Table 2:
Antibodies, vaccines, and peptomers against T3SS components
| Class | Organism | Target | Phenotype/Readout | Therapeutic Potential | Refs. |
|---|---|---|---|---|---|
| Antibody ‒ KB001 |
Pseudomonas aeruginosa |
PcrV ‒ tip | Protects host cells against T3SS mediated toxicity and protects mice against acute pulmonary infection (reviewed in (88)) | Did not meet efficacy endpoints in phase II clinical trials | (60–62) |
| Bispecific Antibody ‒ MEDI3902 |
P. aeruginosa | PcrV ‒ tip Psl ‒ exopolysaccharide | In vitro cytotoxicity protection and in vivo protection of acute pneumonia model in mice | Currently in phase II clinical trials | (63, 64) |
| Single-VH Domain Antibodies |
Shigella flexneri | IpaD ‒ tip | Reduces hemolysis of sheep red blood cells | (66) | |
| rF1V Vaccine | Yersinia pestis | LcrV ‒ tip F1 protein |
Enhances survival of cynomolgus macaques infected with lethal aerosol challenge of Y. pestis | Orphan Drug designation by FDA | (69) |
| Rabbit polyclonal anti-sera | STEC | STECO103 T3SS proteins | Blocks adherence of STEC to host cells; Immunized mice not protected against fecal shedding | (71) | |
| Peptide vaccine | Salmonella enterica | Ssel ‒ effector | Protects mice against acute infection | (72) | |
| Vaccine | S. enterica | Prgl ‒ needle SipD - tip |
Protects mice against infection | (73) | |
| Vaccine | S. enterica | SseB ‒ effector Flagellin |
Protects mice against infection | (74) | |
| Subunit vaccine | S. enterica | S1: Fusion of SipD and SipB-tip and translocon S2: Fusion of SseB and SseC-tip and translocon |
Protects mice against lethal challenge | (75) | |
| Polypeptide |
S. enterica S. flexneri |
SipB ‒ translocon IpaB ‒ translocon |
Inhibits bacterial invasion into host cells | Polypeptide too large for therapeutic potential | (76) |
| Peptides | EPEC | EspA-tip | Inhibits EspA polymerization thereby preventing A/E lesions | (77) | |
| Peptides | EHEC Citrobacter rodentium |
EspA-tip | Protects mice against colon damage after C. rodentium challenge | (78) | |
| Peptomers ‒ phepropeptin D derivatives |
Yersinia pseudotuberculosis P. aeruginosa |
Inhibits secretion of T3SS proteins; Inhibits Yersinia YopM effector translocation and reduces cell rounding | (79) |
STEC = Shiga-toxin producing Escherichia coli; EPEC = Enteropathogenic Escherichia col