Streptococcus pneumoniae, more than 90 serotypes of which exist, is recognized as an etiologic agent of pneumonia, meningitis, and sepsis associated with significant morbidity and mortality worldwide. Immunization with a pneumococcal pep27 mutant (Δpep27) has been shown to confer comprehensive, long-term protection against even non-typeable strains. However, Δpep27 is only effective as a vaccine after at least 3 rounds of immunization. Therefore, treatments capable of enhancing the efficiency of Δpep27 immunization should be identified without delay.

Inflammation is an innate immune response that protect the body from pathogens, toxins, and other dangers and initiated by recognizing pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs) by pattern-recognition receptors (PRRs) expressing on or in immune cells. Intracellular PRRs, including nucleotide-binding oligomerization domain-like receptors (NLRs), absent in melanoma 2 (AIM2), and cysteine aspartate-specific protease (caspase)-4/5/11 recognize various PAMPs and DAMPs and assemble protein complexes called ‘inflammasomes’.