Countercurrent distribution of lymphocytes from human peripheral blood in an aqueous two-phase system. II. Separation into subsets of lymphocytes with distinctive functions

Recombinant leukocyte A interferon as single agent therapy or in combination with cimetidine in patients with advanced colo-rectal carcinoma. A phase II investigation

Recombinant leukocyte A interferon used as single agent therapy (7.5 X 10(6) units/m2 three times weekly intramuscularly) showed very limited clinical efficacy in patients with advanced colo-rectal carcinoma. No objective tumour regressions were documented in 15 evaluable patients, although three patients demonstrated a stable disease status after 12 weeks of treatment. Neither were any objective tumour regressions registered in 13 patients during subsequent combined therapy with Recombinant Leukocyte A Interferon and cimetidine (1 000 mg/day orally). Two of the 3 patients maintained their stable disease status. No change in natural killer (NK) cell activity or in antibody dependent cellular cytotoxicity (ADCC) of peripheral blood mononuclear cells was seen during the two treatment periods.

Feasibility of extracorporeal on-line large-scale plasma adsorptions on protein A-sepharose columns in cancer patients

The feasibility of extracorporeal adsorption of 1.5-3 L plasma on protein A-Sepharose was investigated in six patients with advanced cancer. Anticoagulation with heparin was associated with respiratory distress syndrome in two patients, most likely caused by complement activation as indicated by a transient leukopenia during plasma reinfusion and appearance of C3 degradation products in the extracorporeal circulation. Addition of citrate abolished the respiratory symptoms, C3 degradation, and leukopenia, and no adverse reactions were observed. No objective tumor regression was observed in any of the patients. Three patients progressed during therapy. In one of these, multifocal central tumor necrosis was observed as a possible, although unproven, therapeutic effect. Increased natural killer and/or killer cell activities were recorded in three patients and increased complement-dependent serum cytotoxicity in one patient. The level of circulating immune complexes decreased significantly (18-28%) in three patients studied. It is concluded that extracorporeal plasma adsorption on protein A-Sepharose is feasible when citrate is added to the extracorporeal system, but its therapeutic efficacy is uncertain.

Surface markers and biological functions of PMNC fractionated by countercurrent centrifugal elutriation

Peripheral blood mononuclear cells (PMNC) were separated by countercurrent centrifugal elutriation (CCE) in PBS-EDTA medium into 13 fractions. Properties associated with B cells were restricted mainly to the first fractions (F2 and F4) while those associated with T cells were confined to fractions F4, F6 and F8. The final fraction (FF) contained more than 90% monocytes while fraction F10 contained 40% monocytes and 60% null cells, and F12 contained 50% monocytes and 50% null cells. Natural killer (NK) cell activity against K-562, a human erythroleukaemia cell line, and against an adherent undifferentiated sarcoma target, was distributed between fractions F6 and F8. Using electron and scanning microscopy and a new single cell liquid cytotoxic assay, we studied membrane interaction and binding of the CCE fractionated cells with the 2 targets. Effector/target cell conjugates revealed interdigitations in the area of cell contact but no membrane fusion, although certain effector cells had a distinct large granulocytic lymphocyte morphology. Furthermore, different cell types from different fractions were able to bind to the targets although the killing was associated with certain fractions only. When purified monocytes from fraction FF were added to F6 and F8, NK activity against both targets was depressed. This inhibition was not reversed by indomethacin, and binding of the targets to the effector cells was unaffected. CCE is a powerful technique which allows the fractionation of PMNC without altering their biological functions, contrary to what is seen with nylon wool or dextran fractionation. In this report, the activity associated with CCE fractions is studied and discussed.

Natural killer cell activity and antibody-dependent cellular cytotoxicity in newborn infants

The ability of lymphocytes from the peripheral blood of preterm and term infants and adult women and men to mediate natural killing (NK) and K cell activity (antibody-dependent cellular cytotoxicity) was analysed in 4 hours 51Cr-release assays. K 562 cells were targets for NK activity. K cell activity was assayed on antibody-coated rat thymocytes. Lymphocytes from adult male donors were significantly more cytotoxic to K 562 cells than were lymphocytes from adult female donors. Lymphocytes from both preterm and term infants had significantly lower NK and K cell activity than lymphocytes from adult donors. During the first month of life no increase in NK activity or K cell activity occurred in 7 infants who were re-examined. It is concluded that neither NK nor K cell activities are fully developed during the first month of life.

Countercurrent distribution of human peripheral blood lymphocytes: isolation of a subpopulation enriched with natural killer and K cells

Aqueous solutions of dextran and of poly(ethylene glycol) when mixed give rise to two-phase systems suitable for the separation by partitioning of cells based on subtle differences in their membrane surface properties. Human peripheral blood mononuclear cells were obtained by centrifuging blood over Hypaque-Ficoll and removing the cells from the cushion. Clean lymphocytes were then isolated by velocity sedimentation of the mononuclear cells. Lymphocytes were subjected to countercurrent distribution (i.e., a multiple extraction procedure) in a two-polymer aqueous phase system which separates cells primarily on the bases of surface charge-associated properties. It was found that a small subpopulation of cells with highest partition coefficient (presumably highest surface charge-associated properties) contain virtually all of the natural killer (NK) and K cell activities.