bluuebunny/crossref_metadata_2025 huggingface dataset:
A T cell clone which responds to interkeukin 2 but not to interleukin 4
Authors: Müller Werner , Vandenabeele Peter
Published: March 2007

The T cell clone CSP 2.1 is stimulated into proliferation by interleukin (IL) 2 but not IL 4, whereas many T cells respond to both. This clone is therefore suitable for the identification and quantification of IL 2 in the presence of IL 4.
Effective activation of resting mouse T lymphocytes by cross‐linking submitogenic concentrations of the T cell antigen receptor with either Lyt‐2 or L3T4
Authors: Eichmann Klaus , Jönsson Jan‐Ingvar , Falk Ingrid , Emmrich Frank
Published: March 2007

We studied the activation of small resting mouse T lymphocytes by antibodies to the T cell antigen receptor in combination with antibodies to other T cell surface antigens. Solid‐phase but not soluble antibodies KJ16‐133 and F23.1, both directed to β chains of the Vβ8 family, activate T cells to proliferate in the presence of growth factors, in a dose‐dependent fashion. Antibodies to Lyt‐2 and to L3T4 had no activating effect at any concentration. However, submitogenic concentrations of KJ16‐133 and of F23.1 synergized with a wide range of concentrations of anti‐Lyt‐2 and anti‐L3T4 to cause T cell proliferation similar or greater in magnitude to that caused by high concentrations of anti‐T cell receptor antibody. Synergistic activation was also observed with antibodies to Lyt‐1, LFA‐1 and H‐2 class I antigens but to a significantly lower degree. This was particularly clear in limiting dilution experiments in which the corrected frequencies of T cells proliferating in response to low amounts of anti‐T cell receptor antibody together with anti‐Lyt‐2 were 1/4 to 1/7 for BALB/c T cells. The frequencies of BALB/c T cells responding to high concentrations of anti‐T cell receptor antibody alone were between 1/14 and 1/126 and still lower frequencies of T cells proliferated in synergistic responses with anti‐LFA‐1 or anti‐Lyt‐1. Synergistic activation leads to the induction of functional cytotoxic cells. We interpret these data as suggestive that cross‐linking of the T cell antigen receptor with either Lyt‐2 (CD8) or L3T4 (CD4) represents an optimal activating signal for resting T cells. We think that, in physiological T cell activation, cross‐linking of the T cell receptor to CD8 or CD4 is induced by their simultaneous binding to major histocompatibility complex (MHC) class I (for CD8) or MHC class II (for CD4) molecules on stimulator cells. We consider the possibility that similar cross‐linking requirements may also exist during T cell repertoire selection in ontogeny, thus accounting for the strict coexpression of MHC class I and class II‐restricted T cell receptors with CD8 and CD4 molecules, respectively.
Multiple T cell antigenic determinants identified within a limited region of the horse cytochrome c molecule
Authors: Baumhüter Susanne , Wallace Carmichael J. A. , Proudfoot Amanda E. I. , Bron Claude , Corradin Giampietro
Published: March 2007

The antigen fine specificity of T cell hybridomas recognizing the horse apocytochrome c fragment 1–65, restricted to the I‐Ab molecule, was determined to gain some insight into the molecular nature of T cell antigenic peptides. Two major groups of clones specific for distinct subsites, namely residues 1–38 and 39–65, could be identified. Hybridomas recognizing the latter determinant were further tested with different horse cytochrome c peptides and analogues. This analysis revealed the presence of at least two epitopes encompassed by residues 47–53 and 48–53. Furthermore, clones specific for the amino acid sequence 48–53 showed considerable heterogeneity in respect to the antigen concentration required to obtain 50% of the maximal interleukin 2 secretion. Most prominent was the heteroclitic response towards tuna cytochrome c which differs at positions 44, 46 and 47 from the horse cytochrome c molecule in the relevant region. Comparison of the conformation of the sequence 43–46 between the two cytochrome c suggests that this segment, which forms a 310 bend, may be important in maintaining the proper structure of the antigenic determinant. Moreover, the variations up to 180‐fold in the concentrations of the cross‐reacting cytochrome c and peptides required for stimulation were not always correlated with the maximal interleukin 2 secretion they induced. This indicates that the biological response, that is supposed to be an indication of the affinity of the T cell receptor for its ligand, is not necessarily a function of the antigen concentration.
Detection of HLA‐DP serological allodeterminants by the use of radioiodinated DP molecules
Authors: Tanigaki Nobuyuki , Tosi Roberto , Parodi Barbara , Sorrentino Rosa , Ferrara Giovanni B. , Strominger Jack L.
Published: March 2007

HLA class II molecules were partially purified from cells of an HLA deletion mutant cell line, LCL721.82, that lost DR and DQ expression but retained DPw2 specificity and labeled with radioactive 125I. The radioiodinated preparation bound to DP‐specific monoclonal antibody B7/21 as well as rabbit anti‐HLA class II antiserum. On sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, the component involved in these bindings gave, unlike known HLA class II molecules, a sharp and dense band of ∼ 60 kDa under nonreducing conditions and a single but diffuse band of ∼ 30 kDa under reducing conditions. By screening 401 anti‐HLA class II alloantisera, including those distributed in the 9th International Histocompatibility Workshop and also those locally available, eight were found to possess significant binding activity. Specificity analysis of these eight binding‐positive antisera on a panel of DP‐pretyped HLA homozygous typing cells revealed the presence of two clusters, one corresponding to an allodeterminant associated with DPw1, 2 and 3 and the other to that associated with DPw2 and 4. These two determinants were shown by the sequential binding test to reside on the B7/21‐defined HLA class II molecules. Thus, two major conclusions were drawn: (a) two distinct allodeterminants are carried by a single DP molecule; and (b) these serologically detected DP allodeterminants are supertypic to cellularly defined DP allospecificities.
The majority of “natural” immunoglobulin‐secreting cells are short‐lived and the progeny of cycling lymphocytes
Authors: Lévy Martine , Vieira Paulo , Coutinho António , Freitas António
Published: March 2007

