bluuebunny/crossref_metadata_2025 huggingface dataset:
Interferon‐γ in vivo. Induction and loss of class IIMHC antigens and immature myelomonocytic cells in rat organs
Authors: Steiniger Birte , Falk Peter , der‐Meide Peter H.Van
Published: March 2007

The effects of recombinant rat interferon‐y on class II major histocompatibility complex antigen expression in vivo were studied by immunohistology in LEW rats after continuous intravenous infusion for three days. Interferon‐γ administration led to a systemic induction of class II molecules in previously negative parenchymal and stromal cells. The induction patterns observed were highly reproducible, but not closely dose dependent within a 25‐fold dose difference tested. However, the effect of interferon infusion differed profoundly in individual cell types, and appeared to be related to the differentiation stage of each cell‐ population. Thus, epithelial cells like duct epithelia, urothelium or basal ear skin keratinocytes as well as endothelia in big vessels were strongly and easily induced for class II antigen expression. Parenchymal cells like cardiomyocytes and hepatocytes showed intermediate reactivity, while capillary endothelia, neurons in the brain, straight proximal kidney tubules or endocrine pancreatic islet cells did not express class II antigens. The induced expression was rapidly lost from most cells within one or two days after interferon withdrawal; the only exception occurred in keratinocytes. Long‐term alterations were, however, still found 14 days after infusion. Interstitial class II‐positive dendritic‐shaped cells were increased in the organs and hepatic Kupffer cells carried class II antigens. On conventional histology all organs appeared perfectly normal at this date. After three days of interferon, cells of an immature myelomonocytic phenotype occluded medium‐sized and small veins in all organs and occurred in granuloma‐like lesions in the liver. Although these cells quickly disappeared after interferon withdrawal they might have been at least partially responsible for single deaths on day three. Our study provides a basis for testing the immunological in vivo function of parenchymal class II antigen expression and its differentiation‐specific regulation.
Antigenic heterogeneity of a human melanoma tumor detected by autologous CTL clones
Authors: Degiovanni GéRard , Lahaye Thierry , Hérin Michel , Hainaut Philippe , Boon Thierry
Published: March 2007

Peripheral blood lymphocytes from a melanoma patient were stimulated with autologous melanoma cells in mixed lymphocyte tumor cultures (MLTC). After three restimulations, the lytic activity of the responder cells directed against the autologous melanoma cells was higher than that against K‐562 and autologous Epstein‐Barr virus‐transformed B cell line (EBV‐B) cells. From these MLTC‐responder cells, we derived specific cytolytic T cell (CTL) clones that lysed the autologous melanoma cells and did not lyse K‐562 or autologous EBV‐B cells. Autologous melanoma clones were found that were resistant to some or all of these CTL clones. The autologous CTL clones recognized at least two different antigens (A, B) on the melanoma cells and three types of melanoma clones could be distinguished (A+B+, A+B−, A−B−). This antigenic heterogeneity of melanoma clones was confirmed by testing the CTL clones in cold target competition and also in antigen‐dependent CTL proliferation assays performed with very small numbers of stimulator cells. The data further indicated an instability of the expression of a melanoma‐associated antigen in the course of a long culture period. Among the melanoma clones that expressed antigen A, one was found to stimulate the proliferation of anti‐A CTL clones much more effectively than the others. This represents a new type of heterogeneity among tumor cells which may be of significance for the elicitation of an autologous anti‐tumoral immune response.
Murine Fcγ receptor proteins: identification of a previously unrecognized molecule with a monoclonal antibody (12‐15)
Authors: Altevogt Peter , Heckl‐Oestreichep Gitte , Lang Elke , Kohl Ulrike , Kratzin Hartmut , Schirrmacher Volker
Published: March 2007

Previously we studied differential expression of cell surface molecules between the metastatic murine lymphoma ESb and an adhesion variant ESb‐MP. Here we describe the specificity of a monoclonal antibody (12‐15) that showed strong binding to the adhesion variant and weak reactivity against ESb cells. The antibody also reacted to lymphoid but not to macrophage‐derived cell lines and immunoprecipitated a molecule of approx. 60–69 kDa from ESb‐MP cells. N‐terminal sequencing of the' antigen revealed identity to the beta protein of mouse Fcγ receptors. Using monoclonal antibodies against Fcγ receptors (2.4G2 and K9.361) in immunofluorescence assays and cDNA probes specific for alpha, betal and beta2 Fc receptor transcripts in Northern blot experiments the differential expression of Fc receptors in ESb and ESb‐MP cells was confirmed.

Biochemical analysis of endoglycosidase F‐treated precipitates revealed that antibody 12‐15 reacted to products of all three transcripts with molecular masses for the protein core of 38.5 kDa (betal), 34 kDa (beta2) and 31 kDa alpha). In addition, an unknown protein of 37 kDa (termed beta3) was identified by antibody 12‐15 which could also be detected in ESb cells and EL4 cells. Antibodies 2.4G2 and K9.361 did not react to the beta 3 chain but reacted to varying extents to the other Fc proteins in macorphage and lymphoid cells. Comparison by peptide mapping of the novel beta3 chain to betal, beta2 and alpha proteins revealed similar, but also distinct peptides. The tissue‐specific reactivity of monoclonal antibody 12‐15 is likely to be due to a carbohydrate epitope associated with all Fcγ receptors in lymphoid but not macrophage cell lines.
The processing and presentation of mycobacterial antigens by human monocytes
Authors: Bhardwaj Vatsala , Colston M.Joseph
Published: March 2007

