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R Bataille

Publications and source records attributed to R Bataille.

At least 145 records · Page 8Linked to original sources

The critical role of interleukin-6, interleukin-1B and macrophage colony-stimulating factor in the pathogenesis of bone lesions in multiple myeloma.

Lytic bone lesions and hypercalcemia are common features of multiple myeloma. In contrast, they are exceptional in other B-cell malignancies. Myeloma bone involvement is related to an uncoupling process associating increased osteoclastic resorption with decreased bone formation. Several osteoclast-activating factors, such as interleukin-1, macrophage colony-stimulating factor, and interleukin-6, are involved in this process. However, interleukin-6, the major myeloma cell growth factor, plays a critical role in myeloma-induced bone resorption.

Bone Resorption↗

Conserved natural humoral immunity to thyroglobulin in patients with multiple myeloma.

We studied humoral immunity to human thyroglobulin (hTg) during the course of multiple myeloma (MM). In this report, we describe the anti-hTg antibody activity in the sera of patients with MM. Among 63 sera tested, 28 (44%) had IgG anti-hTg autoantibodies (aAb), 16 (25%) exhibited IgM aAb, and six (9%) had IgA anti-hTg aAb. For the majority of sera the anti-hTg autoantibody activity was associated with more than one immunoglobulin class. IgG anti-hTg antibodies were observed in 9/11 patients with IgA MM and in 19/40 patients with IgG MM. The IgM anti-hTG antibody activity was found in the sera of 11 patients with IgG MM. These results show that the anti-hTg activity in these patients is associated with residual polyclonal immunoglobulins. However, in the serum of one patient presenting a double monoclonal gammopathy (IgG and IgA lambda MM), the anti-hTg activity was carried by both the IgG lambda and the IgA lambda molecules, suggesting that in this case the activity was due to the monoclonal immunoglobulin itself. We also studied the epitopic specificity pattern of all these anti-hTg aAb. Only three sera recognized one antigenic region on hTg, suggesting that the majority of the anti-hTg aAb in MM patients were directed against antigenic regions other than those recognized by our panel of murine mAb. In conclusion, our results demonstrated that humoral immunity to hTg is maintained in MM patients. These data contrast with the well-documented suppression of immunity to foreign, especially bacterial, antigens described in MM.

Adult↗

Mutations of the p53 gene in human myeloma cell lines.

Mutations affecting the p53 gene have been found associated with many human malignancies, but little is as yet known about multiple myeloma. We investigated p53 gene alterations in 10 human myeloma cell lines (HMCL), half of these being dependent upon exogenous interleukin 6 (IL-6) for in vitro growth, similar to freshly explanted myeloma cells. Using a polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) approach, eight of the 10 HMCL were found to bear a mutated p53 gene. All the mutations were single base substitutions with a predominance of G:C to A:T transitions. There was no apparent relation between the presence of a mutation and IL-6 requirement of the cell line. Interestingly, in two cell lines (XG-2 and XG-4) the SSCP pattern showed the presence of both the wild-type and the mutated allele and, upon reverse PCR on RNA, both alleles were found to be concomitantly expressed at the RNA level. Moreover, three freshly explanted tumor samples had the same p53 gene status (mutated versus wild type) as the HMCL that were derived from them. These results show that p53 mutations are frequent in HMCL. Although no apparent relation could be evidenced with the loss of exogenous IL-6 requirement, it may prove interesting to investigate further potential relations between the presence of a mutated p53 allele and gradual autonomy for cell growth.

Base Sequence↗

p53 and RAS gene mutations in multiple myeloma.