Treatment of mice with hydroxyurea to selectively kill all cycling cells has been used to study population dynamics and life expectancy of “natural” immunoglobulin‐secreting cells in the bone marrow and spleen of nonimmunized animals. The results show that 50 to 90% of those cells are eliminated 2 to 3 days after one cycle of hydroxyurea administration, demonstrating their recent origin from cycling precursors. Using a protocol of long‐term hydroxyurea treatment which abrogates cell production from the cycling precursors compartments, it was shown that “natural” immunoglobulin‐secreting cells have a very short half renewal time, in the range of 15–60 h.
T cells expressing delayed‐type hypersensitivity can be derived from a humorally immune lymphocyte population
Authors: Leclercq Sharon A. , Bretscher Peter A.
Published: March 2007

Spleen cells from mice immunizied to produce a potent humoral response do not express delayed‐type hypersensitivity (DTH). These cells, when cultured at low density in the presence of the specific antigen for about 6 days, are able to produce swelling of the footpads of normal mice 24 h after they are injected s.c. into the footpad with the appropriate antigen. This footpad swelling peaks 24‐48 h after the injection of the cells, requires the presence of Ly‐1+Ly‐2− T cells in the immune population, is due to the interaction of antigen‐specific cells with the appropriate antigen and is therefore due to DTH‐mediating cells. The optimal generation of these cells occurs under conditions similar to those favoring the primary induction of DTH. Furthermore, the in vitro generated cells are also able to produce a systemic state of DTH when injected i.v.; a DTH reaction is elicited in recipient mice when antigen alone is injected into their footpads.

The observations reported here demonstrate that a humorally immune population of spleen cells, known to contain T cells able to suppress the induction of DTH, can under appropriate conditions give rise to cells expressing this subclass of cell‐mediated immunity. The decision by the immune system to mount a humoral as opposed to a cell‐mediated response is therefore reversible. These findings provide grounds for believing that it should be possible to develop the means to switch an on‐going in vivo humoral response to a cell‐mediated one, a maneuver that would be of considerable benefit in some well‐recognized clinical situations.
Recognition of alloantigens and induction of experimental allergic encephalomyelitis by a murine encephalitogenic T cell clone
Authors: Sakai Koichiro , Tabira Takeshi , Kunishita Tatsuhide
Published: March 2007

In this communication we report a SJL/J (H‐2s, Mlsc)‐derived encephalitogenic T cell clone 4b.14a which has dual specificities for myelin basic protein/I‐As and allogeneic H‐2Ik gene products. Monoclonal antibodies specific for public class II major histocompatibility complex (MHC) determinants (Ia.17, I‐Ak,r and Ia.7) and anti‐L3T4 antibody inhibited the response of the clone 4b.14a to alloantigens, but a monoclonal antibody specific for a private determinant on I‐Ak (Ia.2) did not inhibit the response. Although this clone proliferated in response to allogeneic spleen cells expressing H‐2Ik determinants regardless of disparate Mlsa,b,c,d alleles, CBA/N cells (H‐2k, Mlsnull) failed to stimulate the clone 4b.14a. These results suggest that recognition of allogeneic class II MHC molecules by this clone requires recognition with non‐MHC gene products such as Mls. In addition, the clone 4b.14a stimulated by alloantigens could mediate clinical signs of experimental allergic encephalomyelitis in syngeneic recipients. However, interleukin 2 of rat spleen cell origin alone failed to activate the clone cells to make them encephalitogenic, though it could make them proliferate. The significance of these findings for T cell recognition and activation is discussed.
Searching for MHC‐restricted anti‐viral antibodies: antibodies recognizing the nucleoprotein of influenza virus dominate the serological response of C57BL/6 mice to syngeneic influenza‐infected cells
Authors: Tamminen Wendy L. , Wraith David , Barber Brian H.
Published: March 2007

An attempt has been made to generate monoclonal antibodies which recognize the same target structures on influenza‐infected cells as those seen by cytotoxic T lymphocyte (CTL) receptors. Such antibodies, if they mimicked the T cell receptor specificity, would be expected to be both virus specific and restricted in their binding by the major histocompatibility complex (MHC) antigens. Approximately 200 hybridomas from C57BL/6 (H‐2b) mice primed and boosted with influenza virus (X‐31)‐infected EL4 (a C57BL/6 T cell lymphoma) were screened for reactivity on infected and uninfected cells of different MHC haplotypes. Of the 10 hybridoma antibodies which were identified as being reactive with X‐31‐infected EL4, but not uninfected EL4, all reacted equally well with X‐31‐infected cells of H‐2b, H‐2d and H‐2k haplotypes, indicating a lack of MHC restriction in their recognition of the infected cells. Unexpectedly, 7 of the 10 monoclonal antibodies were found to react specifically with the purified influenza virus nucleoprotein (NP), a predominant viral antigen in CTL recognition of infected cells. Fluorescence‐activated flow cytometry confirmed that these antibodies were able to recognize NP serological determinants on the surface of viable, infected cells, but the anti‐NP antibodies were unable to block the lytic activity of an NP‐specific CTL clone.
Modulation of expression of class II histocompatibility antigens by secretion of a cellular inhibitor in K562 leukemic cells
Authors: Krief Patricia , Boucheix Claude , Billard Christian , Mishal Zohar , van Agthoven Andreas , Fiers Walter , Azzarone Bruno
Published: March 2007

