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Biomedical subjects

M Bagot

Publications and source records attributed to M Bagot.

At least 163 records · Page 9Linked to original sources
PubMed1986

A human autoreactive T cell line specific for minor histocompatibility antigen(s) isolated from a bone marrow-grafted patient.

A human autoreactive T cell line named Bur-1 has been obtained from a woman 4 mo after an allogeneic bone marrow transplantation (BMT) from one of her HLA-identical brothers. The phenotype of the cell line is 100% T11+ and over 90% T4+, and the karyotype confirms its donor (male) origin. These donor T cells proliferate specifically in the presence of donor's peripheral blood monocytes (PBM) but not recipient's cells, and they kill specifically donor's but not recipient's Epstein-Barr virus (EBV)-induced lymphoblastoid cell lines (LCL). PBM from another HLA-identical brother and from several unrelated donors also stimulate Bur-1 cells, and EBV-induced LCL from the same donors are killed in cytotoxicity assays. All of these donors share HLA-DR5 or HLA-DRw11 (the major split of HLA-DR5) with Bur-1 cells. However, some but not all of the PBM sharing HLA-DR5 with Bur-1 cells are recognized. Therefore, in contrast with the previously described autoreactive T cells, Bur-1 cells are not directed against self-MHC antigens but rather recognize autologous minor histocompatibility (mH) antigens in the context of autologous HLA class II molecules. Because both male and female cells can be recognized, the reacting minor antigen could not be the male-specific HY antigen. It is suggested that autoreactivity against mH antigens can be observed in bone marrow-grafted patients due to the education of bone marrow donor precursors in the recipient thymus not allowing tolerance to autologous (donor) mH antigens not shared by the recipient.

Bone Marrow Transplantation↗
PubMed1986

B cells from leukemic patients are relatively resistant to in-vitro EBV transformation.

Samples of peripheral blood mononuclear cells (PBMC) from normal donors or from leukemic patients were used to obtain Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL). Whereas the rate of transformation was around 85% with normal donors, it was only around 20% with leukemic patients. However no explanation for this resistance of B cells from leukemic patients to in-vitro EBV transformation could be found. Indeed no correlation exists between this EBV resistance and the age, sex, diagnosis or chemotherapeutic regimen. Furthermore no correlation is apparent between the percentage of B2+ cells, which should have EBV receptors, and the successful EBV transformation.

B-Lymphocytes↗
PubMed1986

A possible predictive test for graft-versus-host disease in bone marrow graft recipients: the mixed-epidermal cell-lymphocyte reaction.

The possible ability of the mixed-epidermal-cell-lymphocyte reaction (MECLR) to detect alloreactivities in HLA-identical MLR negative siblings has been investigated before grafting in 30 donor-recipients pairs and their families. Results indicate that recipients' epidermal cells (EC) can induce proliferative responses of HLA-identical MLR-negative donors' lymphocytes in 55% of the pairs tested. Moreover, further evaluation of 21 patients shows that the positivity of the MECLR before the graft is correlated with later appearance of acute and chronic GVHD, and especially with the severity of cutaneous injury. EC have been shown to be more efficient antigen presenting cells than peripheral blood lymphocytes for in vitro primary proliferative responses, so these reactions could be directed against some minor histocompatibility antigens, thus leading to possible improvement in selecting bone marrow graft donors and to the detection of donor-recipient pairs with a high risk of GVHD.

Adolescent↗
PubMed1986

Class II MHC antigen expression by human keratinocytes results from lympho-epidermal interactions and gamma-interferon production.

Human peripheral blood lymphocytes were co-cultured with either allogeneic, autologous or purified protein derivative of tuberculin (PPD) pulsed autologous epidermal cells. In these mixed skin cell-lymphocyte culture reactions (MSLR), lymphocytes are stimulated to proliferate by epidermal cells. The supernatants of MSLR were examined for their capacity to induce class II MHC antigen expression on separately cultured epidermal cells. It is shown that supernatants from allogeneic and PPD pulsed autologous MSLR contained the factor(s) which stimulated HLA-DR antigen synthesis and expression by 30-40% of cultured epidermal cells. Kinetic analysis revealed a production rate maximum between 72 and 96 h of lympho-epidermal co-cultures. The factor mediating the induction of HLA-DR antigen expression on epidermal cells is thought to be gamma-interferon, because it was sensitive to pH 2 as well as heat incubation. Furthermore, anti-gamma-interferon monoclonal antibody abolished its activity. It is proposed, that HLA-DR antigen expression by keratinocytes observed in vivo in different dermatological inflammatory disorders originates from lympho-epidermal interactions and local gamma-interferon production as documented here in experiments in vitro.