The processing and presentation of whole irradiated Mycobacterium tuberculosis (Mtbγ) and its purified protein derivative (PPD) by the peripheral blood monocytes from healthy Bacillus Calmette Guérin (BCG)‐vaccinated individuals was investigated. To study processing and presentation as events distinct from T cell recognition and proliferation, monocytes were pulsed with antigens for varying time intervals and fixed. The kinetics of presentation indicate that up to 2 h was required for effective presentation of PPD and 2–4 h for Mtbγ, and that the ability to activate T cells declined as the time interval for which pulsing occurred was increased, so that responses were abolished by 8–10 h. Prefixed monocytes could not present Mtbγ and PPD to T cells indicating that processing was an essential requisite. Lysosomotropic agents chloroquine, monensin, and leupeptin inhibited the presentation of these antigens suggesting the role of lysosomes/endosomes in processing. Furthermore, monocytes incubated with optimal concentration of antigens for different lengths of time released determinants which were still antigenic but circumvented the need for any further processing.

Addition of nonprimed syngeneic monocytes, both untreated or paraformaldehyde fixed to cells which had been pulsed and fixed, restored the responses even at the later time periods when responses were not detected. This second interaction of the monocyte with T cells was not major histocompatibility complex restricted in that the addition of monocytes from another donor was equally effective.
Liver‐associated macrophage precursor cells proliferate under impairment of regular hemopoiesis
Authors: Decker Thomas , Lohmann‐Matthes Marie‐Luise , Baccarini Manuela
Published: March 2007

We reported previously that immature macrophage precursor cells can be isolated from spleen and liver of cyclophosphamide or pyran copolymer‐pretreated mice. We now extended our investigations to livers of normal, untreated specific pathogen‐free mice. Using the response to the macrophage growth factor colony‐stimulating factor‐1 (CSF‐1) and the presence of the mouse macrophage‐specific F4BO antigen as criteria of definition, in the liver of normal mice we could demonstrate macrophage precursor (MϕP) cells by means of proliferation assays and flow cytometric analysis.

The amount of MϕP present in the normal liver was significantly increased after administration of pyran copolymer. Also an enhanced proliferative response to CSF‐1 as well as augmented natural killer activity and cytostasis of Candida albicans was noted in liver nonparenychymal cells (LNPC) after treatment of bone marrow (BM)‐irradiated, splenectomized mice with pyran copolymer. Since the irradiated BM was actually proven to be silent by assessment of BM number and proliferative capacity and by scoring white blood cells, our findings suggest a response of endogenous liver MϕP under the applied conditions. Further evidence for the presence of endogenous liver hemopoietic cells was obtained from transplantation experiments in which LNPC brought about the survival of lethally irradiated mice. The data point towards a significance of the liver in disposing hemopoietic cells to the organism under impairment of regular hemopoiesis.
Effect of tumor promoter 12‐O‐tetradecanoyl‐phorbol l3‐acetate on CD 7 expression by T lineage cells
Authors: Jung Lawrence K. L. , Fu Shu Man
Published: March 2007

Phorbol esters exert diverse effects on cellular activation and differentiation. CD 7, a differentiation antigen appearing early in T cell ontogeny, may be involved in the activation and differentiation processes. CD 7 was found to be rapidly down‐regulated by 12‐O‐tetradecanoylphorbol l3‐acetate (TPA) from mature T cell surface. The time course of CD 7 down‐regulation was similar to that of other functionally important T cell antigens, CD 3 and CD 4. Within 2 h, TPA at 10 to 30 ng/ml induced a complete down‐regulation of CD 7. Twenty‐four hours later, the reappearance of CD 7 on TPA‐treated cells was observed. This phenomenon was monocyte independent. In contrast, CD 7 expression on thymocytes was resistant to the effect of TPA. In addition, certain leukemic T cells were also resistant to TPA‐induced CD 7 down‐regulation. The mechanism underlying TPA‐induced CD 7 down‐regulation was investigated further. Synthetic diacylglycerol, sn‐l,2‐dioctanoylglycero1, which activates protein kinase C, did not induce down‐regulation of CD 7 on mature T cells. Ionomycin, a calcium ionophore, did not down‐regulate this antigen either. Thus, it is concluded that the processes of protein kinase C activation and/or cytosolic calcium influx are not sufficient for TPA‐induced CD 7 down‐regulation; other pathways induced by TPA may be responsible.
Macrophages pulsed with sterol‐conjugated benzylpenicilloylated eicosa‐lysine induce T cell‐mediated suppression of IgE antibody formation in mice
Authors: Luescher Immanuel F.
Published: March 2007

The conjugation of two lipophilic p‐oxymethylbenzyl‐3β‐cholestanylsuccinate groups to fully benzylpenicilloylated eicosa‐L‐lysine [BP20Lys20(OSuco)2] greatly potentiated its ability to suppress anti‐BPO IgE antibody formation in vivo in mice. This enhanced tolerogenicity was due to the ability of BPO20Lys20(OSuco)2 to induce T suppressor cells (Luescher, I. F. et al., Eur. J. Immunol. 1984.14:68). In the present study the role of adherent cells in the induction of T suppressor cells by BPO20Lys20(OSuco)2 was investigated. Low numbers of macrophages pulsed in vitro with BPO20Lys20(OSuco)2, but not with the hydrophilic analog BP020Lys20‐OH, suppressed anti‐BPO IgE antibody formation upon transfer into syngeneic recipients. This suppression was antigen and IgE specific, and was manifested in naive as well as in previously immunized mice. By cell transfer experiments it was found that the suppression was sensitive to cyclophosphamide. The IgE suppression was not due to carry‐over of BPO20Lys20 (OSuco)2 by the transferred macrophages since the amount of cell‐associated antigen was approximately 500‐fold too low to account for the observed suppressions.

