bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differentiation of human mature thymocytes: Existence of a T3+4−8− intermediate stage
Authors: De La Hera Antonio , Toribio Maria Luisa , Marquez Carlos , Marcos Miguel Angel R. , Cabrero Esther , Martinez‐A. Carlos 
Published: February 2007

AbstractA T3 complex‐bearing subpopulation was characterized within an in vivo cycling T4−8− early thymocyte compartment which contains cells constitutively expressing interleukin 2 and transferrin receptors. We show differentiation in vitro of both mature subsets of thymocytes (T3+4+8− and T3+4−8+) from the above T4−8− compartment, their appearance being preceded by cells in a T3+4−8− intermediate stage. Furthermore, those mature thymocytes generated in vitro contain functionally competent cells which use T3, T4 and T8 structures for their cytolytic activity. The finding of T3+4−8− thymocytes in vivo, together with the observation that T3 antigen expression precedes that of T4 or T8 molecules in vitro, shows that T3 (and presumably Ti) is present early in ontogeny, and suggests that T3+4−8− cells constitute an “intermediate” stage relevant to the connection between early precursors and mature thymocytes during T lymphocyte ontogeny.
Liver‐associated macrophage precursors as natural cytotoxic effectors against Candida albicans and Yac‐1 cells
Authors: Decker Thomas , Baccarini Manuela , Lohmann‐Matthes Marie‐Luise 
Published: February 2007

AbstractLiver nonparenchymal cells of maleic anhydride divinyl ether or cyclophosphamide‐treated mice were assayed for cytotoxic activity against the yeast form of Candida albicans. A strong increase in this activity was observed after both in vivo treatments, as compared to untreated control mice. The effector cell was enriched by nylon wool passage and separation of nonadherent liver nonparenchymal cells on a discontinuous Percoll gradient. By means of direct and indirect rosetting techniques, based on the presence of Fc receptors and the F4/80 and M143 macrophage surface markers, we could separate a nearly homogeneous effector cell population. It displayed, besides the candidacidal activity, Fc receptors and the M143 and F4/80 antigens, also strong natural cytotoxicity against Yac‐1 lymphoma cells. When cultured in medium containing colony‐stimulating factor‐1, this effector population reacted with a strong proliferative response as measured through incorporation of tritiated thymidine. The data presented show that nonadherent, nonphagocytic macrophage precursors, which we characterized previously from in vitro bone marrow cultures, occur in vivo as organ‐associated effector cells in the liver after elicitation with maleic anhydride divinyl ether or cyclophosphamide. These macrophage precursors have prior to their maturation the ability to serve as a microbicidal and tumoricidal natural killer cell.
Cross‐reactive recognition by antigen‐specific, major histocompatibility complex‐restricted T cells of a mitogen derived from Mycoplasma arthritidis is clonally expressed and I‐E restricted
Authors: Lynch David H. , Cole Barry C. , Bluestone Jeffrey A. , Hodes Richard J. 
Published: February 2007

AbstractIn order to determine whether or not the major histocompatibility complex (MHC)‐ encoded restriction element used by a T cell in the recognition of its primary antigen affected its ability to be cross‐reactively stimulated by MAS (a soluble product of Mycoplasma arthritidis), a panel of cloned, soluble antigen‐specific I‐A‐ and I‐E‐ restricted T cells were tested for their ability to cross‐reactively recognize and respond to MAS. Initial studies indicated that all of the cloned T cells tested were capable of responding to MAS in the presence of genetically EαEβ‐expressing (I‐E+), but not EαEβ‐non‐expressing (I‐E‐) accessory cells (AC). However, subsequent studies demonstrated that the ability of most of these T cell clones to mount proliferative responses to MAS in the presence of I‐E+ AC was dependent upon the presence of Lyt‐1+2− T cells in the irradiated spleen cells which were used as AC sources. When T cell‐depleted, I‐E+ populations of spleen cells or an I‐E+ antigen‐presenting line (WEHI‐5) were used as AC sources, only 6 of the 34 clones tested were found to be directly responsive to MAS. Subsequent to stimulation by MAS plus I‐E product, these MAS‐reactive T cell clones were capable of “recruiting” bystander T cells to proliferate. Finally, the ability of a given T cell clone to respond to MAS plus I‐E product did not appear to be influenced by the restriction element used by that clone in its response to other antigens since both I‐A‐restricted and I‐E‐restricted T cell clones were responsive to MAS plus I‐E in equivalent proportions. Thus, the data presented indicate that I‐E‐restricted T cell reactivity to MAS is a clonally expressed property of T cells that is independent of their conventional antigen specificities and MHC restriction patterns.
Discrete stages of human thymocyte activation and maturation in vitro: correlation between phenotype and function
Authors: Blue Marie‐Luise , Daley John F. , Levine Herbert , Schlossman Stuart F. 
Published: February 2007

