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D Charmot

Publications and source records attributed to D Charmot.

32 records · Page 2Linked to original sources
PubMed1978

A weak human MLR locus mapping at the right of a crossing-over between HLA-D, Bf and GLO.

An unexpected MLR reaction has been observed between three HLA-identical sibs; it consists of bidirectional positive MLR between identical female twins and a sister. No argument for a lymphoid mosaic could be found, although twins were frequent in the family; similarly no HLA-A/B or HLA-B/D recombinant could be demonstrated. The MLR, although weak, was highly reproducible. PLTs could be raised between the sibs, without an apparent segregation in this family nor in five other families, but such PLTs discriminated well between the positive and negative controls. In the absence of any proof that such a weak MLR locus could be on another chromosome than chromosome 6, two lines of argument are indirect evidences that such a locus could be indeed on chromosome 6: one of the sibs differs from the two others for two markers outside HLA--D--DR--Bf: glyoxalate (GLO) and red blood group P.

Blood Group Antigens↗
PubMed1977

Suppression of generation of human cytotoxic effectors by lectins or lectin-activated peripheral blood lymphocytes.

The lectins phytohemagglutinin, pokeweed mitogen and concanavalin A used at their optimal mitogenic concentration, or human lymphocytes activated by the same mitogens, were found to suppress the in vitro generation of cytotoxic effectors when added to a cell-mediated lympholysis (CML) mixture during the first 48 h of culture. The data suggest that the suppressive mechanism is mediated to a greater extent by an allogeneic interaction between lectin-activated cells and the allogeneic cells present in the CML mixture than by suppressor cells induced by the lectin. Since partial suppression was observed with supernatants of activated lymphocytes cultured for 18 h with allogeneic stimulating cells (but not activated lymphocytes alone), a soluble mediator may be involved in the suppressive mechanism. The mechanism of suppression therefore may be identical to the preemption phenomenon recently described in primary and secondary CML.

Antigens↗
PubMed1977

Detection of HLA-D clusters using primed LD typing.

Using a set of 17 primed LD typing (PLT) cells tested on a panel of 35 unrelated cells, we showed that certain groups of PLT cells tended to detect similar unrelated cells. The PLT cells were grouped into seven clusters and these tended to correlate with the seven HLA-D specificities represented on the panel, as determined by HTC testing. These data suggest that the antigens that cause restimulation in PLT are similar to those HLA-D antigens detected by the homozygous typing cell (HTC) test or, alternatively but more unlikely, that the two typing methods are detecting genes in close linkage disequilibrium with the HLA-D region.

Epitopes↗
PubMed1977

Detection by three cellular immunological techniques of the antigenic determinants of the Ly-Li system, expressed on human B lymphocytes.

A clear correlation was observed between the presence of an Ia-like antigenic B-cell system Ly-Li, detected serologically, and three cellular immunological techniques: [1] mixed lymphocyte reaction (MLR) inhibition by an anti-Li antiserum; [2] level of restimulation of anti-Ly-Li in-vitro-primed lymphocytes; and [3] detection of HLA-D alleles by homozygous typing cells. These results suggested that the allelic products detected serologically may be identical to those detected by the first two techniques, namely MLR inhibition and in-vitro-primed lymphocyte typing, and, possibly, HLA-D typing using homozygous typing cells, although the correlation was repeatedly found to be less clear for the last technique.

B-Lymphocytes↗
PubMed1977

Detection of HLA-D clusters and segregation studies using primed LD typing.

By testing a group of PLT cells over a panel of unrelated restimulating cells, the PLT's could be grouped into clusters according to their ability to discriminate antigen(s) in unrelated cells. The PLT clusters broadly correlated with the homozygous typing cell-defined HLA-D clusters represented on the panel. The PLTs grouped together clearly segregate with a particular HLA haplotype when tested in both unrelated families not possessing the sensitizing haplotype and in the family with the sensitizing haplotype. No influence of HLA SD antigens could be observed in PLT restimulation in the segregation studies.

Epitopes↗
PubMed1976

[Determination by three technics of cellular immunology of the antigenic determinants of the Ly-Li system expressed on human B lymphocytes].

A clear correlation has been observed between the presence of the antigenic B cell system Ly-Li detected serologically, and 3 cellular immunology techniques: 1. MLR inhibition by anti-Li serum; 2. level of restimulation of anti-Ly-Li in vitro primed lymphocytes; 3. detection of HLA-D alleles by homozygous typing cells. These results suggest that the allelic products detected serologically may be identical to those detected by the first two techniques, namely MLR inhibition and in vitro primed lymphocyte typing, and possibly HLA-D typing using homozygous typing cells, although the correlation was found to be repeatedly less clear for the last technique.

B-Lymphocytes↗
PubMed1976

A rapid HLA-D matching method using PHA blasts as responding cells (preliminary data on PHA blasts HLA-D typing).

Day 3-4 PHA stimulated lymphocytes were found to respond against HLA-D without any period of latency, thus allowing a discriminative MLR reading as early as 24-48 h. The test is therefore characterized by the minute number of responding cells necessary (5 X 10(3)), a one-way reaction without additional treatment of the stimualtion normal lymphocytes (5 x 10(4)), and the rapid obtaining of data. We found the preliminary data testing its concordance with classical HLA-D typing encouraging and worthy of being tested on a larger scale. Using mitogen stimulated recipient cells stored frozen, HLA-D matching with potential donors was found to be feasible within 24-48 h. The mechanism of such a prompt response by mitogen stimulated lymphocytes is unknown but appears to be independent of the nature and dose of a given mitogen.

HLA Antigens↗
PubMed1975

Cell-mediated lympholysis in vitro. Independence of mixed lymphocyte reactions and T-cell mitogen responses from the in vitro generation of cytotoxic effectors in primary immunodeficiency diseases.

Cell-mediated lympholysis (CML) in eighteen patients suffering from primary immune deficiencies was studied. Fourteen of these patients had the variable type. Mixed lymphocyte response (MLR) and CML were clearly found to be independent: as well as two groups of patients in whom the two functions were either both normal or both deficient, two other groups were found in whom they were definitely separate. In one group MLR and T-cell mitogen responses were normal but no CML occurred against allogenic lymphocytes, and in the other cytotoxic effectors were generated normally but MLR and T-cell mitogen responses were very much lower than normal. These results show that the functions are independent, and are compatible with the theory that more than one subpopulation of T cells is involved. Neither the MLR or T-cell mitogen responses of these patients can predict their ability to generate cytotoxic effectors.

Cytotoxicity Tests, Immunologic↗