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Biomedical subjects

P Soubiran

Publications and source records attributed to P Soubiran.

16 recordsLinked to original sources
PubMed1988

Antitubulin antibodies. II. Natural autoantibodies and induced antibodies recognize different epitopes on the tubulin molecule.

Natural and induced antitubulin antibodies were compared for their epitope recognition on alpha- and beta-tubulin subunits by immunoenzymatic assays and Western blot techniques on partially digested tubulin molecules. Our results indicated that natural autoantibodies recognized different epitopes from those recognized by induced antibodies, because: 1) all polyspecific natural autoantibodies tested so far recognized the same or very overlapping epitopes in the central part of both alpha- and beta-subunits (between positions 100 and 300 on the tubulin amino acid sequence) and that this epitope differed from the various epitopes recognized by induced antitubulin antibodies on the amino-terminal or carboxy-terminal parts of the tubulin subunits; 2) one human myeloma protein (monoclonal (m)IgA, kappa) with a monospecific antitubulin activity bound to an epitope around position 310 on both alpha- and beta-subunits and a second human mIg (mIgM, kappa) with a monospecific anti-beta activity bound to an epitope on the carboxy-terminal part of the subunit around amino acid position 350. Both epitopes differed from epitopes recognized by induced antitubulin antibodies. These results thus confirmed our previous findings indicating that natural and induced antitubulin antibodies do not share cross-reactive idiotopes.

Animals↗
PubMed1988

Distribution of Trop 3 and 4 antigens in human endometrial glandular epithelium.

The reactivities of three monoclonal antibodies (MAbs), Trop 3, Trop 4, and W6/32, were studied on human uterine tissue by using an indirect immunoperoxidase method. Nonpregnant endometrial glandular epithelium was stained by all three MAbs. During pregnancy, Trop 3 expression was not detectable, but Trop 4 and W6/32 showed variable staining on the endometrial glandular epithelium, especially during late pregnancy. These findings support previous work suggesting a local regulation of antigenic expression by endometrial glandular epithelial cells.

Antibodies, Monoclonal↗
PubMed1988

Human serum reacting specifically with a subset of beta-tubulin isoforms.

The serum of a patient suffering from myeloma was found to decorate microtubules and mitotic spindles of cultured cells. Immunoblots performed after one- and two-dimensional electrophoresis showed a reaction with a certain subset of beta-tubulin isoforms, but not with beta'- and alpha-tubulins. The tubulin subset contained both ubiquitous (beta-3) and neurospecific (beta-4,5,6) isoforms. An IgM lambda and an IgA kappa myeloma protein were found in this serum. Immunoblots performed with specific anti-isotype second antibodies showed that the tubulin subset could be evidenced using anti-mu, alpha, lambda, and kappa-specific antisera. Moreover, the tubulin subset was also evidenced using an anti-gamma second antibody. These results, which do not exclude a participation of the myeloma proteins in the anti-tubulin reactivity, indicate, however, that the antibody response was polyclonal. The same restricted specificity of all classes of anti-tubulin antibodies of this serum favours the hypothesis that the immune response of the patient was directed against an antigen sharing epitopes with tubulin rather than with tubulin itself.

Animals↗
PubMed1987

IL2-like material is present in human placenta and amnion.

Human term placenta was shown to react with different polyclonal and monoclonal anti-interleukin 2 (IL2) antibodies by using indirect immunofluorescence on frozen sections. Labelling was localized on syncytiotrophoblast membrane, amniotic epithelium and cytotrophoblast of the reactivity [corrected]. The reproducibility of the observations with different basal plate. These features were observed with two different rabbit anti-IL2 polyclonal antibodies, a sheep IL2 antiserum and 15.2, an anti-IL2 monoclonal antibody. However, DMS-1, a second anti-IL2 monoclonal antibody, did not react. Pre-incubation of anti-IL2 sera with IL2 resulted in the disappearance of syncytiotrophoblast reactivity. The reproducibility of the observations with different reagents strongly suggests that the recognized molecule shares several epitopes with IL2. However, it has not been possible to demonstrate the presence of a conventional IL2 receptor by using two monoclonal antibodies directed to the 55 kDa chain of IL2 receptor.

Amnion↗
PubMed1986

Distribution of Trop 3 and 4 antigens as defined by monoclonal antibodies raised against a human choriocarcinoma cell line.

