Role of Antibodies against Outer-membrane Proteins in Murine Resistance to Infection with Encapsulated Klebsiella pneumoniae

Abstract

In the assessment of immunity to the encapsulated virulent strain of Klebsiella pneumoniae and its avirulent mutant defective for capsular polysaccharide (CPS), killed bacterial vaccine of both strains could protect mice equally against challenge with 100 x LD50 of encapsulated wild strain. Antisera to each strain conferred the same level of protection on naive mice upon transfer; the protective anti-mutant serum was highly capable of opsonizing the encapsulated bacteria. In addition to the common antigenic components shared by both strains, the wild strain had antigen(s) unrelated to the mutant since the protective capacity of the anti-wild serum was not affected by preabsorption with the mutant strain; the protection conferred by the anti-mutant serum was mediated by antibodies against non-capsular antigens since the antiserum did not contain antibodies against purified CPS detectable by ELISA. As possible candidates among the non-capsular antigens, outer-membrane proteins (OMPs) extracted from the mutant strain were examined for their immunogenicity. Immunoblotting of the protein-containing fraction and ELISA using LPS-free OMP suggested that a number of proteins were involved in the immune response evoked by K. pneumoniae. Furthermore, mice immunized with OMP or anti-OMP serum could overcome a lethal challenge with the wild strain. These results indicated that OMPs of K. pneumoniae are implicated as the protective antigens and may pave the way for the development of non-capsular, proteinaceous vaccines.

Self-similar colony morphogenesis by gram-negative rods as the experimental model of fractal growth by a cell population

“…described elsewhere (14,16,18,24). Citrobacter freundii NPC 3003, E. coli W3110, Proteus mirabilis NPC 3007, and Listeria monocytogenes EGD are laboratory strains.…”

Porin expression in clinical isolates of Klebsiella pneumoniae

“…pneumoniae have been implicated in protection against lethal challenge with homologous strains (Serushago et al, 1989), in activation of the complement system (Alberti et al, 1993b), in iron Abbreviations : 2D, two-dimensional; ESBL, extended-spectrum p-lactamase; OMP, outer-membrane protein; TEMED, N,N,N',N'-tetramethylethylenediamine.…”

Immunoinformatics Driven Prediction of Multiepitopic Vaccine Against Klebsiella pneumoniae and Mycobacterium tuberculosis Coinfection and Its Validation via In Silico Expression

“…Omps perform in various capacities that include maintaining structure and stability of the membrane, signal transduction, soluble transport, catalysis and defense (Jeannin et al 2002 ). The study conducted in Japan at the Kyushu University, was the first to integrate the proteins of the outer membrane in formulations of vaccines (Serushago et al 1989 ). Up till now, no such vaccine has been reported for coexistent Klebsiella pneumoniae and Mycobacterium tuberculosis .…”