AbstractUsing light scatter, flow cytometric and functional analyses, three major stages in the in vitro activation of human thymocytes were defined. The earliest stage (day 0–2) was characterized by the induction of the interleukin 2 (IL2) and transferrin receptors, the T cell lineage specific Tal antigen, and increased reactivity with anti‐T8 antibody. At this time, major changes in nuclear morphology but not cell size were observed. Early‐stage thymocytes were immature with regard to T3 and cytotoxic capacities. The second stage (day 3–4) of in vitro culture was distinguished by loss of T6, maximal activation (both in cell size and nuclear morphology) and maximal expression of both transferrin and IL2 receptors. At this stage, nearly all thymocytes expressed T3, 30–70% of thymocytes were T4+T8+, and functionally, only small increases in cytotoxic capacities were observed. The third stage of maturation (day 5–7) represented thymocytes with reduced levels of activation as measured by forward and right angle light scatter analysis and declining IL 2 and transferrin receptor expression. However, these thymocytes exhibited high levels of T3 antigen density, loss of T4, T8 coexpression and pronounced cytotoxic and detectable inducer function capabilities.
Interculture variation and evolution of B lineage lymphocytes in long‐term bone marrow culture
Authors: Witte Pamela L. , Kincade Paul W. , Větvička Václav 
Published: February 2007

AbstractA recently described long‐term culture system offers a unique experimental approach for dissecting regulatory mechanisms that control the developmental progression of B‐lineage lymphocytes. Lymphoid cells, including B cells and their precursors, can be maintained for prolonged periods in strict dependence on a layer of adherent cells. However, before this system can yield to interpretable manipulation, much information is needed as to the identity and temporal phenotypic stability of both lymphoid and nonlymphoid cells. The findings reported here provide answers to some of those important questions. Successful establishment of lymphoid cells in culture was extraordinarily dependent on the batch of fetal calf serum used in the medium, and some undesirable serum lots supported cultures that were virtually all myeloid. With standardized culture conditions, various populations of lymphoid cells were identified on the basis of B‐lineage differentiation markers and culture to culture variation was assessed. Lymphocytes that were firmly attached to the adherent cells were carefully compared to nonadherent lymphocytes in terms of cycle status, phenotype, size, and transferrin receptor expression. They were essentially identical in all of these respects and a partitioning of proliferating cells and their progeny in the cultures was therefore not apparent. It is also noteworthy that although a high mitotic rate was maintained, a majority of the cells were small lymphocytes. The outgrowth of identifiable B‐lineage cells (detected with monoclonal 14.8 antibodies) in replicate cultures was initially similar, but the extent of interculture variation increased dramatically during the period 4–6 weeks after initiation of culture. Replicate cultures established from the same marrow cell pool often differed as much as 20‐fold in numbers of 14.8‐positive cells. After this time, the composition of individual cultures evolved much more gradually, and numbers of B cells and pre‐B cells remained relatively constant. This indicates that subsets of lymphocytes become established in each culture dish during a discrete phase.At least two types of supporting adherent cells predominated in these cultures: typical macrophages and very large, nonphagocytic cells resembling adventitial reticular cells. The latter included subpopulations resolved on the basis of alkaline phosphatase content. In contrast to the lymphoid populations, proportions of these adherent cell types were relatively invariant among replicate cultures. The dramatic expansion or contraction of particular B‐lineage populations which occurred prior to 6 weeks of culture did not appear to be reflected in the composition of the adherent layers on which they depended.
Contact interaction between lymphocytes is a general event following activation and is mediated by LFA‐1
Authors: Hamann Alf , Jablonski‐Westrich Dorothee , Thiele Heinz‐Günther 
Published: February 2007

