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J Thèze

Publications and source records attributed to J Thèze.

At least 19 recordsLinked to original sources
PubMed1995

Control of the IL-2 responsiveness of B lymphocytes by IL-2 and IL-4.

A two-step culture system was used to analyze the parameters involved in the acquisition of IL-2 responsiveness by murine B cells. In the first culture, unstimulated, or resting, B cells prepared from spleen of naive animals were challenged during 48 h with IL-2, IL-4, anti-mu, anti-mu+IL-2, anti-mu+IL4, or anti-mu+IL-2 + IL-4. In a second culture, IL-2 responsiveness was followed by measuring either the cell proliferation or the Ig production. It was found that only B cells stimulated by anti-mu+IL-2 were able to respond. The expression of three chains of the IL-2 receptor (IL-2R alpha, IL-2R beta, and IL-2R gamma) was studied by FACS. IL-2R beta and IL-2R gamma were found to be expressed constitutively on resting B cells. IL-2R alpha was induced by anti-mu and anti-mu+IL-2 treatment. Although B cells treated by anti-mu alone are not able to respond to IL-2, they do express an IL-2 binding capacity comparable with B cells treated by anti-mu+IL-2. This paradoxical result suggests that IL-2 has a direct influence on the acquisition of the IL-2 responsiveness. IL-4 exerts a negative effect on the IL-2 response. At the molecular level, IL-4 was found to reduce selectively the IL-2R beta expression at the B cell surface. This effect was confirmed by Northern blot analysis. Maximum expression of the IL-2R beta mRNA is obtained after anti-mu+IL-2 treatment. In the presence of IL-4, expression of the IL-2R beta mRNA is greatly reduced.

Animals↗
PubMed1995

Selective variations in vivo of VH3 and VH1 gene family expression in peripheral B cell IgM, IgD and IgG during HIV infection.

We have analyzed the expression of VH gene families in IgM, IgD and IgG of peripheral blood B cells from a group of HIV-infected patients. CD19+CD20+ cells were purified and anchored reverse transcriptase-polymerase chain reaction products were hybridized with VH gene family probes. IgM, IgD and IgG that expressed a VH3 gene family segment, were decreased in patients with low CD4 counts and to a greater extend in patients with AIDS symptoms (up to 85% for IgG) compared to adult healthy donors. This was correlated with elevated levels of IgM and IgG encoded by a VH1 gene family segment (around 60% for IgG). These results confirm and extend previous work that has detected the VH3 gene family under-representation in HIV infection. Here, we show that, in vivo, this phenomenon actually affects the different B cell populations of the peripheral blood: IgM+ or IgG+ B cells and also IgM+IgD+ naive B cells. In the course of HIV infection, this results in their gradual depletion. Data presented here strengthen the hypothesis that a B-cell superantigen exists in HIV infection. These pronounced variations of the normally most-expressed VH gene family may be related to B cell abnormalities detected in HIV-infected patients.

Adult↗
PubMed1995

Analysis of human VH gene repertoire expression in peripheral CD19+ B cells.

Using CD19 B-cell selection and polymerase chain reaction-amplified cDNA libraries, we analyzed the peripheral immunoglobulin heavy chain variable repertoire of three healthy adult donors. Here we report that most of the CD19+ circulating B cells expressed unmutated VH-D-JH rearrangements. By specific VH family hybridization, we show that VH gene family utilization in the periphery roughly corresponds to the complexity of these families in the germline and appears to be relatively constant among the analyzed subjects. However, sequence data of clones picked at random from one IgM cDNA library reveals that in spite of this "random" utilization, the VH gene expression in naive circulating B cells is highly biased towards the expression of a limited set of VH genes. As previously reported by others, this restricted mechanism is also found for the D and JH segments.

Adult↗
PubMed1992

IL-4 plays a dominant role in the differential development of Tho into Th1 and Th2 cells.

