The objective of this proposal is to develop strategies for lymphocyte chemoattractant lymphokine purification in quantities sufficient to analyze ligand (lymphokine)-T lymphocyte (target cell) interactions. The importance of lymphokines as effector molecules in the pathogenesis of many lung disorders including sarcoidosis, hypersensitivity pneumonitis, and various infectious lung diseases is well accepted. However, the elucidation of their molecular mechanisms of action in these processes remains obscure. Determination of lymphokine structure-function relationships and biological significance requires the availability of purified lymphokine preparations. This has been impeded by three shortcomings of conventionally derived lymphokine preparations: the heterogeneity of the cell populations used for production; the simultaneous induction of numerous biologically active lymphokines by traditional mitogens and antigens; and the limited amounts available for structural analysis. Our laboratory has recently defined a system in humans involving three lymphokines altering non-sensitized, non-transformed T lymphocyte motility which are selectively derived from histamine activated T lymphocytes. This lymphokine system is composed of a lymphocyte chemoattractant factor (LCF) and two non-cytotoxic migration inhibitory factors (LyMIFs). Utilization of histamine as a selective lymphocyte activator combined with further pharmacologic isolation of T cells by incubation in the presence of specific histamine type-1 or histamine type-2 receptor antagonists results in the generation of only a few biologically active lymphokines from a restricted cell population. These culture conditions will make it possible to obtain to obtain purified LCF and LyMIFs using standard methods of separation selected on the basis of their physicochemical characteristics. In addition, development of cloned human T-T hybridomas, coupled with sequential chromatographic purification steps, will permit the preparation of large quantities of the chemoattractant lymphokines. These purified preparations will be applied to defined T lymphocyte subset target populations to characterize ligand-T cell interactions. The results obtained from this line of investigation will provide a better insight into the basic mechanisms of action of chemoattractant lymphokines, an understanding of lymphocyte accumulation in tissues, and may result in new approaches to the modification of certain pulmonary pathobiologic processes such as granulomatous diseases.
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