AbstractWhen lymphocytes are activated in vitro, discrete cell‐cell contacts are initiated which result in cluster formation. This contact interaction is found in syngeneic or allogeneic mixed leukocyte reactions as well as in mitogen‐stimulated cultures (concanavalin A, periodate, lipopolysaccharide). T cells as well as B cells display the binding phenomenon. This activation‐dependent lymphocyte‐lymphocyte adhesion involves LFA‐1, since monoclonal antibodies (including Fab fragments) against this molecule inhibit adhesion between clustering lymphocytes in a dose‐dependent manner, whereas antibodies directed to several other cell surface antigens are inactive. Since a wide variety of functional interactions are inhibited by antibodies to LFA‐1, it may be concluded that LFA‐1‐mediated cell contact is a discrete and essential step between a recognition event and the generation of functional activities by lymphocytes in general.
Production of oligosaccharide‐binding monoclonal antibodies of diverse specificities by immunization with purified tumor‐associated glycolipids inserted into liposomes with lipid A
Authors: Brodin Thomas , Thurin Jan , Strömberg Niklas , Karlsson Karl‐Anders , Sjögren Hans Olov 
Published: February 2007

AbstractTwo species of neutral glycosphingolipids purified from rat colon carcinoma tissue, isoglobotetraosylceramide [GalNAc(β1→3)Gal(α1→3)Gal(β1→3)Glc(β1→1)Cer] and a related 6‐sugar “analogue” were inserted into liposomes together with lipid A (from bacterial lipopolysaccharide) and used for immunization of mice and monoclonal antibody production. The yield of hybridomas producing glycolipid‐specific antibody was 5–10% using a high‐dose booster schedule with liposome‐inserted glycolipid. In contrast the frequency was below 0.1% (no glycolipid‐binding antibodies were found) when using the previously described method of immunizing with glycolipid coated on the surface of acid‐treated S. minnesota. Monoclonal antibodies were screened on the purified glycolipids used for immunization and selected for differential reactivity to the two glycolipids. A diversity of specificities was demonstrated by binding to the purified antigens, in a thin‐layer chromatogram binding assay and in binding tests to tumor and normal target cells.
Immunoglobulin heavy chain gene rearrangements in X‐linked agammaglobulinemia
Authors: Mensink Ewald J. B. M. , Schuurman Ruud K. B. , Schot Johannes D. L. , Thompson Allan , Alt Fred W. 
Published: February 2007

AbstractX‐linked agammaglobulinemia (XLA) appears to involve a defect in human B lymphocyte differentiation which is manifested at the pre‐B cell stage. The defect segregates as an X‐linked recessive trait but is not a single genetic entity. IgM‐producing B cell clones were established by Epstein‐Barr virus transformation of peripheral blood mononuclear cells of patients with the XLA defect linked to the DXS3 and DXS17 chromosomal loci. Individual XLA B cell clones were demonstrated to have rearrangements of the JH regions of both immunoglobulin VH region loci. The rearranged JH regions of the B cell clone ALA 19 were molecularly cloned and their nucleotide sequence was determined. Both JH‐associated rearrangements (designated 191 and 192) resulted from the juxtaposition of variable (VH), diversity (D) and joining (JH) segments (VHDJH rearrangements). The 191 rearrangement employed a VH segment belonging to VH subgroup III and a JH4 segment. The 192 rearrangement employed a VHII and a JH6 segment. The D191 and D192 segments encompassed 21 and 28 nucleotides, respectively, and showed little homology to each other or to previously reported human D sequences. Surprisingly, both VHDJH complexes had open reading frames. However, in accord with principles of allelic exclusion, only the 191 allele was detectably expressed in the total RNA of the cell. A possible mechanism for the lack of expression of the 192 allele is discussed. We conclude that the DXS3‐DXS17‐linked XLA defect does not preclude VH to DJH rearrangements or the expression of VHcontaining heavy chain molecules.
B cell growth and differentiation induced by supernatants of transformed epithelial cell lines
Authors: Rawle Frances C. , Shields John , Smith Susan H. , Iliescu Virginia , Merkenschlager Matthias , Beverley Peter C. L. , Caliard Robin E. 
Published: February 2007

