bluuebunny/crossref_metadata_2025 huggingface dataset:
A noncognate interaction with anti‐receptor antibody‐activated helper T cells induces small resting murine B cells to proliferate and to secrete antibody
Authors: Owens Trevor
Published: March 2007

Culture of small resting allogeneic B cells (of an irrelevant haplotype) with two clones of T helper (Th) cells that were activated by the F23.1 anti‐T cell receptor antibody led to the activation of B cells to proliferate and to secrete antibody. Th cell supernatants by themselves had no effect on resting B cells (even in the presence of intact F23.1 antibody), but could induce antibody secretion by anti‐Ig‐preactivated B cells. Both F23.1‐1 clones (E9.D4 and 4.35F2) and one F23.1‐ clone (D2.2) could synergize with supernatants from activated E9.D4 T cells to induce B cell activation. F(ab'), fragments of F23.1 induced E9.D4 to activate B cells as efficiently as intact F23.1, and B cell populations that had been incubated with F23.1 were not activated when cultured with E9.D4, although T cells recognized cell‐presented F23.1 and were weakly activated. Reduction of the density of F23.1 adsorbed to plastic resulted in weak T cell activation, and these T cells did not induce B cell responses. Haptenated B cell populations, although recognized by E9.D4, were not activated. Separation of T and B cells by a 0.4‐μm membrane prevented T‐dependent B cell activation, although Th cell‐derived B cell‐activating lymphokines would be assayed across these membranes. These results suggest a polyclonal noncognate B cell activation that depends on physical contact between B cells and activated T cells. The requirement for a cognate interaction of Th with B cells for the production and delivery of B help can therefore be overcome by activating Th cells with high densities of T cell receptor ligands.
Induction of the receptor for the Fc portion of IgA by secretory IgA on human T cell lines and T cell clones
Authors: Brière Francine , Paliard Xavier , Vries Jan E. De
Published: March 2007

Human colostral secretory IgA (SIgA; predominantly present in dimeric of polymeric forms) induces receptors for the Fc portion of IgA (FcαR) on cloned and noncloned human T cell lines. The binding of SIgA to its FcR was isotype specific, since it was not inhibited by IgG or IgM. Binding of SIgA was also not affected by ovalbumin or asialoglycoprotein. In addition, SIgA blocked the binding of directly fluorescein isothiocyanate‐labeled SIgA in a dose‐dependent fashion, whereas IgG and IgM were ineffective, confirming the specificity of the binding.

Expression of FcαR was specifically induced by SIgA, whereas serum IgA (predominantly present in monomeric form) had no effect. In addition, IgG, IgM and IgE were ineffective. This induction of FcαR by SIgA was dose dependent. Optimal induction was observed at concentrations of 500 μg/ml after incubation times of 48 h. FcαR were predominantly induced on T cell lines and T cell clones derived from tonsils. T cell lines and T cell clones established from peripheral blood could only occasionally be induced to express FcαR. Induction of FcαR expression was obtained both with CD4+ and CD8+ T cell clones. FcαR were readily induced on T cell clones tested up to 6 days after activation by alloantigen. T cell clones tested 10‐12 days after alloantigen activation failed to respond to SIgA. These results indicate that the inducibility of FcαR is related to the activation stage of the T cell clones.
In human monocytes a strong correlation exists between expression of the m3 antigen, fc‐mediated phagocytic activity and failure to participate in extracellular antibody‐dependent cytotoxicity
Authors: Gidlund Magnus , Rossi Paolo , Cotran Paul , Ramstedt Urban , Wigzell Hans
Published: March 2007

Human fresh blood monocytes can phagocytize and lyse antibody‐coated target cells by contact with membrane Fc receptors. Recently, the monocyte differentiation antigen Leu M3 has been described to be associated with monocytelmacrophage maturation pathway and to be linked to functionally distinct monocyte subsets. In the present study peripheral blood monocytes were separated into M3‐ and M3‐ subsets, and evaluated for their ability to mediate antibody‐driven effector functions. A clear cut functional difference could be demonstrated. M3' monocytes phagocytize antibody‐coated sheep red cells but do not carry out contact‐mediated extracellular lysis. In contrast, M3‐ monocytes have exactly the opposite functional features and they mediate cytolysis without exhibiting any phagocytic activity.

By using phenotypically defined clones of the U937 histiocytic cell line, the segregation of different lytic abilities and their linkage of the M3 phenotype have been confirmed.
Biochemical characterization and biological effects of partially purified b cell‐activating factor (bcaf)
Authors: Roth Claude , Moreau Jean‐Louis , Korner Marie , Jankovic Dragana , Thèze Jacques
Published: March 2007

B cell‐activating factor (BCAF) has been characterized and partially purified from the supernatant of the murine tumor T cell line 373. BCAF has an apparent molecular mass of 15 to 20 kDa when analyzed by Superose 12 fast protein liquid chromatography (FPLC) gel filtration and a PI of 4.5 to 5.0 when analyzed by FPLC chromatofocusing. Concentrated supernatant was applied to a nickel chelating column and unadsorbed active material was further purified by two sequential C4 reversephase high‐performance liquid chromatography steps. This purification procedure allowed a complete separation of interleukin 2 and interleukin 4 activities from BCAF. This partially purified BCAF induces Ia expression, cell size increase and proliferation of small resting B cells. Furthermore, we have shown that the activity of partially purified BCAF is insensitive to treatment by monoclonal antibodies specific for interleukin 4 and interleukin 5.
The glioblastoma‐derived t cell suppressor factor/ transforming growth factor‐β2 inhibits t cell growth without affecting the interaction of interleukin 2 with its receptor
Authors: Siepl Christine , Bodmer Stefan , Frel Karl , MacDonald H. Robson , Martin Rainer De , Hofer Erhard , Fontana Adriano
Published: March 2007

