Characterisation of the in vitro responsiveness of lymphocyte subsets to locomotor stimuli by immunocytochemical methods.

The in vitro locomotion of lymphocyte subsets has previously been determined by use of highly purified cell populations. A method is now described in which mixed peripheral blood lymphocytes (PBL) migrate to the undersurface of polycarbonate filters in a 48 well microassay, the responding cells being characterised by alkaline phosphatase-anti-alkaline phosphatase immunocytochemistry. Recombinant interleukin (rIL)-1 alpha, zymosan activated plasma (ZAP) and rIL-8 were shown to induce concentration-related migration of mixed PBL in the 48 well assay and were therefore used as reference agonists. Total T cells, B cells, T helper/inducer and T suppressor/cytotoxic cells, as well as lymphocytes stained with the monoclonal antibodies UCHL1 and SN130, have now been quantified after migration to the undersurface of 8 microns pore size polycarbonate filters, in response to optimal concentrations of rIL-1 alpha, ZAP and rIL-8. The value of the analytical method was demonstrated by the selective responses seen. rIL-1 alpha selectively stimulated the migration of T helper/inducer and a small number of B cells without affecting T suppressor/cytotoxic cell locomotion. ZAP and rIL-8 significantly stimulated the migration of T helper/inducer, T suppressor/cytotoxic and B cells. ZAP and rIL-1 alpha also stimulated the migration of both UCHL1 and SN130 positively stained cells. This method may therefore be used to investigate the selective actions of lymphocyte locomotor stimuli on PBL sub-populations without the need to purify specific cell subsets, and to study the specificity of certain inhibitors or drugs on lymphocyte responses.