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J Boniver

Publications and source records attributed to J Boniver.

At least 73 records · Page 4Linked to original sources
PubMed1997

Expression of the 67 KD laminin receptor in human cervical preneoplastic and neoplastic squamous epithelial lesions: an immunohistochemical study.

Interactions of cancer cells with laminin play a critical role during the progression of solid malignant tumours. Increased expression of the 67 kD laminin receptor (67LR), one of the several laminin binding proteins, is associated with the invasive and metastatic capacity of various types of cancer, including breast, colon, ovary, lung, and endometrial carcinoma. In this study, 67LR expression was analysed in a series of cervical biopsy specimens including 16 normal cervical tissues, 36 low-grade squamous intraepithelial lesions (SILs), 24 high-grade SILs, and 11 invasive carcinomas. Detection of the 67LR was performed using immunoperoxidase staining and the monoclonal antibody MLuC5 which specifically recognizes the 67LR. Immunostaining of the 67LR was correlated with human papillomavirus (HPV) type detected by in situ hybridization and with proliferative activity of the lesion determined by immunohistochemistry with the MIB-1 monoclonal antibody, specific for the Ki67 antigen. Increased expression of the 67LR was correlated with the histological severity of the lesions, with the strongest immunoreactivity being found in invasive carcinomas. Significant differences in 67LR expression were found between normal cervical epithelium and high-grade SILs (P < 0.05, non-parametric Mann-Whitney test) or invasive carcinomas (P < 0.001), as well as between low- or high-grade SILs and invasive carcinoma (P < 0.01 and P < 0.05, respectively). Ki67 antigen expression also increased with the severity of the lesions. There was a positive correlation for each type of lesion between expression of the 67LR and of the Ki67 antigen. No specific relationship was found between 67LR or Ki67 antigen immunostaining and HPV type detected in SILs, segregated into low-grade and high-grade lesions. These data add weight to the evidence that increased expression of the 67LR is a consistent, but not sufficient feature of the invasive and metastatic phenotype and suggest that high expression of the 67LR might be associated with both more proliferative and more aggressive cervical (pre)neoplastic lesions.

Biomarkers, Tumor↗
PubMed1997

Efficiency of T cell triggering by anti-CD3 monoclonal antibodies (mAb) with potential usefulness in bispecific mAb generation.

T cell triggering can be achieved by monoclonal antibodies (mAbs) specific for the CD3/TcR complex. In the presence of appropriate costimulation and/or progression factors, such triggering permits the generation of effector cells for immunotherapy protocols involving the redirection of T cell lysis against tumor cells by mAbs bispecific for anti-CD3/anti-tumor cells (bs-mAbs). Focusing our analysis on the clinically relevant bs-mAb OC/TR, we found that bs-mAbs generated with the same anti tumor specificity, but two other anti-CD3 mAbs, TR66 and OKT3, have the same and a significantly lower lytic potential, respectively, compared with that of OC/TR. To evaluate the relevance of the anti-CD3 component, we examined several anti-CD3 mAbs with respect to binding parameters and the ability to trigger T lymphocytes. Competitive binding assays suggested that all anti-CD3 mAbs recognized the same or overlapping epitopes, although mAbs BMA030 and OC/TR bound with lower avidity than did alpha CD3 (the bivalent anti-CD3 mAb produced by the hybrid hybridoma OC/TR). TR66 and OKT3, as determined by measurement of the affinity constants. In all lymphocyte populations examined, which included resting peripheral blood mononuclear cells (PBMC), activated PBMC and T cell clones, OKT3, BMA033 and OC/TR failed to mobilize Ca2+ without cross-linking, whereas alpha CD3, in both murine and murine-human chimeric versions, TR66 and BMA030, did not require cross-linking. The ability to induce CD3 modulation was associated in part with the induction of Ca2+ fluxes. Despite the differences in the behavior of these mAbs in triggering the events that precede proliferation, all of them ultimately led to expression of the IL-2 receptor and to proliferation in T cells in the presence of accessory cells. Our data suggest that anti-CD3 mAbs that bind more rapidly (strong Ca2+ mobilizers) and more tightly under physiological conditions are good candidates for retargeting T cells in the bs-mAb clinical application.

