Compounds are provided that have the formula: ##STR00001## where X, A.sup.4, R.sub.a, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.14, L and Q are as described herein. These compounds are useful, for example, as modulators of a chemokine receptor and for treatment of inflammatory and immunoregulatory disorders and diseases. Pharmaceutical compositions and methods of using these compounds for the treatment of inflammatory and immunoregulatory disorders and diseases, such as multiple sclerosis, rheumatoid arthritis and type I diabetes, are also provided.