bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of T cell hybridomas. II. Comparisons among three distinct types of monoclonal suppressor factors.
Authors: Okuda K , Minami M , Furusawa M , Dorf M E
Published: June 2004

Five hybridoma T cell lines were prepared by fusion of Ts3 cells with the BW 5147 thymoma. The culture supernatants from these T cell hybrids contained a factor, TsF3, which specifically suppressed 4-hydroxy-3-nitrophenyl acetyl hapten (NP(-hapten cutaneous sensitivity responses. The properties of this new series of hybridoma factors was compared with those of two previously characterized types of NP-specific suppressor factors (TsF1 and TsF2). TsF3 activity was only observed if the factor was administered during the effector phases of the immune response. TsF3 bears I-J and C57BL anti-NP antibody idiotypic determinants and has binding specificity for the NP hapten. Furthermore, TsF3 does not suppress H-2 (I-J)-incompatible mice. In addition to this H-2 restriction, the monoclonal TsF3 factors also demonstrated an Igh genetic restriction. Finally, the TsF3 factors could be distinguished by their ability to suppress cyclophosphamide-treated recipients.
Receptor activities for low-density lipoprotein and acetylated low-density lipoprotein in a mouse macrophage cell line (IC21) and in human monocyte-derived macrophages.
Authors: Traber M G , Defendi V , Kayden H J
Published: June 2004

IC21 macrophages, a permanent culture of a line of cells derived from a single colony of mouse peritoneal macrophages transformed with simian virus 40, demonstrate most of the characteristics of lipoprotein metabolism that have been described for primary cultures of rodent or canine peritoneal macrophages. IC21 macrophages have low but demonstrable low-density lipoprotein (LDL) receptor activity. They actively degrade acetylated LDL (AcLDL), which has a negative charge and is not recognized by the LDL receptor. Incubation of IC21 macrophages with human lipoprotein-depleted serum leads to a marked increase in cholesterol synthesis, as measured by incorporation of labeled acetate into sterols. Sterol synthesis is inhibited by further incubation with AcLDL; incubation with LDL also decreases cholesterol synthesis with an accumulation of radioactivity from acetate in sterol intermediates, which indicates that some uptake of LDL occurs. Incubation with AcLDL but not LDL leads to a marked stimulation of cholesterol esterification, as measured by labeled oleic acid incorporation into cholesteryl esters, and a concomitant increase in cellular cholesteryl ester content. IC21 macrophages as compared with human monocyte-derived macrophages are shown to have marked difference in their abilities to degrade native LDL and AcLDL. Human monocyte-derived macrophages degrade LDL at low concentrations at a rate sevenfold greater than do IC21 macrophages. The rate of cholesteryl ester synthesis after LDL receptor induction and incubation with LDL increases linearly with LDL concentration in HMD macrophages, but no increase was found in similarly incubated IC21 macrophages. IC21 macrophages degrade AcLDL at a rate two- to fourfold greater than do human monocyte-derived macrophages.
A specific biosynthetic marker for immature thymic lymphoblasts. Active synthesis of thymus-leukemia antigen restricted to proliferating cells
Authors: Rothenberg E
Published: June 2004

Large cortical thymocytes from C57BL/6-Tla(a) mice have been prepared rapidly and in high yield by a combination of centrifugal elutriation and differential binding to peanut agglutinin (PNA)-coated plates. The cells in these lymphoblast-rich fractions were clearly distinct from the majority of thymocytes, with up to 70 percent in the S or G(2) + M phases of the cell cycle and an average rate of [(35)S]methionine incorporation per cell up to 20 times higher than that of the majority population.

The populations of cells resolved in this fractionation were characterized by monitoring their rates of synthesis of specific glycoproteins, thymus- leukemia antigen (TL) and the Lyt-2, Lyt-3 complex (Lyt-2/3), relative to their total protein synthesis. Cells that bound to PNA synthesized high levels of Lyt-2/3, consistent with their identification as cortical thymocytes. Those that failed to bind made little or no Lyt-2/3, as expected for medullary cells, The fraction of dividing lymphoblasts that bound to PNA was enriched in cortical thymocyte precursors, including all the large cells detectably active in synthesizing Lyt-2. It differed sharply from the small cortical cells, however, in the synthesis of TL. Although both populations displayed abundant surface TL, the TL glycoprotein was produced actively in fractions containing dividing cells but made at a drastically reduced rate by the nondividing majority of cortical thymocytes. Thus, TL seems to be made at a narrowly circumscribed stage of early thymocyte development that is correlated with rapid proliferation. In most of the descendants of such blast cells, the TL glycoprotein is presumably retained on the cell surface as long as no substantial membrane turnover takes place. Ongoing TL synthesis may therefore serve as a marker for a unique developmental state which terminates rapidly in normal differentiation but may be extended by agents that give rise to TL(+) thymic lymphomas.
Formation of multinucleated giant cells from human monocyte precursors. Mediation by a soluble protein from antigen-and mitogen-stimulated lymphocytes.
Authors: Postlethwaite A E , Jackson B K , Beachey E H , Kang A H
Published: June 2004