Antibodies, Bispecific↗
PubMed1997

Peyer's patches in murine AIDS: dissociation between lymphoproliferation and anergy.

RadLV-Rs infection induces a murine immunodeficiency syndrome associated with a dramatic enlargement of spleen and lymph nodes. Surprisingly, the lymphoproliferation excludes thymus and Peyer's patches (PP). To understand the cellular interactions underlying lymphoproliferation further, the authors investigated the fate of PP in RadLV-Rs infected mice. The atrophy of PP was mostly due to the depletion of B cells, while the proportion of CD4+ and CD8+ T cells was increased. Nevertheless, B cell phenotype was modified with the emergence of lymphocytes with a low expression of B220 in infected PP. T cells characterized by a memory/activated phenotype in control PP did not undergo phenotypical changes after viral infection (i.e. regarding Thy-1 and CD44 expression). Despite the absence of lymphoproliferation, PP T and B cells displayed altered responses to mitogens in vitro. Finally, alterations of the expression of adhesion molecules and vascular addressins could not explain the atrophy of PP by a reduced homing to this lymphoid site. B cells and T cells from normal PP are clearly different from lymph nodes (LN) lymphocytes. The authors propose that the particular functional state which characterizes PP lymphocytes influences the B cell/T cell crosstalk necessary for RadLV-Rs-induced lymphoproliferation.

Animals↗
PubMed1997

Stages in the development of radiation-induced thymic lymphomas in C57 BL/Ka mice: preleukemic cells become progressively resistant to the tumor preventing effects of a bone marrow graft.

Fractionated whole body irradiation induces thymic lymphomas in C57 BL/Ka mice after 6-12 months. A graft of normal congenic bone marrow cells immediately after the last irradiation prevents the development of lymphomas by inducing the disappearance of preleukemic cells. When such a graft is performed one month later, it does not inhibit the emergence of tumors. It could be because, one month after irradiation, preleukemic cells become insensitive to the effects of the grafted bone marrow on their leukemogenic potential. To check this hypothesis, we have investigated the capacity of grafted bone marrow cells to prevent the development of lymphomas in mice inoculated with radiation-induced preleukemic cells collected at several time intervals after the completion of the radiation regimen. It was found that the bone marrow graft reduced the incidence of thymic lymphoma at day 2 (10 vs. 43%; p < 0.01) and 10 (39 vs. 86%; p < 0.01) but not at day 15 (64 vs. 80%; NS) or 30 (93 vs. 82%; NS). The inefficacy of the marrow graft was not associated with proliferation of the inoculate in the recipient thymus nor with inhibition by preleukemic cells of thymic repopulation by bone marrow precursors. The data provide evidence that preleukemic cells undergo intrinsic changes which are reflected by the acquisition of resistance to bone marrow grafts.

Animals↗
PubMed1996

Prevention of murine radiogenic thymic lymphomas by tumor necrosis factor or by marrow grafting.