Human glioblastoma cells secrete a peptide termed glioblastoma‐derived T cell suppressor factor (G‐TsF) which inhibits T cell activation. Recently, purification and cloning of G‐TsF revealed that G‐TsF is identical to transforming growth factor‐β2. As shown here, G‐TsF suppresses the growth of an ovalbumin‐specific mouse T helper cell clone (OVA‐7 T) independently of the stimulus used being either (a) antigen in the presence of antigen‐presenting cells, or (b) interleukin 2 (IL2) or (c) phorbol ester and calcium ionophore. Furthermore, in the presence of antibodies against IL2 receptors, G‐TsF was able to suppress the residual proliferation still observed when OVA‐7 T were stimulated with phorbol esterhonophore. G‐TsF failed to inhibit the release of IL3 from OVA‐7 T activated with IL2. Taken together, the data provide evidence that G‐TsF does not directly interfere with interactions of IL2 with its receptor but rather inhibits T cell activation by interfering with an as yet unidentified pathway used by both IL2 and phorbol esterhonophore. When analyzing different monokines and lymphokines for its effect on G‐TsF‐induced suppression of T cell growth the only factor found to partially neutralize the effect of G‐TsF was tumor necrosis factor‐α.
Heterohybridomas secreting human monoclonal antibodies against haemophilus influenzae type b
Authors: Martin Denis , Larose Yolande , Hamel JoséE , Lagacé Jacqueline , Brodeur Bernard R.
Published: March 2007

Seven human monoclonal antibodies (HmAb) directed against outer membrane antigens of Haemophilus influenzae type b (Hib) were produced by fusing Sp2/HPT heteromyeloma cells with human tonsillar lymphocytes sensitized in vitro for 6 days. The heterohybridomas were maintained in culture for at least one year and secreted, when cultured in Dulbecco's modified Eagle's medium without fetal calf serum, between 1 and 15 μg/106 cells/m1/24 h. All of the HmAb were IgGs except HiH‐12 which is an IgM. Antibodies directed against the lipopolysaccharide and proteins of apparent molecular masses of 43, 37 and 27 kDa were identified by immunoblotting of sodium dodecyl sulfate‐polyacrylamide gel electrophoresis patterns of outer membrane. Binding radioimmunoassay with live bacteria showed that five out of seven HmAb adsorbed to cell surface‐exposed antigenic determinants. HmAb HiH‐6, HiH‐7 and HiH‐10 reacted with a surface‐accessible determinant on the 43‐kDa outer membrane protein. In a dot enzyme immunoassay, these HmAb recognized 103 out of 111 Hib strains isolated worldwide. The strains were selected to represent the most common genotypic variations among Hib. None of these HmAb reacted with other bacterial species tested. These HmAb may serve to study the bacterial surface antigens implicated in the human humoral response and protection to Hib infections.
Gene transfer of the ly‐3 chain gene of the mouse cd8 molecular complex: co‐transfer with the ly‐2 polypeptide gene results in detectable cell surface expression of the ly‐3 antigenic determinants
Authors: Blanc Dominique , Bron Claude , Gabert Jean , Letourneur FrançOis , MacDonald H. Robson , Malissen Bernard
Published: March 2007

The CD8 molecule is a glycoprotein expressed on a subset of mature T lymphocytes. It has been postulated to be a receptor for class I major histocompatibility complex molecules. In the mouse, CD8 is a heterodimer composed of Ly‐2 and Ly‐3 chains. We have isolated and analyzed cDNA and cosmid clones corresponding to the Ly‐3 subunit. One of the isolated, cosmid clones was subsequently transfected, alone or in combination with the Ly‐2 gene, into mouse Ltk− cells. Analysis of the Ly‐2,3 molecules expressed at the surface of the double transfectants indicated that they are serologically and biochemically indistinguishable from their normal counterparts expressed on lymphoid cells. Ltk− cells transfected with the Ly‐2 gene alone were shown to react with a subset of antLCD8 monoclonal antibodies whereas Ly‐3 transfectants did not stain with any of the anti‐Ly‐3 antibodies employed in this study. Since at least one of these antibodies (53‐5.8) has been previously shown to recognize an epitope which is retained on the Ly‐3 subunit after dissociation of the heterodimeric Ly‐2,3 complex, these observations suggest that the expression of the Ly‐2 polypeptide is required to permit the detectable cell surface expression of the antigenic determinants carried by the Ly‐3 subunit.
Selective stimulation of human t lymphocyte subsets by heteroconjugates of antibodies to the t cell receptor and to subset‐specific differentiation antigens
Authors: Emmrich Frank , Rieber Peter , Kurrle Roland , Eichmann Klaus
Published: March 2007

Ligand binding under conditions that generate microaggregates of the T cell receptor complex (Ti/CD3) with the membrane molecules CD4 or CD8 can induce activation of small resting T lymphocytes. We demonstrate this by using soluble dimeric heteroconjugates consisting of monoclonal antibodies to CD4/CD8 and of a novel anti‐CD3 monoclonal antibody (BMA 030) which even in aggregated form is not stimulatory on its own under limiting conditions in the absence of accessory cells. Using combinations of BMA 030 with either anti‐CD4 or anti‐CD8, the corresponding T cell sub‐population could be selectively expanded in vitro. Selective expansion of T cell sub‐populations in vitro or in vivo might be helpful for certain therapeutical manipulations. In addition, this finding may contribute to a better understanding of major histocompatibility complex‐restricted T cell activation.
At least five dh genes of human immunoglobulin heavy chains are encoded in 9‐kilobase dna fragments
Authors: Ichihara Yoshikazu , Abe Masumi , Yasui Hisashi , Matsuoka Hiroshi , Kurosawa Yoshikazu
Published: March 2007