In this report we show that it is possible to induce the expression of HLA‐DR antigens on K562 cells, previously reported to be unresponsive to interferon‐gamma (IFN‐γ). However, only low cell concentrations and a high dose of IFN‐γ allowed the induction of HLA‐DR antigens. Furthermore, the recombinant glycosylated IFN‐γ is 100‐fold more efficient than the unglycosylated form. This induction of HLA‐DR antigens on K562 was not related to a stage of differentiation or to the presence of cells subsets specifically sensitive to IFN‐γ, since repeated sorting of K562 HLA‐DR‐positive and negative cells did not lead to the selection of a cell subset with a different potential of induction for HLA‐DR. The difficulty in obtaining induction is due to the production of a soluble endogeneous inhibitor of proteic nature, whose action is not restricted to the K562 cell line since it operates also on both epithelial and fibroblastic cells. Treatment of normal human epithelial and fibroblastic cells with conditioned medium from K562 cultures caused a marked decrease in the expression of HLA class II antigens (DR and DP) induced by IFN‐γ (10000 U/ml), but had no effect on cell growth; however, it also affected expression of HLA class I antigens. This inhibition is not mediated by prostaglandin or an IFN‐α or IFN‐β‐dependent mechanism. Production of this inhibitor by pluripotent human leukemic cells could cause an unbalance in the complex control exerted by the immunological system during hematopoietic differentiation or leukemic progression.
Expression of muscarinic cholinergic receptors during T cell maturation in the thymus
Authors: Maśliński Włodzimierz , Gra̧bczewska Ewa , Laskowska‐Božek Hanna , Ryżewski Jan
Published: March 2007

Thymocytes at various stages of their ontogeny have been studied in relation to their ability to bind [3H]quinuclidinyl benzilate ([3H]QNB), a specific radioligand of the muscarinic cholinergic receptors. [3H]QNB‐specific binding to thymocytes from 15–19‐day fetal, newborn and adult thymuses of mice and rats was compared and correlated. Our experiments showed that the kinetics of [3H]QNB binding to thymocytes at 37°C was similar to that of the lymph node lymphocytes (LNL) with maximum after 5 min of incubation and subsequent decrease to 10% of the maximum after 90 min of incubation. Maximal binding for the entire thymocyte population was twice lower than for the cortisone‐resistant thymocytes (CRT) or for LNL. Binding of [3H]QNB carried out at 4°C resulted in disappearance of the maximum, but did not alter the difference between CRT and entire thymocyte population. Depletion of CRT detectable [3H]QNB‐specific binding to thymocytes until 18th day of gestation but the maximal binding increased up to 20% at the day 19 and reached 90% of adult level on the third day after birth. Moreover, carbamylcholine (a muscarinic agonist) treatment in vivo induced a significant decrease in [3H]QNB binding to the thymocytes.

We thus suggest that a subpopulation of thymocytes bearing muscarinic receptors in the periphery acquired these receptors in the thymus as one of the last steps of their maturation. We cannot exclude the possibility that cholinergic stimulation might trigger these lymphocytes to leave the thymus.
Granzyme A secretion by normal activated Lyt‐2+ and L3T4+ T cells in response to antigenic stimulation
Authors: Velotti Francesca , MacDonal H. Robson , Nabholz Markus
Published: March 2007

Granzyme A is a serine esterase initially isolated from cytoplasmic granules of cytolytic T cell lines (Masson, D. et al., EMBO J. 1986. 5: 1595). Among normal T lymphocytes activated by allogeneic stimulation it is found in both Lyt‐2+ and L3T4+ subsets in comparable amounts. Here we show that normal alloantigen‐activated T cells secrete the enzyme specifically when mixed with appropriate stimulator cells. Specific enzyme release is dependent on external calcium and removal of calcium blocks further secretion within a few minutes. Both Lyt‐2+ and L3T4+ cells specifically secrete the enzyme with similar rates, and anti‐L3T4 and anti‐Lyt‐2 antibodies block secretion by the responder cells expressing these markers. Anti‐LFA‐1 antibodies, on the other hand, block secretion by either subset.
Immunoregulatory defects in murine aged Peyer's patches
Authors: Kawanishi Hidenori , Kiely Joan
Published: March 2007

Aging effect on immunoregulatory processes in Peyer's patches (PP) from BALB/c mice of 3–4 months and 24–28 months was studied in vitro. The magnitude of isotype‐specific Ig production by aged or young PP B cells in co‐culture with young or old fresh PP T cells strongly suggested that the suppressor activity of PP T cells was impaired in aged mice. Further studies on in vitro induction of concanavalin A‐activated T helper cells, T suppressor‐inducer cells and T suppressor cells from aged PP indicated that the generation of T suppressor cells was largely impaired, in contrast to a minor defect(s) in that of T helper cells. The findings obtained here at least suggest that in aged PP, a T suppressor‐inducer cell subset appears to be more selectively impaired in the aging process than the other lymphocyte subpopulations, which possess minor intrinsic functional defects. Thus, these abnormal T and B cell responses in PP could be responsible for the senescence‐associated gut mucosal immunologic dysfunction.
Regulation of immunoglobulin gene transcription by labile represser factor(s)
Authors: Kitamura Daisuke , Maeda Hiroaki , Araki Kazuo , Kudo Akira , Watanabe Takeshi
Published: March 2007

