Extending the Host Range of Listeria monocytogenes by Rational Protein Design

Abstract

In causing disease, pathogens outmaneuver host defenses through a dedicated arsenal of virulence determinants that specifically bind or modify individual host molecules. This dedication limits the intruder to a defined range of hosts. Newly emerging diseases mostly involve existing pathogens whose arsenal has been altered to allow them to infect previously inaccessible hosts. We have emulated this chance occurrence by extending the host range accessible to the human pathogen Listeria monocytogenes by the intestinal route to include the mouse. Analyzing the recognition complex of the listerial invasion protein InlA and its human receptor E-cadherin, we postulated and verified amino acid substitutions in InlA to increase its affinity for E-cadherin. Two single substitutions increase binding affinity by four orders of magnitude and extend binding specificity to include formerly incompatible murine E-cadherin. By rationally adapting a single protein, we thus create a versatile murine model of human listeriosis.

PI3-kinase activation is critical for host barrier permissiveness to Listeria monocytogenes

“…This suggests that, in models permissive to both InlA and InlB, InlB-requirement for Lm invasion of Peyer's patch There are apparently conflicting data regarding the role of InlB in the crossing of intestinal barrier: whereas we have repeatedly found no role for InlB in Lm crossing of the intestinal barrier in in vivo models permissive to both InlA-Ecad and InlB-c-Met interactions (Khelef et al, 2006;Disson et al, 2008), it has been reported by others that InlB accelerates invasion at villous tips in an experimental model using murinized InlA (Pentecost et al, 2010) and plays a role at the Peyer's patch level in WT mice (Chiba et al, 2011). Here, we have confirmed these results and revisited their interpretations in light of our new investigations: we compared the infection of murinized InlA (InlA m ) expressing Lm (Wollert et al, 2007) in WT mice (Pentecost et al, 2010) and the infection of WT Lm in KIE16P mice expressing humanized mEcad (Disson et al, 2008) at the villous tip level. Importantly, we have recently demonstrated that InlA m confers to Lm the ability to target both Ecad and Ncad, the latter being accessible on the luminal side of villous M cells (Tsai et al, 2013).…”

Site-Dependent Recruitment of Inflammatory Cells Determines the Effective Dose of Leishmania major

“…T he route or site of inoculation has been shown to significantly influence disease outcome in numerous models of infection, including Leishmania (1-9), Toxoplasma (10), Plasmodium (11), Listeria (12)(13)(14), Borrelia (15), and influenza virus (16,17) infections. Vaccination by different routes has also been shown to influence the efficacy of vaccines against parasitic, bacterial, and viral infections, as well as cancer (3,(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28).…”

IL-17A–producing resident memory γδ T cells orchestrate the innate immune response to secondary oral Listeria monocytogenes infection

“…The Internalin A mutant recombinant strain of L. monocytogenes provides an excellent means to model human L. monocytogenes infection in mice, because the modified Internalin A binds mouse E-cadherin with similar efficiency as the human counterpart (11). Using this model, we previously found the existence of L. monocytogenes-specific protective memory like γδ T-cell population in mice (12).…”