PubMed Health⌕ Search

Biomedical subjects

J L Preud'Homme

Publications and source records attributed to J L Preud'Homme.

At least 19 recordsLinked to original sources
PubMed2000

In vitro induction of nitric oxide synthase in astrocytes and microglia by Trypanosoma brucei brucei.

In stage II human african trypanosomiasis (HAT), which is characterized by central nervous system (CNS) involvement, neurones and oligodendrocytes might be targets of dysimmune processes. Nitric oxide (NO) production by peripheral macrophages is documented in HAT. We studied the production of NO by murine astrocytes and microglia cocultured with Trypanosoma brucei (T. b.) brucei AnTat 1.9. Purified astrocytes or microglia from mouse brains were cocultured with T. b. brucei, and in some instances with interferon (IFN)-gamma, which is known to be released during the disease and also to be a growth factor for trypanosomes. Inducible NO synthase (iNOS) expression was studied by indirect immunofluorescence and reverse transcriptase-polymerase chain reaction. NO production was determined by measuring nitrite generation in culture. Detection of iNOS in astrocytes and microglia in the presence of T. b. brucei, was closely associated with nitrite production and was strongly enhanced by the addition of IFN-gamma to the culture medium. The stimulation of iNOS activity required parasite-cell contact and likely occurred at the transcriptional level. This study demonstrates the induction of iNOS in CNS-related macrophage cells in the presence of trypanosomes and its potentiation by IFN-gamma.

Animals↗
PubMed1999

Heterogeneity of serum IgG subclass deficiencies in B chronic lymphocytic leukemia.

The occurrence of abnormally low serum immunoglobulin (Ig) levels is well-known in B chronic lymphocytic leukemia (CLL), but published data on IgG subclass levels are virtually absent. We measured serum IgG subclass levels in 52 B CLL outpatients, most in stage A and untreated, using an indirect immunoenzymatic assay with monoclonal antibodies. Mean levels of all Ig isotypes were lower than in normal controls in the whole group of patients, except for IgG2 in those studied at diagnosis. Levels of IgG1, IgG2, IgA, and IgM were lower in patients with a long disease duration than in those studied earlier. IgG subclass deficiencies occurred in 54% of cases and the most frequently affected isotype was IgG1. Every possible combination of IgG subclass and Ig class deficiencies from the selective deficiency of a single subclass to a combined deficiency of all isotypes was observed. This marked heterogeneity argues against the occurrence of isolated defects of one of the cytokines involved in Ig switching as a cause of hypoimmunoglobulinemia in CLL.

Aged↗
PubMed1998

Preincubation of human resting T cell clones with interleukin 10 strongly enhances their ability to produce cytokines after stimulation.

Interleukin 10 (IL-10) has been described as a cytokine inhibitory factor downregulating IL-2 secretion and inducing T cell anergy. The data reported in this study show that preincubation of resting T cells from the human CD4+ clone SP-B21 (and clone TA-23.6) with IL-10 strongly enhances their capacity to further produce IL-2, interferon gamma (IFN-gamma), IL-4 and tumour necrosis factor alpha (TNF-alpha) after subsequent activation. In contrast, when IL-10 was added during the activation step, the previously reported specific inhibition of IL-2 synthesis was observed. Flow cytometric analysis of intracellular IL-2- and IL-4-producing cells revealed that preincubation with IL-10 increased the number of cytokine-producing cells, but did not affect their individual ability to produce these cytokines. We further show that IL-10 plays a dose-dependent role of viability maintenance factor. This effect relates to a direct anti-apoptotic effect of IL-10, which is likely independent of the expression of bcl-2, bcl-x and fas. Such paradoxal properties of IL-10 on T cells should be considered when aiming at using IL-10 as an immunosuppressive molecule in the treatment of diseases.

Clone Cells↗
PubMed1998

Absence of anti-beta2 glycoprotein I antibodies in giant cell arteritis: a study of 45 biopsy-proven cases.

