Vaccine 30, 2012. [5023770, IF 3.492, 7 citations]; Mori J, ....,, Benčina M, Jerala R*.. Chimeric flagellin as the self-adjuvanting antigen for the activation of immune response against Helicobacter pylori. Helicobacter pylori infection can cause gastritis and can lead to gastric cancer. Lengthy antibiotic therapy does not protect the host against reinfection. Bakterija H. pylori evolved to evade the recognition of the immune response. TLR5, a member of the Toll-like receptor family, recognizes flagellin of most bacteria, but does not recognize the flagellin FlaA of H. pylori. We restored the ability of FlaA for the recognition by TLR5 by engineering a chimeric flagellin, in which both terminal segments of H. pylori flagellin were replaced by the corresponding segments from TLR5-activating E. coli flagellin. Recombinant chimeric flagellin folded correctly and was able to activate TLR5. Significantly increased serum IgG and IgA antibody responses were determined in mice vaccinated with chimeric flagellin in comparison to mice vaccinated with a control protein (FlaA) or negative control. Antibodies were able to bind native flagellin from H. pylori lysate. Vaccination with chimeric flagellin provided mice with significant protection against H. pylori.
COBISS.SI-ID: 5023770
Biochem biophys res commun 2013, 435. [5222426, IF 1.95, 1 citation]; Ivičak-Kocjan, K, Panter, G, Benčina, M*, Jerala, R*. Determination of the physiological 2:2 TLR5:flagellin activation stoichiometry revealed by the activity of a fusion receptor. Project leader shares corresponding authorship. Authors determined the physiological stoichiometry of TLR5:flagellin activation by the use of a chimeric protein composed of an active flagellin fragment linked to the N-terminus of human TLR5 (SF-TLR5). This construct was constitutively active. Addition of wild-type hTLR5 substantially lowered autoactivation of SF-TLR5 in a concentration dependent manner, an effect which was reversible by the addition of exogenous S. typhimurium flagellin, indicating the biological activity of a TLR5:flagellin complex with a 2:2 stoichiometry. These results, in addition to the combinations of inactive P736H mutation within the BB-loop of the TIR domain of TLR5 and SF-TLR5, further confirm the mechanism of TLR5 activation. KIK, GB performed experiments, MB supervised work and analyzed data. MB and RJ wrote manuscript. The work was also presented as lecture: Molecular mechanism of TLR5 activation by flagellin (Meeting of the Slovenian Biochemical Society with International Participation [36980229]).
COBISS.SI-ID: 5222426
Blood 124. 2014. doi: 10.1182/blood-2014-05-573188; Avbelj M, …, Benčina M, …, Jerala R*.. Mutacija Leu265Pro proteina MyD88 ustvarja pogoje za preživetje limfomnih celic. Recurrent lymphoma-associated mutations, particularly Leu265Pro (L265P), within the MyD88 Toll/interleukin-1 receptor (TIR) domain sustain lymphoma cell survival due to constitutive nuclear factor κB signaling. We found that mutated TIR domains displayed an intrinsic propensity for augmented oligomerization and spontaneous formation of cytosolic Myddosome aggregates in lymphoma cell lines. Molecular dynamics simulations and analysis of additional mutations suggest that constitutive activity is caused by allosteric oligomerization.
COBISS.SI-ID: 5607194
J Biol Chem 2013, 288, [5143066] [IF4.651, 2 citations; Pohar J, Pirher N, Benčina M, Manček Keber M, Jerala R*. The role of UNC93B1 protein in surface localization of TLR3 receptor and in cell priming to nucleic acid agonists. We observed that poly(I:C) up-regulates transcription of UNC93B1 and promotes trafficking of TLR3 to the plasma membrane in human epithelial cell line. Further studies revealed that expression of UNC93B1 promotes trafficking of differentially glycosylated TLR3, but not other NAS TLRs (TLR7/8, TLR9), to the plasma membrane. Our findings identified TLR3 as the important regulator of UNC93B1 expression that in turn governs the responsiveness of all NAS TLRs. JP, NP, MB, MMK performed experiments; MB supervised the work and completed microscopy. RJ developed the ides, JP and RJ wrote the manuscript. Complementary publications: (B) PloS one 2014, 9, doi: 10.1371/journal.pone.0092391. [5462042, IF 3.534]; Pohar J, ..., Benčina M, ..., Jerala R. 2014. The ectodomain of TLR3 receptor is required for its plasma membrane translocation. Those results were also presented in several invited lectures: Annual meeting of the Austrian society for allergology and immunology, Vienna, 2010 [4577562], IEIIS Edinburgh 2008, University of Cambridge, 2008 [4033306]; German Cancer Research Centre, 2010 [4575770]
COBISS.SI-ID: 5143066
J Biol Chem 2012, 287, [5026586, IF 4.65, 2 citations]; Fekonja O, Benčina M, Jerala R*. Toll/interleukin-1 receptor domain dimers as the platform for activation and enhanced inhibition of Toll-like receptor signaling. Authors showed the role of a dimerized TIR (Toll/IL-1 receptor) domain platform for the suppression as well as for the activation of MyD88 signaling pathway. The addition of a strong coiled-coil dimerization domain conferred the superior inhibition against the wide spectrum of TLRs and prevented the constitutive activation by a dimeric TIR platform. We propose a molecular model of MyD88-mediated signaling based on the dimerization of TIR domains as the limiting step. OF and MB performed experiments. MB performed mycroscopic analysis. OF and RJ wrote manuscript. Complementary publications: (A) J Immunol 2012, 188 [4930586, IF 5.745, 2 citations]; Manček Keber M, Benčina M, …, Jerala R*. MARCKS as a negative regulator of lipopolysaccharide signaling.
COBISS.SI-ID: 5026586