Coxiella burnetii Antigen-Stimulated Dendritic Cells Mediated Protection against Coxiella burnetii in BALB/c Mice

Abstract

Coxiella burnetii is the etiological agent of human Q fever. In this study, adaptive transfer of mouse bone marrow-derived dendritic cells (BMDCs) stimulated with C. burnetii antigen, phase I whole-cell antigen (PIAg), lipopolysaccharide (LPS)-removed PIAg (PIIAg), protein antigen Com1, or SecB significantly reduced coxiella burden in recipient mice compared with control mice. Mice that received PIIAg-pulsed BMDCs displayed substantially lower coxiella burden than recipient mice of PIAg-pulsed BMDCs after C burnetii challenge. The protection offered by the antigen-activated BMDCs was correlated with the increased proliferation of helper T (T(H)) T(H)1 CD4(+) cells, preferential development of T(H)17 cells, and impaired expansion of regulatory T lymphocytes. Our results suggest that PIIAg is far superior to PIAg in activating BMDCs to confer protection against C. burnetii in vivo, whereas Com1 and SecB are protective antigens because Com1- or SecB-pulsed BMDCs confer partial protection.

Protective immunity against Rickettsia heilongjiangensis in a C3H/HeN mouse model mediated by outer membrane protein B-pulsed dendritic cells

“…BMDCs were isolated from bone marrow of C3H/HeN mice as described previously [14,18]. Briefly, a single-cell suspension from bone marrow was prepared from the mouse femurs and the bone marrow cells thus obtained were suspended in red blood cell lysis buffer (139.…”

“…Suspensions of BMDCs were dispensed into wells of the plate (1×10 6 cells/well) and stimulated with 10 µg mL 1 of rickettsial WCA or protein antigen (OmpB-p1, OmpB-p2, OmpB-p3, or OmpB-p4) at 37°C and 5% CO 2 for 24 h [14,15]. In parallel, the BMDCs were stimulated with 10 µg mL 1 of TrxA or antigen dilution buffer alone (mock stimulation).…”

“…The spleen tissue was ground and disintegrated into single cells on a 200-mesh sterile copper grid and the lymphocytes was separated from the cell suspension using lymphocyte separation medium (TBD, Tianjin, China) based on a previously described method [14]. The CD4 + or CD8 + T cells were isolated from the lymphocytes using a mouse CD4 + or CD8 + T cells Isolation Kit II and MACS (MiltenyiBiotec GmbH, BergischGladbach, Germany) according to the manufacturer's protocols.…”

“…In the present study, the ompB gene (4875 bp) of R. heilongjiangensis was divided into four fragments, resulting in four recombinant OmpB proteins (OmpB-p1, OmpB-p2, OmpB-p3, and OmpB-p4). In our previous studies, murine bone marrow derived DCs (BMDCs) pulsed by protective antigen proteins of Coxiella burnetii could mediate specific immune responses against Q fever [14,15]. Therefore, in the current study, the four OmpB proteins were used to pulse BMDCs from C3H/HeN mice in vitro and the pulsed BMDCs were transferred to naïve C3H/HeN mice.…”

Serological characterization of surface-exposed proteins of Coxiella burnetii

“…Immunization with bacterial surface proteins such as Com1, Mip, and SecB confer partial protection against Cox. burnetii infection in murine models (Wei et al, 2011;Xiong et al, 2012a). A Cox.…”