OBJECTIVE: To search for a relationship between serum anti-beta2 glycoprotein I (anti-beta2GPI) antibodies and the occurrence of ischaemic complications in giant cell arteritis (GCA), since the latter do not correlate with anti-cardiolipin antibodies (ACL), which are frequently observed in GCA. METHODS: IgG and IgM anti-beta2GPI antibodies and ACL were measured by enzyme-linked immunosorbent assays in sera, collected before treatment, from 45 unselected patients with biopsy-proven GCA, including 15 patients with ischaemic events. RESULTS: IgG and IgM anti-beta2GPI antibodies were not detected in any of the patients, contrasting with the presence of ACL in 51%, of them, without correlation with ischaemia. CONCLUSION: Anti-beta2GPI antibodies are not detectable in GCA, contrasting with the occurrence of ACL, and ischaemic complications are apparently unrelated to the most frequent anti-phospholipid antibodies.

Aged↗
PubMed1996

Mitogenic activity of new lectins from seeds of wild Artocarpus species from Vietnam.

Proliferative response of human peripheral blood mononuclear cells (PBMC) stimulated by new lectins purified from seeds of differents Artocarpus species from Vietnam (A. asperulus, A. heterophyllus, A. masticata, A. melinoxylus, A. parva and A. petelotii) was studied and compared to those of the lectin jacalin purified from jackfruit (A. heterophyllus) seeds collected in the island La Réunion. All lectins stimulated human PBMC to proliferate, with a variable efficiency of the mitogenic activity. Phenotypic analysis of cells recovered after 7 day-cultures showed that these lectins mostly stimulated CD4+ T lymphocytes. These results suggest that these lectins from different Artocarpus species are similar in terms of their mitogenic activity although their structural features are not identical.

CD4-Positive T-Lymphocytes↗
PubMed1993

Chromosomal analysis of purified B-chronic lymphocytic leukemia lymphocyte cultures: comparison with whole blood cultures and in situ hybridization.

Chromosomal analysis of stimulated whole blood cells and purified B lymphocytes was performed in 13 stage A(0) and 1 stage C(IV) chronic lymphocytic leukemia (B-CLL) patients. Abnormal clones were found in 6 cases in purified B lymphocytes cultures and in a single one in whole blood cultures. In situ hybridization with a chromosome 12 probe was in accordance with the chromosomal analysis of purified B-CLL lymphocytes and not with the results obtained using whole blood culture. Cytogenetic analysis of isolated B cells is simple and sensitive. It enhances the detection of abnormal clones in B-CLL and applied to larger series of patients, it should allow a precise evaluation of the incidence of chromosomal abnormalities in CLL and of their clinical (prognostic) significance.

Aged↗
PubMed1991

Changes in serum immunoglobulin patterns in adults with common variable immunodeficiency.

Striking variations of serum immunoglobulin class and IgG subclass levels were observed in five patients with common variable immunodeficiency. They occurred mainly in untreated patients or, in those patients who received substitutive therapy, could not be merely due to replacement. They result in major changes in the immunoglobulin deficiency patterns, such as a shift from profound hypoimmunoglobulinaemia to IgA/IgG2/IgG4 deficiency or to isolated IgG2 deficiency. These findings have practical implications for the diagnosis and management of patients with primary humoral immunodeficiency.

Adult↗
PubMed1990

Structural and functional similarities of breadfruit seed lectin and jacalin.

Aquous extracts from seeds of Artocarpus altilis (breadfruit) and Artocarpus heterophyllus (jackfruit) were compared by polyacrylamide gel electrophoresis. Two bands of the same size (12 and 15 kD) as the jacalin subunits were the major components in breadfruit seed extract. They strongly reacted with anti-jacalin antibodies by western blotting. The breadfruit lectin displayed the same IgAl and IgD precipitation specificity as jacalin in gel double diffusion experiments. It also stimulated in vitro proliferation of human peripheral blood mononuclear cells. These results suggest that lectins from both species of Artocarpus are very similar.

