AUTHOR=Mathew Bijina J. , Gupta Priyal , Naaz Tabassum , Rai Rupal , Gupta Sudheer , Gupta Sudipti , Chaurasiya Shivendra K. , Purwar Shashank , Biswas Debasis , Vyas Ashish Kumar , Singh Anirudh K. 

TITLE=Role of Streptococcus pneumoniae extracellular glycosidases in immune evasion

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=Volume 13 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1109449

DOI=10.3389/fcimb.2023.1109449

ISSN=2235-2988

ABSTRACT=Streptococcus pneumoniae (pneumococcus) typically colonizes human upper airway asymptomatically but upon reaching other sites of the host body can cause an array of diseases such as pneumonia, bacteremia, otitis media and meningitis. Be it colonization or progression to disease state, pneumococcus faces multiple challenges posed by host immunity ranging from complement mediate killing to inflammation driven recruitment of bactericidal cells for containment of the pathogen. Pneumococcus has evolved several mechanisms to evade the host inflicted immune assault. The major pneumococcal virulence factor, polysaccharide capsule helps protect the bacteria from complement mediated opsonophagocytic killing. Another important group of pneumococcal proteins which help bacteria to stablish and thrive in host environment are surface associated glycosidases. These enzymes can hydrolyze host glycans on glycoproteins, glycolipids and glycosaminoglycans and consequently help bacteria acquire carbohydrate for growth. Many of these glycosidases directly or indirectly facilitate bacterial adherence and are known to modulate function of host defense/immune proteins likely by removing glycans and thereby affecting their stability and/or function. Furthermore, these enzymes are known to contribute the formation of biofilms, the bacterial communities inherently resilient to antimicrobials and host immune attack. In this review we summarize the way these versatile proteins help pneumococcus evade host immune response.