Upper respiratory tract infection is a frequent cause of morbidity worldwide. Although the course of infection is usually mild, it is responsible for enormous social and economic costs. Immunostimulation with bacterial extracts consisting of ribosomal RNA and proteoglycans, such as Ribomunyl®, was introduced into the clinic in the 1980s as a new treatment concept, but did not achieve widespread application. Ribomunyl® has been proposed to activate innate immunity, but the contribution of its RNA content as well as its antiviral potential has not been studied.
Methods
Peripheral blood mononuclear cells from healthy donors and immune cells from adenoids were incubated with Ribomunyl® either by itself or formulated in a complex with cationic polypeptides such as poly-l-arginine or protamine, and induction of cytokines was quantified by ELISA.
Results
Ribomunyl® in complex with either poly-l-arginine or protamine, but not on its own, was able to strongly induce interferon-α (P<0.01) and interleukin-12 (P<0.01) in peripheral blood mononuclear cells, whereas induced tumour necrosis factor-α and interleukin-6 levels were independent of the formulation. Comparable results were obtained in immune cells from adenoids, suggesting efficacy also in virus-affected tissue. Cell sorting, RNase digests and selective receptor expression show that the RNA in Ribomunyl® acts as an agonist of Toll-like receptor (TLR)7 and TLR8.
Conclusions
Ribomunyl® is, in principle, able to potently induce antiviral interferon-α and interleukin-12 via TLR7 and TLR8, respectively, but only when formulated in a complex with cationic polypeptides.
References
1.
KirkpatrickG.L.The common cold. Prim Care1996; 23: 657–675.
2.
TurnerR.B.Epidemiology, pathogenesis, and treatment of the common cold. Ann Allergy Asthma Immunol1997; 78: 531–540.
3.
DoughertyR.H., FahyJ.V.Acute exacerbations of asthma: epidemiology, biology and the exacerbation-prone phenotype. Clin Exp Allergy2009; 39: 193–202.
4.
MalliaP., JohnstonS.L.How viral infections cause exacerbation of airway diseases. Chest2006; 130: 1203–1210.
5.
PapiA., BellettatoC.M., BraccioniF.Infections and airway inflammation in chronic obstructive pulmonary disease severe exacerbations. Am J Respir Crit Care Med2006; 173: 1114–1121.
6.
van EwijkB.E., van der ZalmM.M., WolfsT.F., van der EntC.K.Viral respiratory infections in cystic fibrosis. J Cyst Fibros2005; 4Suppl 2: 31–36.
7.
PittetL.A., Hall-StoodleyL., RutkowskiM.R., HarmsenA.G.Influenza virus infection decreases tracheal mucociliary velocity and clearance of Streptococcus pneumoniae. Am J Respir Cell Mol Biol2010; 42: 450–460.
8.
McGillivaryG., MasonK.M., JurcisekJ.A., PeeplesM.E., BakaletzL.O.Respiratory syncytial virus-induced dysregulation of expression of a mucosal beta-defensin augments colonization of the upper airway by non-typeable Haemophilus influenzae. Cell Microbiol2009; 11: 1399–1408.
9.
NavariniA.A., RecherM., LangK.S.Increased susceptibility to bacterial superinfection as a consequence of innate antiviral responses. Proc Natl Acad Sci U S A2006; 103: 15535–15539.
YoungJ., De SutterA., MerensteinD.Antibiotics for adults with clinically diagnosed acute rhinosinusitis: a meta-analysis of individual patient data. Lancet2008; 371: 908–914.
12.
TakataG.S., ChanL.S., ShekelleP., MortonS.C., MasonW., MarcyS.M.Evidence assessment of management of acute otitis media: I. The role of antibiotics in treatment of uncomplicated acute otitis media. Pediatrics2001; 108: 239–247.
13.
BousquetJ., FiocchiA.Prevention of recurrent respiratory tract infections in children using a ribosomal immunotherapeutic agent: a clinical review. Paediatr Drugs2006; 8: 235–243.
14.
SerranoE., DemanezJ.P., MorgonA., ChastangC., Van CauwenbergeP.Effectiveness of ribosomal fractions of Klebsiella pneumoniae, Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae and the membrane fraction of Kp (Ribomunyl) in the prevention of clinical recurrences of infectious rhinitis. Results of a multicenter double-blind placebo-controlled study. Eur Arch Otorhinolaryngol1997; 254: 372–375.
15.
MoraR., RalliG., PassaliF.M.Short ribosomal prophylaxis in the prevention of clinical recurrences of chronic otitis media in children. Int J Pediatr Otorhinolaryngol2004; 68: 83–89.
16.