Cell Division↗
PubMed1990

Human monoclonal IgM with autoantibody activity against two gangliosides (GM1 and GD1b) in a patient with motor neuron syndrome.

Small amounts of oligoclonal immunoglobulins were detected by Western blotting in the serum from a patient with motor neuron syndrome. The prominent one, a monoclonal IgM lambda, reacted strongly with the gangliosides GM1 and GD1b and more weakly with asialo GM1, as shown by immunoenzymatic staining of thin-layer chromatograms of gangliosides, ELISA on purified glycolipid coats and immunoadsorption with purified GM1. Affinity-chromatography with purified GM1 resulted in the purification of monoclonal IgM lambda. This purified IgM and its Fab fragments showed the same pattern of reactivity with gangliosides as that observed with whole serum. Such monoclonal IgM could be responsible for motor neuron diseases in some patients with overt or barely detectable monoclonal gammopathies.

Aged↗
PubMed1989

Functional brain asymmetry and murine systemic lupus erythematosus.

The role of brain lateralization in antibody production was studied in a murine systemic lupus erythematosus model. Male and female New Zealand black mice that spontaneously produce pathogenic auto-antibodies directed against red blood cells and DNA, were divided into right- and left-handers using a paw preference test, and anti-erythrocyte and anti-DNA antibody production was repeatedly determined. In females, antibodies against erythrocytes and double-stranded DNA appeared earlier in left-handers. These results provide the first evidence of an association between a functional brain asymmetry and auto-antibody production and suggest the involvement of the central nervous system in the pathogenesis of autoimmune processes.

Aging↗
PubMed1989

A cross-reactive idiotype on anti-DNA antibodies defines a H chain determinant present almost exclusively on IgG antibodies.

We have previously reported two anti-idiotypic antibodies, 3I and 8.12, that recognize L chain determinants on anti-DNA antibodies. We have generated a new anti-idiotypic antibody, F4, that recognizes a H chain determinant on cationic anti-DNA antibodies. F4 reactivity is present in high titer in serum of approximately 60% of SLE patients and on 84 of 706 myeloma proteins. It is preferentially associated with 3I reactive L chains. Furthermore, antibodies bearing both the F4 and 3I idiotypic determinants preferentially bind DNA. Amino acid sequencing of H chains isolated from four F4-reactive myeloma proteins suggests that they derive from two currently identified VH gene families. F4 reactivity is restricted almost exclusively to Ig of the IgG isotype suggesting that F4 may recognize either a somatically mutated hypervariable region or a variable region used late in the immune response. F4, therefore, represents a new idiotypic family preferentially associated with auto-Ag specificity and having features of an Ag-driven immune response.

Amino Acid Sequence↗
PubMed1989

Serum IgG subclass levels in patients with primary immunodeficiency syndromes or abnormal susceptibility to infections.

Serum IgG subclass levels were measured using an indirect competitive immunoenzymatic assay with monoclonal antibodies in 221 patients affected with definite immunodeficiency (ID) syndromes and 229 patients presenting with infection patterns suggestive of ID, but with normal immunoglobulin class levels and no clear evidence of ID. In common variable ID and IgG-IgA deficiency with normal or high IgM, subclass imbalance (mostly IgG1-IgG3 or IgG2-IgG4 deficiency) was the rule, with a higher incidence of severe infections in IgG2-IgG4 defects. One-fifth of patients with IgA deficiency, especially those with autoimmune cytopenia, had subclass deficiencies with no significant correlation with the occurrence of infections. Subclass (mostly IgG2-IgG4) deficiencies were also observed in severe combined ID, defective expression of HLA class II antigens, chronic mucocutaneous candidiasis, and IgM deficiency. Subclass levels were normal in all but one (who was IgG3 deficient) patient with the Wiskott-Aldrich syndrome and in the Buckley's syndrome, except for an unusual patient who presented with low IgG and IgA levels. Subclass (mainly IgG2) deficiency occurred in 24% of infected patients without known ID.

