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Biomedical subjects

M Fellous

Publications and source records attributed to M Fellous.

At least 181 records · Page 10Linked to original sources
PubMed1980

[Genetic, biochemical and functional study of the H-Y antigen in man].

H-Y antigen, first described as a male minor transplantation antigen, is unvarying associated with testicular differentiation, more than the presence of Y chromosome. The weak reactivity of anti H-Y serum needs quantitative and very sensitive tests to detect presence or absence of H-Y. This antigen may act as an hormone, to induce testicular differentiation of target cells, bearing a specific receptor at their surface. The relationship between an H-Y molecule immunologically defined by its antigenicity and H-Y factor defined by its function to induce testicular organogenesis must be determined.

Animals↗
PubMed1979

Absence of allogeneic restriction in human T-cell-mediated cytotoxicity to Epstein-Barr virus-infected target cells. Demonstration of an HLA-linked control at the effector level.

Peripheral T lymphocytes from patients with infectious mononucleosis (IM) are sensitized in vivo against the Epstein-Barr virus (EBV). The expression of HLA-A, B, or C molecules at the target cell surface is necessary for the cytotoxic reaction because (a) EBV-positive Daudi cells lacking HLA-A, B, and C determinants are resistant to anti-EBV T-cell lysis, (b) cytolysis of EBV-positive target cells can be consistently inhibited by anti-HLA-A, B, and C and anti-beta 2 microglobulin antibodies. However, no evidence for allogeneic restriction in this system was apparent as (a) cytotoxic T lymphocytes (CTL) from one given individual could exert a cytotoxicity of a similar magnitude on different EBV-positive target cells, regardless of the number of HLA-A or B specificities shared by the effectors and targets; (b) CTL from IM patients were able to kill target cells without any HLA-A or B antigen in common; and (c) T5-1 variants lacking one or two HLA antigens at the A, B, or D locus are killed to the same extent as the parental cells. 7 of the 9 IM patients with detectable circulating anti-EBV CTL carried the HLA-A1 antigen, whereas none of the 16 IM patients lacking detectable peripheral CTL were HLA-A1 positive (mean specific lysis of T5-1 target cells by T cells from HLA-A1 positive patients: 29.3 vs. 0.6% in HLA-A1-negative patients) (P less than 10(-9)). These data suggest an HLA-A1-linked gene control of the magnitude of the anti-EBV CTL response. Thus, the HLA region appears to act at two different level sin the T-cell-mediated lysis of EBV-infected cells by controlling first, the development of anti-EBV and second, the expression of HLA-A, B, and C molecules involved as recognition structures at the target cell surface.

Antigen-Antibody Reactions↗
PubMed1979

Phenotype and surface antigens of mouse teratocarcinoma x fibroblast cell hybrids.

Numerous colonies of hybrids between PCC4-aza 1 teratocarcinoma cells and fibroblasts of the heteroploid Cl.1D cell line were examined. All of the hybrids were fibroblasts showing extinction of the multiple developmental potentialities of the teratocarcinoma cell parent, irrespective of whether the teratocarcinoma parent was diploid or tetraploid. The hybrids did not show loss of any specific chromosome contributed by the PCC4-aza 1 cell parent. In contrast with the PCC4 parental cells which carry F9 antigens and do not express H-2b, the hybrids do not express F9 antigens and carry H-2 alloantigens of both parental specificities. These results suggest that in hybrids whose phenotype is that of the Cl.1D parent, a change may occur in the genetic program of the teratocarcinoma cells.

Animals↗
PubMed1979

Distinctive properties of fucosyl glycopeptides on human teratoma cells.

Fucose-labeled glycopeptides from four human teratoma cell lines of independent origin show similar elution profiles on Sephadex G-50 column chromatography. The fucosyl glycopeptides elute in two major regions: one near the void volume, the other in fractions corresponding to a molecular weight of 2500-3000. These elution profiles are very different from those obtained with the other human cell lines examined which included 3 lymphomas, 2 colon carcinomas, and HeLa. The elution profiles of the human teratomas, however, show remarkable similarities to those obtained with murine embryonal carcinoma cell culture and early mouse embryos. These results suggest that the excluded G-50 fraction may well contain glycopeptides playing a role in mammalian embryogenesis.

Carcinoma↗
PubMed1979

Receptors for IgM on human lymphoblastoid B and T cell lines.