The cloned human γ1 heavy chain gene (HIG1) was scarcely expressed in the stable transformants of a mouse fibroblast line, L cell or a T cell line, EL4, and no γ1 heavy chain was produced in these cells. Upon treatment with cycloheximide or other kinds of protein synthesis inhibitors, the transcription of HIG1 gene was induced in L cell transformants as well as in T cell transformants. Transcription rate of bacterial gpt gene, which was derived from the plasmid vector used for transfection of HIG1 gene and located just upstream of HIG1 in the transformants, was also greatly enhanced after cycloheximide treatment. But the expression of several endogenous genes in the L cells tested was not affected by the cycloheximide treatment. Nuclear transcription assay indicated that the appearance of HIG1 gene transcripts after treatment with cycloheximide was mainly due to the induction of the transcription. Deletion of an enhancer element from HIG1 gene lowered the inducing activity of cycloheximide in the L cell transformants, but a low level of HIG1 gene expression was still observed. These results suggested that trans‐acting factors similar to those present in B lymphoid cells are also functioning in non‐B lymphoid cells but their activity is inhibited by short‐lived repressor protein(s). Such repressor protein(s) appear to act on regulatory element(s) of the immunoglobulin heavy chain gene including enhancer region as well as 5′ flanking region.
Antigen presentation and tumor cytotoxicity by interferon‐γ‐treated microglial cells
Authors: Frei Karl , Siepl Christine , Groscurth Peter , Bodmer Stefan , Schwerdel Cornelia , Fontana Adriano
Published: March 2007

In this study microglial cells isolated from brain cell cultures of newborn mice were characterized and investigated for morphology, their responses to growth factors and their functional properties. The microglial cells were phagocytic, contained nonspecific esterase activity and expressed Fc (IgG1/2b) and type‐3 complement receptors. Scanning electron microscopy revealed that in analogy to brain tissue two types of microglial cells are present in the cultures: the ameboid and the ramified type which both display similar appearance by transmission electron microscopy. Interleukin 3 and the granulocyte‐macrophage colony‐stimulating factor were potent growth factors for the cultured microglial cells. The cells were negative for class II antigens (Ia) of the major histocompatibility antigen complex. However, upon treatment with interferon‐γ (IFN‐γ) microglial cells became Ia+ and functioned as antigen‐presenting cells when tested on ovalbumin‐specific Ia‐restricted helper T cells. Furthermore, microglial cells exposed to IFN‐γ and endotoxin developed tumor cell cytotoxicity and produced tumor necrosis factor α. Taken together, microglial cells share the characteristics of cells of the macrophage lineage.
Simultaneous expression of CD4 and CD8 antigens by a substantial proportion of resting porcine T lymphocytes
Authors: Saalmüller Armin , Reddehase Matthias J. , Bühring Hans‐Jörg , Jonjić Stipan , Koszinowski Ulrich H.
Published: March 2007

The existence of four subpopulations in resting porcine T lymphocytes is documented. In addition to the two known subpopulations which are typified by a mutually exclusive expression of either the CD8 or the CD4 differentiation antigen, CD4−CD8+ and CD4+CD8− T lymphocytes, respectively, two unusual subpopulations were prominent not only in peripheral blood, but also in lymphoid tissues: CD4−CD8− T lymphocytes expressing neither of these antigens and CD4+CD8+ T lymphocytes coexpressing both antigens. While CD4+CD8+ lymphoblasts have been found also in other species, resting T lymphocytes with that phenotype are without precedent among all species analyzed to date. This unique composition of the porcine T lymphocyte population has to be taken into consideration when the swine is used as a large animal model in experimental medicine.
Subpopulations of CD4−, CD8− thymocytes
Authors: Gause William C. , Mountz John D. , Steinberg Alfred D.
Published: March 2007

A population of highly purified CD4−, CD8− thymocytes was analyzed by both flow microfluorometry and in situ hybridization in an attempt to further elucidate thymocyte subpopulations. The double‐negative cells had a marked increase in expression of the c‐myb and T cell gamma genes relative to unseparated thymocytes. Approximately 27% were Ly‐24+, 8% Ly‐6C+ and 6% 6B2+. All of the Ly‐6C+ cells were also Ly‐24+. A small population (6%) of the CD4−, CD8− thymocytes had surface expression of the T cell receptor for antigen (F23.1); all were bright Ly‐1+ and half were Ly‐24+. These studies demonstrate that there are further subdivisions of the CD4−, CD8− thymocytes based upon cell surface expression of markers previously found on bone marrow cells and their non‐T cell progeny. Studies are in progress to determine whether these represent different stages of activation‐maturation or different lineages of cells.
Dendritic cells of the mouse recognized by two monoclonal antibodies
Authors: Breel Matthijs , Mebius Reina E. , Kraal Georg
Published: March 2007

A new monoclonal antibody, MIDC‐8, is described which shows a comparable tissue distribution as the recently described NLDC‐145 antibody. It recognizes interdigitating cells, veiled cells and Langerhans cells in lymphoid organs and the skin of the mouse. In contrast to NLDC‐145 it recognizes a cytoplasmic component of these cell types. Its distribution is more restricted to the T cell‐dependent areas than NLDC‐145. Isolation of dendritic cells from lymph nodes, spleen and thymus revealed that both antibodies react with the in vitro isolated dendritic cells. The results show that these antibodies can be used to study dendritic cells in vitro and emphasize the relationship between the in vivo interdigitating cells of the T cell areas and the in vitro isolated dendritic cells.
Three‐cell‐type clusters of T cells with antigen‐presenting cells best explain the epitope linkage and noncognate requirements of the in vivo cytolytic response
Authors: Mitchison N. Avrion , O'Malley Christine
Published: March 2007

Using an established i.p. adoptive transfer system in which primed precursors of cytolytic (Tc) cells are combined with primed helper (Th) cells and alloantigen, the three‐cell‐type hypothesis of T‐T cooperation has been tested. This hypothesis assumes that cooperation takes place through the formation of clusters, consisting of one or more Tc precursors plus one or more Th cells binding to antigen on the surface of antigen‐presenting cells (APC). By using antigens in which the H‐2Db epitopes recognized by the Tc precursors are presented either on the same cell as the BALB minor histocompatibility epitopes recognized by the Th cells, or a different one, the value of epitope‐linkage has been explored. Epitope‐linkage is found to enhance the response at low concentrations of antigen but not at high ones, in accordance with the prediction that at low concentrations individual APC will usually take up either one antigen or the other but not both from an unlinked mixture, while at high concentrations most APC will take up both whether they are linked or not. In a further test of this hypothesis, no requirement for a cognate T‐T interaction could be detected.