BACKGROUND: Split-dose irradiation (1.75 Gy given weekly for 4 weeks) of C57BL/Ka mice induces the emergence of preleukemic cells (PLCs). These cells develop into leukemic cells after a latency period of 3-6 months. The survival and transformation of PLCs are dependent on radiation-induced alterations of the thymic epithelium and of resident lymphocyte (i.e., thymocyte) subpopulations in the thymus. PLCs can be eliminated, concomitantly with the restoration of the thymus, by grafting bone marrow cells immediately after the last irradiation. Our hypothesis was that any agent able to restore the thymus after leukemogenic irradiation would exert the same effects as a bone marrow graft. Tumor necrosis factor-alpha (TNF-alpha) is one such possible agent, since it has been shown to modulate some functions of the thymic epithelium and thymocyte subpopulations. PURPOSE: The goal of this study was to assess the ability of repeated intraperitoneal injections of TNF-alpha to functionally replace bone marrow transplantation in the restoration of normal intrathymic lymphopoiesis and in the prevention of thymic lymphomas in split-dose-irradiated mice. METHODS: We replaced the bone marrow graft with repeated injections of TNF-alpha (25 000 U/injection) in the split-dose-irradiated (4 x 1.75 Gy) C57BL/Ka mouse model. We analyzed the expression of the cell differentiation markers CD4 and CD8 on thymocytes by flow cytometry. We also studied the thymic environment by isolating thymic nurse cells, the bone marrow prothymocyte activity by analyzing thymic repopulation, and the evolution of PLCs by an in vivo transplantation assay. Local production of TNF-alpha after bone marrow grafting was examined by in situ hybridization. Injections of anti-TNF-alpha antibodies were given to split-dose-irradiated mice to test the effect of neutralizing TNF-alpha in vivo. One-way analysis of variance and Newman-Keuls two-tailed tests were used to test statistical significance. RESULTS: Multiple injections of TNF-alpha into split-dose-irradiated mice did not influence bone marrow prothymocyte activity but restored thymocyte subpopulations and thymic epithelium, induced the disappearance of PLCs, and prevented the development of lymphomas. Moreover, a bone marrow graft significantly stimulated intrathymic production of TNF-alpha messenger RNA (P<.01), and anti-TNF-alpha antibodies partially inhibited the antilymphomatous effects of bone marrow graft in split-dose-irradiated mice (P<.05). CONCLUSION: These data strongly suggest that TNF-alpha is a mediator that is involved in the mechanisms by which bone marrow transplantation functions to prevent thymic lymphomas in split-dose-irradiated mice. IMPLICATIONS: Cytokines might be used in some biological systems, particularly in the hemopoietic system, as a therapeutic agent for the secondary prevention of cancer.

Animals↗
PubMed1996

Improved four-color flow cytometry method using fluo-3 and triple immunofluorescence for analysis of intracellular calcium ion ([Ca2+]i) fluxes among mouse lymph node B- and T-lymphocyte subsets.

A visible-light, dual-laser, flow cytometric method was developed for the simultaneous analysis of intracellular ionized calcium concentration ([Ca2+]i) and three cell-surface markers (CD4, CD8, and Thy-1.2 antigens) by using the calcium probe fluo-3 and using R-phycoerythrin (PE), peridinin chlorophyll-alpha protein (PerCP), and allophycocyanin (APC) conjugated monoclonal antibodies (MoAbs). This improved method was used in the analysis of [Ca2+]i mobilization upon in vitro stimulation with mitogenic lectins [phytohaemagglutinin (PHA) or concanavalin A (ConA)], anti-CD3 MoAbs, or A23187 calcium ionophore in the heterogeneous lymph node cell populations from healthy C57BL/Ka mice. The present results show that the calcium responses were heterogeneous and dependent on the cellular immunophenotype, not only on lectins or anti-CD3 MoAbs stimulation, but also on the receptor-independent A23187 ionophore stimulation. An in situ fluo-3 calibration method (using A23187 and metabolic poisons in Ca2+ /EGTA buffers with known free calcium concentrations) indicated a resting [Ca2+]i in lymphocytes of 103 +/- 23 nM (mean +/- S.D.) but with significant differences between the [Ca2+]i in B cells and in all of the T-cell subsets (CD4+Thy-1+, CD4+Thy-1-, and CD8+T cells). Both the B cells and the T-cell subsets showed an increase of fluo-3 fluorescence upon in vitro stimulation with ConA or PHA, but the calcium mobilization following lectin stimulation was time delayed in all T-cell subsets. Only the T cells, including the CD4+Thy-1- subset, responded to anti-CD3 MoAbs. The percentage of responding cells upon stimulation with ConA was higher in T cells than in B cells. By contrast, PHA gave a higher response in B cells. After stimulation with different mitogens, [Ca2+]i increased in both CD4+ and CD8+ T-cell subsets. However, the percentage of responding cells was far higher in the CD4+Thy-1+ subset than in the CD4+Thy-1- or the CD8+T-cell subsets. The stimulation with A23187 ionophore induced a higher calcium response in B cells than in T cells. Interestingly, it also induced greater Ca2+ mobilization in CD4+ than in CD8+T cells. These results demonstrate the potential use of fluo-3 simultaneously with three fluorescein (FITC)-compatible fluorochromes. This technique may be useful for investigating the role of the CD4+Thy-1-T cells, a rare subset that is abnormally expanded in a murine acquired immunodeficiency syndrome (murine AIDS).