We have analyzed the evolution of the pattern of lymphokine secretion by Th cell lines specific for either the synthetic terpolymer Glu60Ala30Tyr10 (GAT) or killed bacillus Calmette Guérin. When cultured in the presence of exogenous rIL-2 as a growth factor, GAT-specific Th cell lines secreted mainly IL-4, whereas bacillus Calmette Guérin-specific lines produced predominantly IL-2. However, culturing in the presence of rIL-4 or of anti-IL-4 mAb and rIL-2 led to the establishment of Th2-like and Th1-like lines, respectively, regardless of their Ag specificity. Inasmuch as we show that the proliferative response of mature Th1 and Th2 cells was identical in the presence of IL-4, these results indicate that IL-4 influences the development of Th cell subsets. To understand the mode of IL-4 action, we isolated immature GAT-specific Tho clones able to secrete IL-2 and IL-4. Two types of Tho cells were isolated: ThoA cells that secreted IL-2 and IL-4, but not IFN-gamma, and ThoB cells that secreted IL-2, IL-4, and IFN-gamma. We show for the first time that such cells are indeed Th precursors able to differentiate into Th1 or Th2 cells. We demonstrate that IL-4 positively and negatively controls the differentiation of Tho cells into Th2 and Th1 cells, respectively. When cultured in rIL-4, Tho cells stop secreting IL-2 and IFN-gamma, but maintain IL-4 secretion. Moreover, endogenous IL-4 produced by Tho cells has similar effects: when cultured in rIL-2 alone, Tho cells either keep their immature phenotype or become Th2 cells, but do not become Th1 cells. In contrast, neutralization of secreted IL-4 completely prevents the differentiation of Tho into Th2 cells, but permits the development of Th1 cells. The presence of exogenous IFN-gamma does not affect the development of Tho into Th1 and Th2 cells, because it does not modify either mode of IL-4 action. However, it influences the ratio between the two types of Tho cells: when IL-4 is neutralized, added IFN-gamma can induce IFN-gamma secretion by ThoA cells and thereby facilitate their passage into ThoB cells. Taken together, our results demonstrate that IL-4, in addition to mediating T cell growth, is a principal factor that controls the differential development of Tho cells into Th1 and Th2 cells.

Animals↗
PubMed1992

Interleukin-1 and interleukin-6 synergize in preparing resting murine B cells to respond to anti-mu: correlation with c-myc expression.

We demonstrate that stimulation with interleukin (IL)-1 and IL-6 prepares high-density B cells to enter the S phase more promptly in response to subsequent stimulation with anti-mu F(ab')2. The stimulatory effect of IL-1 and IL-6 is compared to the one described for IL-4. In contrast to IL-4, preculture in IL-1 and IL-6 does not induce an increase in cell volume or in expression of class II major histocompatibility complex antigens on resting B cells. Similarly, the expression of the p55 subunit of the IL-2 receptor and of the transferrin receptor was not detected on resting B cells stimulated with IL-1 and IL-6. However, the stimulatory effect of IL-1 and IL-6 is correlated with an increased expression of c-myc proto-oncogene mRNA in resting murine B cells.

Animals↗
PubMed1992

Immunochemical characterization of antigenic domains on human IL-2: spatially distinct epitopes are associated with binding to the p55 and p70 subunits of IL-2 receptor.