The variable region of immunoglobulin (Ig) heavy chain is encoded by three separate genes: variable (VH), diversity (DH) and joining (JH) genes on the germ‐line genome. In mice, most complementarity determining region (CDR) 111 of the heavy chains of myelomas and hybridomas sequenced so far can be assigned to one of the 12 already identified germ‐line DH genes by the homology of nucleotide sequences of DH gene‐coding regions although extranucleotides, the so‐called N segments, are found at the boundaries between DH and JH as well as VH and DH. On the other hand, Siebenlist et al. (Nature 1981. 294: 631) identified two DH gene families in human genome: DHQ52, located at 45 bp upstream of the JH gene cluster, and another family encoded at 9‐kb regular intervals possibly between VH and JH gene clusters. However, the somatic DH sequences found in VH‐DH‐JH structure (the somatic DH segment being defined as the region which is not encoded either by germ‐line VH or JH gene) are relatively long and apparently random, and do not seem to have the homology to any of the germ‐line DH sequences. To explain the origin of high diversity in the CDR III of human Ig heavy chains, Siebenlist et at. predicted the presence of another mechanism, namely DH‐DH joinings. In the present study, we identified five DH genes in one of the above 9‐kb repeats. This suggests that the total number of germ‐line DH genes is much higher in man than in mouse. The comparison between somatic DH sequences and germ‐line DH sequences indicates that most somatic DH sequences in human Ig heavy chains are also produced by VH‐DH and DH‐JH joinings without the joining of multiple DH gene segments.
Induction of rat acute‐phase proteins by interleukin 6 in vivo
Authors: Geiger Thomas , Andus Tilo , Klapproth Jan , Hirano Toshio , Kishimoto Tadamitsu , Heinrich Peter C.
Published: March 2007

Recombinant human interleukin 6 (rhIL 6) was injected i.p. into male Wistar rats to investigate its role as a mediator of the acute‐phase response. Hepatic mRNA levels of β‐fibrinogen, α2‐macroglobulin, cysteine proteinase inhibitor, α1‐acid glycoprotein and albumin were measured at different times after the administration of rhIL 6. Maximal increases of mRNA concentrations were observed already 4 h after the injection of rhIL 6 leading to 4.8‐, 19.7‐, 10‐ and 16‐fold stimulations in mRNA levels of β‐fibrinogen, α2‐macroglobulin, cysteine proteinase inhibitor or α1 acid glycoprotein, respectively.

The rhIL 6‐induced stimulation of acute‐phase protein mRNA was much more rapid than the acute‐phase induction after turpentine, where maximal mRNA levels were found between 16 and 24 h. For all acute‐phase proteins studied, the stimulation of mRNA synthesis was found to be dependent on the dose of rhIL 6 injected. In the case of α2‐macroglobulin mRNA a sex‐specific induction by rhIL 6 was found. Only male rats showed an acute‐phase response, whereas in female rats an acute‐phase reaction of α2‐macroglobulin mRNA was not inducible by IL 6.

The increases in mRNA levels of the acute‐phase proteins studied were followed by corresponding changes of the proteins in the serum determined by rocket immunoelectrophoresis. It is concluded that IL 6 represents a potent mediator of the acute‐phase response in the rat.
Expression and function of a CD 5 cDNA in human and murine T cells
Authors: Nishimura Yasuharu , Bierer Barbara E. , Jones William K. , Jones Nancy H. , Strominger Jack L. , Burakoff Steven J.
Published: March 2007

In order to define the function of the CD 5 (T1, Leu 1, Tp 67 in the human; Ly‐1 in the mouse) molecule, a cDNA clone of human CD 5 was expressed in a CD 5‐deficient Jurkat cell line and in a murine T cell hybridoma. A Jurkat subclone (Jurkat 9.9) produced interleukin 2 (IL 2) in response to anti‐CD 3 monoclonal antibody (mAb) cross‐linked to solid support. IL 2 production was enhanced by co‐culture with the anti‐CD 5 mAb OKT1. A CD 5‐deficient mutant clone Jurkat 1.15 was generated by treatment with ethyl methanesulfonate followed by selection with anti‐CD 5 mAb plus complement. Jurkat 1.15 did not demonstrate enhancement of IL 2 production by OKT1 in the presence of cross‐linked anti‐CD 3 mAb. A cDNA encoding human CD 5 was introduced into a defective retrovirus which was used to infect Jurkat 1.15. A Jurkat clone stably expressing CD 5 was established. In response to OKT1, a rise in intracellular calcium was observed in both the parent Jurkat 9.9 and the CD5− infectant but not in the CD5‐ mutant or a G418‐ resistant control. Furthermore, expression of CD 5 restored the augmentation of IL 2 production by OKT1 in response to cross‐linked anti‐CD 3 mAb. A murine T cell hybridoma By 155.16 which produces IL 2 in response to HLA‐DR antigens was also infected with the CD 5‐recombinant retrovirus and three stable CD5− infectants were generated. These hybridomas showed enhancement of IL 2 production by stimulation with OKT l in the presence of suboptimal concentrations of soluble anti‐murine CD 3 mAb. These results provide further evidence that CD 5 provides a co‐stimulatory signal for T cell activation.
Allele and locus‐specific differences in cell surface expression and the association of HLA class I heavy chain with β2‐microglobulin: differential effects of inhibition of glycosylation on class I subunit association
Authors: Neefjes Jacques J. , Ploegh Hidde L.
Published: March 2007

The assembly of HLA class I antigens, and the contribution of the single N‐linked glycan to this process were examined. We observed a requirement for N‐linked glycosylation in the proper assembly and surface expression of HLA‐B locus products in particular, although considerable variation was seen within the allelic series of the HLA‐A and B loci. We conclude that the single N‐linked glycan can contribute in a major way to that conformation of the heavy (H) chain which is competent to associate with the light chain β2‐microglobulin, and that the presence, rather than the type, of carbohydrate chain is important in this respect.

