A primary Chlamydia trachomatis genital infection of rhesus macaques identifies new immunodominant B-cell antigens.

Arlo Randall,Luis M De La Maza,Sukumar Pal,Xiaowu Liang,Joseph Fike,Peter A Barry,Andy Teng,Alice F Tarantal,Nicholas J Mantis

doi:10.1371/journal.pone.0250317

Abstract

To identify immunodominant antigens that elicit a humoral immune response following a primary and a secondary genital infection, rhesus monkeys were inoculated cervically with Chlamydia trachomatis serovar D. Serum samples were collected and probed with a protein microarray expressing 864/894 (96.4%) of the open reading frames of the C. trachomatis serovar D genome. The antibody response to the primary infection was analyzed in 72 serum samples from 12 inoculated monkeys. The following criteria were utilized to identify immunodominant antigens: proteins found to be recognized by at least 75% (9/12) of the infected monkeys with at least 15% elevations in signal intensity from week 0 to week 8 post infection. All infected monkeys developed Chlamydia specific serum antibodies. Eight proteins satisfied the selection criteria for immunodominant antigens: CT242 (OmpH-like protein), CT541 (mip), CT681 (ompA), CT381 (artJ), CT443 (omcB), CT119 (incA), CT486 (fliY), and CT110 (groEL). Of these, three antigens, CT119, CT486 and CT381, were not previously identified as immunodominant antigens using non-human primate sera. Following the secondary infection, the antibody responses to the eight immunodominant antigens were analyzed and found to be quite different in intensity and duration to the primary infection. In conclusion, these eight immunodominant antigens can now be tested for their ability to identify individuals with a primary C. trachomatis genital infection and to design vaccine strategies to protect against a primary infection with this pathogen.

Highlights

Chlamydia trachomatis is the most common notifiable disease in the USA and is thought to be the most common bacterial sexually transmitted infection (STI) worldwide [1, 2]
Activities related to animal care including housing, feeding, and environmental enrichment were performed in accordance with Institutional Animal Care and Use Committee (IACUC)-approved standard operating procedures (SOPs) at the California National Primate Research Center
Following the primary cervical C. trachomatis serovar D infection, vaginal cultures were collected at weekly intervals (Figs 1 and 2, and S1 Table)

Summary

Introduction

Chlamydia trachomatis is the most common notifiable disease in the USA and is thought to be the most common bacterial sexually transmitted infection (STI) worldwide [1, 2]. Primary C. trachomatis genital infection of macaques. Antigen Discovery Inc was the primary awardee of the NIAID Advanced Technology STTR grants, numbers R41AI072847 and R42AI072847, and provided support in the form of salaries for authors [AR, AT, XL]. The funders did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section

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Conclusion