Autoimmune Diseases↗
PubMed1988

Glomerular and serum immunoglobulin G subclasses in membranous nephropathy and anti-glomerular basement membrane nephritis.

The distribution of human IgG subclasses among the glomerular deposits of 53 patients with glomerulonephritis was examined by immunofluorescence (IF) with subclass-specific monoclonal antibodies (Mab). A subclass restriction was observed in idiopathic membranous nephropathy (MN) with glomerular deposits predominantly containing IgG4 (81% of the studied biopsies) and IgG1 (75%). In de novo MN, occurring after transplantation, the restriction was markedly different, with a predominance of IgG1 (100%) and IgG2 (69%). In anti-glomerular basement membrane (a-GBM) nephritis the restriction was considerable with deposits containing almost exclusively IgG1 (91%) and IgG4 (73%). The same restriction was observed for circulating anti-GBM antibodies detected by indirect IF assay. By contrast IgG1, IgG2, and IgG3 deposits were identified in lupus proliferative glomerulonephritis. Serum IgG subclass levels were measured in 29 patients with idiopathic MN and a-GBM nephritis by an indirect competitive immunoenzymatic assay using Mab. Mean percentage of IgG2 serum level was significantly lower in patients. In spite of high variations from patient to patient, a serum IgG subclass imbalance was clearly present in 10 cases with low IgG2 and high IgG1 and IgG3 levels. The imbalance in these patients was not due to urinary loss since it was observed with a similar frequency in hypo- and normoimmunoglobulinemic patients. In 5 out of these 10 patients IgG2 levels were very low, analogous to those observed in selective IgG2 deficiency. Whether the important subclass restriction of glomerular IgG (in which patterns differed according to the type of glomerulonephritis) and the serum subclass imbalances were due to a clonally restricted antibody response to a particular antigen or to a host immune response defect, or both, remains to be elucidated.

Autoantibodies↗
PubMed1988

Isotypy of serum monoclonal immunoglobulins in human immunodeficiency virus-infected adults.

The classes, subclasses and light chain types of 78 serum monoclonal immunoglobulins (MoIg) from adult patients affected with various clinical forms of human immunodeficiency virus (HIV) infection were studied by a sensitive Western blot technique. The incidence of MoIg-containing sera was 26% in a systematic study. Most of these sera contained several (up to eight) detectable MoIg. These MoIg were IgG (91%) and IgM (9%) with a predominance of light chains of the lambda type (kappa:lambda ratio 0.6). The subclass distribution of monoclonal IgG was strikingly different from that observed in myeloma; much less IgG1 and much more IgG3 and IgG4.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Preferential expression of the systemic lupus erythematosus-associated idiotype 8.12 in sera containing monoclonal immunoglobulins.

The 8.12 idiotype defines a population of anti-DNA antibodies present in the serum of patients with systemic lupus erythematosus. As part of our studies to elucidate the genetic origin and structural features of anti-DNA antibodies, we examined monoclonal immunoglobulin (Ig)-containing sera from 706 patients for expression of the 8.12 idiotype. We found 41 such sera to have significant 8.12 reactivity (greater than 4 SD above the mean of normal controls) and demonstrated that in 24 of these sera (8 IgM, 14 IgG, and 2 IgA) this reactivity could be localized to the monoclonal protein. In addition, 12 of the 8.12-reactive monoclonal Ig (11 IgG and 1 IgA) bind dsDNA. In the other 17 sera, the 8.12 reactivity could be attributed to polyclonal antibody. These findings provide further evidence that the serum monoclonal Ig frequently express the antigenic and idiotypic reactivities of autoantibodies. Furthermore, these data support the contention that anti-DNA specificity may result from somatic diversification of germ-line Ig gene sequences.

Antibodies, Antinuclear↗