Modification of the clonogenic assay for the detection of lymphokine activated killer cell activity

Agar capillary clonogenic microassays for cellular immunocytotoxic activities in human leukaemia and lymphoma

Current concepts of immunotherapeutic approaches in leukemias and lymphomas using activated cytotoxic lymphocytes and macrophages are briefly reviewed. Defective cellular immunocytotoxic activities and effects of interleukins and chemotherapeutic drugs thereupon are discussed. In vitro assays to measure lymphokine-activated killer (LAK) and natural killer (NK) cell activities suffer from various problems, depending on the quality of the endpoints. Our clonogenic microassay for LAK cell activity, using agar-containing glass capillaries, avoids some of the potential artifacts and offers several advantages that are discussed. As an example the stimulatory effect of low mafosfamide concentrations on the LAK cell activity versus K562 human myeloid leukemia cells is demonstrated. Thus, our clonogenic LAK microassay provides a valid tool for preclinical screening of immunomodulatory agents.

Additive effects of antitumor drugs and lymphokine-activated killer cell cytotoxic activity in tumor cell killing determined by lactate-dehydrogenase-release assay

The effect of pretreatment with antitumor drugs on lymphokine-activated killer (LAK) cell cytotoxic activity, determined by lactate-dehydrogenase(LDH)-release assay, was investigated. LAK cells were induced by incubating peripheral blood lymphocytes of healthy donors in medium containing interleukin-2 (IL-2) and monoclonal anti-CD3 antibody for 6-7 days. A human lung squamous carcinoma cell line, SQ-5, was used as an adherent target. After 24 h exposure of the target cells to cisplatin, doxorubicin, or mitomycin C, the drugs were washed off and LAK cells were added at an E/T ratio of 5. During further incubation for 48 h, LDH release from cisplatin- or doxorubicin-pretreated target cells was markedly higher than that from non-pretreated target cells. The combination of cisplatin and LAK cells has an additive cytotoxic effect and that of mitomycin C and LAK cells does not; there may also be an additive effect late in the toxicity mechanism between doxorubicin and LAK cells.

Computerised transfer and processing of data from experiments measuring cellular proliferation by incorporation of tritiated thymidine

One of the major endpoints of cellular immunological tests remains the quantitative assessment of lymphocyte proliferation as estimated from incorporation of tritiated thymidine into dividing cells. These data are usually generated by beta scintillation counting as strings of counts per minute which require considerable data reduction and processing. A computer system for the collection, transfer, presentation, processing and storage of these data is outlined here. This is based on modules operating from a basic system of maximal simplicity and flexibility in which data are stored in ASCII files and where the particular data processing requirements of different investigators can be easily met. This is exemplified by using a number of examples from the authors' own experiments, also illustrating the point that proliferative responses of non-lymphoid cells can be processed in the same way. In addition, suggestions are made concerning the standardisation of data processing for the exchange of results between different laboratories collaborating in large scale investigations, for example, the International Histocompatibility Workshops.