The capability of BPO20Lys20 (OSuco)2 to elicit anaphylaxis in passively sensitized rats was significantly lower in comparison to the hydrophilic analog BPO21Lys20OH. Adherent cells pulsed with BPO20Lys20 (OSuco)2, although strongly suppressing IgE antibody formation, failed to elicit any detectable anaphylaxis. The role of adherent cells in the induction of T cell‐mediated suppression of IgE antibody formation by lipid‐modified antigens is discussed and novel therapeutical concepts to achieve desensitization of drug allergic individuals are suggested.
Action of recombinant human interleukin 6, interleukin 1β and tumor necrosis factor α on the mRNA induction of acute‐phase proteins
Authors: Andus Tilo , Geiger Thomas , Hirano Toshio , Kishimoto Tadamitsu , Heinrich Peter C.
Published: March 2007

The rat hepatoma cell line Fao was used to study the role of three inflammatory mediators on the mWA regulation of several acute‐phase proteins. In the presence of 10−6 M dexamethasone β‐fibrinogen mRNA levels increased 6‐fold after addition of recombinant human IL6 (rhIL6). rhIL1β or recombinant human tumor necrosis factor a (rhTNFα) had essentially no effect on β‐fibrinogen mRNA induction but led to a 20‐fold increase in α1‐acid glycoprotein mRNA in the presence of dexamethasone. On the other hand, rhIL6 was a much weaker stimulator of α1‐acid glycoprotein mRNA synthesis. All three mediators reduced albumin mRNA concentrations to about 30% of controls.

Whereas the induction of β‐fibrinogen mRNA was potentiated by dexamethasone, the synthetic glucocorticoid analog was an absolute requirement for the stimulation of αl‐acid glycoprotein mRNA. The mRNA levels of the negative acute‐phase protein albumin were induced 5‐fold by dexamethasone alone. The β‐fibrinogen mRNA induction started immediately after addition of rhIL6 and reached a maximum between 12 and 18 h. In contrast, the time‐course for α1‐acid glycoprotein mRNA synthesis showed a lag phase of 8 h followed by an increase up to 20 h after rhIL 1β. RhTNFα led to an even more delayed increase in αl‐acid glycoprotein mRNA. Whereas in the case of β‐fibrinogen mRNA induction no synergistic effect was observed between various concentrations of the three mediators, the combination of rhIL6/rhIL1β as well as rhIL6/rhTNFα or rhIL 1β/rhTNFα regulated synergistically α1‐acid glycoprotein and albumin mRNA. It is concluded that discrete acute‐phase proteins are regulated differently by the inflammatory mediators IL6, IL1β and TNFα, indicating that the acute‐phase response is more complex than previously assumed.

The Fao cell line used in this study turned out to be an ideal model for acute‐phase protein regulation, suitable for the discrimination between the inflammatory mediators IL6 and IL1/TNFα.
Immunomodulation by α2‐macroglobulin and α2‐macroglobulin‐proteinase complexes: the effect on the human T lymphocyte response
Authors: Heumann Didier , Vischer Thomas L.
Published: March 2007

Alpha2‐macroglobulin (α2M), various α2M‐proteinase complexes and methylamine‐treated α2M were added to human lymphocyte cultures stimulated with the specific antigen purified protein derivative of tuberculin (PPD), pokeweed mitogen (PWM) and anti‐CD3. α2M‐trypsin diminished all reactions in a dose‐dependent way. In the PPD‐induced stimulation of peripheral blood mononuclear cells, both change of configuration and remaining proteinase activity contributed to the suppressive activity. Separate exposure of adherent cells or the highly purified T lymphocytes to α2M‐trypsin complexes indicated that the effect was mediated through adherent cells. Addition of indomethacin did not modify the results. In the interleukin 2 (IL2)‐dependent stimulation of purified T lymphocytes by anti‐CD3 the effect of α2M‐proteinase complexes was probably due to the digestion of IL2 through remaining proteinase activity. As α2M‐proteinase complexes are formed at sites of inflammation, the multiple immunomodulatory effects of α2M‐proteinase complexes might contribute to the dysregulation of the immune system in inflammatory diseases.
Epitopes associated with major histocompatibility complex (MHC) restriction site of T cells IV. I‐J epitopes on MHC‐restricted cloned T cells
Authors: Nakayama Toshinori , Kubo Ralph T. , Kubo Masato , Fujisawa Isao , Kishimoto Hidehiro , Asao Yoshihiro , Tada Tomio
Published: March 2007

We studied the expression of an I‐Jk epitope on class II‐restricted cloned L3T4+ T cells established from H‐2k, H‐2b, F1 and semiallogeneic radiation bone marrow chimeras by the inhibition of antigen‐induced T cell proliferation and in vitro secondary antibody response, and by the direct immunofluorescence with a monoclonal anti‐I‐Jk. Both I‐Ak‐ and I‐Ek‐restricted T cells were shown to carry the identical I‐Jk epitope regardless of their genotypic origins, antigen specificity, and helper or suppressor function. None of the I‐Ab‐restricted clones derived from similar animals showed the I‐Jk epitope. This isomorphism, regardless of the restriction specificity for I‐Ak or I‐Ek, contradicts the idea that I‐J is an idiotypic determinant on class II‐restricted T cell antigen receptor (TcR). In fact, the I‐Jk epitope was not comodulated with TcR/T3 complex when incubated with an anti‐T3 antibody, indicating that I‐J is a new isomorphic receptor for self different from TcR α/β heterodimers.
Interleukin 4 (BSF‐1) induces growth in resting murine CD8 T cells triggered via cross‐linking of T3 cell surface structures
Authors: Miethke Thomas , Schmidberger Ruth , Heeg Klaus , Gillis Steven , Wagner Hermann
Published: March 2007