We analysed genomic DNA from 30 patients with multiple myeloma (MM), searching for alterations in the p53 and RAS genes by a combination of polymerase chain reaction and single-strand conformation polymorphism techniques. Mutations in the p53 gene were observed in 20% (6 out of 30) of the patients, and were located in conserved sequence blocks within exons 5 and 7. These were single-nucleotide substitutions and consisted predominantly (4/6) of G:C to A:T transitions. Of the six patients with a mutated p53 gene, four were in the terminal phase of the disease. RAS gene mutations were found more frequently since they occurred in 47% (14 out of 30) of the patients. Mutations consisted of single-nucleotide substitutions, located in codons 12, 13 and 61 of either K- or N-RAS, to the exclusion of H-RAS. Moreover, one patient bore two simultaneous mutations, affecting simultaneously the K- and the N-RAS genes. RAS gene mutations were more frequently observed in patients with fulminating disease (10/15, 67%) than in patients with less aggressive forms of the disease (4/15, 26%). We also analysed genomic DNAs from 10 human myeloma cell lines, of which two bore mutations affecting codon 12 of the K-RAS gene, and one codon 12 of the N-RAS gene. The first two cell lines were obtained from freshly explanted tumor cells in which we observed identical mutations. Results presented here show that activating mutations in the RAS genes are, in MM, more frequent than those affecting the p53 gene and suggest that both events are related to terminal phases of the disease.

Amino Acid Sequence↗

Major immunoglobulin capping deficiency in the peripheral blood B cells of patients with Sjögren's syndrome.

The capping of surface immunoglobulins (sIg) is a major characteristic of normal B lymphocytes. Thus, we have investigated sIg capping by peripheral blood (PB) B cells of patients with Sjögren's syndrome (SS) and we have found a major deficiency in these patients. In 12 healthy donors (HD), 8 +/- 2.8% of PB mononuclear cells were B cells (i.e. expressing the B-cell antigens CD19, CD20 and CD21 simultaneously) and more than 90% of these PB B cells were able to cap their sIg. In 12 experiments performed using PB lymphocytes from seven patients with SS, a major capping deficiency was noted with only 30% of PB B lymphocytes being able to cap sIg. This defect was not related to an expansion of the B-cell subpopulation expressing the CD5 antigen and was not observed in five patients with rheumatoid arthritis lacking SS. Capping of sIg via antigen binding (i.e. antigenic modulation) constitutes the initial signal for B-cell activation. This process is involved in anti-viral defence and could have a potential pathogenetic role in autoimmune diseases. This impaired B-cell function presently described represents an immune defect which could be important in the pathogenesis of SS.

Aged↗

Cytokine network in human multiple myeloma.

In multiple myeloma (MM), an overproduction of IL-6, indicated by increased plasma C-reactive protein levels, is found in 37% of MM patients at diagnosis and is associated with disease aggressiveness, myeloma-cell proliferation, and poor prognosis. IL-6 is produced by the tumoral environment mainly and not by myeloma cells themselves. IL-6 is a major growth factor for malignant plasmablastic cells in vitro, and it is possible to reproducibly obtain IL-6-dependent myeloma-cell lines. Moreover, anti-IL-6 therapies in patients with terminal disease block myeloma-cell proliferation in vivo. The myeloma-cell growth factor activity of IL-6 is probably the consequence of IL-6 being a growth factor for normal plasmablastic cells. Hematopoietic cytokines (GM-CSF, IL-3, IL-5, G-CSF) synergize with IL-6 to support myeloma-cell proliferation. IFN-alpha and TNF induce an autocrine production of IL-6 in myeloma-cell lines and make possible the autonomous growth of these cell lines. On the contrary, IFN-gamma completely inhibits the IL-6-mediated myeloma-cell proliferation. The identification of some major cytokines involved in the control of the myeloma clone has immediate therapeutic implications, because some of these cytokines are, or might be, used in the treatment of patients with MM.

Cell Division↗

Mechanisms of bone lesions in multiple myeloma.

Lytic bone lesions and hypercalcemia are common features of multiple myeloma; however, they are exceptional in other B-cell malignancies. Myeloma bone involvement is related to an uncoupling process associating an increased osteoclastic resorption with decreased bone formation. Several osteoclast-activating factors such as interleukin-1 (IL-1), tumor necrosis factor, and interleukin-6 (IL-6) are involved in this process. IL-6, the major myeloma cell growth factor, could play a critical role in myeloma-induced bone resorption in association with other known or unknown hematopoietic growth factors, however.

Bone Resorption↗

IFN-alpha induces autocrine production of IL-6 in myeloma cell lines.

