Role of antibody in Coxiella burnetii infection

Abstract

BALB/c mice infected with Coxiella burnetii phase I developed a state of acquired resistance which could be detected during week 2 postinfection. Immune serum, administered to normal mice 24 h before challenge with C. burnetii, appeared to accelerate the development of resistance. An increased clearance rate could be measured in these serum recipients 1 week postinfection. Simultaneous administration of immune serum and C. burnetii did not affect the normal clearance rate of rickettsiae from the spleens of infected mice during week 1, but enhanced clearance of the organism by 14 days postchallenge. Passive transfer of immune serum 24 h after challenge of normal mice with viable C. burnetii had no effect on rickettsial growth within the spleens of animals treated in this fashion. Treatment of athymic mice with immune serum 24 h before challenge with C. burnetii had no effect on rickettsial multiplication within the spleens of these T-cell-deficient animals.

Protective Immunity against Q Fever Induced with a Recombinant P1 Antigen Fused with HspB of Coxiella burnetii

“…21,22 However, a role for antibody was also shown to alter the course of C. burnetii infections in mice that received specific antiserum before infection. 22,23 In the present study, although both P1 and HspB could induce CMI and humoral immunoresponses, the immunoresponses elicited by P1 or HspB could not efficiently protect mice from coxiella infection. However, the efficient protection against C. burnetii was offered by immunization of fusion protein P1-HspB, suggesting that both CMI induced by P1 and humoral immunoresponses elicited by HspB play important roles in resisting C. burnetii.…”

Gamma-irradiated scrub typhus immunogens: development of cell-mediated immunity after vaccination of inbred mice

“…It is possible that the lack of circulating rickettsiae after challenge of mice immunized with viable rickettsiae is due to the presence of circulating antibody in these animals. The mechanism of this clearance simply may be due to a more rapid removal of rickettsiae antigen-antibody complexes by the reticuloendothelial system or to an antibodymediated adjuvant effect, as described by Humphres and Hinrichs (10). The potential implications of these possibilities in the production of a scrub typhus vaccine are of importance, and further studies are in progress to attempt to answer these fundamental questions.…”

“…However, one major difference noted in this study and previous studies (3) was the relatively low antibody levels in mice immunized with irradiated rickettsiae compared with the antibody response of mice immunized with viable rickettsiae. Other studies have shown that passive transfer of immune serum to naive mice protects against homologous R. tsutsugamushi challenge (25), and Humphres and Hinrichs (10) recently have shown that passive administration of immune serum to naive mice enhances the clearance of C. burnetii, apparently through an augmentation of the development of CMI. It is possible that the lack of circulating rickettsiae after challenge of mice immunized with viable rickettsiae is due to the presence of circulating antibody in these animals.…”

Profiling the Humoral Immune Response of Acute and Chronic Q Fever by Protein Microarray

“…Recent studies indicated that antibodies plays an important role in protective immunity in several intracellular pathogens (28 -30). Adoptive transfer of serum from vaccinated mice protects against C. burnetii challenge in naïve mice (29,30), which suggests that antibodies also contribute to protective immunity against C. burnetii. In both our previous studies (13,14) and here we have identified several seroreactive antigens, that may be important for protective immunity in infection (CBU1910, CBU0891, CBU0109, CBU1143, CBU0612, CBU0092, and CBU0545).…”