To analyze the role of interleukin 4 (IL4, BSF‐1) during primary activation of resting (high‐density) murine CD8 T cells, a model system was used which bypasses antigen‐presenting cells by the use of anti‐T3 monoclonal antibodies immobilized on Sepharose beads. In high, but not in low cell density cultures, IL4 alone induced cell growth. In low cell density cultures, further to T3 cross‐linking a soluble macrophage product was required as co‐stimulator to induce sensitivity to IL4. This co‐stimulator activity was unrelated to recombinant (r)IL1, rIL6 and rTNF‐α (tumor necrosis factor α). In primary CD8 T cell responses rIL4‐driven growth was about half of that induced by rIL2, and not inhibitable by anti‐IL 2 receptor antibodies. Higher concentrations of IL4 down‐regulated cell proliferation. In the course of IL4‐driven growth, the proliferating cells acquired sensitivitiy to the growth‐promoting effect of IL2. Activated CD4 or CD8 T cells were found to be equally sensitive to the IL4 and IL2‐driven growth pathway. Taken together, these results define a physiologic role of IL4 as growth factor during primary activation of resting CD8 T cells and thus extend the spectrum of target cells for IL4.
Chemiluminescence microscopy reveals functional heterogeneity in single neutrophils undergoing oxygen burst
Authors: Fritzsche Rainer , Weck Alain L.De
Published: March 2007

Activated polymorphonuclear leukocytes (PMN) respond to various triggers with an oxygen burst, during which the release of reactive oxygen species (ROS) plays a key role in microbial killing. The biological function of the ROS‐associated light emissions is not known. However, this particularly weak cell‐derived chemiluminescence (CL) may serve as a parameter for the identification of PMN activation. In this study we describe a novel technique which we termed CL microscopy. A microscope‐based low‐light image‐processing system was applied which was sensitive enough to detect single photons, capable of two‐dimensional signal accumulation, and digital image analysis.

This technique permitted, for the first time, the visualization of the oxygen burst in single cells. Furthermore, quantitative evaluation of cell‐derived luminol‐enhanced CL revealed functional heterogeneity. Single‐cell investigations of activated living PMN of normal human donors showed clear differences in kinetics and intensity of the oxygen burst related to different stimuli. The chemical agent (phorbol 12‐myristate 13‐acetate) induced CL in 83% of PMN. In contrast, the complement‐mediated phagocytic stimulation by opsonized zymosan gave much higher light intensities of individual cells, but only in part of the PMN population (30%). CL microscopy presents a new and highly sensitive technique with considerable potential for single‐cell analysis in immunological research.
Establishment of mouse thymic nurse cell clones from a spontaneous BALB/c thymic tumor
Authors: Itoh Tsunetoshi , Doi Hideyuki , Chin Shinshi , Nishimura Takashi , Kasahara Shigeru
Published: March 2007

This is the first report on the establishment of the readily identifiable and functioning thymic nurse cell (TNC) clones from the mouse thymus. In the course of the culture of an epithelial cell line using a medium with a low concentration of Ca2+ from the spontaneous BALB/c thymic tumor, lymphocytes as well as thymic stromal cells which were not apparently typical epithelial cells by light microscopy seemed to grow relatively well in one flask. The culture medium was exchanged with regular Dulbecco's modified Eagle's medium in the third week, and from that flask TNC clones were established together with lymphoblast cell clones. The established cells (IT‐79MTNC3) were easily identified as TNC. They formed complexes with simultaneously established lymphoblast cells and were remarkably similar to those of fresh TNC and thymocytes. Cloned TNC could express Ia antigens.

In co‐culture experiments, cloned TNC together with recombinant interleukin 2 (rIL 2) appeared to support the growth of fetal thymocytes which with rIL 2 alone failed to proliferate. The supernatant of IT‐79MTNC3 was previously found to contain the growth factor for some T cell clones. It remains to be solved whether the TNC affects fetal thymocytes through direct contact or secretes an active growth‐promoting factor. Experiments along this line are now in progress.
T and B cells have similar recirculation kinetics in sheep
Authors: Reynolds John D. , Chin Warren , Shmoorkoff Jeff
Published: March 2007

T and B cells continually migrate around the body by recirculating between blood and lymph via lymphoid tissues. This is an important way of fostering the cell‐cell interactions required for the initiation of an immune response. Data from previous studies of T and B cell recirculation, based on relatively complex approaches, have been interpreted as evidence that the recirculation of B cells is more sluggish than for T cells. We have shown from a study in sheep that this is not the case. Lymphocyte migration through both the intestine and the prescapular lymph node was analyzed by cannulating efferent lymphatics. The lymph cells were labeled in vitro with Hoechst 33342, or other fluorochromes, then injected i.v., and the rate of their recirculation into the lymph was determined by fluorescence microscopy. A multicolor immunofluorescence assay was used to classify each recirculated cell as either a T or B cell. This established that the T and B cells from intestinal lymph and from prescapular lymph recirculate with similar kinetics. The recovery of i.v. injected T and B cells was the same in prescapular lymph, but fewer injected B cells than T cells were recovered in intestinal lymph. Thus, although the recirculation kinetics are the same for T and B cells, the two populations are handled differently in intestinal tissues and a lymph node remote from the gut.
“Radioresistant” intrathymic T cell precursors express T cell receptor Cγ4‐ and Cδ‐specific gene messages
Authors: Kishihara Kenji , Yoshikai Yasunobu , Matsuzaki Goro , Tomooka Suguru , Nomoto Kikuo
Published: March 2007