The association of human class IH chains with β2‐microglobulin shows biphasic kinetics, where an initially rapid phase is followed by a prolonged period during which no further association can be measured. It appears that HLA‐C H chains are initially synthesized in amounts similar to HLA‐A and B H chains, but associate inefficiently with β2‐microglobulin, resulting in low expression of HLA‐C at the cell surface. The individual stages of assembly and maturation of class I antigens including the transfer from Golgi to cell surface were found to display characteristic allelic variation.
Anti‐CD27 monoclonal antibodies identify two functionally distinct subpopulations within the CD4+ T cell subset
Authors: Lier René A. W.Van , Pool Marco Oudkerk , Kabel Peter , Mous Saskia , Terpstra Fokke , Rie Menno A.De , Melief Cornelis J. M. , Miedema Frank
Published: March 2007

Anti‐CD27 monoclonal antibodies react with a cell surface molecule expressed on medullary thymocytes and a large subpopulation (75%) of peripheral blood T lymphocytes. This study was undertaken to analyze the functional capacities of CD27− and CD27− subpopulations within the CD4+ subset. In addition, we investigated whether CD27 subpopulations belong to two mutually exclusive T cell sublineages. Proliferation upon lectin stimulation by either phytohemagglutinin or pokeweed mitogen (PWM) was found to be consistently higher in CD4+CD27− cells compared to CD4+CD27− cells. In contrast, CD27+ and CD27− cells did not differ in anti‐CD3, soluble antigen or interleukin (IL) 2‐induced proliferation. In PWM‐driven B cell differentiation, CD4+CD27+ cells provided helper activity on IgM production, while CD4+CD27− cells did not. The differences observed between CD4+CD27+ and CD4+CD27− cells in both proliferation and T helper activity on IgM production can, at least in part, be explained by the inadequate production of IL2 by CD27− cells upon lectin stimulation. In contrast, CD27+ and CD27− subpopulations did not differ in the production of interferon‐γ. CD27− cells could be induced to express the CD27 antigen through stimulation of these cells with immobilized anti‐CD3 antibodies. After 3 days of culture, approximately 50% of the cells had CD27 membrane expression, whereas after 6 days 80% of the cells express the antigen. We conclude that anti‐CD27 antibodies identify two functionally distinct T cell populations within the CD4+ subset. These subpopulations apparently do not belong to two separate T cell sub‐lineages, but may reflect differences in the activation state of CD27+ vs. CD27−peripheral blood T lymphocytes.
CD45R gives immunofluorescence and transduces signals on mouse T cells
Authors: Marvel Jacqueline , Mayer Anton
Published: March 2007

The expression of CD45R on mouse T cells has been studied. This antigen is expressed on the two higher molecular weight bands of CD45 (or T200) and in mouse it is currently used as a marker of B cells (B220). Here we confirm that CD45R is expressed on some mouse T cell clones. We show that a small but measurable proportion of mouse spleen and peripheral blood lymphocyte T cells gives positive immunofluorescence with B220. Also CD45R‐specific antibodies increase the proliferation response to phytohemagglutinin up to 3‐fold, thus confirming that CD45R molecules transduce a signal into mouse T cells.
T cell epitopes on the 36K and 65K Mycobacterium leprae antigens defined by human T cell clones
Authors: Schooten Wim C. A.Van , Ottenhoff Tom H. M. , Klatser Paul R. , Thole Jelle , Vries René R. P.De , Kolk Arend H. J.
Published: March 2007

To identify the molecular localization and specificity of Mycobacterium leprae antigenic determinants inducing T cell activation, we studied the reactivity of M. leprae‐reactive T cell clones from two tuberculoid leprosy patients towards a battery of different mycobacterial strains and purified mycobacterial antigens. Of the 38 T cell clones tested 8 appeared to be M. leprae specific (specificity A), another 8 were cross‐reactive with at least one of the three mycobacterial strains, M. lepraemurium, M. vaccae and M. scrofulaceum (specificity B), 5 were reactive with most but not all strains (specificity C) and the remaining 18 were reactive with all 17 mycobacterial strains tested (specificity D), but not with nonmycobacterial antigens. All T cell clones were tested with the 36K and 65K antigen isolated from M. leprae, and with the M. leprae and M. bovis BCG 65K proteins produced in E. coli by recombinant DNA. Four T cell clones appeared to recognize epitopes on the 36K antigen, nine T cell clones recognized the 65K antigen. These 2 M. leprae antigens, 36K and 65K, thus seem to contain major T cell epitopes. At least 3 different epitopes could be defined on the 36K antigen of which one is M. leprae specific, one of specificity B and one of specificity C. Two distinct epitopes were discerned on the 65K antigen of which one is M. leprae specific and one of specificity D. The M. leprae‐specific epitopes on the 36K and 65K antigen may help in the development of a specific serodiagnostic and skin test.
Quantification of the progenitors for thymic T cells in various organs
Authors: Katsura Yoshimoto , Kina Tatsuo , Takaoki Yuko , Nishikawa Shin‐Ichi
Published: March 2007

Partial characterization and frequency determination of the progenitors for thymic T cells in various organs were made b transferring cells directly into the thymus (intrathymically, i.t.). B0.Thy‐1.1 (H‐2b, Thy‐1.1) mice were used as the donor, and C57BL/6 (H‐2b, Thy‐1.2) mice that had been whole body irradiated with 800 rads and reconstituted with 107 syngeneic (B6) bone marrow (BM) cells were used as the recipient. BM cells, spleen cells and thymus cells from young adults and fetal liver cells (day 14 of gestation) were treated with anti‐Thy‐1.1 antibody plus complement, and trasferred i.t. The generation of Thy‐1.1+ donor type cells in the recipient's thymus was investigated by using flow cytometry. From the time course of generation, it was shown that the progenitor cells in the thymus were distinct from those in other organs. After the transfer of thymic non‐T cells, donor‐type cells began to generate on the 4th day, the proportion of donor‐type T cells increased quickly thereafter, and the progenitors in this organ ceased to produce T cells by day 21. On the other hand, a latent period of about 10 days was required for progenitor cells in the BM, spleen or fetal liver to generate T cells, and T cell producing‐activity of the progenitor cells in these organs lasted as long as 7 weeks.

