Studies on ciliary dyskinesia factor in cystic fibrosis. II. Short term leukocyte cultures and long term lymphoid lines

The cell-free medium obtained after 48 hour culture of phytohemagglutinin (PHA)- stimulated leukocytes of three cystic fibrosis (CF) subjects and two carriers, contained a ciliary dyskinesia factor (CDF) detected by a modified rabbit tracheal bioassay. Positive CDF responses began to be observed in supernates of parallel non-stimulated cultures of leukocytes from these same CF affected and carrier individuals by 72 hours of culture. Cell-free media from leukocyte cultures of four normal donors did not produce a positive CDF response with or without PHA over a period of 6 days. The cell-free medium of long-term lymphoid lines derived from three CF affected and four CF carrier subjects demonstrated a positive CDF response, while media from similar lymphoid lines derived from normal subjects contained no CDF. Distinction between homozygous and heterozygous lymphoid lines was not always possible, although there was a tendency of the homozygous lines to give an earlier CDF response than the heterozygous ones. Addition of rabbit anti-human IgG to the CDF positive cell line supernates resulted in the elimination of their ability to elicit a positive CDF response in each instance. Speculation: CDF is a manifestation of a normal cellular product which is a small molecule bound to IgG. The resulting complex represents the CDF detected by bioassay. The defect in CF is in the production or release of a factor inhibiting the CDF.