Adult↗
PubMed1986

Mixed epidermal cell-lymphocyte reaction in prediction of acute graft-versus-host disease in bone marrow recipients.

Peripheral blood lymphocytes (PBL) and epidermal cells (EC) of 44 patients to be grafted with bone marrow from an HLA-identical sibling have been used as stimulator cells in primary cultures with effector PBL of one or several potential donors. Proliferative responses against PBL did not differ from those obtained with effector cells cultured in medium alone, whereas EC induced clearly positive proliferation in 21/53 (40%) of the pairs tested. Evaluation of 30 patients followed for more than 3 months after the graft shows that a high level of response in the mixed epidermal cell lymphocyte reaction is directly correlated with the incidence of acute graft-versus-host disease.

Acute Disease↗
PubMed1985

Human epidermal cells are more potent than peripheral blood mononuclear cells for the detection of weak allogeneic or virus-specific primary responses in vitro.

Human epidermal cells (EC) and peripheral blood mononuclear cells (PBMC) have been used as antigen-presenting cells in allogeneic reactions or in self-restricted antiviral responses. Comparison of results from both cell types indicates that: (1) EC were better stimulators of primary proliferative responses in all the antigenic systems tested. (2) In secondary reactions, EC and PBMC functioned similarly for allogeneic responses, while a weak but significant difference could be observed in both (HSV1 or influenza A) virus-specific reactions. (3) By comparing pairs of HLA-identical mixed lymphocyte reaction (MLR)-negative siblings, positive responses were observed in several different families when lymphocytes of potential bone marrow donors were stimulated by EC of the recipient. This suggests that EC might be useful in detecting relatively weak proliferative responses in a number of antigenic systems, but especially in primary reactions against viral or putative minor histocompatibility antigens. (4) Despite this stronger antigen-presenting capacity in proliferative responses, EC induced lower levels of cytotoxic T lymphocyte (CTL) reactions than PBMC, not only in allogeneic responses but also in virus-specific self-restricted reactions.

Adult↗
PubMed1984

[Lumbar puncture: indications and limitations].

Fast deterioration of the neurological status of patients with raised intracranial pressure after lumbar puncture is not rare. Cerebral coning or rebleeding occur in consequence of cerebrospinal fluid leak. An experimental model correlates leakage with needle gauge. Computed tomography is indicated for diagnosis at the time of the initial examination. Puncture with needles of small diameter (less than 0.5 mm) is recommended.

Acute Disease↗
PubMed1984

[The Gardner-Diamond syndrome or painful recurrent ecchymotic purpura].

A case of Gardner-Diamond's syndrome is reported in which the lesions were localized to the face. The syndrome is characterized by the spontaneous onset of recurrent painful ecchymoses mainly in young women. The elective site of the lesions is on the limbs, sometimes on the abdomen or thorax, and only rarely on the face. They are accompanied by a very rich symptomatology contrasting with normal biological test results. An autoerythrocytic sensitization mechanism has been suggested but few biological arguments exist to support this auto-immune hypothesis of its origin. In contrast, the psychological background is hysterical in type, and the affection can be included among the psychogenic purpuras.

Adult↗
PubMed1983

Influence of HLA class I- and class II-specific monoclonal antibodies on DR-restricted lymphoproliferative responses. I. Unseparated populations of effector cells.

