Differential expression of corticostatins/defensins: higher levels of CS-4 (NP-2) transcripts compared with CS-6 (NP-5) in rabbit lung.

cDNA clones encoding two members of the corticostatin (CS)/defensin family of peptides have been isolated from a rabbit bone marrow cDNA library through cross-hybridization with cDNA encoding the human corticostatin HP-4. They encode the precursors of CS-4 (NP-2, MCP-2) and CS-6 (NP-5). Highly specific probes were generated for Northern blotting of RNA from various normal rabbit tissues. Both detected high levels of message in bone marrow, moderate in spleen, and low in thymus. In lung, however, while moderate levels were detected with the CS-4 probe, CS-6 message was barely detectable. This correlates with the report of CS-4, but not CS-6 peptide in lung macrophages, and implies that differential regulation of CS/defensin expression in rabbit lung is at the level of gene transcript abundance.