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Published on: April 5, 2019
The vaccine potential of Streptococcus pneumoniae surface lectin- and non-lectin proteins
Maxim Portnoi1, Eduard Ling, Galia Feldman
1Pediatric Infectious Disease Unit, Soroka University Medical Center, Beer Sheva, Israel.
Abstract:
We have fractionated S. pneumoniae surface proteins into lectin and non-lectin fractions and tested their ability to elicit protective immune responses in the mouse model system. The total cell wall protein fraction (CW-T) was separated into lectin (CW-L), and non-lectin (CW-NL) fractions and used for immunization of mice. Immunized mice were challenged intranasally or intraperitoneally with S. pneumoniae strain WU2 (serotype 3). CW-T, CW-NL and CW-L and adjuvant only vaccination protected 55%, 43%, 44% and 0% of the intranasally challenged mice, respectively and 67%, 86%, 11% and 0% of mice challenged intraperitoneally, respectively. Immunogenic proteins in each fraction were sequenced and identified using MALDI-TOF. CW-L proteins provided a significantly better protection against intranasal inoculation and CW-NL proteins provided a significantly better protection from intraperitoneal inoculation. Proteins identified by sera from mice immunized with the cell-wall derived fractions may constitute candidates for future development of anti S. pneumoniae vaccines.
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