We have isolated and characterized 8 mAb against human rIL-2. All recognize nonglycosylated rIL-2 in liquid phase with similar affinities (Kd approximately 1 nM). Based on the epitopes of the IL-2 molecule that they recognize and their pattern of reactivity against glycosylated and non-glycosylated IL-2, they have been classified into four groups. The first group of anti-IL-2 mAb (2C4, 19B11 and 12C2) inhibits IL-2 binding to p70 IL-2R, while the second one (16F11, 18E1 and 2A4) prevents its binding to p55 IL-2R. These two groups neutralize IL-2 activity in a T cell proliferation assay equally well, due to their similar inhibition of IL-2 binding to high affinity IL-2R. Two mAb, 3H9 and 17F4, recognize separate epitopes on IL-2 molecule, are poor inhibitors of IL-2 binding, and they are inefficient in the neutralization of its biological activity; they have been assigned to the third and fourth groups, respectively. These results show that mAb from the first and second group recognize two epitopes of the human IL-2 molecule which probably overlap the p70 IL-2R and p55 IL-2R binding sites, respectively. In addition, these areas together form the high affinity IL-2R binding site. The two mAb from the third and fourth group recognized epitopes of IL-2 not directly involved in IL-2 binding to its receptor. All eight mAb anti-human IL-2 recognize murine IL-2 and with the exception of one, 17F4 mAb are also able to neutralize it in a T cell proliferation assay. The relationship between the structure and the function of the IL-2 molecule is discussed.

Animals↗
PubMed1992

Idiotypic expression of anti-gp120 antibodies in unrelated human immunodeficiency virus-infected individuals.

Although it is recognized that human immunodeficiency virus (HIV) env genes exhibit a high degree of variability, little is known about the molecular heterogeneity of gp120-specific antibodies in infected individuals. As a first step to approach this issue, we investigated the idiotypic relatedness of anti-gp120 antibodies present in the serum of HIV-infected individuals. Idiotypic determinants (idiotopes) are fingerprints of the variable region of the antibody molecule and, as such, they represent unique probes with which to explore the diversity of the immune response. We isolated IgG anti-gp120 antibodies from the serum of a seropositive asymptomatic individual by affinity chromatography. The purified antibodies were shown to bind gp120 and gp160 by ELISA, Western blotting and radio-immunoprecipitation. They also recognized HIV-infected human T cells as detected by immunofluorescence. Anti-idiotypic reagents were generated against this gp120 idiotype, and one of them was used to study anti-gp120 idiotypic diversity in a panel of 65 sera drawn from AIDS and AIDS-related complex patients, and from HIV seropositive asymptomatic individuals. Sixty normal human sera were used as negative controls. We found no evidence for common idiotopes on anti-gp120 antibodies of unrelated individuals. In contrast, we also noticed that the idiotypic profile expressed sequentially at two different intervals in a persistently infected individual showed little variation. Finally, when the diversity of murine anti-gp120 antibodies with a monoclonal anti-idiotype was analysed, no evidence of cross-reactive idiotopes in the murine system was found.

Adult↗
PubMed1991

UV-treated polystyrene microtitre plates for use in an ELISA to measure antibodies against synthetic peptides.

Detection of peptide-specific antibodies by the conventional ELISA technique is sometimes hampered by the difficulties encountered in immobilizing stretches of amino acids on the solid support. To improve the attachment of synthetic peptides to the solid phase, we have developed a sensitive and rapid immunoassay based on the irradiation of polystyrene plates with UV light prior to coating the target peptide. This pretreatment increases the specific signal in a dose-dependent manner without augmenting the background or altering the specificity of the assay. This simple method was shown to be suitable for the quantitation of murine monoclonal antibodies as well as human and rabbit polyclonal antibodies. It should be applicable to a variety of synthetic peptides and polystyrene ELISA plates. Using this technique, we were able to localize the antigenic motifs recognized by neutralizing monoclonal antibodies generated against the envelope protein gp120 of the human immunodeficiency virus.

Amino Acid Sequence↗
PubMed1991

Cloning of a gene encoding a lupus-associated human autoantibody VK region using the polymerase chain reaction and degenerate primers.

The variable light-chain-encoding gene of a human autoantibody secreted by a B-cell hybridoma derived from a patient with systemic lupus erythematosus was amplified using the polymerase chain reaction and degenerate primers. After cloning, the nucleotide sequence of the EcoRI-HindIII region was determined. It is highly homologous to a previously described gene expressed by a human lymphoid cell line.