Aniline Compounds↗
PubMed1996

Further characterization of cytotoxic T cells generated by short-term culture of human peripheral blood lymphocytes with interleukin-2 and anti-CD3 mAb.

In this study we have specifically investigated the participation of T cells in the cytotoxic activity of peripheral blood lymphocytes (PBL) activated by interleukin-2 (IL-2, 50 U/ml) alone or in combination with an anti-CD3 mAb (BMA030, 10 ng/ml, IgG2a). Purified CD3+ T cells, incubated in the presence of the anti-CD3 mAb for 4 days, mediated a cytotoxic activity against HL60 and U937 tumor cell lines. Several findings suggested the involvement of a redirected-cytotoxicity phenomenon, since the lytic process was restricted to target cell lines bearing the high-affinity Fc gamma receptor (Fc gamma RI) and T lymphocytes stimulated by IL-2 alone did not lyse these cell lines. Furthermore, anti-CD3 mAb F(ab')2, anti-CD3 IgG1 (UCHT1), phytohemagglutinin or staphylococcal enterotoxin A did not induce a similar cytotoxic activity in T lymphocytes. The cytotoxic process occurred in the presence of a very low level of anti-CD3 antibodies (in the nanomolar range). The cytotoxic activity of T cells stimulated by IL-2 or by IL-2 + BMA030, against OVCAR-3 cells (MOv18+ ovarian tumor cell line), was also compared in the presence of a bispecific antibody OC/TR, anti-CD3 x MOv18). The stimulation by IL-2 + BMA030 induced approximately a twofold higher cytotoxic activity than IL-2-activated T cells. This could be related to the state of activation of effector cells stimulated by IL-2 + BMA030, since the phenotypic analysis showed an increased proportion of T cells expressing several activation/differentiation markers (CD25, HLA-DR, CD45R0, adhesion molecules). These findings could be applied to the design of therapeutic protocols using anti-CD3 x antitumoral bispecific antibodies.

Antibodies, Bispecific↗
PubMed1996

Subset-specific analysis of calcium fluxes in murine AIDS.

Infection of susceptible strains of mice with the Duplan strain of murine leukemia viruses induces a syndrome called MAIDS (murine acquired immunodeficiency syndrome) characterized by immunodeficiency and lymphoproliferation. In addition to a complete refractoriness of most subsets of lymphocytes to mitogen stimulation, the development of phenotypic abnormalities occurs such as the appearance of an abnormal CD4+ T cell subset lacking membranes Thy-1. This study was performed to compare the calcium responses during the early stages of MAIDS (week 9 or earlier) between T cells and B cells and between CD4+Thy-1- and CD4+Thy-1+ T cells. B cells were strikingly less affected than T cells: their baseline [Ca2+]i did not significantly increase, and their calcium response to anti-IgM antibody and concanavalin A (Con A) was partially maintained. In contrast, the response to Con A was completely abolished in T cells. Interestingly, calcium mobilization in response to membrane receptor-independent stimuli such as ionophores and thapsigargin was strongly inhibited in T cells, while no such inhibition was found in B cells. In comparison with their CD4+Thy-1+ counterparts, CD4+Thy-1- T cells had blunted calcium responses in controls, as well as in infected mice. However, CD4+Thy-1+ T cells were also strikingly altered, suggesting that the loss of membrane Thy-1 could be associated with, but not directly responsible for abnormalities of calcium responses in CD4+ T cells from RadLV-Rs-infected mice.

Animals↗
PubMed1996

In vivo expression of interleukin-1 beta (IL-1 beta), IL-2, IL-4, IL-6, tumour necrosis factor-alpha and interferon-gamma in the fetal murine thymus.