The frequency of progenitor cells was analyzed by transferring serial dilutions of anti‐Thy‐1.1 plus complement‐treated cells i.t. and investigating the generation of donor‐type T cells in the recipient's thymus on day 11 in the case transferred with thymic cells and on day 21 in other cases. The proportion of negative recipients which did not contain detectable levels of donor‐type cells was plotted on a logarithmic scale against the number of cells transferred on a linear scale. The progenitor cell frequencies in BM, spleen, thymus and fetal liver were estimated to be 12.5 × 10−5, 6.25 × 10−5, 0.22 X10−5 and 0.14 × 10−5, respectively. The reliability of the frequency determination was supported by the finding that when a limited number (103) of a 1:1 mixture of BM cells from two mutually identifiable donors was transferred it., most of the recipients were negative for donor‐type T cells and 3 out of 4 positive recipients were seeded by progenitor cells of a single donor.
Nucleic acid‐binding specificity and idiotypic expression of canine anti‐DNA antibodies
Authors: Zouali Moncef , Migliorini Paola , Mackworth‐Young Charles G. , Stollar B.David
Published: March 2007

Serum samples collected from eleven lupus dogs during an active phase of the disease all bound native and denatured DNA, poly(dT), poly(I) and poly(G). Nine bound poly(C); 10 bound poly(U); and 3 bound poly(A). Sera from 22 normal dogs were negative with all of these antigens. The canine sera were also probed for the presence of three idiotypic markers, one related to human lupus anti‐DNA antibodies and two related to murine lupus antibodies. One canine lupus serum expressed idiotopes related to a murine anti‐DNA idiotype (Id) termed H130: (a) the canine serum bound to anti‐H130 anti‐Id; (b) it inhibited the binding of anti‐H130 Id to its homologous Id; and (c) the anti‐H130 Id inhibited the binding of the canine serum to DNA. These findings suggest that anti‐DNA variable regions exhibit interspecies similarities, probably reflecting the conservation of the encoding gene segments through evolution.
CD2 is involved in regulating cyclic AMP levels in T cells
Authors: Carrera Ana C. , Rincón Mercedes , Landázuri Manuel O.De , López‐Botet Miguel
Published: March 2007

The human T lymphocyte‐specific CD2 (T11) molecule, that regulates T cell activation, is capable of mediating increases of intracellular cAMP. Monoclonal antibodies directed to different epitopes of the CD2 molecule which either induce or inhibit T cell proliferation are capable of triggering an increase of cAMP comparable to that induced by reagents which activate adenylate cyclase. These results indicate that there is a relationship between the CD2 membrane molecule and the adenylate cyclase system.
Prediction and identification of an HLA‐DR‐restricted T cell determinant in the 19‐kDa protein of Mycobacteriurn tuberculosis
Authors: Lamb Jonathan R. , Rees Ann D. M. , Bal Vineeta , Ikeda Hitoshi , Wilkinson David , Vries Rene R. P.De , Rothbard Jonathan B.
Published: March 2007

An allele‐specific motif has been identified in the sequence of several peptides which are recognized by T cells in association with HLA‐DR1. In order to test the predictive values of such a motif we analyzed the 19‐kDa antigene from Mycobacterium tuberculosis and identified a sequence containing a pattern characteristic of DR1 restriction. Peripheral blood mononuclear leukocytes from every DR1 and 4 individual tested responded to the corresponding synthetic peptide. Nine other donors, constituting seven different DR alleles, failed to recognize this sequence. Recognition of the peptide in association with DR1 and DR4 was confirmed using T cell clones and transfected murine L cell lines expressing DR molecules.
Direct and indirect nickel‐specific stimulation of T lymphocytes from patients with allergic contact dermatitis to nickel
Authors: Kapsenberg Martien L. , Pouw‐Kraan Tineke Van Der , Stiekema Frank E. , Schootemeijer Annelies , Bos Jan D.
Published: March 2007

Fourteen T lymphocyte clones (TLC) specific for the contact allergen nickel were prepared either from lesional tissue biopsies or from peripheral blood of patients with allergic nickel‐contact dermatitis.Two nickel‐specific TLC, obtained from lesional tissue, responded to nickel without the participation of antigen‐presenting cells (APC). This direct stimulation by nickel was not restricted by major histocompatibility complex‐encoded molecules, since antibodies against HLA class I and I1 molecules did not block nickel‐specific proliferation. Proliferation of other nickel‐specific TLC was dependent on the presence of APC and was diversely restricted by HLA class I1 molecules. With one exception, the restriction determinants were present on HLA‐DR and HLA‐DQ molecules. Four TLC recognized nickel in association with subtypes of these serologically defined molecules. Five TLC seemed to recognize nickel in the context of highly unusual restriction determinants, since their restrictions could not be explained by the function of single polymorphic HLA class I1 epitopes. The absence of HLA class I1 restrictions and the occurrence of deviant HLA class I1 restrictions in part of the nickel‐specific TLC are suggested to result from direct interactions of nickel with critical immune response molecules.
Identification of individual tumor necrosis factor/ cachectin‐producing cells after lipopolysaccharide induction
Authors: Henter Jan‐Inge , Söder Olof , Andersson Ulf
Published: March 2007

