Title |
Gamma-irradiation of Streptococcus pneumoniae for the use as an immunogenic whole cell vaccine |
Author |
Min Yong Jwa1, Soyoung Jeong1, Eun Byeol Ko1, A Reum Kim1, Hyun Young Kim1, Sun Kyung Kim1, Ho Seong Seo2, Cheol-Heui Yun3, and Seung Hyun Han1* |
Address |
1Department of Oral Microbiology and Immunology, DRI, and BK21 Plus Program, School of Dentistry, Seoul National University, Seoul 08826, Republic of Korea, 2Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup 56212, Republic of Korea, 3Department of Agricultural Biotechnology and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea |
Bibliography |
Journal of Microbiology, 56(8),579–585, 2018,
|
DOI |
10.1007/s12275-018-8347-1
|
Key Words |
vaccine, Streptococcus pneumoniae, gamma-irradiation,
killed whole cell vaccine |
Abstract |
Streptococcus pneumoniae is a major respiratory pathogen
that causes millions of deaths worldwide. Although subunit
vaccines formulated with the capsular polysaccharides or
their protein conjugates are currently-available, low-cost
vaccines with wide serotype coverage still remain to be developed,
especially for developing countries. Recently, gamma-
irradiation has been considered as an effective inactivation
method to prepare S. pneumoniae vaccine candidate.
In this study, we investigated the immunogenicity and protective
immunity of gamma-irradiated S. pneumoniae (r-SP),
by comparing with heat-inactivated S. pneumoniae (h-SP)
and formalin-inactivated S. pneumoniae (f-SP), both of which
were made by traditional inactivation methods. Intranasal
immunization of C57BL/6 mice with r-SP in combination
with cholera toxin as an adjuvant enhanced S. pneumoniaespecific
antibodies on the airway mucosal surface and in sera
more potently than that with h-SP or f-SP under the same
conditions. In addition, sera from mice immunized with r-
SP potently induced opsonophagocytic killing activity more
effectively than those of h-SP or f-SP, implying that r-SP
could induce protective antibodies. Above all, immunization
with r-SP effectively protected mice against S. pneumoniae
infection. Collectively, these results suggest that gamma-
irradiation is an effective method for the development
of a killed whole cell pneumococcal vaccine that elicits robust
mucosal and systemic immune responses. |