Multinucleated giant cells are associated with granulomas arising from immunological and nonimmunological inflammatory reactions. They are an integral part of the host immune response to chronic infectious diseases. In the present study we have demonstrated that human lymphocytes when stimulated by specific antigens of T cell mitogens produce a soluble factor that causes peripheral blood monocytes to fuse and form multinucleated giant cells in vitro. Production of the giant cell factor by antigen-stimulated peripheral blood lymphocytes correlates with the existence of cell-mediated immunity to specific antigen. Monocyte-depleted blood lymphocytes, but not purified blood monocytes, produce the giant cell factor when cultured with antigens or T cell mitogens. Gel filtration and physiochemical studies indicate that the lymphocyte-derived giant cell factor is a heat-labile protein of approximately 60,000 mol wt. These findings suggest that multinucleated giant cells in granulomas may be formed by fusion of circulating monocytes in response to the release of a 60,000-mol wt protein from antigen-stimulated T lymphocytes.
Suppression of interstitial nephritis by auto-anti-idiotypic immunity.
Authors: Neilson E G , Phillips M
Published: June 2004

Rats immunized with renal tubular antigens were protected from the development of interstitial nephritis by pretreatment with tubular antigen-reactive T lymphoblasts. Protected animals developed anti-idiotypic antibodies against idiotypes primarily within the antigen-binding region of monoclonal antitubular basement membrane antibodies. These studies extend the concept of auto-anti-idiotypic regulation to autoimmune disease, and they also provide an experimental basis for further efforts to develop biologically relevant mechanisms for attenuating the expression of other kidney diseases.
Activation of the guinea pig alternative complement pathway by mouse IgA immune complexes.
Authors: Pfaffenbach G , Lamm M E , Gigli I
Published: June 2004

Activation of the complement system by IgA was investigated with immune complexes containing a mouse IgA myeloma protein with specificity for phosphorylcholine linked to bovine serum albumin (PC-BSA). These IgA anti-PC-BSA immune complexes activated the alternative complement pathway in mouse and guinea pig serum, while human complement was not affected. The activation proceeded with consumption of C3 but little or no consumption of C5. C3 did not bind to the IgA immune complexes during complement activation although it did bind covalently to IgG immune complexes. It is suggested that IgA immune complexes do not supply a suitable surface for C3 binding and effective alternative pathway convertase assembly; therefore, cleavage is limited and occurs primarily in the fluid phase. Without C3 binding, C5 cleavage does not occur nor can the alternative pathway activation proceed to the amplification step.
Immune response genes controlling responsiveness to major transplantation antigens. Specific major histocompatibility complex-linked defect for antibody responses to class I alloantigens.
Authors: Butcher G W , Corvalán J R , Licence D R , Howard J C
Published: June 2004

We have identified two major histocompatibility complex (MHC)-linked Ir genes that control the antibody response made by rats against class I major alloantigens. We have named these genes Ir-RT1Aa and Ir-RT1Ac. These Ir genes determine responsiveness of the immunized animal in a typical codominant fashion. There is no evidence so far for trans-complementation between low-responder haplotypes. Detailed studies of Ir-RT1Aa indicate that it controls the antibody response to at least two distinct alloantigenic determinants on RT1Aa molecules. These class I molecules thus behave like hapten-carrier conjugates when the response against the carrier is under Ir gene control. Analysis of the origin of alloantibody-forming cells in tetraparental radiation chimeras indicates that Ir-RT1Aa must control the provision of effective help to B cells. In many respects therefore, the properties of Ir-RT1Aa are broadly similar to those described for Ir genes controlling antibody responses to conventional antigens. The existence of apparently conventional Ir genes controlling the antibody response to major alloantigens strongly suggest that the processing of these transmembrane molecules by host antigen-presenting cells is a prerequisite for immune induction, and that it is the MHC of the responder rather than that of the allograft to which T helper cells are restricted in alloimmune responses in vivo.
Immune response gene function correlates with the expression of an Ia antigen. I. Preferential association of certain Ae and E alpha chains results in a quantitative deficiency in expression of an Ae:E alpha complex.
Authors: McNicholas J M , Murphy D B , Matis L A , Schwartz R H , Lerner E A , Janeway C A , Jones P P
Published: June 2004

These studies were stimulated by the observation, reported in the accompanying paper (19), that IEu failed to interact with I-Ak or I-As in F1 mice to allow a response to the antigen, pigeon cytochrome c, unlike I-E subregions derived from other Ia.7+ haplotypes. Serological and biochemical analyses were performed to determine whether or not cells from these F1 mice express the Ak,se:E alpha complexes that should function as restriction elements for T cell recognition of pigeon cytochrome c on antigen-presenting cells. Using the Y-17 monoclonal antibody, which recognizes the combinatorial or conformational determinant Ia.m44 on certain Ae:E alpha complexes, we were able to distinguish between Aue:Eu alpha and Ab,k,se:Eu alpha complexes on cell surfaces. Although complement-dependent microcytotoxicity with Y-17 failed to detect Ab,k,se:Eu alpha complexes on cells from appropriate F1 mice, these molecules were detected by both quantitative absorption and quantitative immunofluorescence studies. However, Ab,k,se:Eu alpha complexes were found to be present at levels only one-seventh to one-eighth the levels expressed by homozygous I-Ab, I-Ek; I-Ak, I-Ek; and I-As, I-Ek cells. The results of two-dimensional polyacrylamide gel electrophoresis analyses suggest that the low levels of expression of Ab,k,se:Eu alpha complexes are a consequence of the preferential association of Aue and Eu alpha chains with each other in the F1 cells. As will be shown in the following paper (19), the quantitative deficiency in the expression of Ake:Eu alpha and Ase:Eu alpha complexes results in a corresponding defect in antigen-presenting cell function, thus providing strong evidence that Ia antigens represent products of Ir genes.
Lack of oral tolerance in C3H/HeJ mice.
Authors: Kiyono H , McGhee J R , Wannemuehler M J , Michalek S M
Published: June 2004

