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Volume 38, Number 6, December 2005

Comparison of multiple genital tract infections with Chlamydia trachomatis in different strains of female mice


Joseph M. Lyons, Servaas A. Morré, Lucy P. Airo-Brown, Amado S. Peña, James I. Ito
Department of Infectious Diseases, City of Hope National Medical Center and Beckman Research Institute, Duarte, California, USA; Laboratory of Immunogenetics, Section Immunogenetics of Infectious Diseases, VU University Medical Center, Amsterdam, The Netherlands; and Analytical Cytometry Laboratory, City of Hope National Medical Center and Beckman Research Institute, Duarte, California, USA

Received: July 26, 2005    Revised: September 1, 2005    Accepted: September 9, 2005   

 

Corresponding author:

Dr Joseph M. Lyons, Department of Infectious Diseases, City of Hope National Medical Center and Beckman Research Institute, Duarte, California 91010, USA. E-mail: jlyons@coh.org This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

 



 

Methods:

We have previously shown that female outbred CF-1 mice are susceptible to prolonged genital tract infection with the oculogenital serovars (D-K) of Chlamydia trachomatis, and that partial homotypic and heterotypic protection against reinfection is induced. To understand the possible role of inherent T-helper 1 (Th1)/Th2 polarity bias on both the course of infection and the level of acquired immunity induced by infection, 2 immunologically different and well-characterized inbred strains of mice, BALB/c and C57BL/6, were studied in this model. Groups of mice were inoculated intravaginally with C. trachomatis serovar D (Ct D) and monitored by culture to determine the duration of initial infection. Two months later, mice were reinfected, and monitored along with age- and condition-matched control groups. Plasma and vaginal secretions were collected for serologic analysis and specific delayed-type hypersensitivity was assessed by footpad swelling. Initial infection in C57BL/6 mice was comparable in duration to outbred CF-1 mice (median duration 42 versus 43.5 days), while BALB/c mice had a shorter median duration of initial infection (12 days). All strains had significantly shorter durations of infection following reinfection. BALB/c mice shed 4-10 times more inclusion-forming units (IFU) than both C57BL/6 and CF-1 mice on sample days during the first week of infection and all strains shed less IFU during reinfection. C57BL/6 and BALB/c mice had significantly lower anti-Ct D immunoglobulin G titers in both plasma and vaginal secretions than CF-1 mice following resolution of infection; the frequency of immunoglobulin A seropositive vaginal secretions was less in both inbred strains, being significantly less in the case of C57BL/6 mice. Qualitative analysis of the antigen specificity and isotype composition revealed differences among the mouse strains. All 3 strains had detectable levels of specific footpad swelling on day 14 of infection, whereas only BALB/c mice showed a significant response at 70 days post-infection. Significant differences between 2 strains of mice that differ in Th1/Th2 polarity bias were observed in: 1) the duration of infection; 2) the level of bacterial shedding during infection; and 3) the quantitative and qualitative cellular and humoral responses made in response to female genital tract infection with a human oculogenital isolate of C. trachomatis. In addition, a similar and significant level of partial acquired immunity to reinfection was observed in both strains, suggesting that inherent Th1/Th2 polarity bias present upon initial infection does not prevent the development of a protective immune response within the genital tract during infection with an oculogenital isolate of C. trachomatis.

 



 

Key words:

Active immunity, Chlamydia trachomatis, female genital diseases, inbred C57BL mice, inbred BALB C mice


 



 

J Microbiol Immunol Infect 2005;38:383-393.