MoraR., DellepianeM., CrippaB., SalamiA.Ribosomal therapy in the prophylaxis of recurrent pharyngotonsillitis in children. Int J Pediatr Otorhinolaryngol2007; 71: 257–261.
17.
FiocchiA., ArancioR., CinquepalmiP.Recurrent respiratory infections in childhood: experience with a bacterial extract plus bacterial ribosomes (Immucytal). J Int Med Res1990; 18: 50–60.
18.
BarchetW., WimmenauerV., SchleeM., HartmannG.Accessing the therapeutic potential of immunostimulatory nucleic acids. Curr Opin Immunol2008; 20: 389–395.
19.
HornungV., BarchetW., SchleeM., HartmannG.RNA recognition via TLR7 and TLR8. Handb Exp Pharmacol2008; 183: 71–86.
20.
SchleeM., BarchetW., HornungV., HartmannG.Beyond double-stranded RNA-type I IFN induction by 3pRNA and other viral nucleic acids. Curr Top Microbiol Immunol2007; 316: 207–230.
21.
KabelitzD., MedzhitovR.Innate immunity – cross-talk with adaptive immunity through pattern recognition receptors and cytokines. Curr Opin Immunol2007; 19: 1–3.
22.
PalmN.W., MedzhitovR.Pattern recognition receptors and control of adaptive immunity. Immunol Rev2009; 227: 221–233.
JeanninP., BottazziB., SironiM.Complexity and complementarity of outer membrane protein A recognition by cellular and humoral innate immunity receptors. Immunity2005; 22: 551–560.
25.
JeanninP., MagistrelliG., GoetschL.Outer membrane protein A (OmpA): a new pathogen-associated molecular pattern that interacts with antigen presenting cells-impact on vaccine strategies. Vaccine2002; 20Suppl 4: A23–A27.
26.
PortalèsP., ClotJ.Immunostimulants revisited: focus on the pharmacology of Ribomunyl. BioDrugs2006; 20: 81–84.
HerberholdS., Eis-HubingerA.M., PanningM.Frequent detection of respiratory viruses by real-time PCR in adenoid samples from asymptomatic children. J Clin Microbiol2009; 47: 2682–2683.
29.
KrugA., RothenfusserS., HornungV.Identification of CpG oligonucleotide sequences with high induction of IFN-alpha/beta in plasmacytoid dendritic cells. Eur J Immunol2001; 31: 2154–2163.
30.
HornungV., Guenthner-BillerM., BourquinC.Sequence-specific potent induction of IFN-alpha by short interfering RNA in plasmacytoid dendritic cells through TLR7. Nat Med2005; 11: 263–270.
31.
SiegalF.P., KadowakiN., ShodellM.The nature of the principal type 1 interferon-producing cells in human blood. Science1999; 284: 1835–1837.
32.
WeideB., PascoloS., ScheelB.Direct injection of protamine-protected mRNA: results of a phase 1/2 vaccination trial in metastatic melanoma patients. J Immunother2009; 32: 498–507.
33.
KriegA.M.Therapeutic potential of Toll-like receptor 9 activation. Nat Rev Drug Discov2006; 5: 471–484.
34.
MillerR.L., MengT.C., TomaiM.A.The antiviral activity of Toll-like receptor 7 and 7/8 agonists. Drug News Perspect2008; 21: 69–87.
35.
HenggeU.R., RuzickaT.Topical immunomodulation in dermatology: potential of toll-like receptor agonists. Dermatol Surg2004; 30: 1101–1112.
36.
PockrosP.J., GuyaderD., PattonH.Oral resiquimod in chronic HCV infection: safety and efficacy in 2 placebo-controlled, double-blind Phase IIa studies. J Hepatol2007; 47: 174–182.
37.
SorianoV., PetersM.G., ZeuzemS.New therapies for hepatitis C virus infection. Clin Infect Dis2009; 48: 313–320.
38.
TilgH., KaserA.Type I interferons and their therapeutic role in Th2-regulated inflammatory disorders. Expert Opin Biol Ther2004; 4: 469–481.
39.
SongE., ZhuP., LeeS.K.Antibody mediated in vivo delivery of small interfering RNAs via cell-surface receptors. Nat Biotechnol2005; 23: 709–717.
40.
ChonoS., LiS.D., ConwellC.C., HuangL.An efficient and low immunostimulatory nanoparticle formulation for systemic siRNA delivery to the tumor. J Control Release2008; 131: 64–69.
41.
ChoiY.S., LeeJ.Y., SuhJ.S.The systemic delivery of siRNAs by a cell penetrating peptide, low molecular weight protamine. Biomaterials2010; 31: 1429–1443.
42.
YooJ.W., GiriN., LeeC.H.pH-sensitive Eudragit nanoparticles for mucosal drug delivery. Int J Pharm2011; 403: 262–267.