We have studied the expression and sequences of T cell receptor γ and δ chain gene messages in intrathymic T cell precursors of mice irradiated with 600 rads. On day 7 after irradiation a high level of expression of γ and δ chain messages was detected in thymocytes which were composed of a relatively high proportion of CD3+CD4−CD8‐thymocytes. During further development of the precursors from day 7 to day 14 after irradiation, γ and δ chain messages fell to low levels and α and β mRNA levels increased. Nucleotide sequence analysis of 14 γ and 10 δ chain complementary DNA (cDNA) in the thymocytes on day 7 revealed that there were 7 functional γ chain transcripts composed of Vγ2‐Jγ2‐Cγ2 or Vγ1‐Jγ4‐gene segments, and only 1 functional δ chain transcript composed of the VδM23‐Dδ1‐Dδ2‐Jδl‐Cδ gene segments. The repertoire of γ chain and δ chain genes used in “radioresistant” intrathymic T cell precursors of adult mice appears to be limited.
Induction of T cell serine proteinase 1 (TSP‐1)‐specific mRNA in mouse T lymphocytes
Authors: Simon Hans‐Georg , Fruth Uli , Eckerskorn Christoph , Lottspeich Friedrich , Kramer Michael D. , Nerz Gabi , Simon Markus M.
Published: March 2007

An oligonucleotide probe corresponding to nucleotides of a cDNA encoding the T cell‐associated proteinase 1 (TSP‐1) was chosen to study the induction and expression of TSP‐1‐specific transcripts in mouse T lymphocytes and tissues. We demonstrate that TSP‐1 mRNA is only expressed in activated T lymphocytes and is absent from all mouse tissues tested including those containing resting mature T lymphocytes. Expression of the TSP‐1 gene was observed in T lymphoctes in vitro in response to either phorbolester (phorbol 12‐myristate 13‐acetate), Ca2+ ionophore (A23187), lectin or alloantigen. In general, TSP‐1 mRNA appeared and peaked later compared to interleukin 2 transcripts. Furthermore, TSP‐1 mRNA was inducible in vitro in both Ly‐2+ and L3T4+ lymphocyte populations treated with alloantigen and/or lectin. The transcription of the TSP‐1 gene was always accompanied by the expression of proteinase activity. High expression of TSP‐1 transcripts was also observed in in vivo derived T effector cells specific for lymphocytic choriomeningitis virus. However, TSP‐1 mRNA was predominantly associated with virus‐specific Ly‐2+ T cells and correlated with their proteinase and cytolytic activities. The data suggest that TSP‐1 gene transcription is a useful marker to characterize T effector cells in vitro and in vivo.
Stromal cell lines which support lymphocyte growth: characterization, sensitivity to radiation and responsiveness to growth factors
Authors: Pietrangeli Carolynn E. , Hayashi Shin‐Ichi , Kincade Paul W.
Published: March 2007

Stromal cells which grow as an adherent layer of Whitlock‐Witte cultures are thought to be an essential component of the lymphohemopoietic microenvironment. Stromal cell lines from bone marrow (BM) and spleen have been obtained by treatment of cultures with 5fluorouracil and selected for their lymphocyte support capacity by measuring the clonal growth of stromal cell‐dependent lymphocyte lines in methyl cellulose.

Established stromal cell lines differed significantly from stromal cells in primary Whitlock‐Witte cultures with respect to expression of certain hemopoietic cell surface markers. For example, the Thy‐1 and Mac3 antigens were expressed by stromal cell lines obtained from BM and spleen, but not by stromal cells in primary cultures. Features common to all stromal cells include synthesis of actins, the neural adhesion molecule N‐CAM, and a variety of collagens. Two types of common leukocyte antigens were not significantly expressed.

The proliferation and total protein synthetic capacity of lymphocyte‐supportive stromal cell lines was sensitive to ionizing radiation. After exposure of the cells to 200 rads, the incorporation of either [3H]thymidine or [3H]Leucine was reduced to less than 50% of control values, but the growth of lymphocytes was augmented in the presence of an irradiated stromal cell layer.

The proliferation of stromal cell lines was also affected by exposure to a variety of growth factors. Addition of epidermal growth factor or endothelial cell growth factor augmented BM or spleen‐derived stromal cell proliferation, while interferon‐γ had the opposite effect. In general, but not exclusively, lymphocyte growth was inhibited by factors which augmented the proliferation of stromal cells.

Novel methods are described for isolating stromal cells and determining their capacity to support lymphocyte growth in vitro. Evidence is presented that this ability is not restricted to BM‐derived stromal cells. The function of stromal cells was not dependent on their ability to proliferate, and this may be modulated by immunoregulatory and other growth factors.
Complex regulation of the T cell receptor α gene: three different modes of triggering induction
Authors: Wilkinson Miles F. , Macleod Carol L.
Published: March 2007

The T cell receptor (TcR) for antigen is composed of variable α and β subunits in noncovalent association with the invariant T3 multimer. TcR/T3 transcripts accumulate in a specific sequence during T cell development; TcR α transcripts are the last in the series to accumulate. To explore the regulation of TcR α gene expression, we investigated a T lymphoma cell clone which constitutively expresses TcR β, T3 † and T3 e mRNA, but essentially lacks detectable TcR α mRNA. The cell clone can be induced to accumulate substantial amounts of TcR α mRNA in response to phorbol myristate acetate (PMA) or calcium ionophore A23187. Two different protein synthesis inhibitors also induce TcR α mRNA. The following evidence indicates that PMA, A23187 and cycloheximide induce TcR α by different mechanisms: (a) treatment with a combination of two agents induces greater than additive amounts of TcR a mRNA than that induced by a single agent; (b) the immunosuppresent cyclosporin A specifically inhibits A23187‐mediated TcR α mRNA induction, whereas it fails to inhibit PMA or cycloheximide‐mediated induction; and (c) both A23187 and PMA increase the rate of TcR α gene transcription, while cycloheximide influences TcR α mRNA accumulation by post‐transcriptional mechanisms.
Functional differentiation and repertoire diversification of T cells derived from single progenitor cells
Authors: Kina Tatsuo , Amagai Takashi , Nishikawa Shin‐Ichi , Araya Shin‐Ichi , Katsura Yoshimoto
Published: March 2007

