Conformationally-stable peptide analogs of the response selective C5a agonist EP67 having the formula Tyr-Ser-Phe-Lys-Asp-Met-Xaa-(Xaa2)-(D-Ala)-Arg (SEQ ID NO:1), wherein Xaa is a modified proline residue or a residue substitution for proline, and Xaa2 is leucine or N-methyl leucine. The conformationally-stable peptides selectively bind and activate APCs without directly engaging/binding C5a receptor-bearing cells involved in pro-inflammatory activities of natural C5a. Compositions and methods of using the peptide analogs are also described.