Cyclicdi-AMP (c-di-AMP) is a second messenger produced by bacteria but not by mammals. Generated by a family of diadenylate cyclases, c-di-AMP can impact bacterial cell growth, cell wall homeostasis, pathogenicity, and other cellular functions. Bacteria-derived cyclicdinucleotides, including c-di-AMP, trigger the expression of interferon genes in mammalian cells.
5'-pApA is a linearized form of cyclicdi-AMP, a bacterial second messenger that activates the host innate immune system through stimulator of interferon genes (STING).1,2,3,4It is a metabolite of cyclicdi-AMP formedviahydrolysis by various phosphodiesterases (PDEs).55'-pApA is intended for use as a negative control for cyclicdi-AMP signaling. 1.Burdette, D.L., Monroe, K.M., Sotelo-Troha, K., et al.STING is a direct innate immune sensor of cyclic-di-GMPNature478(7370)515-518(2011) 2.Parvatiyar, K., Zhang, Z., Teles, R.M., et al.DDX41 recognizes bacterial secondary messengers cyclicdi-GMP and cyclicdi-AMP to activate a type I interferon immune responseNat. Immunol.13(12)1155-1161(2012) 3.Woodward, J.J., Iavarone, A.T., and Portnoy, D.A.c-di-AMP secreted by intracellular Listeria monocytogenes activates a host type I interferon responseScience328(5986)1703-1705(2010) 4.Witte, C.E., Whiteley, A.T., Burke, T.P., et al.Cyclicdi-AMP is critical for Listeria monocytogenes growth, cell wall homeostasis, and establishment of infectionmBio4(3)e00282-00213(2013) 5.Fahmi, T., Port, G.C., and Cho, K.H.c-di-AMP: An essential molecule in the signaling pathways that regulate the viability and virulence of gram-positive bacteriaGenes (Basel)8(8)197(2017)
Cyclicdi-IMP (sodium salt) (c-di-IMP) is a synthetic second messenger structurally related to the bacterial second messengers cyclicdi-GMP and cyclicdi-AMP . C-di-IMP has adjuvant properties when co-administered with antigens in vitro and by mucosal routes in vivo. C-di-IMP enriches the population of MHC class I and II, CD80, CD86, CD40, and CD54 positive dendritic cells derived from murine bone marrow. It also stimulates macrophages at 500 ng ml. Mice immunized with β-galactosidase (β-gal) plus c-di-IMP through the intranasal route show a humoral immune response, evidenced by an increase in IgG titers up to 2-fold compared to mice immunized with β-gal alone. Mice immunized with β-gal plus c-di-IMP also exhibit a Th1 Th2 response, indicating that the adjuvant activity of c-di-IMP leads to a cellular immune response as well.
Cyclicdi-UMP is a pyrimidine-containing cyclicdinucleotide (CDN).1It is produced by bacterial cGAS DncV-like nucleotidyltransferases (CD-NTases), such as LpCdnE02 fromL. pneumophila, and binds to cGAS, in the apo or dsDNA-bound forms, with reduced affinity compared to 2'3'-cGAMP or 3'3'-cGAMP .1,2Cyclicdi-UMP is intended for use as a negative control for cyclicdi-GMP signaling. 1.Whiteley, A.T., Eaglesham, J.B., de Oliveira Mann, C.C., et al.Bacterial cGAS-like enzymes synthesize diverse nucleotide signalsNature564(7747)194-199(2019) 2.Hall, J., Ralph, E.C., Shanker, S., et al.The catalytic mechanism of cyclic GMP-AMP synthase (cGAS) and implications for innate immunity and inhibitionProtein Sci.26(12)2367-2380(2017)
C82 acts as an inhibitor of Mycobacterium tuberculosis (Mtb) cyclicdinucleotide phosphodiesterase (CdnP), with an IC50 value of 17.5 µM. This particular enzyme is responsible for breaking down cyclicdi-AMP (c-di-AMP) into adenosine 5'-monophosphate (AMP). Notably, C82 demonstrates selectivity for Mtb CdnP over other bacterial cyclicdinucleotide phosphodiesterases (CDN PDEs) such as Yybt, RocR, and Group B Streptococcus (GBS) CdnP, as well as the mammalian CDN PDE ENPP1, and the viral CDN PDE poxin, showing effectiveness at a concentration of 200 µM.