I don't think ECIES uses any PKI. The setup is: given a DH pubkey P, generate a DH ephemeral key Q, do the DHKE to derive k, encrypt your message m, then send (Q, E_k(m)).
My bad, I meant to say that it doesn't use any public key encryption like ElGamal. Or at least, I've only ever seen ECIES implemented with ECDH + symm enc