IL-6 is a major tumor growth factor in human multiple myeloma. Myeloma cell lines, which have the same phenotypic characteristics and Ig gene rearrangements as the original fresh myeloma cells and whose growth is strictly dependent on exogenous IL-6 similar to fresh myeloma cells, have been reproducibly established. We show here that IFN-alpha stimulated the growth of five of six of these human myeloma cell lines by inducing an autocrine production of IL-6 in myeloma cells. Indeed, IFN-alpha induced IL-6 mRNA accumulation and IL-6 production in myeloma cells and the IFN-alpha-induced growth of these cells was inhibited by anti-IL-6 mAb. Moreover, IFN-alpha made possible the rapid emergence of autonomously growing myeloma cell sublines, which produced IL-6 as an autocrine growth factor. As IFN-alpha has a potential therapeutical interest for multiple myeloma, the present study opens up new directions for studying its effects on the myeloma clone in vivo.

Cell Division↗

No expansion of the pre-B and B-cell compartments in the bone marrow of patients with multiple myeloma.

We have recently demonstrated that the CD24 antigen density of bone marrow (BM) lymphoid cells discriminates between pre-B cells and mature B-cells. Using this new method, we evaluated the B-cell lineage in the BM and peripheral blood (PB) of 18 patients with multiple myeloma (MM). First, the percentage of pre-B cells was significantly reduced by 40% in the BM of patients with MM: 2.3% +/- 2.2% versus 5.7% +/- 2.8% of normal BM lymphoid cells (P less than 0.01). This finding was associated with a significant reduction (50%) of the percentage of mature B-cells in both BM and PB, especially in patients with progressive disease (P less than 0.05). In contrast to what has been reported previously, we have not found any pre-B cells in the PB of these patients with MM. Secondly, BM pre-B and B-cell patients with MM did not express any activation markers (CD23, CD25, or CD71 antigens) and no CD5+ B-cells were found in the BM unlike in PB (8% CD5+ B-cells). Taken together, these data do not support the concept of a direct involvement (i.e, expansion or activation) of pre-B cells in MM without excluding the possibility of an early oncogenic event at the pre-B cell stage. Furthermore, our data emphasize this important reduction of the B-cell compartment (including that of pre-B cell) as a major cause of the humoral immunodeficiency in MM.

Antibodies, Monoclonal↗

Autoimmunity to human thyroglobulin. Respective epitopic specificity patterns of anti-human thyroglobulin autoantibodies in patients with Sjögren's syndrome and patients with Hashimoto's thyroiditis.

We evaluated the epitopic specificity pattern of anti-human thyroglobulin (anti-hTg) autoantibodies from patients with primary Sjögren's syndrome (SS). All of the primary SS sera tested contained both IgG and IgM anti-hTg autoantibodies recognizing at least 1 region on hTg; in 65% of the cases, 3 or more regions were recognized. A strong recognition of region II, as is seen in Hashimoto's thyroiditis, was associated with thyroid disorder in primary SS. These results emphasize the importance of region II in autoimmune thyroid disease.

Adult↗

In vivo interleukin 6 gene expression in the tumoral environment in multiple myeloma.

Whether interleukin 6 (IL 6) is an autocrine or paracrine myeloma cell growth factor in vivo remains unresolved. To identify which cells are producing IL 6 in vivo, we have studied the IL 6 gene expression in bone marrow mononuclear cells (BMMC) of 19 patients with multiple myeloma (MM) and in peripheral blood mononuclear cells (PBMC) of 9 patients with plasma cell leukemia (PCL). We found that the IL 6 gene was transcribed by BMMC of most patients with MM (79%). Further, IL 6 mRNA was not produced by purified myeloma cells from patients with either MM (5 patients) or PCL, but by the bone marrow environment, mainly by monocytes and myeloid cells (CD13+CD15+ cells). For 2 patients with PCL, for whom PBMC and BMMC samples were available, IL 6 mRNA could be detected in BMMC but not in PBMC. Finally, no IL 6 mRNA was detected in five freshly established IL 6-dependent myeloma cell lines. The present data give a clear-cut demonstration of the paracrine origin of IL 6 in vivo in human MM.

Bone Marrow↗