AbstractGrowth and differentiation of B cells is thought to be regulated by soluble factors derived from T cells. However, human T cell lines and hybridomas have proved to be notoriously unreliable and unstable sources of such factors. We report here that three stable human bladder carcinoma cell lines T24, RT4 and 5637 produce, in a constitutive fashion, factors which promote growth and differentiation of human B cells.
Ligation of the CD23, p45 (BLAST‐2, EBVCS) antigen triggers the cell‐cycle progression of activated B lymphocytes
Authors: Gordon John , Rowe Martin , Walker Leonie , Guy Graeme 
Published: February 2007

AbstractCD23, p45 (BLAST‐2, EBVCS) is a 45‐kDa lineage‐restricted antigen which appears on the surface of human B cells shortly after activation. A monoclonal antibody (MHM6) to CD23, p45, as well as a polyclonal rabbit antibody raised against the purified antigen were found to promote DNA synthesis in purified tonsillar B cells which had been activated with phorbol ester. Interleukin 1, which was not, by itself, stimulatory for either resting or activated B cells, significantly augmented the growth‐promoting properties of MHM6. Kinetic studies indicated that while MHM6 exerted its influence in early G1, interleukin 1 acted later in the cycle just prior to the entry of cells into S phase. The findings demonstrate a role for CD23, p45 in triggering the progression of activated B lymphocytes through the G1 phase of the cell cycle. The possibility that this antigen serves as a receptor for a B cell stimulatory factor is discussed.
Antigen‐Ia interaction and the proteolytic processing of antigen: the structure of the antigen determines its restriction to the A or E molecule of the major histocompatibility complex
Authors: Puri Joseph , Lonai Peter , Friedman Varda 
Published: February 2007

AbstractThe effect of a protease inhibitor, leupeptin, on the presentation of hen egg lysozyme (HEL) to cloned T cells was investigated. We found that leupeptin‐sensitive thiol proteases are apparently less involved when HEL is presented by the I‐Ad molecule, than when it is presented by the I‐Ed molecule. This selectivity was more of a function of the antigen than that of the Ia molecule because presentation of denatured or fragmented HEL was not sensitive to leupeptin whereas antigen presentation to a number of I‐A‐restricted T cell clones specific to other antigens was sensitive to leupeptin. These data demonstrate that the particular combination of major histocompatibility complex/nominal antigen recognized by a certain T cell clone may require processing of the antigen molecule through a certain group of proteases and that other combinations are independent of that particular processing pathway. Furthermore, there is a preference for a certain type of processing depending on the Ia molecule involved.
Possible T4‐HLA class II interaction as an essential event in antigen‐specific helper T lymphocytedependent B cell activation
Authors: Fischer Alain , Sterkers Ghislaine , Charron Dominique , Durandy Anne 
Published: February 2007

AbstractWe have previously shown that the interaction between influenza virus‐specific helper T lymphocytes and B lymphocytes is HLA class II restricted (Fischer, A. et al., Eur. J. Immunol. 1985. 15: 620). In the present study, we used a panel of antibodies specific for the T4 and HLA‐DR molecules to investigate the role of both structures in T‐B lymphocyte interaction. Several anti‐T4 monoclonal antibodies were shown to block the in vitro antibody production to A/Bangkok influenza virus while they were unable to inhibit the A/Bangkok‐induced proliferation of specific helper T cell clones. Some anti‐HLA‐DR monoclonal antibodies inhibited the antibody production to A/Bangkok, the target of the inhibition being either monocytes or B lymphocytes. The incubation of helper T cell clones with an infra‐inhibitory concentration of anti‐ T4 antibody and of B lymphocytes with an infra‐inhibitory concentration of anti‐ HLA‐DR antibody resulted in a mutual enhancement of inhibition. Such synergistic interactions were not observed using combinations of (a) anti‐T4 and anti‐B membrane structures such as p35 or LFA‐1 or (b) anti‐HLA‐DR and anti‐T membrane structures such as T11 or LFA‐1. First, these results indicate that the T4 molecule plays an essential role in T‐B cell interaction even when it is not absolutely required for T cell proliferation. Second, they strongly suggest that the T4 molecule directly interacts with HLA‐DR at the B cell surface. Whether such interaction is required to enhance the stability of T3/T cell receptor‐antigen plus HLA class II association or whether T4‐HLA‐DR may transduce a signal towards B lymphocytes that is required in B cell activation remains unknown.
Impaired humoral immune response in complement C3‐deficient guinea pigs: absence of secondary antibody response
Authors: Böttger Erik C. , Metzger Susanne , Bitter‐Suermann Dieter , Stevenson George , Kleindienst Sabine , Burger Reinhard 
Published: February 2007

