Study of the lymphocyte fractions in the mixed lymphocyte culture in vitro

Résumé Les lymphocytes du sang périphérique d'un sujet ont été fractionnés. Trois fractions ont été obtenues. Chaque fraction a été cultivée avec les lymphocytes vivants d'un autre individu non apparenté au premier. Le pourcentage des cellules transformées a été évalué pour chaque culture. Seule la fraction ribosomale dans laquelle se trouvent également les membranes cellulaires est active et donne un pourcentage de transformations comparable à celui obtenu lorsqu'on met en culture dans les mêmes conditions les lymphocytes, entiers et tués par congélation-décongélation, qui ont servi pour la préparation des fractions.

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Supported by a Grant from Lady Tata Foundation.     

Alkaline phosphatase in human lymphocyte subpopulations

Summary The levels of membrane alkaline phosphatase have been measured on different lymphocyte fractions from human peripheral blood separated on bovine serum albumin discontinuous gradients. The peak in enzyme activity was observed in a non-T-, non-B-cell fraction, rich in null lymphocytes; the lowest values were found in the fraction with the highest proportion of T-cells.     

Lymphopenia and lymphocyte transformation in alcoholics

Summary The basis of peripheral blood lymphopenia observed in patients with chronic alcoholism and liver disease was investigated by examining the effect of sera of these patients on in vitro transformation of normal human peripheral blood lymphocytes. A positive correlation was demonstrated between the serum inhibition of phytohaemagglutinin- and pokeweed mitogen-induced transformation and the degree of lymphopenia. Thus serum factors may contribute to the observed lymphopenia by inhibiting lymphocyte production in vivo.This study was supported by grants from the National Health and Medical Research Council of Australia, Royal Australasian College of Physicians and Alfred Hospital Henry Laurie Scholarship Fund.     

Lymphopenia and lymphocyte transformation in alcoholics.

The basis of peripheral blood lymphopenia observed in patients with chronic alcoholism and liver disease was investigated by examining the effect of sera of these patients on in vitro transformation of normal human peripheral blood lymphocytes. A positive correlation was demonstrated between the serum inhibition of phytohaemagglutinin- and pokeweed mitogen-induced transformation and the degree of lymphopenia. Thus serum factors may contribute to the observed lymphopenia by inhibiting lymphocyte production in vivo.     

Alkaline phosphatase in human lymphocyte subpopulations.

The levels of membrane alkaline phosphatase have been measured on different lymphocyte fractions from human peripheral blood separated on bovine serum albumin discontinuous gradients. The peak in enzyme activity was observed in a non-T-, non-B-cell fraction, rich in "null" lymphocytes; the lowest values were found in the fraction with the highest proportion of T-cells.     

Mixed lymphocyte reaction in human monoclonal gammopathies

Summary Ten multiple myeloma (MM) and 5 monoclonal gammopathies of undertermined significance (MGUS) were studied. The mixed lymphocyte reaction (MLR) proliferative response was of the same order of magnitude in MM and in MGUS as in normal controls. Normal results were obtained when pathological lymphocytes were used as either responding or stimulating cells. The addition of monoclonal anti-Ia antibodies completely abrogates the proliferative response as in healthy individuals. These results suggest that the immunological mechanisms supposed to be important in MLR are functionally normal in MM and in MGUS, although both the B and T cell lineages are involved in monoclonal gammopathies.This work was supported by CNR-PPFF Controllo della crescita neoplastica No. 82.00387.96. We thank Regione Piemonte which purchasel most of the technical equipment.     

Immunoglobulins and lymphocyte populations

Resumen Se ha estudiado la relación existente entre la concentración de Ig. sericas y las poblaciones linfocitarias T y B en un grupo de sujetos ancianos, encontrandose un notable descenso de la transformación blasticá al tiempo que se incrementa el porcentage de linfocitos portadores de Ig. en su membrana. De nuestros resultados parece deducirse una relación entre el nivel de Ig. sericas y la población medulo-derivada.     

Kinetics of lymphocyte division in blood cultures studied with the BrdU-giemsa technique

Summary Normal human lymphocytes were cultured for 72 h with different doses of BrdU. The analysis of metaphases processed with the BrdU-Giemsa method shows that in leukocyte cultures 3 different lymphocyte populations coexist which are able to perform 1, 2 or 3 rounds of replication in vitro. Moreover, it was concluded that 5 g/ml is the minimal dose of BrdU inducing good differentiation in the areas of sister chromatid exchanges.This work was supported by grants from the International Atomic Energy Agency, the Consejo Nacional de Investigaciones Cientificas and the Comisión de Investigaciones Cientificas.     

Double stranded ribonuclease activity in human lymphocyte nuclei

Summary Ribonuclease activity directed against the synthetic duplex polyrC: polyrI was detected in nuclear extracts from both unstimulated and PHA-stimulated human lymphocytes. In the latter cells, the activity was about twice that of small lymphocytes.     

Alloantigens directed by the SL-A region control the mixed lymphocyte reaction in swine]

Immunizations between a pig bearing a recombined SL-A haplotype and related animals revealed serological defined antigens under the MLR region control. These antigens seemed to be carried by all types of lymphocytes so far studied, but with large quantitative differences. The blood nonadherent on nylon fiber lymphocytes carried very few antigens and platelets none at all. The data are compatible with the assumption that these newly discovered antigens are equivalent to the mouse Ia antigens.     

Suppression of PHA-induced lymphocyte blastogenesis by concomitant presence of PPD in the culture

Summary PHA-induced lymphocyte blastogenic response was remarkably suppressed by the simultaneous presence of PPD in cultures of lymphocytes derived from individuals sensitized to PPD, but not affected by the presence of PPD when the cultures contained lymphocytes from an individual not sensitized to the protein. This double stimulation blastogenesis study with PHA and a specific antigen is feasible as a simple and rapid test to measure cell-mediated immunity to the antigen.Supported by United States grant USPHS Grant AM 27384.     

Double stranded ribonuclease activity in human lymphocyte nuclei.

Ribonuclease activity directed against the synthetic duplex polyrC:polyI was detected in nuclear extracts from both unstimulated and PHA-stimulated human lymphocytes. In the latter cells, the activity was about twice that of small lymphocytes.