisms and functional receptors for these mitogens on the B cell membrane.
Murine intestinal intraepithelial lymphocytes. II. Comparison of freshly isolated and cultured intraepithelial lymphocytes
Authors: Ernst Peter B. , Petit Agnes , Befus A. Dean , Clark David A. , Rosenthal Ken L. , Ishizaka Teruko , Bienenstock John 
Published: February 2007

AbstractHighly enriched preparations of intraepithelial lymphocytes (IEL) containing a large subpopulation of granulated cells were isolated from the murine small intestinal mucosa. We cultured IEL in media containing interleukin 2 (growth media conditioned with 20% concanavalin A supernatant; Con ACM) or mast cell growth factor(s) (growth media conditioned with 40% WEHI‐3 supernatant; WEHI CM) and compared the physical and functional properties of the cultured cells to freshly isolated IEL. IEL cultured in Con A CM developed enhanced cytotoxicity against YAC‐1, compared to freshly isolated IEL, and spontaneous cytotoxicity for P815 targets. Most of these cultured cells were Thy‐1+ Lyt‐1− Lyt‐2+, and contained cyto‐ plasmic granules similar to those seen in electron photomicrographs of other cytotoxic cell populations.IEL cultured in WEHI CM gave rise to cells that morphologically resembled mast cells. Unlike freshly isolated IEL, the cells stained metachromatically, contained 20C‐450 ng of histamine/106 cells and expressed high‐affinity receptors for IgE. Our data clearly show that, although IEL do not themselves have physical characteristics of mast cells, they do contain mast cell precursors. In addition, IEL grown in the presence of T cell growth factors give rise to an activated cytotoxic cell population which is mostly granulated and Thy‐1+ Lyt‐1− Lyt‐2+.
Macrophage Fcγ2b receptor expression and receptor‐ mediated phospholipase activity: regulation by endogenous eicosanoids
Authors: Rhodes John , Salmon John , Wood John 
Published: February 2007

AbstractThe expression of Fcγ2b receptors and receptor‐mediated arachidonic acid metabolism by murine peritoneal macrophages was examined in vitro. The expression of Fcγ2b receptors was found to increase progressively with time in culture and this increase was dependent on protein synthesis and glycosylation. The increase in Fcγ2b receptor expression was inhibited by hydrocortisone and by BW755C, an inhibitor of both the lipoxygenase and cyclo‐oxygenase pathways of arachidonic acid metabolism. Inhibition by BW755C was found to be reversed in the presence of exogenous leukotriene D4. In contrast, selective inhibition of the cyclo‐oxygenase pathway by indomethacin enhanced the increase in receptor expression. This enhancement was only partially reversed by exogenous prostaglandin (PG)E2. Interaction of the FCγ2b receptor with ligand in the form of erythrocytes specifically sensitized with IgGzb resulted in the release and subsequent metabolism of arachidonic acid. PGE2 was found to be the principal product. Occupation of the Fcγ2a receptor did not result in arachidonic acid release. Down regulation of Fcγ2b receptor expression produced a commensurate reduction in receptor‐mediated phospholipase activity measured by arachidonic acid release. Macrophages cultured for 24 h in the presence of fetal calf serum without additional stimuli produced substantial amounts of eicosanoids. PGI2 was the principal product. Taken together these data demonstrate a potential feedback regulation of receptor‐triggered arachidonic acid metabolism by eicosanoids acting at the level of Fcγ2b receptor expression.
T helper cell recognition of idiotopes on λ2 light chains of M315 and T952: evidence for dependence on somatic mutations in the third hypervariable region
Authors: Bogen Bjarne , Jørgensen Trond , Hannestad Kristian 
Published: February 2007