Cytokines are known to play a role in T-cell lymphopoiesis as potent growth or differentiation factors, but many experiments focusing on their role in the thymus have been conducted only in vitro. We have thus used frozen sections obtained from fetal thymuses of normal C57BL 6 mice to investigate by immunohistochemistry the presence of interleukin-1 beta (I4-1 beta), IL-2. IL-4. IL-6. interferon-7 (IFN-7) and tumour necrosis facor-alpha (TNF-alpha). The results reveal that apart from IL-2, which was not detected, all these cytokines display a time-dependent expression pattern in the normal fetal thymus. First, production of IL-4, IL-6 and TNF-alpha is detected around days 13 14; this is followed by a second wave on days 16 17, with a production of IL-1 beta, IL-4 and IL-6, and finally, just before birth (day 19), by a third wave of IL-1 beta, IL-4, IL-6, IFN-7 and TNF-alpha production. This supports the hypothesis that cytokines play a rote in T-cell lymphopoiesis.

Animals↗
PubMed1995

Inverse modulation of intraepithelial Langerhans' cells and stromal macrophage/dendrocyte populations in human papillomavirus-associated squamous intraepithelial lesions of the cervix.

Ninety-four cervical biopsies from normal tissue to high-grade squamous intraepithelial lesion (SILs) were examined for the presence of intraepithelial Langerhans' cells and subpopulations of stromal macrophages/dendrocytes by immunohistochemistry using anti-S100, -L1, -CD68 and -factor XIIIa antibodies. Human papillomavirus (HPV) detection was performed in all cases by using first a mixture of DNA probes for 14 HPV types commonly found in anogenital biopsies at low stringency conditions (Tm -40 degrees C) and by reanalyzing the tissues at high stringency (Tm -10 degrees C) with HPV 6/11, 16/18 and 31/33/35 biotinylated probe cocktails and individual digoxigenin-labelled probes. SILs and metaplastic tissues were significantly associated with a depletion of S100-positive intraepithelial Langerhans' cells when compared with normal epithelium. In contrast, there was a significant increase in L1-positive stromal macrophages in SIL biopsies compared with normal or metaplastic cervix. A significantly higher density of CD68-positive macrophages was also observed in high-grade SILs compared with normal or metaplastic biopsies and with low-grade SILs. The density of factor XIIIa-positive dendrocytes was found to be higher in SILs compared with metaplastic tissues and in high-grade SILs when compared with normal cervical biopsies. No specific relationship was found between the densities of these cells and the HPV type detected in SILs separated into low grade and high grade. The significance of this inverse modulation of intraepithelial Langerhans' cells and stromal macrophages/dendrocytes in normal and SIL biopsies is discussed in relation to HPV infection and malignant transformation.

Biomarkers↗
PubMed1995

Morphological changes of thymus in retrovirus-induced murine acquired immunodeficiency syndrome (MAIDS).

The possible contribution of the thymus in the setting of acquired immunodeficiencies is still questioned. Here we report some new findings regarding a potential involvement of the thymus in mice infected with RadLV-Rs, a viral mixture inducing murine acquired immunodeficiency syndrome (MAIDS). Thymi were sequentially removed, weighted and morphologically analyzed at different time intervals post-infection. Infection with RadLV-Rs led to a decrease in thymus weight mostly apparent from the fourth week. The first changes were seen at the third week as perivascular clusters of B-cells at the cortico-medullary junction. The ensuing process of atrophy mainly involved the cortex, while a mixed population of large T- and B-cells filled the medulla. These observations are discussed with regard to the pathological changes occurring in other lymphoid and non-lymphoid organs, in the context of the lymphoproliferation and immunodeficiency characterizing the disease, and by comparison with other models of retrovirus-induced immunodeficiencies.

Animals↗
PubMed1995

Assessment of Ki-67 antigen immunostaining in squamous intraepithelial lesions of the uterine cervix. Correlation with the histologic grade and human papillomavirus type.