Autoantibodies↗
PubMed1991

Anti-idiotypic antibodies to human anti-gp120 antibodies bind recombinant and cellular human CD4.

The presence of anti-CD4 antibodies in sera of human immunodeficiency virus (HIV)-seropositive individuals has been recently documented, but its origin remains unknown. To test the hypothesis that anti-idiotypic antibodies to gp120, the HIV envelope glycoprotein with high affinity for CD4, mimic the configuration of gp120 and bind CD4, we performed two sets of experiments. First, we tested the possibility that anti-CD4 antibodies present in sera of a proportion of HIV-positive individuals exhibit variable region complementarity to autologous anti-gp120 antibodies. We show here that affinity-purified human anti-gp160 antibodies recognize specifically autologous affinity-purified anti-CD4 antibodies. We also demonstrate that antibodies to CD4 competitively inhibit anti-gp160 autologous antibodies binding to gp160. This implies that at least some anti-CD4 antibodies are directed towards idiotypic motifs located on anti-gp120 antibodies and that they may result from an anti-idiotypic response to anti-gp120 antibodies. In a second set of experiments, we examined the effect of anti-idiotypic immunization of experimental animals against human anti-gp120 antibodies. We found that anti-idiotypic antibodies produced in a rabbit immunized against affinity-purified human anti-gp120 antibodies specifically recognize recombinant and cellular human CD4, and that this interaction is competitively inhibited by soluble CD4. The data support the concept of idiotypic mimicry whereby anti-idiotypic antibodies produced against anti-gp120 antibodies recognize CD4, the cellular receptor of HIV.

Antibodies, Anti-Idiotypic↗
PubMed1991

Quantitative clonal analysis of the B cell repertoire in human lupus.

To gain further insight into the origin of autoantibody hyperproduction in human lupus, we quantitated the B cell repertoire toward exogenous and self-antigens. Using the Spot-ELISA method and two panels of nine exogenous and 10 self-antigens, we found that the normal human immune repertoire comprises a high frequency of B cell precursors secreting IgM antibodies to self- and exogenous determinants. This repertoire was markedly deficient in precursors producing IgG able to bind self-antigens. In lupus patients, the absolute numbers of clone precursors of the immune repertoire expressing IgM receptors whose paratopes impart affinity to self- and exogenous determinants were higher than in control individuals. Additionally, IgG antibody-forming cell precursors with binding specificity for lupus-associated antigens were detectable in the repertoire of these patients. Based on these results, we propose that hyperproduction of human lupus-associated autoantibodies arises in a two-stage mechanism whereby a general activation of the multireactive immune B cell repertoire precedes an oligospecific expansion of selected B cell clonotypes.

Antibodies, Antinuclear↗
PubMed1990

IL-2-dependent proliferation of murine T cells requires expression of both the p55 and p70 subunits of the IL-2 receptor.

An IL-4-dependent T cell clone (LD8) was isolated from the murine IL-2-dependent cytotoxic T cell line C30.1. This clone has lost the capacity to proliferate in response to IL-2 after long-term culture in IL-4. LD8 cells express the p70, but not the p55, subunit of the IL-2R on their cell surface. The number of p70 IL-2R molecules on LD8 cells is comparable with the number of high-affinity IL-2R on the parental C30.1 cell line. LD8 cells can efficiently internalize IL-2 through the p70 IL-2R subunit. Following stimulation by IL-2, LD8 cells up-regulate p70 IL-2R mRNA, but do not express p55 IL-2R mRNA. IL-2-dependent proliferation of LD8 cells was reconstituted after introduction and expression of a human p55 IL-2R cDNA. To further investigate the role of p70 IL-2R, we have measured IL-2-induced proliferation of C30.1 cells in the presence of three anti-p55 IL-2R mAb (5A2, PC61, and 7D4) that recognize different epitopes. Under the experimental conditions used, the combination of anti-p55 IL-2R mAb prevents the formation of high-affinity IL-2R, but does not affect the binding of IL-2 to p70 IL-2R or IL-2 internalization. However, these three mAb inhibit proliferation of C30.1 cells even in the presence of IL-2 concentrations sufficient to saturate p70 IL-2R. Together these results demonstrate that p70 IL-2R alone is not sufficient to transmit IL-2-induced growth signals and that formation of p55-p70 IL-2R complex is required for IL-2-dependent proliferation of murine T cells.

