Table 4.

Key mechanistic platforms in bacterial immunotherapy and their developmental status.

Platform	Mechanism	Key example	Development stage	Reference
Innate Immune Agonists	TLR and inflammasome activation	CpG oligodeoxynucleotides (TLR9); MCC950 (NLRP3)	Preclinical/Phase I	(39)
cGAS–STING Agonists	Type I IFN induction via cytosolic DNA sensing	Synthetic cyclic dinucleotide analogs	Preclinical	(40)
Monoclonal Antibodies	Toxin neutralization and opsonization	Bezlotoxumab (C. difficile toxin B)	Approved/Phase III	(31)
Checkpoint Inhibitors	Reversal of T-cell exhaustion	Anti–PD-1 in tuberculosis models	Preclinical/Phase I	(42)
CAR-Engineered Myeloid Cells	Antigen-specific phagocytosis	CAR-macrophages against P. aeruginosa biofilms	Preclinical	(43)
CRISPR-Based Antimicrobials	Sequence-specific bacterial killing or gene silencing	CRISPR–Cas9 phagemids targeting resistance genes	Preclinical	(44)

Overview of key mechanistic platforms in bacterial immunotherapy, highlighting representative examples and their current stage of clinical or preclinical development. This table summarizes innovative modalities ranging from innate immune agonists to genetic antimicrobials, emphasizing the translational continuum from bench to bedside.

TLR, toll-like receptor; NLRP3, NOD-like receptor family pyrin domain containing 3; IFN, interferon; PD-1, programmed cell death protein 1; CAR, chimeric antigen receptor; FDA, U.S. Food and Drug Administration; Preclinical, not yet tested in humans.