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B Guilbert

Publications and source records attributed to B Guilbert.

47 records · Page 3Linked to original sources

Natural antibodies against tubulin, actin myoglobin, thyroglobulin, fetuin, albumin and transferrin are present in normal human sera, and monoclonal immunoglobulins from multiple myeloma and Waldenström's macroglobulinemia may express similar antibody specificities.

Sera from a pool of 800 healthy donors and from 3 individual healthy donors were passed through tubulin, actin, thyroglobulin, myoglobin, fetuin, transferrin and albumin immunoadsorbents. Proteins were eluted in all the immunosorbents and were found to be essentially composed of the three major Ig classes and albumin. The isolated Ig fractions were shown to react specifically, via their Fab fragment with the antigens and were specifically inhibited by them. These results strongly suggest that natural antibodies against the seven antigens are present in normal human serum, and probably against a high variety of self antigens. These results prompted us to search in the sera of patients with monoclonal gammapathies, paraproteins having natural antibody-like function. Among the 62 sera studied 3 were shown to react with actin and 1 with tubulin. Most important, these 4 monoclonal immunoglobulins exhibited similar specificities to that found with natural antibodies. This seems to indicate, that at least for some patients, the monoclonal immunoglobulins produced may represent the expansion of a clone producing a natural antibody.

Actins↗

Regulation of the humoral immune response by polyspecific natural autoantibodies.

Two different BALB/c IgMk polyspecific monoclonal natural autoantibodies E7 and D23 were administered to neonatal BALB/c mice. When adults, these mice were immunized and challenged with calf myosin, BALB/c actin, human transferrin, calf thymus DNA or TNP-coupled bovine serum albumin (TNP/BSA), in complete Freund's adjuvant. The levels of serum antibody were evaluated by enzyme immunoassay. No differences in anti-actin, anti-transferrin and anti-DNA antibody titres were noted between control and antibody-treated mice. However, anti-myosin antibody titres significantly increased in mice treated with either the E7 or D23 antibody, and anti-TNP antibody titres significantly decreased in mice treated with E7 but not with D23. These differences persisted after antigenic challenge and involved only the IgG response of treated mice. These results suggest that polyspecific natural autoantibodies may be involved in the regulation of the humoral immune response.

Animals↗

Comparative study of natural autoantibodies in the serum and cerebrospinal fluid of normal individuals and patients with multiple sclerosis and other neurological diseases.

Using a panel of antigens (actin, myosin, tubulin, albumin, transferrin, peroxidase, thyroglobulin, DNA, prolactin, TNP and myelin basic protein (MBP], we have tested the antibody activity of serum and cerebrospinal fluid (CSF) from healthy individuals, patients with multiple sclerosis (MS) and individuals with other neurological diseases. No differences in the concentrations and specificities of the serum antibodies were observed among the 3 groups. In contrast, we found that MS patients often had elevated CSF antibody levels against many antigens of the panel. The MS patients with local immunoglobulin production in the central nervous system (CNS) had the highest antibody levels. Restricted antibody activity against a given antigen of the panel was not observed. Compared to the two other groups, the MS group had equivalent titres of anti-MBP antibodies in the CSF. These results suggest that, in MS, a general immune dysregulation exists which leads to a local expansion of B lymphocytes producing autoantibodies with reactivities similar to those of serum natural autoantibodies.

Antibody Specificity↗

[Anti-actin and anti-tubulin antibodies in the serum of non-immunized animals].

The preparation and the purification of anti-action and anti-tubulin antibodies is reported. The occurrence of low amount of IgG anti-tubulin was also found in the sera of non-immunized animals from various species. The staining of the cellular network of microtubules as well as of tubulin paracrystals was observed with both induced and natural antibodies.

Actins↗

Analysis of autoantibody reactivities in hybridoma collections derived from normal adult BALB/c mice.

Hybridoma collections were produced from lipopolysaccharide-stimulated adult BALB/c spleen cells, small resting spleen B cells and large activated spleen lymphocytes. The hybridomas were examined for production of immunoglobulins and of antibodies directed against a panel of self (actin, myosin, tubulin, DNA) and non-self antigens (myoglobin, spectrin, trinitrobenzene). From the 345 hybridomas secreting immunoglobulin, 68% did not react with any antigen of the panel, 17% reacted with only one, 5.5% with 2 and 7.9% with 3 or more. Apparently, each of the monoclonal multispecific antibodies exhibited a pattern of reactivity which was quite unique. There were no apparent differences in antibody reactivities between self and non-self antigens; moreover, with the exception of DNA, no differences were noted among the 3 different hybridoma collections.

Animals↗

[Bulimia and autoimmunity].

In the first part of this study, we investigated the rate of natural autoantibodies, in a sample of 31 female inpatients with bulimia nervosa according to DSM III-R criteria. The control (age and sex matched) group consisted in high school students including 10 females without eating disorders, depressive disorder or immunological disease. We investigated especially natural autoantibodies reacting with compounds of the central nervous system (Dopamine, Dopamine beta Hydroxylase, Serotonin). Our first conclusion is that there is a lower level of these natural auto-antibodies among female patients with bulimia nervosa. In the second part of the study, we have especially investigated the correlation between impulsivity in bulimia nervosa and the rate of natural autoantibodies against serotonin.

Adolescent↗