With the three‐cell‐type interaction thus better established, its implications in terms of efficiency compared with linked‐cognate interactions and its evolution are discussed.
Induction of T cell proliferation with anti‐CD3 switch‐variant monoclonal antibodies: effects of heavy chain isotype in monocyte‐dependent systems
Authors: Van Lier René A. W. , Boot Johan H. A. , De Groot Els R. , Aarden Lucien A.
Published: March 2007

Monoclonal antibodies (mAb) directed against the CD3 (T3) antigen are able to induce proliferation in resting human T lymphocytes. T cell proliferation only occurs in the presence of monocytes that carry the proper Fc receptor for the mAb used. To further analyze the role of the Fc portion of anti‐CD3 mAb in proliferation induction, we isolated, starting from a γ1 anti‐CD3‐producing hybridoma, four heavy‐chain isotype switch‐variant antibody‐secreting clones, producing γ2b, γ2a, ϵ and α, respectively. All variant antibodies recognize the CD3 antigen as determined by immunoprecipitation and cross‐blocking experiments. With this series of isotype variant antibodies we were able, in proliferation induction experiments, to confirm the Fc receptor polymorphism for murine IgG2a, IgG2b and IgG1 on human monocytes. Moreover, we found that all 30 donors tested responded to the IgE anti‐CD3 antibody, while no IgA responders could be identified. The induction of proliferation by the IgE variant antibody does not require the 72‐kDa Fc receptor which is responsible for the interaction with mouse IgG2a. Nonresponsiveness to the IgG1 antibody, but not to the IgG2b or IgA variant antibodies, could be overcome by the addition of exogenous interleukin 2 to the cultures. When the switch‐variant antibodies were used to induce IgM synthesis in peripheral blood mononuclear cells only low IgM synthesis was found, with the exception of the IgE variant, which induced excellent T cell help for IgM production.
Activation of resting T lymphocytes by cross‐linked anti‐CD3 (T3)
Authors: Heumann Didier , Vischer Thomas L.
Published: March 2007

In this study we have examined the role of small numbers of adherent cells in the stimulation of highly purified resting T lymphocytes by cross‐linked monoclonal anti‐CD3 antibodies (T3). T cells were obtained by 3 cycles of purification, using adherence to plastic surface, nylon wool column separation and rosetting with 2‐aminoethyl isothiouronium bromide‐treated sheep red blood cells. They were stimulated either with T3 antibodies or with solid‐phase rabbit anti‐mouse IgG‐T3 complexes. In standard high density cultures (1 × 105−2 × 105 cells), soluble T3, interleukin (IL) 1 and IL 2, used separately, did not induce proliferation of T cells. Soluble T3 together with IL 2 slightly activated T cells to proliferate. Rabbit anti‐mouse IgG‐T3 complexes attached to the plastic wells induced stimulation in some cultures. The response was markedly increased after addition of IL 2, but not IL 1. The irregular response of these cultures suggested the presence of another variable signal. When cell numbers were reduced (12 × 103 cells), neither cross‐linking of the CD3‐Ti complex nor addition of exogenous IL 1 or IL 2, alone or in combination, stimulated the T cells to increase DNA synthesis. A positive response, comparable to complete peripheral blood mononuclear cells, was restored with 0.5% supplemented adherent cells, provided that IL 2 was present.
Rapid decrease in lymphocyte adherence to high endothelial venules in lymph nodes deprived of afferent lymphatic vessels
Authors: Hendriks Hans R. , Duijvestijn Adrian M. , Kraal Georg
Published: March 2007

Occlusion of the afferent lymph flow to the lymph node (LN) results in both flattening of the endothelium of high endothelial venules (HEV) and a severe decrease in numbers of lymphocytes in transit across the walls of the flattened HEV. In the present study we have used the in vitro lymphocyte‐binding assay to investigate the ability of HEV in rat LN to bind lymphocytes at various time points after occlusion of the afferent lymph flow. In addition the specificity of T and B lymphocyte adherence to HEV of such operated LN was studied.

In normal LN, lymphocytes adhered to virtually all HEV using the in vitro binding assay. However, 1 and 2 weeks after operation lymphocytes bound to only 50–60% of the HEV and by 3–6 weeks 20–30%. The total numbers of lymphocytes bound to these HEV had also diminished to 10% of the control value 3–6 weeks after operation. Morphometric analysis showed that this was not only due to a reduction in the area of HEV endothelium available for lymphocyte adherence by flattening of the high endothelial cells, but also to a strong decrease in the numbers of bound lymphocytes per unit area high endothelium. In spite of the reduction in numbers of adhering lymphocytes the T/B cell ratio did not change. The results show that the reduction in lymphocyte binding of HEV in operated LN is a rapid event, probably due to loss of high endothelial cell determinants involved in binding of lymphocytes. The decrease in lymphocyte binding clearly precedes flattening of HEV endothelium suggesting that the height of high endothelial cells is of secondary importance to lymphocyte adherence.
Bovine cytotoxic T cell clones which recognize lymphoblasts infected with two antigenically different stocks of the protozoan parasite Theileria parva
Authors: Morrison W. Ivan , Goddeeris Bruno M. , Teale Alan J.
Published: March 2007

