Immunogenic and Protective Properties of Neisseria meningitidis IgA1 Protease and of Its Truncated Fragments

Four recombinant proteins, MA²⁸–P¹⁰⁰⁴LEH₆, ME¹³⁵–H³²⁸LEH₆, MW³²⁹–H⁶²²LEH₆ and MH⁸³⁵–P¹⁰⁰⁴LEH₆, were prepared based on the genomic sequence of IgA1 protease from Neisseria meningitidis serogroup B strain H44/76. The immunogenic and protective properties of these proteins were studied in a mouse model. The predicted T- and B-epitopes located in the N-terminal part of amino acid sequence of this enzyme are very important for the formation of effective protection against meningococci of the three main epidemic serogroups A, B, and C. The small-sized recombinant protein having the sequence ME¹³⁵–H³²⁸LEH₆ (molecular weight 23367 Da) appears to be as protective against meningococci of the tested serogroups as the high molecular MA²⁸–P¹⁰⁰⁴LEH₆ (molecular weight 109019 Da), the latter being a large-sized analog of full-length IgA1 protease. These proteins can be promising candidates for a polyvalent meningococcal vaccine.