K. pneumoniae expresses various acidic factors such as capsule, lipopolysaccharide (LPS), siderophore, and adhesin, which play a crucial role in its pathogenesis. The capsule is a loose mucous substance that surrounds the cell wall and is involved in two pathogenic mechanisms: 1) protecting bacteria from phagocytosis; 2) suppressing the host's immune response. K. pneumoniae evades serum killing of phagocytes by producing amounts of capsular polysaccharide (CPS), which enhances its survival and ensures its pathogenicity. LPS is a T cell-dependent antigen that promotes lymphocyte mitosis and activates immune responses. Siderophores are high-affinity extracellular iron ion chelators secreted by bacteria. K. pneumoniae cannot directly obtain iron in the host body, and it overcomes the limitation of iron by secreting siderophore. Adhesins are cell surface factors or bacterial appendages that facilitate adhesion or attachment to other cells or shells, usually on the host they infect or live on.
Fig.1 The scheme of host innate immune response and virulence of K. pneumoniae. (Riwu, et al., 2022)
LPS and CPS are the two main factors in the pathogenesis of K. pneumoniae. LPS contains antigens required for microbial rejection of complement mediation, whereas CPS acts as a physical barrier against phagocytosis by polymorphonuclear cells. The study found that monoclonal antibodies against LPS and CPS have the potential to reduce K. pneumoniae infection and transmission. CD BioGlyco provides K. pneumoniae CPS and LPS production services for our global clients. We will extract CPS and LPS from cultured K. pneumoniae strains, and purify them through chromatographic columns to obtain pure target polysaccharides. To better induce T cell-dependent immune responses, we also provide clients with polysaccharides conjugation services with carrier proteins such as tetanus toxoid (TT) and cross-reacting material 197 (CRM197) by Physical Crosslinking and Chemical Methods.
CD BioGlyco has a professional Carrier Protein Design team, advanced Polysaccharide Production methods, and rich Conjugation Technologies to provide clients with satisfactory services. If you are interested in our K. pneumoniae polysaccharide antigen production services, please contact us for more details.
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