Immune Response Characterization after Controlled Infection with Lyophilized Shigella sonnei 53G

mSphere

卷:5

Robert W. Frenck¹  Amy Hoeper¹  Susan Parker¹  Monica McNeal¹  Michelle Dickey¹  Akamol E. Suvarnapunya²  Hailey P. Weerts²  Lakshmi Chandrasekaran²  Robert W. Kaminski²  Malabi M. Venkatesan²  Kristen A. Clarkson²  Christopher D. Heaney³  Kate Detizio⁴  Chad K. Porter⁴  August L. Bourgeois⁵ 

[1] Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA;

[2] Department of Enteric Infections, Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA;

[3] Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA;

[4] Naval Medical Research Center, Silver Spring, Maryland, USA;

[5] PATH, Washington, DC, USA;

关键词: Shigella;    immunogenicity;    controlled human infection model;    antibody;    immunological memory;    gut-homing responses;   

DOI  :  10.1128/mSphere.00988-19

来源: DOAJ

【 摘 要 】

ABSTRACT Shigella is a major cause of moderate to severe diarrhea largely affecting children (<5 years old) living in low- and middle-income countries. Several vaccine candidates are in development, and controlled human infection models (CHIMs) can be useful tools to provide an early assessment of vaccine efficacy and potentially support licensure. A lyophilized strain of S. sonnei 53G was manufactured and evaluated to establish a dose that safely and reproducibly induced a ≥60% attack rate. Samples were collected pre- and postchallenge to assess intestinal inflammatory responses, antigen-specific serum and mucosal antibody responses, functional antibody responses, and memory B cell responses. Infection with S. sonnei 53G induced a robust intestinal inflammatory response as well as antigen-specific antibodies in serum and mucosal secretions and antigen-specific IgA- and IgG-secreting B cells positive for the α4β7 gut-homing marker. There was no association between clinical disease outcomes and systemic or functional antibody responses postchallenge; however, higher lipopolysaccharide (LPS)-specific serum IgA- and IgA-secreting memory B cell responses were associated with a reduced risk of disease postchallenge. This study provides unique insights into the immune responses pre- and postinfection with S. sonnei 53G in a CHIM, which could help guide the rational design of future vaccines to induce protective immune responses more analogous to those triggered by infection. IMPORTANCE Correlate(s) of immunity have yet to be defined for shigellosis. As previous disease protects against subsequent infection in a serotype-specific manner, investigating immune response profiles pre- and postinfection provides an opportunity to identify immune markers potentially associated with the development of protective immunity and/or with a reduced risk of developing shigellosis postchallenge. This study is the first to report such an extensive characterization of the immune response after challenge with S. sonnei 53G. Results demonstrate an association of progression to shigellosis with robust intestinal inflammatory and mucosal gut-homing responses. An important finding in this study was the association of elevated Shigella LPS-specific serum IgA and memory B cell IgA responses at baseline with reduced risk of disease. The increased baseline IgA responses may contribute to the lack of dose response observed in the study and suggests that IgA responses should be further investigated as potential correlates of immunity.

【 授权许可】

Unknown