AbstractA recently described egenetically controlled C3 deficiency (C3D) in guinea pigs (GP) provided a unique model for studying the role of C3 in the afferent limb of the humoral immune response in a direct manner. These C3D animals, which have only 5–7% of normal serum C3 level, were immunized with the bacteriophage ϕX174, a T cell‐dependent antigen, followed by a booster injection after 4 weeks (1.5 × 109plaque‐forming units/kg). The formation of IgM and IgG antibody in the course of the primary and secondary response was determined and compared with a control group of inbred strain 2 GP. The C3D animals showed a markedly diminished antibody response to this antigen. Amplification of the antibody titer as well as regular isotype switching from IgM to IgG was absent in the secondary response. Increasing the amount of antigen to a high dose (1 × 1010 plaque‐forming units/kg) led to a normalization of the antibody response. The impairment in antibody formation resembles closely the impaired antibody response in C4‐deficient or C2‐deficient GP, which both have a block in activation of C3 via the classical pathway. However, in contrast to C4D GP or C2D GP the C3D GP do not exhibit serological characteristics of immune complex disease. They have normal levels of total serum IgM, of IgM anti‐ 2,4‐dinitrophenyl antibodies and of IgM rheumatoid factors.
Generation of bovine cytotoxic cell lines, specific for cells infected with the protozoan parasite Theileria parva and restricted by products of the major histocompatibility complex
Authors: Goddeeris Bruno M. , Ivan Morrison W. , Teale Alan J. 
Published: February 2007

AbstractCytotoxic cell lines specific for cells infected with the protozoan parasite Theileria parva were generated in vitro by repeated stimulation of peripheral blood mononuclear cells (PBMC) from immune animals with autologous parasitized cells from continuously growing cell lines. In PBMC of 5/7 immune animals tested, maximal levels of killing (80–100%) were obtained at effector to target ratios of 10/1 following 3 to 5 stimulations. No killing of uninfected lymphoblasts was observed. Cytotoxic activity was contained in the BoT4− lymphocyte population. The results of analyses of cytotoxicity on panels of target cells of diverse major histocompatibility (MHC) phenotypes indicated that the effectors were restricted by class I MHC antigens. Only autologous targets and allogenic targets sharing one or other bovine lymphocyte antigen A locus‐encoded specificity with the cytotoxic cell line were killed. In addition, two of the three cytotoxic cell lines, when tested on targets infected with different parasite stocks, exhibited a high degree of specificity for the stock used for immunization and stimulation of the cultures. The capacity to generate highly cytotoxic, MHC‐restricted effectors from peripheral blood was dependent on the immune status of the donor animals. This was confirmed by comparing cytotoxicity generated from the same animal before and after immunization using the same autologous infected cell line as a stimulator. These results indicate that these effector cells are analogous to the cytotoxic cells detected in vivo in cattle undergoing immunization or challenge with T. parva.
Suppression of the local graft‐vs.‐host reaction in ratsby treatment with a monoclonal antibody specific for the interleukin 2 receptor
Authors: Volk Hans‐Dieter , Brocke Stefan , Osawa Hisao , Diamantstein Tibor 
Published: February 2007

AbstractLocal graft‐vs.‐host reaction (GVHR) was induced in rats by injecting parental cells into young F1 recipients. As a consequence of antigenic stimulation in the course of developing GVHR in the responding lymph nodes, the number of interleukin 2 receptor (IL2R)‐bearing T cells increased from less than 1% up to 10% of the total population. The IL2R‐bearing cells were located mainly in the T cell areas of there active lymph nodes. As assessed by the determination of the GVHR indices, treatment of the recipients with anti‐T‐helper subset‐specific mAb (W3/25) or with anti IL2R mAb (ART‐18) inhibited the GVHR. In parallel, the number of IL2R‐bearingcells was reduced to the normal levels. W3/25 mAb treatment changed the helper/suppressor subset ratio and reduced the number of circulating lymphocytes in the peripheral blood. In contrast, ART‐18 mAb treatment did not induce any detectable changes in the subset distribution and it did not affect the number of circulating lymphocytes. The results demonstrate the key role that the IL 2R‐positive cells play in the proliferative phase of acute GVHR, and favor the use of anti‐IL2R mAb as selective immunosuppressive agents.