Functions of T cells derived from single progenitor cells were investigated. B10. Thy‐1.1 recipient mice were either whole body‐irradiated and marrow reconstituted or thymus‐shielded, irradiated and marrow reconstituted, and limited numbers (3 × 103 or 6 × 103) of a 1:1 mixture of bone marrow cells from C57BL/6 and B6.Lyt‐2.1 mice were transferred intrathymically (i.t.). Donor‐type (Thy‐1.2+) cells of the thymus of a small portion of recipients which expressed the phenotype of either Ly‐2.2 or Ly‐2.1 but not both were regarded to be a clone of T cells derived from a single progenitor cell, and such clones were assayed for polyclonal helper (Th) and polyclonal cytolytic (CTL) activities as well as alloantigen‐specific proliferative (mixed lymphocyte reaction; MLR) and CTL activities. Clones taken 4 weeks after transfer (4‐week‐old clones) which were generated in the thymus of whole body‐irradiated recipients showed polyclonal CTL but not polyclonal Th activity, whereas 4‐week‐old clones generated in the thymus of thymus‐shielded recipients showed both polyclonal CTL and Th activities. Similarly, 4‐week‐old clones generated in whole body‐irradiated recipients responded with CTL to alloantigens when induced in the presence of T cell growth factors but not with MLR, whereas 4‐week‐old clones generated in thymus‐shielded recipients showed both MLR and CTL to alloantigens. Repertoire difersifi‐cation of 4‐week‐old clones, however, was incomplete, since clones generated in whole body‐irradiated recipient did not necessarily respond with CTL to all alloantigens examined, and those generated in thymus‐shielded recipients did not necessarily respond with MLR to all the antigens. On the other hand, T cell clones were shown to fully mature by 7 weeks after transfer in terms of cell function as well as repertoire diversification.
The Y chromosome from autoimmune BXSB/MpJ mice induces a lupus‐like syndrome in (NZW × C57BL/6)F1 male mice, but not in C57BL/6 male mice
Authors: Izui Shozo , Higaki Megumu , Morrow Dwight , Merino Ramon
Published: March 2007

The Y chromosome of the BXSB mouse has been shown to be responsible for the acceleration of lupus‐like autoimmune syndrome in inbred BXSB mice and in their F1 hybrids with NZB or NZW mice. To further define the role of this as yet unidentified gene linked to the BXSB Y chromosome, designated Yaa (Y chromosome‐linked autoimmune acceleration), the Y chromosome was transferred from the BXSB strain to nonautoimmune C57BL/6 (B6) mice. The effect of the Yaa gene on the autoanti‐body formation and the development of glomerulonephritis was investigated in B6 mice and in their F1 hybrids with NZW mice. The presence of the BXSB Y chromosome was not able to induce significant autoimmune responses in B6 mice. However, (NZW × B6)F1 males bearing the BXSB Y chromosome developed a severe lupus‐like autoimmune syndrome, as documented by the production of anti‐DNA antibodies and gp70‐anti‐gp70 immune complexes and the development of lethal lupus nephritis. Both sexes of (NZW × B6)F1 hybrids without the BXSB Y chromosome were essentially normal. Our results suggest that (a) the BXSB Y chromosome by itself is not sufficient to initiate autoimmune responses in nonautoimmune B6 mice, and (b) it is able to induce autoimmune responses in mice potentially capable of developing the disease, but whose autosomal abnormality by itself is not sufficient to develop autoimmune diseases.
Specific lysis by CD8+ T cells of Schwann cells expressing Mycobacterium leprae antigens
Authors: Steinhoff Ulrich , Kaufmann Stefan H. E.
Published: March 2007

In vitro cultured murine Schwann cells which were devoid of class I and class II gene products of the major histocompatibility complex expressed class I, though not class 11, antigens after stimulation with recombinant interferon‐γ. Recombinant 1FN‐γ‐stimulated Schwann cells after priming with M. leprue were lysed by antigen‐specific CD8+ T lymphocytes in vitro. These findings suggest that specific lysis of M. leprae‐infected Schwann cells by CD8+CTL plays a role in leprosy.
Human immune response to allergens of house dust mite, Dermatophagoides pteronyssinus
Authors: Saint‐Remy Jean‐Marie R. , Lebecque Serge J. , Lebrun Philippe M. , Jacquemin Marc G.
Published: March 2007