Daily gastric intubation of lipopolysaccharide (LPS)-responsive C3H/HeN, BALB/c, and Swiss mice with SRBC for 2 wk resulted in oral tolerance, whereas similarly treated LPS-nonresponsive C3H/HeJ mice gave splenic anti-SRBC PFC responses, including the IgA isotype, after systemic challenge with antigen. Oral tolerance in LPS-responsive C3H/HeN mice was due to T suppressor (Ts) cells because significant Ts cell activity was demonstrated in both Peyer's patches (PP) and spleens of these animals. On the other hand, T cells from PP and spleens of identically treated C3H/HeJ mice exhibited mainly T helper cell activity. Prior treatment of PP or spleen cell preparations from tolerant C3H/HeN mice with anti-Lyt-2.1 resulted in good in vitro anti-SRBC PFC responses, especially IgA isotype responses in PP cell cultures. These results indicate that oral administration of a thymic-dependent antigen (SRBC) to LPS-responsive mice induced a Ts cell population in PP, which, after migration to peripheral lymphoid tissue (e.g., spleen), suppressed responses to systemically administered antigen. LPS-nonresponsive mice lack this Ts cell pathway and continually respond to oral administration of antigen.
Antigen-specific soluble helper activity for murine major histocompatibility complex-encoded molecules. I. Kinetics of factor production after skin transplantation and genetic mapping of the H-2 region specificity.
Authors: Plate J M , McDaniel C A , Flaherty L , Stimpfling J H , Melvold R W , Martin N Q
Published: June 2004

Antigen-specific soluble helper molecules are produced during major histocompatibility complex-disparate allograft priming. Genetic mapping studies with appropriate recombinant and mutant lines of mice have defined the antigen specificities of the soluble helper molecules described here as being directed against the H-2Dd molecules. The production of antigen-specific helper molecules is a relatively early event after H-2Dd-region allograft priming. A later phase of factor production near the time of graft rejection also contains nonspecific helper factors and IL-2.
Low zone desensitization: a stimulus-specific control mechanism of cell response. Investigations on anaphylatoxin-induced platelet secretion.
Authors: Meuer S , Zanker B , Hadding U , Bitter-Suermann D
Published: June 2004

The biologic activity of the anaphylatoxic peptides C5a and C3a is regulated efficiently at the target-cell level by the phenomenon of desensitization. Desensitization of platelets is stimulus specific and can be induced by low concentrations of anaphylatoxins without any preceding secretory event. In contrast to activation to secretion, desensitization is Ca++ independent but much more time consuming, especially at lower temperatures where both processes differ markedly in reaction velocity. This low zone desensitization insures that secretion from platelets only occurs when high amounts of anaphylatoxins are rapidly generated in the vicinity of the target-cell. Consequently, stimulus-specific unresponsiveness of the target cells can be induced by slowly increasing the concentration of the respective stimuli in their vicinity. Cellular control seems to act as a first-line mechanism of regulation, whereas the role of fluid-phase control is considered as preventing longer persistence and systemic accumulation of active anaphylatoxins.
Studies on the mechanism of bacterial resistance to complement-mediated killing. II. C8 and C9 release C5b67 from the surface of salmonella minnesota S218 because the terminal complex does not insert into the bacterial outer membrane
Authors: Joiner KA , Hammer CH , Brown EJ , Frank MM
Published: June 2004

The mechanism for consumption of terminal complement components and release of bound components from the surface of serum-resistant salmonella minnesota S218 was studied. Consumption of C8 and C9 by S218 occurred through interaction with C5b67 on the bacterial surface because C8 and C9 were consumed when added to S218 organisms previously incubated in C8-deficient serum and washed to remove all C5b67 on the bacterial surface because C8 and C9 were consumed when added to S218 organisms previously incubated in C8- deficient serum and washed to remove al but cell bound C5b67. Rapid release of (125)I C5 and (125)I C7 from the membrane of S218 was dependent on binding of C8 because (125)I C5 and (125)I C7 deposition in C8D serum was stable and was twofold higher in C8D than in PNHA, and addition of purified C8 or C8 and C9 to S218 previously incubated in C8D serum caused rapid release of (125)I C5 and (125)I C7 from the organism. Analysis by sucrose density gradient ultracentrifugation of the fluid phase from the reaction of S218 and 10 percent PNHS revealed a peak consistent with SC5b-9, in which the C9:C7 ratio was 3.3:1, but the NaDOC extracted bound C5b-9 complex sedimented as a broad peak with C9:C7 of less than 1.2:1. Progressive elution of C5b67 and C5b-9 from S218 but not serum-sensitive S. minnesota Re595 was observed with incubation in buffers of increasing ionic strength. Greater than 90 percent of the bound counts of (125)I C5 or (125)I C9 were released from S218 by incubation in 0.1 percent trypsin, but only 57 percent of (125)I C9 were released by treatment of Re595 with trypsin. These results are consistent with the concept that C5b-9 forms on the surface of the serum-sensitive S. minnesota S218 in normal human serum, but the formed complex is released and is not bactericidal for S218 because it fails to insert into hydrophobic outer membrane domains.
Two Ly-2 T helper cell subsets distinguished by Qa-1 phenotype. The priming environment determines whether one or both subsets will be generated.
Authors: McDougal J S , Shen F W , Cort S P , Bard J
Published: June 2004