AbstractPrevious work has indicated that BALB/c T helper cells (Th) recognize an idiotope expressed on a 88‐114/117 fragment of Vλ2 of BALB/c myeloma protein 315. In the present study the antigenic structure of this idiotope was further analyzed. Conventional carrier‐specific Th elicited by immunization of BALB/c mice with free λ2315 did not cross‐react with the free λ2 chain of the BALB/c myeloma protein T952 which differs from λ3″ in five amino acid positions (38,94, 95,96, 99). Similarly, Th primed with free λ2T95 did not respond to a boost with free λ2315. Thus, BALB/c h2315‐specific Th recognize an idiotope that depends on some or all of the residues at positions 94, 95, 96 and 99. Furthermore, free λ2T952 contains an idiotope immunogenic to Th that depends on some or all of residues 38, 94, 95, 96 and 99. Th recognition of the free λ2T952 idiotope was quenched upon H + L chain assembly because Th elicited by free λ2T952 did not respond to a boost with the complete T952 myeloma protein. In contrast to the lack of Th cell cross‐reactivity, some of the antisera from BALB/c mice immunized with free λ2T952 cross‐reacted with free λ315, free λJ558 and free λ3CBPC49 but not with free ϰw3129 or polyclonal L chains. The H chain of T952 (α,ϰ2) myeloma protein was abnormally short (Mr = 48 000) and T952 existed as a halfmere probably due to this H chain deletion. Furthermore, H and L chains were disulfide bonded to each other.
Structural in variance of T4 molecules from T cell clone Of different antigen and major histocompatibility complex specificities
Authors: Sayre Peter H. , Reinherz Ellis L. 
Published: February 2007

AbstractRecent studies have suggested that the T4 molecule may bind to class I1 major histocompatibility complex (MHC) gene products on target cells. Such an interaction could be with either a polymorphic or monomorphic determinant on class II MHC genes. The first would imply that T4 is structurally variable and represents a compo‐ nent of a dual receptor, whereas the latter would suggest that T4 is structurally invariant and serves as an accessory binding molecule. To resolve this question we studied the structural variability of T4 molecules isolated from four clones of differing antigen/MHC specificities. By one‐ and two‐dimensional electrophoretic analysis and by peptide mapping, we detected no differences among the 55‐kDa T4 molecules from these clones. We conclude that T4 serves as an invariant accessory binding structure and that T4 does not confer MHC specificity on T cells.
Human monocyte cytotoxin is not identical with lymphoblastoid lymphotoxin
Authors: Matthews Nicholas 
Published: February 2007

AbstractMononuclear phagocytes and lymphocytes can both synthesize cytotoxins which kill certain tumor cell lines and recent evidence suggests that these cytotoxins may be identical. In this study, human monocyte cytotoxin and lymphoblastoid lymphotoxin have been critically compared in terms of specificity, physicochemical characteristics and antigenicity. Despite their similar pattern of reactivity with a panel of cell lines, lymphotoxin was less readily adsorbed than monocyte cytotoxin by tumor cells. The cytotoxins could also be distinguished by their behavior on high performance liquid chromatography and by the failure of antibody to monocyte cytotoxin to react with lymphotoxin.
Mice varying in resistance to African trypanosomiasis respond differently to treatments with variant surface glycoprotein
Authors: Diffley Peter 
Published: February 2007

AbstractA comparative analysis of responses between resistant and susceptible hosts revealed that DBN/2 mice, after treatment with variant surface coat glycoprotein (VSG) from virulent or avirulent African trypanosomes, developed splenomegaly as the result of a near‐doubling of the splenic cell population, had less polyclonal activation of B cells and were protected upon challenge with homologous trypanosomes. The susceptible C3H/Anf and C3W/HeJ mice on the other hand increased their splenic cell population by only 12%, had about twice the production of unelicited antibodies and were not immunized by the VSG treatments. This indicated that (a) proliferation of spleen cells during African trypanosomiasis may reflect an attempt to generate a specific and protective immune response and is not merely the result of polyclonal activation of lymphocytes; (b) production of unelicited antibodies is not merely a “bystander reaction” to the generation of antigen‐specific responses; and (c) polyclonal antibody production in response to VSG is not linked to the LPS gene. Nonspecific immunosuppression as measured in mitogen assays was not elicited by VSG in either resistant or susceptible mice, indicating that polyclonal lymphocyte activation and nonspecific immunosuppression are unlinked phenomena.Mice injected with VSG from either virulent or avirulent isolates at levels normally encountered by hosts during severe, acute infection developed the same degree of splenomegaly and production of unelicited (polyclonal) antibodies. Therefore, any differences in polyclonal activation of lymphocytes measured between mice with acute vs. chronic African trypanosomiasis can be attributed to quantitative and not qualitative differences in VSG.
Immunosuppression by cell‐free translation products from monoclonal antigen‐specific suppressor T cell mRNA
Authors: Ricciardi‐Castagnoli Paola , Robbiati Federico , Barbanti Eiena , Colizzi Vittorio , Pini Carlo , De Santis Rita , Doria Gino , Adorini Luciano 
Published: February 2007