L1-16, a DR-specific, nonpolymorphic monoclonal antibody (MoAb) recognizing the beta-chain of the molecule, blocked virus-specific as well as allogeneic-proliferative T cell responses, whereas another nonpolymorphic anti-DR MoAb blocked proliferative responses to allogeneic cells only. IL 2-supernatants reversed the blocking induced by L1-16. On the other hand class I-specific MoAb B1-23-2 (HLA-A-B-C-specific) and M 18 (beta 2 microglobulin-specific) and their F(ab')2 fragments blocked equally virus-specific or allogeneic proliferative responses. IL 2-containing supernatants did not reverse this phenomenon. Neither anti-class I nor anti-class II MoAb inhibited the IL 2-induced proliferation of IL 2-dependent established T cell lines. MoAb acted neither at the antigen-presenting cell level nor by a toxic effect nor by inducing suppressor cells. These results suggest that a) different epitopes of the DR molecule can be involved during responses to influenza viruses and allogeneic antigens; b) the epitope recognized by L1-16 on the beta-chain of the DR molecule seem necessary for IL 2 production by lymphocytes after activation with influenza antigens; and c) class I-specific MoAb block DR-restricted proliferative responses of lymphocytes by an as yet unknown mechanism.

Adult↗
PubMed1982

[Acquired angioneurotic edema caused by acquired deficiency of C1 esterase inhibitor disclosing lymphoproliferative syndrome. Apropos of a case, review of the literature].

One case of acquired angio-neurotic oedema is described and discussed with the other cases recorded in literature since Caldwell's one in 1972. This entity is characterized by: --the late onset of angio-oedema but its presence only in about half cases, --a complement deficiency resulting from the lack of C1-esterase inhibitor, --the absence of familial identical cases, --the great frequency of associated illnesses overall lympho-proliferative diseases, --the therapeutic response to either etiologic treatment of the associated disease or to the symptomatic effect of drugs used in hereditary angio-neurotic oedema.

Aged↗
PubMed1979

[Hepato-pulmonary Nocardia infections (report of one case) (author's transl)].

Actinomycosis due to Nocardia asteroides is a mainly pulmonary disease; the metastases are due to migration of the germ in the blood from the primary lung focus. The case reported here concerned a patient whose initial symptoms were mainly hepatic, suggesting an amoebic abscess of the liver. The pulmonary lesions appeared only secondarily with presence in the sputum of the nocardia which was responsible. Prolonged treatment with trimethoprime sulfamethazole led to complete and lasting cure of the lesions, confirmed radiographically and by a liver scan.

Aged↗
PubMedDate not supplied

Induction of rat CD4+ proliferative and mouse CD8+ cytotoxic T-cell lines specific for human papillomavirus type 16 antigens.

Infection by human papillomavirus type 16 (HPV16) has been associated with cervical dysplasia and carcinoma. To detect a possible cellular immune response against HPV16, we investigated the induction of T cells specific for antigens encoded by the virus. Two CD4+ T-cell lines with a specific proliferative response were isolated from the spleens of rats vaccinated using vaccinia virus vectors expressing E6 or E7 and challenged with syngeneic HPV-transformed cells. Two CD8+ T-cell lines with a specific cytotoxic activity were obtained from mice immunized using a syngeneic squamous cell tumour cell line transfected with the full-length HPV16 DNA. These results demonstrate that both CD8-mediated cytotoxic responses and CD4-mediated delayed-type hypersensitivity responses are involved in immunologic reactions to HPV antigens.

Animals↗
PubMedDate not supplied

[Granuloma with lymphocytic hyperplasia following vaccination: 10 cases. Presence of aluminium in the biopsies].

BACKGROUND: Few cases of cutaneous lymphocytic hyperplasia secondary to vaccination have been published, although such lesions are not rare. PATIENTS AND METHODS: We report a series of 10 cases registered between 1993 and 2003. RESULTS: Mean age was 25. The clinical aspect was solitary or multiple subcutaneous nodules, located on the arm, developing after a delay of 1 to 18 months after vaccination. Histologic examination showed a lymphocytic infiltration of the subcutaneous fat, with diffuse and/or follicular pattern, without nuclear atypia, the morphological and immunohistochemical analysis of which revealed the benign nature. In all cases, there was fibrosis and granuloma composed of lymphocytes, plasma cells, eosinophils and macrophages with basophilic cytoplasm. Morin stain showed intralesional aluminium in the 6 investigated cases. Evolution was always benign, with no relapse following exeresis. DISCUSSION: Cutaneous lymphocytic hyperplasia secondary to vaccination has to be suspected in a young patient with subcutaneous nodules appearing at a vaccination site. Evidence of aluminium in the lesions supports the diagnosis and the hypothesis that aluminium in the vaccine excipient might have a role in the onset of such lesions.

Adolescent↗