A method to detect single tumor necrosis factor alpha (TNFα)‐producing cells, based on immunofluorescence staining, is presented. We have developed a rapid and simple procedure to permeabilize blood leukocytes for antibodies without causing cell aggregation. Using monoclonal as well as polyclonal TNFα‐specific antibodies cytoplasmic TNFα could be detected in lipopolysaccharide (LPS)‐stimulated monocytes in identical ways. In addition, one out of 15 tested fresh blood samples from healthy blood donors contained occasional TNFα‐producing cells. We found a well‐defined staining of the intracellular TNFα with a local, polar accumulation in a juxtanuclear position of the cell. This finding most probably indicated the presence of the monokine in the Golgi organelle because the sequential staining for TNFα and the Golgi zone by specific antibodies coincided. Thus, we believe the TNFα accumulation at this site reflects the production rather than cellular uptake of the cytokine, since the incubation of blood leukocytes with recombinant TNFα did not lead to any detectable staining.

By performing two‐color staining of cell surface antigens and cytoplasmic TNFα of LPS‐stimulated blood leukocytes we could demonstrate that monocytes exclusively contributed to the TNFα synthesis. At the peak of the response, which occurred 2–3 h after LPS exposure, 50–60% of the blood monocytes produced TNFα. We noted a rapid decline in the number of TNFα‐producing cells already 6 h after initiation of these cultures.
Production of granulocyte colony‐stimulating factor (G‐CSF) by human cells: T lymphocyte‐dependent and T lymphocyte‐independent release of G‐CSF by blood monocytes
Authors: Nioche Sophie , Tazi Abdellatif , Lecossier Denise , Hance Allan J.
Published: March 2007

To evaluate the production of granulocyte colony‐stimulating factor (G‐CSF) by human immune and inflammatory cells, an assay specifically measuring G‐CSF activity in the presence of other cytokines was developed which was based on the proliferation of 32Dcl cells induced by G‐CSF. Successful use of the 32Dcl cells to specifically measure G‐CSF activity required the selection of cells highly responsive to G‐CSF and with reduced responsiveness to interleukin 2 (IL2) by intennittant culture in medium containing G‐CSF. Furthermore, the addition of exogenous IL2 to standards and experimental samples was necessary to ensure that the concentration of IL2 was similar in all samples, since IL 2 directly stimulated the proliferation of 32Dcl cells and increased their responsiveness to G‐CSF. A variety of stimuli were found to induce G‐CSF release by blood monocytes. Lipopolysaccharide and monocyte adherence appeared to directly stimulate G‐CSF release, whereas stimulation of G‐CSF release from monocytes by mitogenic lectins required the presence of T lymphocytes. In all cases, release of G‐CSF was detectable as soon as 4 h after stimulation and was essentially complete after 48 h. These findings indicate that G‐CSF release can be initiated by a variety of pathways, and therefore suggest that the production of this mediator may occur in the course of many immune and inflammatory reactions.
Interleukin 1α acts as an autocrine growth factor for RPMI1788, an Epstein‐Barr virus‐transformed human B cell line
Authors: Vandenabeele Peter , Jayaram Bettadapura , Devos René , Shaw Alan , Fiers Walter
Published: March 2007

The Epstein‐Barr virus‐transformed B cell line RPMI 1788 constitutively produces autocrine growth factors with molecular masses of 17 kDa, 24 kDa and 35 kDa. All three molecular forms were completely neutralized with anti‐interleukin (IL) lα anti‐serum. Although IL1α and IL1β mRNA were both equally detectable by Northern blotting, no IL 1β activity was found in partially purified RPMI 1788 supernatant. The growth of low density‐seeded RPMI 1788 cells is specifically dependent on the presence of either IL1α or IL1β. Since no other cytokine was found to be capable of sustaining proliferation, this cell line is suitable for the identification and quantification of IL1, even in the presence of other cytokines.
Restriction fragment haplotypes in the human immunoglobulin IGHG locus and their correlation with the Gm polymorphism
Authors: Ghanem Nada , Dugoujon Jean‐Michel , Bensmana Mylène , Huck Sylvie , Lefranc Marie‐Paule , Lefranc GéRard
Published: March 2007

Of the four human IgG subclass heavy chain (IGHG) genes, three ‐ IGHG1, IGHG2 and IGHG3 ‐ have allelic forms which encode antigenic determinants called Glm, G2m and G3m allotypes for markers of the IgG1, IgG2 and IgG3 molecules. The alleles at these three closely linked loci are transmitted as Gm haplotypes, together with the IGHG4 and the TGHGP (or pseudo gamma) genes. Restriction Fragment Length Polymorphisms (RFLPs) have been described for all these IGHG genes, allowing us to define at least 15 RFLP alleles (N. Ghanem et al., Eur. J. Immunol. 1988.18:1059). In this article, we determine unambiguously the Gm alleles and haplotypes and the associated RFLPs in French, Lebanese and Tunisian families, chosen for the various Gm phenotypes of their members, in order to correlate both these polymorphisms and to know the evolution of the IGHG multigene family. We were able to assign all the IGHG alleles to the Gm alleles and to their linked IGHG4 and IGHGP genes allowing us to define restriction fragment haplotypes of the IGHG gene family.
Rearrangement and expression of T cell receptor and immunoglobulin loci in immortalized CD4−CDS−T cell lines
Authors: Primi Daniele , Clynes Raphael A. , Jouvin‐Marche Evelyne , Marolleau Jean‐Pierre , Barbier Eliane , Cazenave Pierre‐André , Marcu Kenneth B.
Published: March 2007

