ABIMMUNE Repurposing disused antibiotics with immune modulators as antimicrobial strategy for respiratory tract infections

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1 ABIMMUNE Repurposing disused antibiotics with immune modulators as antimicrobial strategy for respiratory tract infections Jean-Claude Sirard Christophe Carnoy Fiordiligie Casilag Delphine Cayet

2 The partners of the ABIMMUNE project

3 The seminal idea of the ABIMMUNE project: Target innate immunity (host-directed therapy) innate immunity is rapidly activated, is selflimiting, and involves a broad spectrum of effectors, i.e. multiple killer cells and antibacterial molecules ubiquitous and universal defense mechanisms antibacterial activities of innate immunity are mostly independent of antibiotics mode of action it is difficult for the pathogen to develop resistance to innate immunity since this latter involvesmultiple mechanisms targeting host innate immunity may reinstate some immune defense in vulnerable patients Relative level of immune responses Inducible innate defenses X Constitutive innate defenses Time Microbe

4 Toll-like receptors (TLR), receptors of microbes for stimulation of innate immunity LTA LAM zymosan dsrna LPS Flagellin ssrna CpG DNA Uropathogenic bacteria Profilin Flagellin 23S rrna TLR13 NF-kB Transient activation of immune effectors

5 Flagellin is the main sructural protein of flagellum cap protein < 240 Å > D2 D3 N D1 C D0 < > 20 Å C N Flagellin FliC from Salmonella typhimurium 52 KDa Ramos et al. Trends Microbiol (2004)

6 Flagellin activates Toll-like receptor 5 (TLR5) signaling TLR5-specific activation motif (89-96) èflagellin TLR5mut and Tlr5 -/- animals Toll-like receptor 5 (TLR5) MyD88 N MAPK activation NF-kB C Chemokines, cytokines Anti-microbial compounds

7 Flagellin induces an immediate and transient TLR5 signaling in the respiratory tract Intranasal instillation Flagellin hours + - 0h 1h 2h 6h 12h 24h flagellin IgG 0h$ 2h$ 4h$ 18h$ Chemokine$signaling$pathway$ Van Maele et al. Mucosal Immunol (2014); Fougeron et al. Vaccine (2015)

8 Mucosal flagellin stimulates innate immunity via epithelium antimicrobial molecules TLR5 Epithelial cells pathogen phagocytosis and clearance phagocyte-specific chemokines Neutrophils Inflammatory monocytes

9 Flagellin stimulates lung innate immunity during Streptococcus pneumoniae pneumonia S. pneumoniae S. pneumoniae ± flagellin ± intranasal FliC h 2h Lung RNA S. pneumoniae ± ± FliC flagellin h 6h 8h Lung RNA S. pneumoniae ± ± FliC flagellin h 16h 18h Lung RNA S. pneumoniae ± ± FliC flagellin relative mrna levels (versus mock) 1 time of treatment flagellin PBS Cxcl1 * * * * 0h 6h 16h 24h FliC PBS FliC PBS FliC PBS FliC h 24h 26h Lung RNA Porte et al. Antimicrob Agents Chemother (2015)

10 Combination therapy with direct antimicrobial agent (antibiotic) and host-directed agent (TLR agonist) ß-lactamin (aminopenicillin) à amoxicillin is a very effective penicillin through oral route à most common antibiotics prescribed for pneumococcal infection S. pneumoniae intranasal (i.n) amoxicillin 250 µg/kg oral ± flagellin 2.5µg i.n Amoxicillin ± flagellin survival 0h 12h 42h 60h body weight bacterial load histological analysis

11 Flagellin improves the therapeutic efficacy of amoxicillin during pneumococcal infection 100 Untreated FliC amoxicillin 110 *** ** ** 75 amoxicillin + FliC flagellin % Survival 50 % initial weight days AMX FliC flagellin Porte et al. Antimicrob Agents Chemother (2015)

12 Flagellin improves the therapeutic efficacy of amoxicillin during pneumococcal infection lung spleen flagellin flagellin Porte et al. Antimicrob Agents Chemother (2015) WO ; EP

13 Flagellin combine with amoxicillin does not exacerbate lung inflammation A B B B Mock PV PV PV PV S. pneumoniae B S. pneumoniae + amoxicillin C PV B D PV B S. pneumoniae + amoxicillin + flagellin PV PV : pulmonary venule ; B : bronchiole

14 Combination therapy improves treatment of influenza A virus/pneumococcal superinfection IAV S. pneumoniae Sp CFU i.n amoxicillin +_ + flagellin d-7 lung 9 *** 0h 12h 42h 60h spleen 7 *** bacterial load 8 6 Log 10 CFU / lung Log 10 CFU / spleen amoxicillin FliC flagellin amoxicillin flagellin FliC Porte et al. Antimicrob Agents Chemother (2015); Sirard et al. EP , 23 decembre 2014

15 The general idea of the ABIMMUNE project: Combine ND-AB and approved immune modulators immune modulators and ND-AB may synergize to kill bacteria thereby allowing for dose reduction of ND-AB and potentially reducing side effects of ND-AB (toxicity or disruption of normal flora) using ND-AB may globally dampen the proportion of bacteria resistant to first-line antibiotics, allowing their maintenance in clinics Design in vitro assays for the PK and activity evaluation of combination of ND-AB and immune modulators (DAAand IAA) Test antibacterial activity on clinical strains and MDR strains Characterize how immune system and antibiotics cooperate for killing/elimination ofbacteria

16 The ABIMMUNE objectives The first objective is to screen combination therapies based on in vitro antibacterial efficacy, immunological studies and PK/PDmodeling. The second objective is to demonstrate the proof-of-concept of increased efficacy of selected combination therapies compared to standalone treatments in validated mouse models of bacterial pneumonia. The third objective is to assess the efficacy of combination therapies on clinical isolates resistant to first-line antibiotic or MDR and the impact on emergence of resistance to ND-AB and immune-modulators.

17 The disease and causing agents ABIMMUNE will focus on pneumonia caused by bacteria. The main agents are: 1. Pseudomonas aeruginosa 2. Klebsiella pneumoniae 3. Staphylococcus aureus 4. Streptococcus pneumoniae

18 What are the immune targets? 1. the central receptors of innate immunity (TLRs) 2. phagocytes (macrophages/monocytes and neutrophils) 3. the autophagy pivotal regulator mtor (mammalian Target Of Rapamycin) 4. the inhibition of inflammation via PPARγ

19 What are the ND-AB? 1. Streptomycin (protein) 2. Fosfomycin (cell Wall) 3. Colistin (membrane)

20 Targeting TLR4 with MPLA MonoPhosphoryl Lipid A [MPLA ], pleiotropic activator of immune defenses

21 Targeting TLR4 with MPLA