ABSTRACT
The mature serine-type IgA1 protease from Neisseria meningitidis serogroup B strain H44/76 (IgA1pr1_28-1004) is considered here as the basis for creating a candidate vaccine against meningococcal meningitis. In this work, we examine the primary structure similarity of IgA1 proteases from various strains of a number of Gram-negative bacteria (N. meningitidis, Neisseria gonorrhoeae, Haemophilus influenzae) in order to find a structural groundwork for creating a broad-spectrum vaccine based on fragments of this enzyme. BLAST has shown high similarity between the primary structure of IgA1pr1_28-1004 and hypothetical sequences of mature IgA1 proteases from N. meningitidis (in 1060 out of 1061 examined strains), N. gonorrhoeae (in all 602 examined strains) and H. influenzae (in no less than 137 out of 521 examined strains). For these enzymes, common regions of sequence correspond to IgA1pr1_28-1004 fragments 28-84, 146-193, 253-539, 567-628, 639-795 and 811-1004, with identity of at least 85%. We believe that these fragments can be used in the development of a vaccine to prevent diseases caused by pathogenic strains of N. meningitidis and N. gonorrhoeae as well as a significant number of strains of H. influenzae.
ABSTRACT
Immunization of mice with recombinant IgA1 protease of Neisseria meningitidis or several structural derivatives thereof protects the animals infected with a variety of deadly pathogens, including N. meningitidis serogroups A, B, and C and 3 serotypes of Streptococcus pneumonia. In sera of rabbits immunized with inactivated pneumococcal cultures, antibodies binding IgA1-protease from N. meningitidis serogroup B were detected. Thus, the cross-reactive protection against meningococcal and pneumococcal infections has been demonstrated in vivo. Presumably it indicates the presence of common epitopes in the N. meningitidis IgA1 protease and S. pneumoniae surface proteins.