The Muguga and Marikebuni stocks of Theileria parva differ on the basis of cross‐protection and in their schizont antigen profile determined with a panel of parasitespecific monoclonal antibodies. The phenotype and specificity of six cytotoxic T cell clones generated from an animal immunized against T. parva (Marikebuni) were investigated. All six clones had the BoT2+ BoT4− BoT8+ phenotype, were dependent on both specific antigen and T cell growth factor for proliferation and were restricted by determinants on class I major histocompatibility complex molecules. The clones killed target cells infected with either the Muguga or Marikebuni stocks of the parasite; the target cell lines tested included T cell clones which were infected in vitro with the two parasite stocks and subsequently recloned. The specificity of these cytotoxic T cell clones contrasts with that of T cell clones generated previously from animals immunized against T. parva (Muguga), in that the latter were specific for target cells infected with the Muguga stock of the parasite. Moreover, one of the clones generated against T. parva (Marikebuni) was restricted by the same major histocompatibility complex molecule as the Muguga‐specific T cell clones. The difference in parasite strain‐specificity between the two sets of clones appears to reflect the capacities of the two parasite stocks to cross‐protect, since animals immunized against T. parva (Marikebuni) are protected against challenge with T. parva (Muguga) whereas a proportion of animals immunized with T. parva (Muguga) are susceptible to challenge with T. parva (Marikebuni). Another difference between the two sets of T cell clones was that those generated against T. parva (Marikebuni) only killed a proportion of cells of a given cell line in a 4‐h cytotoxicity assay, whereas Muguga‐specific T cells invariably kill the majority of cells. However, despite this partial killing, the clones markedly inhibited growth of parasitized cell lines when cultured with them for a period of 5 days.
Cytotoxicity of tumor necrosis factor for thyroid epithelial cells and its regulation by interferon‐γ
Authors: Taverne Janice , Rayner David C. , van der Meide Peter H. , Lydyard Peter M. , Bidey Stephen P. , Cooke Anne
Published: March 2007

The FRTL‐5 line of differentiated rat thyroid epithelial cells was shown to be sensitive to the cytotoxic action of recombinant tumor necrosis factor. The sensitivity of the cells varied with the conditions of culture. It was markedly increased by preincubation with recombinant interferon‐γ, and the magnitude of this enhancement was affected by the presence of thyroid‐stimulating hormone. The increased susceptibility of the cells to the cytotoxicity of tumor necrosis factor was clear as early as 2–4 h after the addition of interferon‐γ and greatly preceded the induced expression of major histocompatibility complex class II antigen. Since cells secreting interferon‐γ and tumor necrosis factors may co‐exist in inflammatory infiltrates, our observations suggest that these factors may be early mediators of cell destruction in autoimmune thyroid disease.
Immunogenic presentation of an immunoglobulin “tolerogen” requires interleukin 2
Authors: Sadegh‐Nasseri Scheherazade , Phipps Richard P.
Published: March 2007

Previously it has been reported that hapten‐specific B cell unresponsiveness could be elicited by macrophages pulsed with the tolerogen deaggregated fluoresceinated sheep gamma globulin (FL‐SGG; R. P. Phipps and D. W. Scott, J. Immunol. 1983. 131: 2122). In contrast, FL‐SGG‐pulsed P388AD.2, a lymphoid dendritic cell‐like tumor line, presents this signal as an immunogenic one leading to augmented anti‐FL antibody responses. In the present study, we examined the role of T cells and their secreted lymphokines in the immunogenic presentation of FL‐SGG by P388AD.2. Lymphocytes and FL‐SGG‐pulsed P388AD.2 form large clusters in vitro. In order to examine whether the clustered lymphocytes were responsible for the augmented antibody responses, cultures of P388AD.2 and lymphocytes were separated into P388AD.2 adherent (clustered) and nonadherent fractions. Interestingly, the clustered fraction was entirely responsible for the augmented responses and contained Ly‐1+ T cells and B cells primed by FL‐SGG on P388AD.2. Moreover, a requirement for T cells in the presentation of a normally tolerogenic signal as an immunogenic one was demonstrated as responses of T‐depleted spleen cells could be reconstituted by addition of normal T cells or by an autoreactive T cell clone. Furthermore, the requirement for T cells could be bypassed using supernatant from concanavalin A‐stimulated spleen cells or by culture supernatant from AOFS, an ILZsecreting Tcell hybridoma. This suggested that a cognate interaction between T and B cells was not required to induce B cell priming and the augmented anti‐FL antibody responses. Further studies revealed that doses of recombinant IL2 > 12.5 units/ml, in conjunction with FL‐SGG‐pulsed P388AD.2, replaced the need for T cells. Overall, our data suggest that one mechanism of presentation of FL‐SGG in an immunogenic fashion involves T cell secretion of IL2 by autoreactive T cells triggered by close association with P388AD.2.
CDw40 and BLCa‐specific monoclonal antibodies detect two distinct molecules which transmit progression signals to human B lymphocytes
Authors: Clark Edward A. , Yip Timothy C. , Ledbettep Jeffrey A. , Yukawa H. , Kikutani Hitoshi , Kishimoto Tadamitsu , Ng Mun H.
Published: March 2007