The Qa-1 cell surface phenotype reportedly distinguishes two Ly-1 T cell subsets conjointly required for T helper effector activity. Ly-1 cells, obtained from several different priming regimens, were negatively selected with anti-Qa-1 plus complement and compared with unselected Ly-1 cells for helper cell activity. Priming isolated T cells on antigen-pulsed macrophages in the absence of B cells favors the generation of the Ly-1:Qa1- subset, which is capable of efficient helper activity in the absence of the Ly-1:Qa-1+ subset. Priming T cells in an environment containing B cells generates both Ly-1:Qa-1- helper effector cells and Ly-1:Qa-1+ cells which contribute to the helper effect. Whether Ly-1:Qa-1+ cells are capable of independent helper activity cannot be determined, and, as such, Ly-1:Qa-1+ cells are more appropriately termed "help associated" rather than "helper effector." Our results assign a membrane phenotype, Qa-1, which distinguishes an Ly-1 help-associated B cell requiring subset in our system and may prove to be a general marker in a number of systems of Ly-1 inducer cell subsets which functionally require or recognize B cells or their products.
Definition of T cell idiotypes using anti-idiotypic antisera produced by immunization with T cell clones.
Authors: Infante A J , Infante P D , Gillis S , Fathman C G
Published: June 2004

Alloreactive T cell clones with distinct specificities were used to raise anti-idiotypic antisera via an F1 anti-(parent anti-F1) protocol. Antisera were raised that could stimulate the proliferation of the appropriate T cell clone, but not other clones. The active fraction of the antisera for T cell proliferation was immunoglobulin. In addition to proliferation, an anti-idiotypic antiserum could induce the appropriate T cell clone to secrete substantial amounts of interleukin 2 (IL-2). Production of IL-2 appeared independent of the involvement of accessory cells. These accessory cells may be unnecessary for IL-2 production in our assay, or their effect may be produced by anti-idiotype. Thus, anti-idiotype may provide two or more specific T cell signals.
Antibodies to laminin in Chagas' disease.
Authors: Szarfman A , Terranova V P , Rennard S I , Foidart J M , de Fatima Lima M , Scheinman J I , Martin G R
Published: June 2004

We have found that sera from humans with Chagas' disease and Rhesus monkeys infected with Trypanosoma cruzi contain IgM and IgG antibodies, which react with structures in a variety of connective tissues. These antibodies react with laminin but not with various other purified connective tissue components like collagen types I, III, IV, and V, fibronectin, heparan sulfate (BM-1) proteoglycan, or chondronectin. The tissue-reacting antibodies were isolated by absorption to a laminin-Sepharose column. The bound fraction contained all the tissue-reacting antibodies. These antibodies strongly stained trypomastigotes and amastigotes, but weakly stained epimastigotes. These studies show that sera from T. cruzi-infected primates contain antilaminin antibodies, which may be produced by those host in response to a laminin-like molecule present in the parasite.
Human dendritic cells. Enrichment and characterization from peripheral blood
Authors: Van Voorhis WC , Hair LS , Steinman RM , Kaplan G
Published: June 2004

Previous studies demonstrated that lymphoid tissues of mice and rats contain small numbers (less than 1 percent of nucleated cells) of dendritic cells (DC) with special cytologic, surface, and functional properties. We show here that similar DC represent 0.1-0.5 percent of human peripheral blood mononuclear cells. DC can be enriched to 20-60 percent purity by a multistep procedure analogous to that used in mice. Adherent peripheral blood mononuclear cells are cultured overnight, and the released cells are depleted of monocytes and B cells by readherence to plastic, rosetting with erythrocytes coated with anti-human IgG, and centrifugation in dense albumin columns. Enriched DC have similar cytologic features to rodent DC by light and electron microscopy.

DC express HLA, and HLA-DR and the leukocyte-common antigens. They lack phagocytic capacity, receptors for antibody-coated and neuraminidase-treated erythrocytes, surface and intracellular Ig, esterase, peroxidase, and azurophilic granules. DC do not react with several monoclonal antibodies directed to phagocytes (OKM 1, "mac-1," 63D3, and 61D3) and T cells (OKT 3, 6, 8). Unlike the mouse, human DC express complement receptors. When maintained in culture for 4 d, human DC did not give rise to either B cells or monocytes. Therefore, DC identified by cytologic criteria are distinct from other leukocytes.

Enriched populations of DC have been compared to fractions enriched in monocytes, B cells, and T cells in three functional assays: stimulation of the primary allogeneic mixed leukocyte reaction, stimulation of the primary syngeneic MLR, and accessory function for the proliferation of periodate- modified T cells. In each case, the DC fraction was 10-fold or more active than other cell fractions. We conclude that DC circulate in man, and represent the principal cell type required for the initiation of several immune responses.
T cell regulation of B cell activation. T cells independently regulate the responses mediated by distinct B cell subpopulations.
Authors: Asano Y , Hodes R J
Published: June 2004

