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D Fradelizi

Publications and source records attributed to D Fradelizi.

107 records · Page 6Linked to original sources
PubMed1978

Human Ia-like DRw lymphocyte antigens stimulating activity in primary mixed lymphocyte reaction.

The intensity of the primary mixed lymphocyte reaction (MLR) seems to be influenced by at least two distinct determinants of the HLA-D region: the HLA-Dw stimulating products and the human Ia-like B lymphocyte DR (D-related) antigens. In three families, the primary MLR is significantly higher in case of HLA haploidentity, when stimulating and responding cells differ with regard to both Dw and DRw determinants, than when only Dw products are different. Thus, an additional effect of DR antigens during primary MLR is observed. The role of DRw antigens in primary MLR and the results obtained by a primed lymphocyte test which can discriminate between Dw3 and DRw3, indicate that DRw and Dw products could be distinct determinants.

Epitopes↗
PubMed1978

HLA-DR-specific suppressor cells after repeated allogeneic sensitizations of human lymphocytes in vitro.

In conclusion, DR-specific suppressor cells can be induced by repeated in vitro sensitizations. They were able (1) to decrease a secondary proliferation, (2) to suppress consistently, in a primary proliferative assay, when added as third cells (primed twice against a DR antigen [PLT II] and gamma-irradiated), the response of unprimed cells towards stimulating cells, which share a DR specificity with the priming cell of the PLT II. The suppression follows the D part of the recombinant haplotype within an HLA-B/D recombinant family and is specific for the DR antigen used twice as stimulator for production of the PLT II.

Epitopes↗
PubMed1977

[Close genetic relation between determinants coding for the HLA-D region, detected by the technique of mixed primary and secondary lymphocyte culture and by serology of B lymphocytes].

In this study we report that: 1. Li determinants serologically detectable or closely linked structures are more associated to secondary responses than HLA-D specificities defined by HTC testing; 2. Other determinants from loci, MHC linked, or cross reactivity between Li determinants must be postulated to explain discrepancies between secondary responses and B serology; 3. Li determinants have an effect on the intensity of the reaction in primary allogenic proliferation.

Adult↗
PubMed1977

[Detection of a minor stimulating product involved in secondary allogenic proliferation of human lymphocytes in vitro].

In a family with a shared parental haplotype studied in MLR I and II we report that: 1) A secondary proliferation can be induced without a primary positive MLR; 2) In these conditions a minor determinant activating secondary proliferation is detected; 3) No significant association of this product with the available makers (HLA-A, B, C, D, Ly-Li) of the HLA region has been found so far; its localisation within or outside the MHC is under investigation.

Adult↗
PubMed1975

Mixed lymphocyte reactivity of human lymphocytes primed in vitro. I. Secondary response to allogenic lymphocytes.

In order to study the mixed lymphocyte culture reactivity of human lymphocytes primed in vitro, a nucleopore culture chamber technique allowing human lymphocytes to be cultured for a period of at least two weeks has been developed. During the primary culture period in nucleopore chambers, human lymphocytes were sensitized against mitomycin-treated allogenic stimulating cells. It was shown that the stimulated lymphocytes underwent a blastogenic reaction and the results suggest a reversion to the state of small, resting, primed lymphocytes. In vitro primed lymphocytes displayed allogenic memory. This was characteristic of a secondary response, which is shown by the following: 1) acceleration, the peak of thymidine incorporation occurring on day 4,2) specificity, the accelerated response was observed only when the primed lymphocytes were confronted with the cell used for priming. Contact with a third party cell did not produce this kind of activation. 3) Amplitude; the peak DNA synthesis response was greater than that of unprimed lymphocytes cultivated for the same length of time.

Cell Survival↗
PubMed1975

Third HL-A segregant series: genetic analysis and molecular independence on lymphocyte surface.

Five sera which detect two alleles of the third HL-A locus (T2 and T4) are described. Statistical analysis of a panel of 220 donors gave gene frequencies in a French Parisian population which are comparable to the results of Scandinavian authors. Segregation observed in 50 families emphasized the linkage disequilibrium with SD2 alleles. T1 was found to be associated with one part of W22 (Da30) and T3 with the other part non-Da30). No recombination was observed between SD2 and SD3, and the distance between these two loci can be estimated at less than 0.0042 U. Differential capping experiments showed that redistribution of SD3 antigens did not affect the SD2 or SD1 products, indicating that they are borne on the cell surface by independent structures. Moreover, capping of SD1, SD2 and SD3 antigens did not provoke complete redistribution of beta2microglobulin which suggests that not all beta2M molecules are linked to HL-A antigens.

Adult↗