A formalin-fixation and paraffin-processing resistant epitope of Ki-67 cell proliferation-associated antigen was immunohistochemically detected by the MIB-1 monoclonal antibody (Immunotech, Marseille, France) in 25 routinely processed cervical biopsies showing normal squamous epithelium or squamous metaplasia and in 65 cervical intraepithelial lesions (SILs) (44 low grade and 21 high grade SILs) with human papillomavirus (HPV) infection. Expression of Ki-67 antigen was exclusively confined to the parabasal and basal layers of normal and metaplastic epithelium. There was no significant difference of Ki-67 antigen immunostaining between normal cervical biopsies and cases of squamous metaplasia. In SIL specimens, the staining was markedly increased in the parabasal and basal layers and Ki-67-positive cells were also distributed in the intermediate (low grade SIL) or all layers of epithelium (high grade SIL). Statistically significant differences for the density of Ki-67 antigen-labeled cells, which were assessed with an image analysis system, were found in comparisons between normal or metaplastic epithelium and SILs (P < .001) and between low grade SILs and high grade SILs (P < .001). In our series of SILs, HPV 16/18 and 31/33/35/novel types, which were found in both low grade and high grade SILs, were significantly associated with higher densities of Ki-67 antigen-positive cells than HPV 6/11 types that were found exclusively in low grade SILs. There was no significant difference found between the densities of Ki-67 antigen-labeled cells in HPV 16/18-positive and HPV 31/33/35/novel types-positive tissues in our series of SILs taken as a whole or when segregating SILs into low grade and high grade.

Cervix Uteri↗
PubMed1995

Spontaneous and induced apoptosis after whole body radiation exposure: experimental approaches. Observations in radio-induced thymic lymphomagenesis.

Radio-induced thymic lymphomagenesis is associated with alterations in the balance between thymocyte subsets and cytokinetic perturbations. The objectives of this work were to investigate whether these alterations are associated with alterations in the basic levels of thymocyte apoptosis. For this purpose, we tested DNA fragmentation by gel electrophoresis, analyzed DNA content by propidium iodide staining of ethanol fixed cells and looked for DNA strand breaks on tissue sections by in situ end labeling. We described an increase of the levels of apoptosis in cultured thymocytes during the preleukemic period, while the basic levels of apoptosis observed in situ are similar in normal and in preleukemic thymuses. We propose that after leukemogenic irradiations, there is an increase of cells wherein the cell suicide program is activated but that environmental thymic factors rescue them from apoptosis. Preleukemic cells could belong to this abnormally surviving population of cells "programmed to die," wherein additional genomic abnormalities would lead to fully neoplastic transformation.

Animals↗
PubMed1995

Inhibition of growth of normal and human papillomavirus-transformed keratinocytes in monolayer and organotypic cultures by interferon-gamma and tumor necrosis factor-alpha.

The growth response of normal and human papillomavirus (HPV)-transformed cervical keratinocytes to interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha was investigated in monolayer and organotypic raft cultures. The proliferation rates of monolayer cultures were assessed by [3H]TdR incorporation and fluorimetric DNA titration. The growth of keratinocytes in organotypic cultures was estimated by their ability to stratify on collagen rafts and by immunohistochemistry for Ki67 antigen expression. IFN-gamma reduced the DNA synthesis of normal and HPV-transformed keratinocytes in monolayer cultures and exerted a marked growth inhibitory effect in organotypic raft cultures. In control raft cultures, normal keratinocytes produced an epithelial sheet of approximately 10 cells in thickness that closely resembled normal cervical epithelium and was characterized by sparse Ki67 antigen-positive cells whereas HPV-transformed keratinocytes produced up to 15 poorly differentiated epithelial layers that were reminiscent of high grade cervical lesions seen in vivo and exhibited a full thickness Ki67 antigen expression. When normal and HPV-transformed keratinocytes were maintained in the presence of IFN-gamma, the epithelial sheet was reduced to a few cells in thickness and the density of Ki67 antigen-positive cells was decreased. A more pronounced growth inhibitory effect in monolayer and organotypic cultures was observed when IFN-gamma was associated with tumor necrosis factor-alpha Tumor necrosis factor-alpha alone reduced the DNA synthesis of normal keratinocytes but was significantly less effective than IFN-gamma to inhibit the growth of HPV-transformed keratinocytes. These results suggest that similar responses in vivo to regulatory molecules may play a role in the development of HPV-related lesions.

Cell Division↗