The present studies have been carried out to characterize the regulatory influences acting upon defined pathways of T cell-dependent B cell activation. In these studies, it was demonstrated that high concentrations of free carrier strongly inhibited the MHC-restricted in vitro T cell-dependent antibody responses of primed Lyb-5- B cells to the corresponding carrier-hapten conjugate. In contrast, these same concentrations of free carrier failed to inhibit the T cell dependent responses of Lyb-5+ B cells to the same antigen. The inhibition of Lyb-5- B cell responses by free carrier was shown to result from active suppression mediated by carrier-specific primed Lyt-1+2- T cells and to require the additional participation of unprimed Lyt-1-2+ T cells. The activation of this suppression was antigen-specific, but suppression once activated was antigen nonspecific in its effect. These findings thus demonstrate that distinct pathways of B cell activation can be independently regulated by T suppressor network influences, and that these pathways therefore constitute potentially independent components of the immune response to a given antigenic stimulus.
Specialized antigen-presenting cells. Splenic dendritic cells and peritoneal-exudate cells induced by mycobacteria activate effector T cells that are resistant to suppression.
Authors: Britz J S , Askenase P W , Ptak W , Steinman R M , Gershon R K
Published: June 2004

We have tested the ability of several types of trinitrophenyl (TNP)-labeled Ia+ cells to induce contact hypersensitivity (CS) after intravenous injection. Most labeled cell types (spleen cells, splenic macrophages, various types of peritoneal-exudate cells) not only fail to induce CS after this type of inoculation but, rather, activate T suppressor cells leading to specific immunological tolerance. Occasionally, some of these immunizing cells managed to bypass the T suppressor system and induced CS. In those cases the response was short-lived and could be blocked by concomitant injection of trinitrobenzelsulphonic acid (TNBS), a potent inducer of T suppressor cells. In sharp contrast to these results, TNP-labeled splenic dendritic cells and TNP-labeled peritoneal-exudate cells induced by complete Freund's adjuvant had the following distinctive features: (a) They were always able to sensitize when injected intravenously, and the degree of sensitization they produced was roughly equivalent to that achieved by cutaneous application of picryl chloride, the chemically reactive form of TNP. (b) The response they elicited was long lived (i.e., lasted for greater than 3 wk). (c) Their sensitizing capacity could not be blocked by the concomitant injection of TNBS. (d) They elicited a response that could be adoptively transferred to untreated, normal recipients. These results indicate that the type of cell that first presents antigen to the immune system plays an important, even essential, role in determining the strength and duration of the subsequent immune response. In particular, the results suggest that some special antigen-presenting cells can induce a response that is relatively resistant to host suppressor mechanisms. Evidence that they do so by activating contrasuppressor cells is discussed.
Induction of in vitro proliferation and maturation of human aneuploid myelogenous leukemic cells.
Authors: Chiao J W , Andreeff M , Freitag W B , Arlin Z
Published: June 2004

Human leukemic cells were induced to proliferate and mature to macrophage-like cells in primary cultures supplemented with conditioned medium (CM) from phytohemagglutinin and alloantigen-stimulated normal T lymphocytes. Blast and promyelocyte-enriched preparations, isolated after depletion of adherent phagocytic cells and lymphoid cells from samples of myelogenous leukemia patients, were suspended in liquid cultures with 30% CM. Cell cycle analysis was performed throughout the course of induced cellular maturation. Within 24 h of exposure to CM, cells with macrophage-like morphology were identified among the developing adherent cells. Approximately 15-30% of the cells in culture suspensions also developed macrophage-like morphology and esterase reactivity with alpha-napthyl acetate after incubation for 2 d. The number of these nonproliferating cells increased and became predominant in the later culture period. Flow cytometric measurement of DNA content showed that these mature cells had the same aneuploid stemline as the undifferentiated leukemic cells, indicating that genetically abnormal leukemic cells can be induced to differentiate. Reduction in the total RNA content of the macrophage-like cells was also determined by flow cytometry. Reduction in RNA and development of adherent cells served as early markers of maturation, in addition to the later acquisition of complement receptors and phagocytic capacity. Cell cycle analysis showed that CM stimulated the proliferation of immature cells. This initial proliferation may precede intertwined events of proliferation and concurrent maturation of immature cells. Later in the culture period, cellular proliferation decreased, leading to termination of the cultures.
Deposition of idiotype-anti-idiotype immune complexes in renal glomeruli after polyclonal B cell activation.
Authors: Goldman M , Rose L M , Hochmann A , Lambert P H
Published: June 2004

We investigated the possible role of idiotypic interactions in the pathogenesis of the glomerular lesions observed in mice undergoing polyclonal B cell activation. BALB/c mice were studied for the presence of renal deposits of T15 idiotype-anti-T15 idiotype-immune complexes (IC) after injection of bacterial lipopolysaccharides (LPS). The T15 idiotype is the major idiotype of BALB/c mice anti-phosphorylcholine (PC) antibodies, which are cross-reactive with the idiotype of the TEPC-15 myeloma protein. This model was used because T15 idiotype-anti-T15 idiotype IC have been detected in the circulation of BALB/c mice after polyclonal B cell activation. First, an idiotype-specific immunofluorescence technique allowed us to detect T15 idiotype-bearing immunoglobulins in glomeruli from day 6 to day 28 after LPS injection. Second, fluorescein isothiocyanate-conjugated TEPC-15 myeloma protein was found to localize in the glomeruli after in vivo injection 18 d after LPS administration. This renal localization was shown to be idiotype-specific and could be quantified in a trace-labeling experiment. Third, kidney-deposited immunoglobulins of mice injected with LPS were eluted, radiolabeled, and analyzed by radioimmunoassay. Both T15 idiotype-bearing immunoglobulins and anti-T15 idiotype antibodies were detected in the eluates, providing further evidence for a renal deposition of T15 idiotype-anti-T15 idiotype IC. Polyclonal B cell activation is likely to result in a simultaneous triggering of many idiotypic clones and of corresponding anti-idiotypic clones represented in the B cell repertoire. This could lead to the formation of a variety of idiotype-anti-idiotype IC that could participate in the development of glomerular lesions.
Frequency of B lymphocytes responsive to anti-immunoglobulin.
Authors: Defranco A L , Raveche E S , Asofsky R , Paul W E
Published: June 2004