AbstractPolypeptides synthesized in a rabbit reticulocyte lysate system directed by mRNA from the T cell line LH8‐105, obtained by radiation leukemia virus‐induced transformation of hen egg‐white lysozyme (HEL)‐specific suppressor T lymphocytes, are able, when injected into mice, to specifically suppress the antibody response and delayed‐type hypersensitivity to HEL. The suppressive activity exerted by in vitro translated proteins appears to be independent from post‐translational modifications. These in vitro translated polypeptides display fine antigenic specificity in immunosup‐ pression and bind to HEL but not to the closely related ring‐necked pheasant egg‐ white lysozyme immunosorbents. Suppressive molecules obtained by cell‐free translation of LH8‐105 mRNA or by culture supernatant of LH8‐105 cells display, by gel filtration, a similar molecular mass of about 82–90 kDa.
Syngeneic mixed lymphocyte reactions to murine Fc receptor‐bearing, nonadherent low density lymph node cells and epidermal Langerhans cells
Authors: Bienenstock Arielle N. , Belsito Donald V. , Baer Rudolf L. , Rosen Judy , Fossick Lisa E. , Thorbecke G. Jeanette 
Published: February 2007

AbstractBoth Langerhans cells from BALB/c mouse epidermis and nonadherent, low density (LD) cells, obtained from collagenase‐treated minced lymph node, are stimulatory for isolated T cells in syngeneic mixed lymphocyte reaction (SMLR). The method of preparation of LD cells influences whether Fc receptor (FcR) can be detected on them. Fc receptors on nonadherent LD lymph node cells can be detected only if the same procedure is employed as that for Langerhans cell isolation, i.e., Ig‐free bovine albumin must be used during gradient centrifugation and EA resetting must be done overnight at 4°C. Thus, both FcR+ and FcR− LD lymph node cells, as well as FcR+ Langerhans cells, stimulate SMLR. Although Ig+ cells in the LD fraction a lso stimu late the SMLR, their removal does not affect the stimulating capacity of the LD lymph node fraction.
Clonal specificity of concanavalin A‐induced cytotoxic T lymphocytes
Authors: Larsson Eva‐Lotta , Beretta Alberto , Ermonval Myriam 
Published: February 2007

AbstractThe specificity of polyclonally induced cytotoxic T lymphocyte (CTL) precursors has been analyzed under clonal conditions. Primary clones of concanavalin A‐inducible CTL, if tested on different targets, revealed that they could distinguish between (a) two different allogeneic tumor targets; (b) allogeneic and syngeneic tumor targets, and (c) syngeneic B blasts and tumor targets. No “nonspecific” CTL clones were generated under these culture conditions, and all clones were found to display classical immunological specificity.
Lack of inhibition of mitogen‐induced lymphoproliferation by interferon gamma
Authors: Pischedda Franca , Landolfo Santo , Kirchner Holger 
Published: February 2007

AbstractInterferon (IFN) gamma has been shown to have enhancing effects on immunocompetent cells, as for example induction of the expression of I‐A antigens. In this report the effect of purified mouse IFN‐γ on mitogen‐induced proliferation was studied. In contrast to the situation observed with IFN‐a or IFN‐β, treatment by IFN‐γ had no suppressive effect on mitogenesis. Enhancing effects on DNA synthesis induced by phytohemagglutinin were observed at low concentrations of IFN‐γ in the early stage of lymphocyte activation. The effects on T cell proliferation, however, were not consistent under all experimental conditions.
The large sialoglycoprotein of human lymphocytes. II. Biochemical features
Authors: Axelsson Bernt , Hammarström Sten , Finne Jukka , Perlmann Peter 
Published: February 2007

AbstractLarge sialoglycoprotein of human lymphocytes (L‐LSGP) from thymocytes and from peripheral blood lymphocytes (PBL) of normal donor and of B chronic lymphocytic leukemia (CLL) patients was purified by affinity chromatography to Mucluru pornifera agglutinin (MPA)‐Sepharose followed by preparative sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). L‐LSGP from the three different sources was very similar in amino acid composition. It contained a high proportion of acidic and hydroxy amino acids and also significant amounts of cystein. No reduction in mobility in SDS‐PAGE was noted for unreduced L‐LSGP. The molecule may already in its native form have an extended conformation containing either free sulfhydryl groups or small S‐S loops not affecting mobility in SDS‐PAGE. L‐LSGP was found to be highly glycosylated, the thymocyte glycoprotein containing somewhat less carbohydrate by weight (44%) than that of PBL (normal PBL 53% and B CLL 52%). This was due primarily to a lower content of sialic acid. The molecules contained mannose, galactose, N‐acetyl galactosamine, N‐acetylglucosamine and sialic acid in molar ratios 1.0:3.0:1.1:1.2:1.3 (thymocyte L‐LSGP), 1.0:3.8:1.2:1.0:1.7 (PBL L‐LSGP) and 1.0:3.5:2.2:1.3:2.8 (B CLL L‐LSGP). The weak interaction of L‐LSGP with lentil lectin, concanavalin A (Con A) and leucoagglutinin (La), its unchanged mobility in SDS‐PAGE after tunicamycin treatment and its high amount of hydroxy amino acids suggest that most carbohydrate chains are O‐glycosidically linked to the peptide chain. Native as well as Nase‐treated L‐LSGP show size microheterogeneity. This is probably due to small chemical differences in the L‐LSGP molecules from different lymphocyte subsets.
Expression of interleukin 2 receptor on murine fetal thymocytes
Authors: Habu Sonoko , Okumura Ko , Diamantstein Tibor , Shevach Eathan M. 
Published: February 2007