From the serum of 10 allergic subjects we have prepared IgG antibodies recognizing idiotopes carried by specific antibodies to Dermatophagoides pteronyssinus (Dpt) allergens, and studied cross‐reactivity of anti‐Dpt IgG bystander and antigen‐binding site‐associated idiotopes by latex agglutination assays. Idiotopes of specific anti‐Dpt IgE were evaluated by radioimmunoassays. Depending on the assay, a binding or inhibition of more than 50%, as compared to the reactivity of specific antibodies with the corresponding anti‐idiotypic (anti‐Id) IgG, was considered significant. Cross‐reactivity of antigen‐binding site‐associated idiotopes attained a mean proportion of 6/10 for IgG and 9.6/10 for IgE. By contrast, bystander idiotopes cross‐reacted only occasionally with a mean proportion of 2/10 for both IgG and IgE antibodies. Anti‐Id antibodies from two subjects have been isolated by adsorption on insolubilized anti‐Dpt antibodies of the corresponding patient. Using this purified material we have confirmed that (a) the majority of anti‐Id antibodies carry an “internal image” of the initial antigen and compete in a dose‐dependent manner with Dpt allergens for the binding to the anti‐Dpt antibodies and (b) paratope‐associated idiotopes of anti‐Dpt antibodies are shared by unrelated individuals.
Structure and rearrangement of the T cell receptor J alpha locus in T cells and leukemic T cell lines
Authors: Champagne Eric , Sagman Uri , Biondi Andrea , Lewis William H. , Mak Tak W. , Minden Mark D.
Published: March 2007

The vast majority of T cells express an antigen receptor (TcR) composed of an α/β heterodimer. The α and β chains are encoded for by a set of variable (V), joining (J) and constant (C) region genes. Unlike the J genes of the β chain which are limited in number and are clustered close to the constant region, the Jα, genes are spread over an 85‐kilobase DNA region, upstream of the C, gene. We have isolated the complete J, locus, bounded on the 5' side by the C sequence of the 6 gene and on the 3' side by the C sequence of the a gene. The experiments described here demonstrate that the J gene segments extend 75 kb 5' of Cα, and participate equally in generating the diversity of the a chain in peripheral T cells. Similarly, in leukemic T cell lines, rearrangements occurred over the entire locus and involved both alleles. Densitometry data suggest that in most peripheral T cells both alleles also are rearranged; thus, allelic exclusion in the α locus does not occur at the level of rearrangement. In three cell lines, an rearrangement has occurred on one allele in a region located 10 kb from the 5' end of the locus.
Functional T cell receptor δ chain gene messages in athymic nude mice
Authors: Yoshikai Yasunobu , Matsuzaki Goro , Takeda Yasuyuki , Ohga Shouichi , Kishihara Kenji , Yuuki Hiroyuki , Nomoto Kikuo
Published: March 2007

The rearrangement and expression of T cell antigen receptor (TcR) δ chain genes were investigated in congenitally athymic nude mice. The lymphoid cells derived from nude mice showed evidence of rearranged δ chain genes and a relatively high level of δ chain gene messages. Nucleotide sequence analysis revealed that nude mice contained an in‐frame δ chain transcript, composed of Vδ5‐Dδ1‐Dδ2‐Jδ1‐Cδ genes in the spleen. We have previously described functionally rearranged TcR γchain genes in the spleen of nude mice. Taken together, T cell precursors appear to proliferate and differentiate along the extrathymic pathway into TcR γ/δ‐bearing T cells in nude mice.
Profiles of lymphokine activities and helper function for IgE in human T cell clones
Authors: Maggi Enrico , Prete Gianfranco Del , Macchia Donatella , Parronchi Paola , Tiri Antonio , Chrétien Isabelle , Ricci Mario , Romagnani Sergio
Published: March 2007

A large panel of phytohemagglutinin (PHA)‐induced T cell clones (690 in total), established from four different human lymphoid tissues (peripheral blood, tonsils, lymph nodes and spleens) by a high‐efficiency cloning technique, was characterized according to their pattern of lymphokine production. The majority of both CD4+ and CD8+clones from all lymphoid tissues produced interleukin (IL) 2 and/or interferon (1FN)‐γ response to 24‐h stimulation with PHA. In contrast, higher proportions of IL4‐producing clones were found among CD4+clones from tonsils and spleens than from peripheral blood and lymph nodes, whereas only a minority of CD8+ clones from all lymphoid tissues were found to produce IL4.

It was not possible to divide the CD4+ (helper/inducer) clones on the basis of their pattern of lymphokine activity into two clear‐cut groups analogous to Thl and Th2 helper clones described in mice. Although 21 out of 503 (4%) CD4+ T cell clones produced IL4, but not IFN‐γ or IL2, and 208 (41%) produced IL2 and/or IFN‐γ, but not IL4, a total number of 185 (37%) CD4+ clones showed the ability to produce IL4 plus IL2 and/or IFN‐γ.

All types of CD4+ T cells (as classified according to their pattern of lymphokine activity) provided help for IgG production in allogeneic B cells. In contrast, helper function for IgE was detectable only among the IL4‐producing clones. However, the proportion of CD4+ clones providing help for IgE synthesis was significantly lower among those producing IL4 and IFN‐γ or IL4, IL2 and IFN‐γ than among those producing IL4 alone or IL4 and IL2.

Thus, a clear‐cut dichotomy between IL4‐ and IFN‐γ‐producing Th cells, as found in mice, does not seem to exist in humans. However, IL4 and IFN‐γ, even if not always produced by distinct T cell subsets, appear to regulate reciprocally the synthesis of IgE in humans as well.
Definition of the RFLP alleles in the human immunoglobulin IGHG gene locus
Authors: Ghanem Nada , Lefranc Marie‐Paule , Lefranc Gerard
Published: March 2007