The frequency of murine B lymphocytes that respond to antibodies directed against membrane IgM was measured. These anti-mu antibodies induced all, or almost all, resting B cells to enlarge over the first 24 h of stimulation. This probably represents the transition from the resting state (G0) to active transit through the cell cycle. In contrast, only a fraction of these cells, approximately 60% for BDF1 mice, continued through the cell cycle into S phase. This is consistent with previous experiments that had suggested there were some types of B cells that did not proliferate in response to anti-mu. The results presented here demonstrate that many, perhaps all, of these nonresponding B cells, both from normal mice and from mice with the xid defect, actually do respond to the presence of anti-mu by going through early parts of the cell cycle. These cells appear to become blocked at some point before the beginning of S phase, perhaps requiring a signal from a T cell or a macrophage to continue through the cell cycle. Thus, the role of antigen may be to prepare all B cells for proliferation. Different subpopulations of B cells may then require different regulatory signals before actually proliferating or before differentiating into antibody-secreting cells.
Localization of paternal H-2K antigens on murine trophoblast cells in vivo.
Authors: Chatterjee-Hasrouni S , Lala P K
Published: June 2004

We have previously shown the presence of H-2K and D antigens of both parental haplotypes on dispersed murine trophoblast cells. The question still remained whether such antigens are sequestered away from the sinusoidal face of these cells making them inert as allografts. The in vivo expression of H-2 antigens on these cells was therefore examined radioautographically after perfusion of 125I-labeled monoclonal and anti-H-2Kk (anti-paternal) antibody directly into individual placental branches of the uterine artery suppling 15-d-old (C57BL/6J female) X CBA/J male) placentae. Syngeneic C57BL/6J placentae served as negative controls. A radioautographic examination of 0.5-micrometer-thick sections revealed specific labeling of labyrinthine trophoblasts lining the sinusoids of allogeneic placentae. Most of this labeling was localized to the sinusoidal face of the cells as opposed to a weak labeling of the intracellular aspect. Spongiotrophoblasts and trophoblast giant cells did not label, but specific labeling of fetal capillary endothelium and some macrophages was also noted.
Dissection of the proliferative and differentiative signals controlling murine cytotoxic T lymphocyte responses.
Authors: Wagner H , Hardt C , Rouse B T , Röllinghoff M , Scheurich P , Pfizenmaier K
Published: June 2004

Evidence is presented that interleukin 2 (IL-2) is not sufficient to cause the differentiation of primary cytotoxic T lymphocytes (CTL). Sources of IL-2 were compared for their ability to cause proliferation as well as differentiation into CTL. Whereas all factors caused proliferation, only the crude Con A supernatant had cytotoxic T cell differentiation factor (CTDF) activity. Furthermore, factors absorbed with an IL-2-dependent cell line to remove IL-2 still retained CTDF activity. Thus, IL-2 functions to cause clonal expansion of CTL precursors preactivated by antigen or mitogen, but for their differentiation into CTL, an additional factor is required, here called CTDF.
A monoclonal T cell-replacing activity can act directly on B cells to enhance clonal expansion.
Authors: Wetzel G D , Swain S L , Dutton R W
Published: June 2004

We have used a B cell cloning system in which the response of a single isolated B cell to lipopolysaccharide and dextran sulfide can be followed. We have shown that culture supernatants from the Dennert long-term alloreactive T cell line C.C3.11.75 increase the frequency of B cells stimulated to clonal expansion by mitogens. These culture supernatants are devoid of interleukin 1 and 2 but contain the T cell-replacing factor activity (DL)TRF. These experiments provide unequivocal proof that a T cell-derived factor or factors can act directly on a B lymphocyte in the absence of any other cell.
Acute autoimmune encephalomyelitis in mice. II. Susceptibility is controlled by the combination of H-2 and histamine sensitization genes.
Authors: Linthicum D S , Frelinger J A
Published: June 2004

The expression of acute experimental autoimmune encephalomyelitis (EAE) in mice is controlled by several dominant genes, H-2 and histamine sensitization genes. SJL/J and SWR/J, which are H-2s and H-2q, respectively, are susceptible to EAE and sensitive to Bordetella pertussis histamine-sensitizing factor (HSF), which produces a vasoactive amine hypersensitivity. Other H-2s or H-2q strains such as A.SW, B10.Q and several others do not develop acute EAE and are not sensitive to B. pertussis HSF. One strain tested, DDD (KsIsD?) is HSF sensitive but does not develop EAE (presumably because it lacks the appropriate responder H-2 haplotype). However, F1 hybrids between B10.S and DDD are sensitive to HSF and develop EAE. The induction and effector phases of acute EAE are apparently controlled by the combination of H-2 and HSF genes. A combination of the correct H-2 hapotype and histamine sensitivity is required for the development of acute EAE.
Genetic interactions in the spontaneous production of endogenous murine leukemia virus in low leukemic mouse strains.
Authors: McCubrey J , Risser R
Published: June 2004

