Enhancement of nonspecific immunity to Klebsiella pneumoniae infection by a synthetic immunoadjuvant (N-acetylmuramyl-L-alanyl-D-isoglutamine) and several analogs.

Abstract

N-Acetylmuramyl-L-alanyl-D-isoglutamine and 4 other synthetic adjuvants that are structural analogs of part of the mycobacterial peptidoglycan monomer enhance the nonspecific immunity of mice infected by K. pneumoniae. These compounds are active by various routes, including oral administration; they are also effective when administered after challenge. Of the 17 other analogs tested, none is able to significantly increase resistance to infection, although 7 of these molecules are adjuvant-active in saline. Previous results showed that in contrast to lipopolysaccharides, these synthetic adjuvants are devoid of immunogenicity, mitogenicity and toxicity in normal or adrenalectomized mice.