Two monoclonal antibodies (mAb), MA6 and G28‐5, have the common property of detecting markers expressed on both B lymphocytes and carcinomas: BLCa (B lymphocyte carcinoma cross‐reacting antigen) and CDw40 (Bp50). A comparison of the reactivity of these mAb revealed that MA6 and G28‐5 detect distinct epitopes with different cell line and tissue distributions. L cell transfectants expressing CDw40 were not bound by MA6 anti‐BLCa, but were bound by G28‐5 anti‐CDw40. G28‐5 or a CDw40‐specific heterantiserum could not block the migration of BLCa, while MA6 antibody could. These results indicate that CDw40 and BLCa are distinct surface molecules. Both G28‐5 anti‐CDw40 and MA6 anti‐BLCa mAb could provide progression signals for B cells activated by appropriate B cell activators such as phorbol esters or anti‐immunoglobulin; however, only G28‐5 anti‐CDw4O and not MA6 was co‐stimulatory with the anti‐CD20 competence signal, demonstrating a clear difference in the CDw40 and BLCa‐mediated progression signals. Apparently, these molecules, although structurally distinct, have related functions in B cell activation.
Involvement of soluble mediator(s) different from interleukin (IL)1 in the antigen‐induced IL 2 receptor expression and proliferation of L3T4+ (CD4+) T lymphocytes
Authors: Germann Tieno , Schmitt Edgar , Huhn Helga , Rüde Erwin
Published: March 2007

Proliferation of T lymphocytes (T cells) requires the interaction of interleukin 2 (IL 2) with the high affinity form of the IL2 receptor (IL2R). IL2 production as well as IL 2R expression are generally induced simultaneously in T cells by the recognition of specific antigen displayed on the surface of syngeneic antigen‐presenting cells. The experiments described herein show that the expression of IL2R has different requirements than the production of IL2 (and other lymphokines). Stimulation of antigen‐specific L3T4+ T cell lines with antigen‐pulsed spleen cells (SC) treated with ultraviolet (UV) light results in efficient IL 2 production but only minimal proliferation due to reduced IL2R expression, as compared to T cells stimulated by antigen and SC without UV light treatment. The reduced IL 2R expression/proliferation correlates with the absence of a soluble mediator(s) termed T cell‐stimulating factor (TSF) in the supernatants of T cells stimulated with antigen‐pulsed, UV light‐irradiated SC. Addition of TSF of these T cells could at least partially restore the proliferative response or enhance IL2R expression. Because TSF is present in the supernatant of T cells triggered by antigen and SC but is absent when the latter are UV light treated, we suggest that TSF is a product of metabolically active splenic antigen‐presenting cells. The macrophage products interleukin 1α β p as well as some other cytokines show no TSF activity.
T cell proliferation induced by anti‐cd3 antibodies: requirement for a t‐t cell interaction
Authors: Bentin Jacques , Vaughan John H. , Tsoukas Constantine D.
Published: March 2007

In the presence of interleukin 2 (IL2), soluble anti‐CD3 monoclonal antibodies can stimulate highly purified normal T lymphocytes to proliferate. In these experiments HLADR+ T cells constituted 13 to 20% of the total cell population, and other HLADR− cells, such as monocytes and B lymphocytes, constituted less than 1% of the population. When the HLADR+ T cells were removed from the total T cell population by cytofluorometric sorting, the residual HLADR− T cells failed to respond to soluble anti‐CD3 plus IL2. When the separated HLADR+ T cells were recombined with the HLADR− T cells, a response was again found. This response was dependent on the dose of HLADR− T cells added in the mixture. Irradiation individually of the HLA DR+ and DR− T cells revealed that the proliferation in the cell mixture was predominantly, if not exclusively, by the HLADR− T cells. The ability of the HLA DR+ T cells to provide a signal necessary to this proliferation was radioresistant. These data indicate that under the conditions of these experiments HLADR+ (“activated”) T cells provide a signal necessary to the responsiveness of previously resting T cells.
The transmembrane orientation of the ϵ chain of the TcR/CD3 complex
Authors: Clevers Hans , Dunlap Sabrina , Terhorst Cox
Published: March 2007

The antigen receptor of the T lymphocytes is one of the most complex eukaryotic membrane structures studied to date. The T cell receptor (TcR) consists of two disulfide‐linked glycoprotein chains (α/βor γ/δ) and is noncovalently associated with a group of small and invariable CD 3 proteins. Four CD 3 chains have been recognized: two highly homologous glycoproteins CD 3 γ and δ, the more distantly related nonglycosylated CD 3 E chain, and the nonglycosylated CD 3 ζ, the latter being present as a homodimer. The unraveling of the architecture of the TcWCD 3 complex is crucial to our understanding of the processes underlying its assembly, recognition and trans‐membrane signaling. The transmembrane orientation of the TcR chains and of CD 3 γ and CD 3 δ can be directly inferred from their primary structure, based on the presence of concensus N‐linked glycosylation sites N‐terminal of their transmembrane domains. This prediction can not be made, however, for nonglycosylated molecules like the CD 3 E chain. In order to determine the transmembrane orientation of CD 3 E, anti‐peptide antisera directed against the N‐termini of the human and murine CD 3 E chains were generated in rabbits. Both antisera stained intact T cells, demonstrating that the N‐terminus of the CD 3 E chain was located at the outer surface of the plasma membrane. The anti‐human CD 3 E peptide antiserum was found to be mitogenic for peripheral blood T cells, a finding previously reported only for monoclonal anti‐TcW CD 3 reagents. Using a novel transient expression system in murine T lymphocytes, the human CD 3 E chain could be expressed on the surface of CD 3+, but not CD 3−murine T cells, as indicated by fluorescence staining with the anti‐peptide antiserum. This experiment confirmed the specificity of the anti‐peptide antiserum and, perhaps more importantly, indicated that the human CD 3 E chain was correctly assembled in the murine CD 3 complex. Moreover, the anti‐human CD 3 monoclonal antibody UCHT1 was found to stain T cells expressing the human CD 3 E chain.
Determination of frequency of T cells expressing the T cell‐specific serine proteinase 1 (TSP‐1) reveals two types of L3T4+ T lymphocytes
Authors: Fruth Uli , Nerz Gaby , Prester Marlot , Simon Hans G. , Kramer Michael D. , Simon Markus M.
Published: March 2007