The spontaneous expression of ecotropic murine leukemia virus (MuLV) in spleen cells of BALB/c, C57BL/6 (B6), and derivative mice was examined as a function of age. The patterns of spontaneous virus induction in vivo correlate with the patterns of virus induction in vitro, which result from the action of two loci, Inc-l and Inb-l (7). Whereas mice carrying Inc-l or Inb-l have similar phenotypes in vitro, they have significantly different phenotypes in vivo. Mice of the Inb-l+/+ genotype, e.g., B6, rarely expressed MuLV, and the titer of MuLV recovered from rare MuLV-positive mice of this genotype was usually low. Mice of the Inc-l+/+ genotype, e.g., BALB/c, expressed low amounts of MuLV early in life, however, from 6-12 mo of age approximately one-half of the Inc-l+/+ mice expressed virus, frequently of high titer. Equal numbers of N-tropic and B-tropic MuLV were recovered from Inb-l+ mice, but predominantly N-tropic MuLV was recovered from Inc-l+ mice. Strains that carry dominant (+) alleles at both Inc-l and Inb-l show higher titers of MuLV earlier in life than strains that carry only Inc-l or Inb-l. The presence of dominant alleles at both loci results in the appearance of predominantly N-tropic virus early in life. These results demonstrate that the principal determinants of spontaneous virus expression in these low leukemic strains of mice are the In loci or genes linked to them. A further inference that can be drawn from these studies is that the appearance of B-tropic virus is by no means a random process but rather results from predictable patterns of MuLV expression and alteration.
Analysis of the interactions between two molecules that are required for the expression of Ly-2 suppressor cell activity. Three different types of focusing events may be needed to deliver the suppressive signal.
Authors: Flood P , Yamauchi K , Gershon R K
Published: June 2004

We described a T suppressor factor made by an I-J- Ly-2 T cell (Ly-2 TsF) that expresses biological activity only when its acceptor cell shares H-2-linked polymorphic genes with the cells that made the Ly-2 TsF (or when the producer cell had differentiated in a thymic environment where the gene products of the acceptor cell were expressed). The Ly-2 TsF requires the presence of I-J+ Ly-1 cells in the assay culture to express its suppressive activity, although removal of the I-J+ Ly-1 cells in the assay cultures with an I-J+ soluble factor derived from them. This I-J+ molecule not only fails to bind antigen but is also antigen nonspecific in that it can come from Ly-1 cells making factors of irrelevant specificities. For the I-J+ molecule to replace the activity of the I-J+ Ly-1 cell in the assay population, in restoring suppressive function in cultures depleted of I-J+ Ly-1 cells, it must share genetic polymorphisms linked to the I-J subregion with the Ly-2 TsF and genetic polymorphisms linked to Igh-V with the target cell. These results indicate that an I-J+ antigen-nonspecific molecule combines with an antigen-specific Ly-2 TsF via an I-J- anti-I-J "type" of interaction. The resultant molecular complex is focused on a cell surface receptor of the acceptor cell. This focusing event is controlled by the antigen-nonspecific I-J+ molecule, and the precise interaction with the receptor on the acceptor cell is controlled by Igh-V-linked polymorphic gene products. The antigenic specificity of the interaction is controlled by a receptor for antigen on the I-J- component of the complex. Thus, three focusing events are required for Ly-2 TsF to express biologic activity: (a) the Ly-2 TsF must be focused on an acceptor cell that has the same antigenic specificity (most likely via an antigen bridge); (b) it must also be focused onto an I-J+ antigen-nonspecific molecule that we refer to as a "schlepper" molecule (most likely via an I-J anti-I-J bridge); and (c) the schlepper molecule must focus the molecular complex on an Igh-V-controlled receptor on the antigen-specific target cell.
Requirement for three signals in B cell responses. II. Analysis of antigen- and Ia-restricted T helper cell-B cell interaction.
Authors: Zubler R H , Kanagawa O
Published: June 2004

We have recently reported that resting B cells must receive at least three different signals in a T helper cell (TH)-dependent as well as in a lipopolysaccharide (LPS)-induced B cell response (3), i.e., a specific TH signal (that can be bypassed by LPS), a nonspecific TH signal (mediated by Ia or antigen-nonspecific B cell helper factor), and an antigen (hapten) signal. In a system using male (H-Y) antigen-specific cloned TH of C57BL/6 origin and male (or female) B cells, we now confirm and extend these findings by demonstrating that H-Y-specific TH must see both H-Y and Ia determinants on the B cells (and not only on macrophages) to provide the first specific TH signal required for a plaque-forming cell (PFC) response. This signal was interfered with by a monoclonal anti-I-Ab antibody at the B cell level, was not mediated by detectable soluble factors (in contrast to the nonspecific signal also provided by the TH), and could be bypassed by LPS, in which case anti-I-Ab antibody had no effect. However, although the H-Y-specific TH induced a polyclonal PFC response (B cell differentiation) in the apparent absence of an antigen seen by the B cells, significant clonal expansion of PFC precursors occurred only when the B cells also recognized an antigen (hapten).
Conversion of immunity to suppression by in vivo administration of I-A subregion-specific antibodies.
Authors: Perry L L , Greene M I
Published: June 2004