AbstractRat monoclonal antibodies AMT‐13, 3C7 and 7D4 which react to the mouse interleukin 2 (IL2) receptors were used to define cell populations with the putative IL2 receptors in the mouse thymus as a part of series of investigations to elucidate the mechanism of intrathymic cell proliferation and differentiation. With freshly dissociated cells from the thymus of 15 gestational days, the anti‐IL2 receptor monoclonal antibodies (anti‐IL 2 receptor) reacted with about half of them. The proportion of the reactive cells decreased rapidly thereafter till birth as the numbers of thymus cells expanded. The antibodies reacted with only two to three percent of thymic cells from newborn mice and less than one percent of cells from adult thymus. Through the gestational period, the fetal liver cells did not react with the antibodies. When the thymus cells at early gestational days were subjected to a two‐color analysis, one for the anti‐IL2 receptor and the other for anti‐Thy‐1 or anti‐asialo GM1, by a fluorescence‐activated cell sorter, it was found that the majority (up to 80%) of anti‐IL2 receptor‐reactive cells (IL2 receptor‐positive cells) was also reactive with anti‐Thy‐1. Some of the IL2 receptor‐positive cells but Thy‐1‐negative cells reacted with anti‐asialo GM1, a marker of the immature thymocytes. Immunohistochemically, the IL2 receptor‐positive cells were found mainly in the subcapsular area and in the border region of cortex and medulla. Collectively, these results suggest that the pre‐T lymphocytes are stimulated immediately after their arrival to the thymus from the stem cell source such as fetal liver and bone marrow and are driven into the proliferation via the IL2 receptor system.
The mitogenic lectin from Phaseolus vulgaris does not recognize the T3 antigen of human T lymphocytes
Authors: Kanellopoulos Jean M. , De Petris Stefanello , Leca Gerald , Crumpton Michael J. 
Published: February 2007

AbstractHuman peripheral blood T lymphocytes are stimulated to grow and divide by lectins such as concanavalin A (Con A) and Phaseolus vulgaris phytohemagglutinin (PHA), as well as a few anti‐T cell monoclonal antibodies. The latter antibodies recognize the T3 antigen. It has been suggested previously that PHA and Con A mediate T cell growth by interacting with T3. However, as reported in this study, affinity chromatog‐raphy on immobilized lectins, and immunoprecipitation by lectin plus anti‐lectin antibodies showed that T3 binds Con A but not PHA. Fab fragments of a monoclonal antibody against T3 (namely Leu‐4) inhibited T lymphocyte proliferation induced by T3 antibodies and Con A, but not by PHA. Nevertheless, co‐capping experiments performed with fluorescein‐labeled lectins and rhodamine‐labeled T3 antibodies showed that T3 co‐caps with Con A and PHA receptors, although the co‐capping with PHA was incomplete. Since the T cell receptor for antigen (Ti) has been shown to co‐cap with T3 on the cell surface, we reasoned that PHA induced capping of the T3 antigen by interacting with Ti. A disulfide‐linked heterodimer comprising subunits of about 49 000 and 41 000 mol. wt. that resembled the Ti molecule was detected in PHA‐anti‐PHA immunoprecipitates of various surface‐ and biosynthetically‐labeled T cells, by two‐dimensional (nonreduced vs. reduced) sodium dodecyl sulfate‐poly‐acrylamide gel electrophoretic analysis. The results suggest that PHA triggers T lymphocytes by interacting with the carbohydrate moieties of Ti and imply that T lymphocytes can be stimulated by mitogens via at least two different cell surface molecules (Ti and T3).