In order to define more precisely the polymorphism of the human immunoglobulin IGHG (Cγ) genes and, consequently, to understand the structure and evolution of this multigene family, we have investigated the Restriction Fragment Length Polymorphisms (RFLP) of the IGHG genes in 113 unrelated individuals and 18 families. Using the restriction enzymes Bam HI, Sac I and Eco RI, and hybridization to a IGHG probe and to a specific IGHG3 (Cγ3) probe, we describe 47 different restriction fragments (RF) in the IGHG locus, allowing us to define at least 15 RFLP alleles for the different IGHG genes. Our data demonstrate that the restriction fragment length polymorphism is occasionally due to the presence or absence of a given restriction site as a consequence of a point mutation, such as the creation of an Eco RI site, at the codon 3 of exon 2 in one IGHG4 allele (IGHG4*D2). However, most of the RFLP we observed seem to result from the insertion or deletion of a few hundred base pairs as illustrated by the IGHG3 polymorphism.
Interleukin 4 instructs uncommitted B lymphocytes to switch to IgGl and IgE
Authors: Bergstedt‐Lindqvist Susanne , Moon Hee‐Bom , Persson Ulla , Möller Göran , Heusser Christoph , Severinson Eva
Published: March 2007

Mouse interleukin 4 (IL4) is a T cell‐produced lymphokine with multiple effects on different cells types of the hematopoietic lineages. IL4 has pronounced effects on B lymphocytes, where it induces high levels of IgGl and IgE secretion in lipopolysaccharide‐stimulated cultures that would otherwise secrete predominantly IgG3 and IgG2b (of the non‐IgM isotypes). An important question is how IL4 exerts its effect. Two main possibilities exist: (a) IL4 instructs uncommitted B lymphocytes to IgGl and IgE production; (b) IL4 selects and expands an already precommitted B cell. In this study we show, by the use of limiting dilution analysis, that IL4 dramatically increases the precursor frequency of IgGl and IgE‐secreting cells with no significant effect on the clone size, clearly suggesting that IL4 instructs uncommitted B cells to switch to IgGl and IgE. The fraction of total Ig precursors that can switch to the two isotypes is furthermore high. The high precursor frequency for IgE obtained in the presence of IL4 further demonstrates that IL4 is an important modulator of IgE responses.
Autoantibody production is associated with polyclonal B cell activation in autoimmune mice which express the lpr or gld genes
Authors: Ishigatsubo Yoshiaki , Steinberg Alfred D. , Klinman Dennis M.
Published: March 2007

Systemic autoimmune disease in humans and mice is characterized by hypergamma‐globulinemia and abnormally high levels of serum autoantibodies. The presence of certain genes, such as the lpr and gld genes, induces otherwise normal mice to spontaneously develop systemic autoimmunity. To better understand the effect of these genes on the development hypergammaglobulinemia, we quantitated the absolute number of splenic B cells producing antibodies reactive with each of four autoantigens and two conventional antigens and compared this to the total number of Ig‐secreting spleen cells present in these mice. Whereas autoimmune mice had significantly greater numbers of autoantibody‐secreting spleen cells than normal mice, they also had significantly greater numbers producing antibodies of conventional specificity. When expressed as a proportion of the total repertoire, no bias towards autoantibody production was present when autoimmune lpr and gld animals were compared to their congenic nonautoimmune C57BL/6 and C3H/HeJ counterparts

We also examined the B cell repertoires of recombinant inbred mice derived by mating autoimmune NZB with normal NFS mice. Some recombinant inbred (RI) lines developed hypergammaglobulinemia and produced large quantities of autoantibody. While evidence for specific (auto) antigenic stimulation was present in some RI lines, hypergammaglobulinemia was commonly associated with polyclonal B cell activation in these autoimmune mice as well.
A requirement for the CD5 antigen in T cell activation
Authors: Mcateer Michael J. , Lagarde Anne‐Catherine , Georgiou Harry M. , Bellgrau Donald
Published: March 2007

Treatment of adult rats with a monoclonal antibody specific for the CD5 antigen led to a dramatic reduction in the number of CD5+ cells. However, a substantial number of T cells remained as assessed by other T cell‐specific antibodies. These CD5− T cells did not proliferate in response to alloantigen or mitogenic stimulation, did not generate cytotoxic T lymphocytes in vitro, and did not induce graft‐vs.‐host disease when injected into susceptible recipients in vivo. Re‐expression of the CD5 antigen occurred when CD5‐ T cells were placed in an environment devoid of the anti‐CD5 antibody. Re‐expression of the antigen was followed by return of the T cell proliferative responses.

While CD5− T cells could not proliferate in response to alloantigen they could produce interleukin 2 following a short pulse with the T cell mitogen concanavalin A. However, T cell proliferative or cytotoxic responses could not be rescued by the addition of an exogenous source of interleukin 2. We conclude that the CD5 antigen appears to be required for proliferation of resting T cells.
Division of human helper T cells into two sets on the basis of the induction of anti‐tumor cytotoxicity by phorbol ester and calcium ionophore
Authors: Pawelec Graham , Bush Friedrich , Reinhold Uwe , Rehbein Arnika , Balko Irene , Bühring Hans‐Jörg
Published: March 2007

Fourteen noncytotoxic human helper T cell clones were examined for autocrine proliferative responses and cytotoxicity to tumor cells after stimulation with 12‐0‐tet‐radecanoylphorbol 13‐acetate (TPA) and ionomycin (Io). Although all clones responded to alloantigen, they could be divided into two groups based on their proliferative response or lack of it to TPA/Io. Nonresponders could not be converted to responder status by addition of interleukin (IL) 1 or indomethacin to the cultures. Responder status did not correlate with any of the following properties of the clones: originating donor, recognitive specificity, B cell helper activity, proliferative response to IL2 or 4, lymphokine secretory capacity or density of expression of antigen receptors, CD4 or HLA class II molecules. Responder status did, however, correlate with the ability of TPA/Io to induce major histocompatibility complex‐unrestricted cytolytic activity directed towards natural killer‐resistant tumor cells. These results divide human helper cells into two types on the basis of induction of anti‐tumor cytotoxicity.