Receptors for the Fc of IgM were studied together with other lymphocyte markers on cells from nineteen human lymphoblastoid cell lines. Receptors for IgM were found on three of seven T lines and three of twelve B lines studied. Culture conditions needed for an optimal detection of the receptor were different for B and T lines. The presence of the receptor for IgM could not be correlated with that of any other membrane marker.

B-Lymphocytes↗
PubMed1979

Regional mapping of the HLA on the short arm of chromosome 6.

A detailed gene marker study was performed on a partial 6p trisomic child resulting from a balanced maternal translocation t (2;6) (p 2505; p2105). HLA typing and mixed lymphocyte reaction showed that the breakpoint on chromosome 6 was located within the HLA gene cluster, allowing an accurate location of the D determinants. Localization of the P blood group locus within the region 6 p 2105 to 6 p ter was excluded.

Cells, Cultured↗
PubMed1979

Cytogenetic study of a European Burkitt's lymphoma cell line.

The chromosomes of an Epstein-Barr virus-negative European Burkitt's lymphoma cell line were studied. All the cells carried the t(8;14) translocation. One clone had 51 chromosomes and was (+1,+7,+16,+15,+21), whereas another clone also had 51 chromosomes but was (+1q+,+7,+16,+15,+21). A third clone had 46 chromosomes (4q+/-).

Adolescent↗
PubMed1978

Association of the H-Y male antigen with beta2-microglobulin on human lymphoid and differentiated mouse teratocarcinoma cell lines.

The expression of the H-Y antigen has been tested on several human lymphoid lines and mouse teratocarcinoma cell lines during differentiation. The human male lymphoid cell line Raji is a very useful target for studies of the H-Y antigen by lymphocytotoxicity test with rat anti-H-Y sera. With a few exceptions, all cells carrying the Y chromosome were H-Y positive. One of the exceptions is the human Daudi cell line which, besides lacking H-Y antigen, also lacks beta2-microglobulin. We have studied a possible association between the H-Y antigen, beta2-microglobulin, and HLA antigen with redistribution experiments. The results strongly suggest that H-Y antigen is not associated with HLA antigens but with beta2-microglobulin.

Animals↗
PubMed1978

Presence of SLA and Ia-like antigen on boar spermatozoa.

Several parameters for serological tests on boar spermatozoa were studied, and a reliable technique was developed and employed. Using SLA (the MHC system in pig) genotyped boars, and specific reagents, SLA and Ia-like antigens were demonstrated on the sperm using both the cytotoxic and the absorption test. No SLA activity was detected in the seminal fluid.

Animals↗
PubMed1978

[beta2-Microglobulin in human seminal fluid (author's transl)].

The expression of human beta2-microglobulin (beta2m) on human spermatozoa cell surface was investigated by cytotoxicity and immunofluorescence tests. beta2m was also found in human seminal fluid by use of immunochemical techniques. Seminal fluids obtained from couples with infertility problems were tested for beta2m, albumin and total proteins concentration. A higher level of beta-2m was found in azoospermia compared with that of normal sperms.

Adult↗
PubMed1977

[Cytotoxicity of human T-lymphocytes sensitized by Epstein-Barr virus. Role of HLA antigens at the surface of target cells infected by the virus].

Peripheral T-lymphocytes from patients with infectious mononucleosis are cytotoxic towards target cells from Epstein-Barr virus-genome carrying human lumphoblastoid lines. Thus, these T-cells appear to be sensitized to viral coded determinants. Daudi cells, that carry EBV-genome, but lack HLA antigens are resistant to specific cytolysis in this model. These results suggest direct HLA involvement in the target structure recognized by birus-sensitized cytolytic T-lymphocytes in human.

Antigen-Antibody Reactions↗
PubMed1977

The expression and relation of HLA, beta2-microglobulin and receptor for marmoset red blood cells on man/mouse and man/Chinese hamster hybrid cells.

The expression of HLA, human and mouse beta2-microglobulin (beta2m), P red blood cell antigen and a receptor for marmoset red blood cells (MaRBC) were studied on 18 man/mouse and man/Chinese hamster hybrids. A positive correlation was found between the expression of HLA, P, and the receptor for MaRBC, which we interpret as a possible synteny between these different loci. We studied 3 hybrid clones where HLA antigens are still expressed despite the absence of human beta2m and where redistribution experiments demonstrate that HLA is associated with mouse beta2m. Synteny between HLA and the receptor for MaRBC can be a useful tool to select HLA-positive hybrid clones.

Animals↗