The in vivo administration of antibodies specific for gene products of the I-A subregion represents an immunologically specific approach to the manipulation of Ly-1+ T cell responses to antigen. This has been demonstrated previously by the capacity of anti-I-A antibody treatment to abrogate T cell-mediated delayed-type hypersensitivity (DTH) responses to syngeneic tumor antigen, hapten, and non-H-2 histocompatibility antigens. Evidence obtained in these studies suggested that the primary action of antibody was related to its ability to interfere with macrophage-T cell interactions during antigen presentation, consistent with the demonstration that similar antibodies inhibit T cell binding to antigen-pulsed macrophages in vitro. Results presented in this report provide evidence for an additional consequence of in vivo antibody administration that may be secondary to any direct effects on I-A-restricted antigen presentation. Thus, animals treated with I-A subregion-specific antibodies also develop a population of antigen-specific suppressor T cells (Ts) capable of inhibiting recipient Ly-1+ T cell responses to tumor antigen. The induction of suppression appeared to be an essential component of the total biological activity of these antibodies, because elimination of Ts precursors by cyclophosphamide also abrogated the antibody-mediated inhibition of DTH responsiveness. These results are discussed with respect to the possible mechanisms of Ts activation by anti-I-A antibody administration, and the general applicability of this approach as a means of clinical immunotherapy to limit inappropriate T cell responses in human disease.
Restriction molecules involved in the interaction of T cells with allogeneic antigen-presenting cells.
Authors: Ishii N , Nagy Z A , Klein J
Published: June 2004

The proliferative responses of T cells, depleted of alloreactive cells, were tested upon stimulation by antigens presented on allogeneic antigen-presenting cells (APC). Restriction molecules involved in these responses were identified by inhibition of T cell proliferation with monoclonal antibodies against A(A alpha A beta) and E(E alpha E beta) molecules of the APC. The responses to all three antigens tested [Poly(Glu40Ala60) (GA), lactate dehydrogenase B (LDHB), and poly(Glu51, Lys34, Tyr15) (GLT)] were A plus E restricted when the allogeneic APC expressed both molecules, and only A restricted when the APC did not express cell surface E molecules. In contrast, when T cells and APC are syngeneic, the same antigens are recognized only in the context of either A molecules (GA and LDHB) or E molecules (GLT). The data indicate that the immune response gene control of these responses is not associated with either a failure of antigen presentation, or the lack of certain T cell specificities from the germ line repertoire, but probably with selective somatic elimination (tolerance) of certain clones from the T cell repertoire.
Fibronectin is produced by blood vessels in response to injury.
Authors: Clark R A , Quinn J H , Winn H J , Lanigan J M , Dellepella P , Colvin R B
Published: June 2004

During the time of tissue repair that ensues subsequent to tissue injury, blood vessel wall fibronectin increases concomitantly with endothelial proliferation and angiogenesis. However, the source of this blood vessel fibronectin had not been delineated. In this report we have demonstrated that microvascular fibronectin is produced in situ by the proliferating vessels surrounding excisional wounds. This finding was established by extirpating 3 mm of skin from the center of a well-healed rat xenograph on the flanks of immunosuppressed mice, harvesting the injured skin sites at various stages during the healing process, and staining the specimens with reciprocal species-specific anti-fibronectin. The proliferating donor vessels that surrounded the wounded graft had increased fluorescence staining with FITC conjugated mouse anti-rat fibronectin and no staining with rat anti-mouse fibronectin. This finding was taken as direct evidence that the fibronectin was produced in situ by the rat vessels and not derived from circulating mouse plasma.
Products of the IgT-C region of chromosome 12 are maturational markers for T cells. Sequence of appearance in immunocompetent T cells parallels ontogenetic appearance of Tthyd, Tindd, and Tsud.
Authors: Owen F L
Published: June 2004

Monoclonal antibodies specific for three T cell alloantigens linked to the immunoglobulin complex on chromosome 12 were used to establish the order of expression of these antigens on immunocompetent cells and in ontogeny. Modification of monoclonal antibodies with fluorescein isothiocyanate (FITC) and use with anti-FITC and complement has amplified lytic capacity of the monoclonals and allowed us to complete a distribution study of Tsud, Tindd, And Tthyd alloantigens on immunocompetent cells. Tthyd is expressed on both cortisone-sensitive and cortisone-resistant thymocytes; Tsud and Tindd are on "mature" cortisone-resistant cells. Tthyd is also expressed on a Thy-1.2-bearing recirculating marrow cell but is undetectable in the peripheral T cell pool. In contrast, resting spleen and lymph node T cells express Tsud and Tindd; antigen-activated populations express these two cells in high frequencies. These antigens must be markers for relatively differentiated cells because "nude" animals, which have pre-T cells, fail to express these determinants. All three antigens segregate independently in our T cell hybrids, arising from adult peripheral node cells, supporting the hypothesis that these are three separate structural products of a gene complex. In contrast, fetal T cell hybrids fail to express these antigens. The appearance of all three antigens on the cell surface in ontogeny is postnatal; Tthyd is expressed at days 1-2, Tindd at days 2-3, and Tsud at days 5-6. If the T cell isotype genes are organized similar to the immunoglobulin loci, then the parallels in maturational expression on immunocompetent cells and in ontogeny would lead one to speculate a gene order of Tthyd leads to Tindd leads to Tsud. Orientation with respect to the centromere is unknown.