Injection of newborn mice with mixtures of wild‐type moloney murine leukemia (Mo‐MuLV) virus and other recombinant retroviruses harboring the myc oncogene alone or in combination with the H‐ras oncogene resulted in a 100% incidence of lymphatic leukemias from which permanent cell lines could be established in vitro. These cells are immunoglobulin (Ig)−, Thy‐1+BP− and CD8−CD4− indicating that they are early thymocytes. Such transformed pre‐T lines lack retroviral myc and ras genes but occasionally possess proviral insertion near to their endogenous myc and pim genes. We show that both Ig heavy chain (Igh) and T cell receptor (TcR) genes are rearranged in most of these lines. In some cases, a primary recombination was followed by a secondary rearrangement at the same locus. We show that VTγ genes can rearrange outside of their known cluster suggesting that TcRγ diversification in such pre‐T cells may be different to that in more mature T cells. Ig D‐JH recombinations may precede TcR gene recombination in these early T cell lines, and some but not all express sterile Cu transcripts. Some of these lines express surface heterodimers that appear composed of α and β chains that can be immunoprecipitated with a monoclonal anti‐T3 antibody but not with the anti‐Vβ8 monoclonal antibody F23.1. This established pre‐T cell line represents novel biological material for the dissection of T cell development and function analogous to A‐MuLV transformed pre‐B cells.
Activation signals via CD2 molecule and interleukin 2 receptor act in synergy for helper function induction
Authors: Hu Jian , Vaquero Catherine , Bismuth Georges , Eljaafari Assia , Bernard Alain , Levy Jean Paul , Sterkers Ghyslaine
Published: March 2007

The membrane CD2 molecule appears to play an important role in T cell activation. Indeed, T cell stimulation by some combinations of anti‐CD2 monoclonal antibodies (mAb) can result in antigen‐independent expression of helper function as assessed by proliferation and lymphokine secretion. We report here that T cell stimulation by a combination of two anti‐CD2 mAb recognizing GT2 and T111 epitopes, respectively, cannot alone induce T helper clones to proliferate when preincubated in culture medium devoid of exogenous interleukin 2 (IL2). The concerted action of both anti‐GT2 + T111 mAb and exogenous recombinant IL2 is required to induce cloned helper T cells to produce IL 2 and interferon‐γ to significantly increase IL 2 receptors (IL2R) and finally to divide by an autocrine mechanism, whereas each signal alone has no effect. This therefore suggests that, under some conditions of CD2 stimulation, two minimal signals may be delivered through CD2 and IL 2R and act synergistically to achieve a complete expression of T helper cell functions. Moreover, analysis of phosphatidylinositol and phosphatidic acid metabolic changes mediated by each signal separately or together suggests that, in this model, IL2 increases the phosphoinositid turnover induced by anti‐CD2 antibodies up to a level required for helper function acquisition.
Tolerance in rats by transplacental transfer of Dipetalonema viteae microfilariae: recognition of putative tolerogen(s) by antibodies that inhibit antigen‐Specific lymphocyte proliferation
Authors: Haque Azizul , Cuna Washington , Pestel Joel , Capron André , Bonnel Bernadette
Published: March 2007

We have previously reported (Nature 1982. 299: 361) that the transplacental transfer of Dipetalonema viteae microfilariae (mf) can induce an antigen‐specific tolerance in rats. Rats thus tolerized have serum factor(s) which block(s) antigen‐specific lymphocyte proliferation. The results of experiments involving fractionation of antisera from tolerant animals indicate that the inhibitory activity for antigen‐specific blastogenesis resides in IgG antibodies. Absorption of IgG (eluted from protein A) with specific filarial antigens reduced the inhibition from 58% to 9% whereas a similar immunosorption of IgG size fraction (obtained by applying to AcA 34 Ultrogel) resulted in a decrease from 72% to 35%. This suggests that IgG size fraction might include factor(s) derived from mf and was partially blocking the blastogenic response. Since the tolerant animals harbor only mf, we have used radiolabeled mf surface antigens for immunoprecipitation by antisera from tolerant animals. Antibodies from tolerant animals have a different specificity for filarial antigens compared to those from immunocompetent and mf‐resistant rats.
Two subsets of human CD4+T helper cells differing in kinetics and capacities to produce interleukin 2 and interferon‐γ can be defined by the Leu‐18 and UCHLl monoclonal antibodies
Authors: Dohlsten Mikael , Hedlund Gunnar , Sjögren Hans‐Olov , Carlsson Roland
Published: March 2007