The reactivities of Trop 3 and 4 monoclonal antibodies (MAbs) were studied on human term and 7-week extraembryonic membranes, adult tissues, and cell lines. Trop 3 MAb reacted with cells of chorionic villi, decidua, amniotic epithelium, and basal plate trophoblast. Trop 4 MAb reacted only with syncytiotrophoblast. On epithelium, Trop 3 MAb bound to stratified and glandular epithelium, but Trop 4 MAb reactivity was limited to basal keratinocytes. On peripheral blood mononuclear cells, Trop 3 MAb reacted with the majority of cells and Trop 4 MAb with the totality. Most cell lines were positive with both MAbs. However, one chemically induced MHC mutant was negative and another decreased its expression of Trop 3 antigen. Our results suggest Trop 3 MAb might recognize a monomorphic determinant of TLX antigens and Trop 4 is involved in cell proliferation or in cell-to-cell interaction.

Antibodies, Monoclonal↗
PubMed1986

[Physiology of Langerhans cells and their potential role in oral pathology].

Langerhans cells represent a minor epidermal cell population in mammals. They are also observed in squamous epithelia of the oesophagus, vagina and cervix, as well as in oral epithelia. They occur in higher density in the non keratinized epithelium. These cells are characterized by a dendritic pattern, a clear cytoplasm and ultrastructurally by the presence of Birbeck granules. They are usually located in a suprabasal position. Their bone marrow origin is now well established. Surface markers and functional properties identify them as belonging to the macrophage/monocyte lineage. Langerhans cells can be identified in tissue sections by immunofluorescence or immunoperoxidase techniques using monoclonal antibodies directed against surface antigens such as class II histocompatibility antigens, T6 marker, or possibly T4 marker. There is also a cytoplasmic marker, the S-100 protein. A renewed interest in Langerhans cells comes from evidence of their role in the cutaneous immune response. At present these cells are considered as dendritic cells expressing a high density of class II histocompatibility antigens and behave as very potent antigen presenting cells that activate mainly helper T lymphocytes. However, experimental data on antigen processing and interleukin 1 secretion are still lacking. This review also examines the oral pathology literature with respect to modifications in the number or localization of Langerhans cells and their proximity to T lymphocytes, for example in lichen planus, Behcet's syndrome, erythema multiforme, gingivitis and oral carcinoma. Histiocytosis X represents a particular case in which the Langerhans cell itself is affected.

Behcet Syndrome↗
PubMed1985

HLA in families with Down's syndrome children.

Thirty couples having a DS child were typed for HLA-A and B antigens and compared to twenty control families and 176 blood donors. Although differences in frequency of B antigens exist between DS families and controls, they are not significant after correction for the number of antigens tested. No excessive HLA sharing was found in DS parents contrarily to two previous studies (Mattironi et al. 1981, Aymé et al. 1983).

Adult↗
PubMed1979

[Modifications of the maternal immune response associated to pregnancy (author's transl)].

The author reviews the literature on the immune status of pregnant women. No major alteration of the immune response was observed. If any, the modifications are not important and involve the synthesis of immunoglobulins, the presence of circulating immune complexes, some sub-populations of mononuclear cells and the in vitro lymphocyte response to T dependent antigens. Phagocytosis, the number of B and T cells and mitogen lymphocyte response are normal. Studies on the immuno-suppressive effect of both pregnant women sera and serum substances (hormones, pregnancy associated or specific proteins, carcino-embryonic antigens) are reported. Discrepancies are observed between conclusions drawn by various authors: they relate to the efficiency of the measurement and to the observed effect. The contradictory results obtained with alpha-foetoprotein provide an illustration of the critical analysis of these studies. Finally, the in vivo immune status of pregnant women is reported as observed in cutaneous tests, transplantations and auto-immune diseases. The most relevant observations are: a defect of the expression of delayed hypersensitivity reaction, a facilitating effect of pregnancy in kidney transplantation similar to that obtained after transfusion and an inconstant and mild defect of graft immunity. Therefore, pregnancy produces a specific immune status about which tests presently available give few relevant results, similar to those obtained in some cancers.

Animals↗
PubMed1976

[Hematologic manifestations of thymomas].

The hematologic manifestations during thymomas are dominated by erythroblastopenia. Though, the other series can be affected and red series can present other troubles. The authors report two cases, one with erythroblasto-penia-hypogammaglobulinemia, the other with polycythemia, and a review of the literature attempt to make the point on the subject.

Agammaglobulinemia↗