Plaque-forming cell capability in the senescent.
The number of plaque-forming cells (PFC) developed in pokeweed mitogen (PWM)-activated unfractionated or T/B separated, 4:1 reconstituted cultures of peripheral blood lymphocytes (PBL) with well-characterized subpopulations obtained from healthy, aged subjects was compared to that of young blood donors. The absolute number of PBL in the aged was reduced by 36%, and the percentage of sheep erythrocyte-rosette-forming cells (E-RFC) by 27%, compared to the percentage obtained in young donors. The IgM-, IgG- and IgA-immunoglobulin (Ig) secretion was monitored with a protein A PFC assay. The number of PFC in PBL cultures of the aged was 58% of the number found in cultures of the young controls. The number of PFC generated in cultures of autologous irradiated T and untreated B cells showed a 104% increase in the aged whereas a 63% increase was obtained using cells from young individuals. Co-cultures of young B cells with untreated or irradiated young or aged T cells showed a significant rise in the PFC response in cultures with irradiated aged T cells, while an equal number of PFC was generated in cultures of young B cells with young or aged untreated T cells. Our results demonstrate a decreased number of PBL, especially T cells, an impaired B cell function and a pronounced enhancement of the PFC response in cultures of irradiated aged T cells and young or aged B cells, whereas the T helper function of untreated cells was found to be normal. The influence of monocytes on the PFC response did not differ in the two groups.
Tauris
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Andersen
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Christiansen
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D000368:Aged; D000375:Aging; D001402:B-Lymphocytes / Q000276:immunology / Q000502:physiology*; D002469:Cell Separation; D005260:Female; D006462:Hemolytic Plaque Technique; D006801:Humans; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000502:physiology