Human CD4T helper cells were separated into CD4+45R+and CD4+45R− cells. When stimulated with the polyclonal activator staphylococcal enterotoxin A in the presence of autologous monocytes, these two subsets exhibited a striking difference in production of interleukin 2 (IL2) and interferon‐gamma (IFN‐γ). While the CD4+45R_ subset produced maximal amounts of IL2 within 24 h and IFN‐γ within 72 h, the CD4+45R+ subset produced no IL2 within 24 h and merely marginal amounts of IFN‐γ as assayed after 24 to 96 h. This discrepancy between the subsets was found when the cells were stimulated by other accessory cell‐dependent activators and by the accessory‐independent combination of the calcium ionophore A23187 and the phorbol ester 12‐O‐tetradecanoylphorbol 13‐acetate as well. The inability of the CD4′+45R− cells to produce IL2 during the first day of culture was not due to any modulation of either the CD4+or the CD45R antigens, as purified CD4+45R− cells obtained by negative panning selection with the reciprocal UCHLl monoclonal antibody responded in a similar manner as the positively selected sorted CD4+45R− cells. Analysis of the kinetics of IL2 production by the two T helper cell subsets clearly demonstrated that the IL2 recorded after 1 day of culture was entirely produced by the CD4+45R− cells, whereas the CD4+45R− cells produced IL2 during and after the second day of culture. This discrepancy in kinetics was not due to an increased absorption of IL2 by the CD4+45R− cells during the first day of culture. In contrast, the rate of absorption of IL2 during the first and second day of culture and the expression of IL2 receptors were higher in the CD4+45R− than in the CD4+45R− cell cultures. Despite these findings the CD4+45R− cells consistently showed a stronger proliferative response than the other cell subset. Addition of recombinant IL 2 (rIL 2) did not render the CD4′45R′ cells capable of producing IFN‐γ, but small amounts of RIL2 enhanced their proliferative response more efficiently than that of the CD4+45R− cells. Addition of anti‐Tac resulted in a reduction of IFN‐y production and of DNA synthesis by the CD4+45R− cells. Similarly the DNA synthesis and the small amounts of IFNγ produced by activated CD4+45R− cells were inhibited by anti‐Tac.
The required interaction between monocytes and peripheral blood T lymphocytes (T‐PBL) upon activation via CD2 or CD3. Role of HLA class I molecules from accessory cells and the differential response of T‐PBL subsets
Authors: Huet StéPhane , Bournsell Laurence , Dausset Jean , Degos Laurent , Bernard Alain
Published: March 2007

Previously, we have shown that paraformaldehyde‐fixed monocytes are able to fully complement, in terms of [3H]dThd incorporation, a primary stimulus delivered to purified T cells by monoclonal antibodies (mAb) reacting with CD3 or CD2 molecules. Here, we show that depending on the stimulus used (CD3 mAb or different pairs of CD2 mAb) HLA class I molecules from monocytes are directly involved in complementary signals provided to T cells. This was evidenced by the following observations: (a) mAb reacting with the heavy or light chain of class I molecules, or their Fab fragments, completely blocked proliferation of peripheral blood lymphocytes (PBL) activated by CD3 mAb; (b) mAb against the heavy chain of HLA class I but not against p2‐microglobulin partially blocked (= 50%) PBL activation by the CD2 "GT2 + T1l1" mAb pair but did not block activation by CD2 "D66 + T111" mAb; (c) this pattern of inhibition was observed when anti‐class I mAb were used in the soluble phase or when they were bound to monocytes subsequently fixed with paraformaldehyde and cultivated with purified autologous T cells; (d) fixed monocytes are able to restore interleukin (IL) 2 receptor expression on purified T cells stimulated by CD3 mAb or CD2 "GT2 + T111 contrary to anti‐HLA class I mAb‐pretreated monocytes. The inhibitory effects of anti‐HLA class I mAb bound to monocytes were not found to be reversed by recombinant IL2 or recombinant IL1. We assume that HLA class I would be involved in two or more signals delivered to T cells by monocytes, the requirement in those signals depending on the initial stimulus applied to T cells. Transmission of one signal would require a conformation of the HLA molecule inhibitable by both or either anti‐heavy and anti‐light chain mAb. In searching for the counterpart to the accessory cell HLA class I molecule, we found that both CD4+ and CD8+ cells responded to stimulation via CD2 or CD3 mAb. However, within the CD4 subsets, the CD4+w29− subset did not respond while the reciprocal subset did. This was not due to a lack of IL2, as shown by adding rIL2. Since the CD4+w29− subset is committed to the induction of suppression while the reciprocal subset to the induction of help, one can forsee how the immune response could develop in one direction or the other depending on the type of interaction that occurs during T cell activation.
Molecular mechanisms underlying lymphocyte recirculation I. Functional, phenotypical and morphological characterization of high endothelial cells culturedin vitro
Authors: Ise Yayoi , Yamaguchi Kazuhito , Sato Koei , Yamamura Yasuko , Kitamura Fujiko , Tamatani Takuya , Miyasaka Masayuki
Published: March 2007

Large‐scale extravasation of lymphocytes takes place in vivo under physiological conditions in lymph nodes at very specialized vascular segments called high endothelial venules (HEV). When circulating lymphocytes leave the blood, they first bind to endothelial cells of HEV (HE cells) and subsequently enter lymph nodes by crossing the endothelial lining of HEV. Although the lymphocyte‐HEV interaction has recently been the subject of intense research by many laboratories, it has been studied almost exclusively by the use of the lymphocyte‐binding assay in which lymphocyte binding is examined on nonviable HEV present on frozen sections and, hence, no dynamic interaction between HE cells and lymphocytes has been studied. We report herein that endothelial cells of rat HEV can be grown in vitro and that the lymphocyte‐HEV interaction can be studied dynamically using viable cells in culture vessels. The identification of the cultured line, termed Ax, as HE cells was based on their phenotypic, morphological, cytochemical and biochemical characteristics, and most importantly on its in vitro behavior, particularly in terms of its specific ability to interact with mature lymphocytes. Phenotypic analysis demonstrated that not only did monoclonal antibodies, known to react with HE cells, recognize the Ax but also a monoclonal antibody raised against the Ax specifically recognized HE cells in vivo, as determined by an immunoperoxidase staining of frozen sections, supporting the notion that the cell strain, Ax, is derived from HEV. This Ax, even after long‐term culture (>50 passages), allowed mature, but not immature, lymphocytes to bind to the cell surface and subsequently transport bound cells underneath their cytoplasm. This phenomenon was inhibited in a dose‐dependent manner by various reagents known to inhibit lymphocyte recirculation in vivo. The cultured line derived from HE cells should provide a means to investigate the biochemical nature of lymphocyte‐HEV interaction, and to understand the molecular mechanisms underlying the large‐scale lymphocyte traffic taking place in vivo.