TSP‐1 is a murine T cell‐specific serine proteinase which is exclusively expressed in activated but not in resting T lymphocytes. Among T lymphocyte clones tested so far the enzyme was found to be associated with all Ly‐2+ but only with a fraction of L3T4+ lines. Here we have applied a limiting dilution system to determine the frequency of precursor cells of resting L3T4+ and Ly‐2+ lymphocytes which can be induced in vitro by antigen/lectin to express TSP‐1. T cell subsets were either positively enriched by flow cytofluorometry cell sorting or by negative selection using monoclonal antibodies and complement. Following stimulation of lymphocytes in vitro, individual microwells were tested for growth by visual examination and for the TSP‐1 protein/enzyme by analyzing cell lysates using either a specific rabbit anti‐TSP‐1 antiserum and/or the chromogenic model peptide substrate H‐D‐Pro‐Phe‐Arg‐p‐nitroanilide. Moreover, a large panel of L3T4+ and Ly‐2+ T lymphocyte clones generated from primary cultures were similarly investigated. In some cell cultures the presence of TSP‐1 was also tested on the mRNA level using a TSP‐1‐specific oligonucleotide probe. The data show that the majority, if not all, of antigenflectin‐induced‐Ly‐2+ T cells expressed TSP‐1. In contrast, only 12%‐27% of the growing lectin or antigen‐reactive L3T4+ lymphocytes were positive for the enzyme. Studies performed in parallel with L3T4+ and Ly‐2+ lymphocyte populations sensitized in bulk culture showed that under these conditions similar levels of TSP‐1‐specific mRNA and enzyme activity are detected in both subsets. The finding of primary L3T4+ T lymphocyte clones with distinct patterns of TSP‐1 production provides evidence for the existence of two types of L3T4+ effector cells with different functional capacities. The data also suggest a cooperation between distinct L3T4+ lymphocytes for induction of optimal TSP‐1 activity in L3T4+ T cells.
Recombinant human interferon‐γ induces increased IgE receptor expression on human platelets
Authors: Pancré VéRonique , Joseph Michel , Capron André , Wietzerbin Juana , Kusnierz Jean‐Pierre , Vorng Han , Auriault Claude
Published: March 2007

Human recombinant interferon‐gamma (IFN‐γ) significantly increased the expression of receptors for IgE (FceRII) on blood platelets. FceRII was measured by specific binding of 25I‐labeled IgE or flow cytometry experiments. Scatchard analysis of 125I‐labeled IgE binding curves revealed that treatment with IFN‐y increased the number of FceRII but did not change the value of the association constant of FCERII for l25I‐labeled IgE. IFN‐a had no effect on the expression or affinity of FcERII. In addition to FceRII, IFN‐γ also modified the expression of the glycoprotein IIb‐IIIa complex on the platelet membrane.
V genes of the primary antibody response of C57BL110 mice to the hapten phenyloxazolone
Authors: Kaartinen Matti , Pelkonen Eila , Even Jos , Mäkelä Oiii
Published: March 2007

The mRNA of ten monoclonal phenyloxazolone (phOx) antibodies originating from the primary (day 7) response of C57BL/10 mice were partially sequenced. The sequences were analyzed together with those of two previously published antibodies. The C57BL response does not have a predominant subset of antibodies like the BALB/c response has (VH‐OX1/VX‐OX1 JK5). Probably, C57BL mice lack the VH‐Ox1 gene and, as a consequence, their Vx‐Ox1 gene does not have a main role in the anti‐phOx response. Five Vx, and six VH genes were found to participate. All five Vx genes or their “alleles” had previously been found from the BALB/c response to 2‐phenyl‐oxazolone (phOx). On the other hand, the two strains use different VH genes for the anti‐phOx response. Most C57BL antibodies were coded by VH genes of group 1 which has only minor role in the BALB/c response. The remaining VH genes were from group 7. Our data show that one Vx, segment (e.g. Vx‐Ox1) can code for anti‐phOx antibodies with several, even widely different, VH genes. On the other hand, they emphasize the role of certain VH/VL gene combinations for the anti‐phOx specificity. Thus, VH genes of group 7 were found to code for anti‐phOx antibodies only together with the Vx45.1 gene.
T cell activation: distinct pathways involve phosphorylation of different cellular proteins
Authors: Peyron Jean‐François , Pont Suzanne , Pierres Michel , Fehlmann Max
Published: March 2007

The murine T cell clone D10.G4.1 can be induced to proliferate by monoclonal antibodies (mAb) to the T cell receptor (TcR) or to Thy‐1 molecules. When cells were stimulated by anti‐TcR mAb, a group of 4 proteins (19–25 kDa) was specifically phosphorylated. This effect was completely mimicked by the Ca2+ ionophore A23187, whereas only two of these proteins (19 kDa and 25 kDa) were phosphorylated after cell exposure to the phorbol ester 12‐O‐tetradecanoylphorbol 13‐acetate. By contrast, anti‐Thy‐1 mAb had no effect on the phosphorylation of these proteins, but induced specifically the phosphorylation of a protein of 32 kDa. These results therefore demonstrate that distinct activating pathways in T cells involve the phosphorylation of different proteins, suggesting that the stimulation of protein kinases in T lymphocytes is an early event in cell activation.