Animals↗
PubMed1990

Further evidence for a human B cell activating factor distinct from IL-4.

Supernatants from activated human T cell clones were previously shown to contain B cell-activating factor (BCAF), an activity which results in polyclonal resting B cell stimulation. In the present study, we investigate the relationship between this activity and human interleukin-4 which was also shown to act on resting B cells. The supernatant of the T cell clone TT9 contains IL-4 but anti-IL-4 antiserum does not affect the response of B cells as measured by thymidine uptake or cell volume increase. Furthermore, IL-4 induces Fc epsilon-receptor (CD23) expression on 30% of unstimulated human B cells, whereas BCAF-containing supernatants from clone P2, that do not contain detectable amounts of IL-4, promote B cell proliferation without inducing CD23 expression. Our results therefore establish that IL-4 and BCAF are distinct activities and suggest that they trigger different activation pathways in human B cells. In addition, culture of B cells with T cell supernatants for 72 hr induces a three- to fourfold increase in the expression of HLA-DR, -DP, and -DQ antigens in 50% of B cells. The addition of inhibiting concentrations of anti-IFN-gamma, LT, or IL-4 antisera to the cultures does not change these results. Finally, 30% of B cells cultured with T cell supernatants leave the G1 phase of the cell cycle and 20% reach mitosis. Taken together, our findings further support the existence of a B cell-activating factor responsible for the activation of resting human B cells.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1989

Transient nuclear location of the IL-2 receptor during T cell activation.

Binding of interleukin-2 (IL-2) to its membrane receptor (IL-2R) on target cells is followed by internalization of the IL-2R. The subsequent intracellular fate of IL-2R is not known. This paper describes the intracellular location of the p55 subunit of the IL-2R during IL-2 mediated T cell activation and growth of two mouse T helper clones. IL-2R was visualized by immunohistochemistry using two rat monoclonal antibodies (5A2 and 7D4). Immunostaining shows that the p55 subunit of the IL-2R is transiently present in the nucleus of activated T cells. The intranuclear location of the IL-2R suggests that the p55 subunit, either alone or in conjunction with the IL-2 or the p70 subunit, may be implicated in the regulation of gene expression involved in T cell proliferation.

Animals↗
PubMed1988

p55 IL-2 receptor mRNA precursors in murine T lymphocyte nuclei.

An unusual family of cDNA clones homologous to human p55 IL-2R sequences was isolated from the murine HT-2 Th cell line. These clones were mapped, partially sequenced, and compared with previously published human and mouse IL-2R sequences. They appear to consist of various combinations of exons and introns, suggesting that they are derived from p55 IL-2R mRNA precursors. The configuration of exons in the splicing intermediates indicates that the murine and human gene organizations are similar and that the 3' end of intron 3 is well conserved between the two species. RNA mapping experiments using nuclear, cytoplasmic, and total RNA and probes derived from various parts of the p55 IL-2R gene support and extend the sequence data. They indicate that detectable amounts of immature p55 IL-2R mRNA are found specifically in the cell nucleus of the HT-2 cell line. Similar data were obtained for the Th cell clone 52.3 and the cytotoxic T cell line CTLL. All these results indicate that the T cell nucleus contains significant amounts of immature p55 IL-2R mRNA.

Animals↗
PubMed1988

Biochemical characterization and biological effects of partially purified B cell-activating factor (BCAF).

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 reverse-phase 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.

Animals↗