Antigen-Specific Cell Mediated Immune Response to Chlamydia Trachomatis

Antigen-specific Cell Mediated Immune Response to Chlamydia Trachomatis

This is an exploratory study in which the investigators will develop a way to identify the cell responses most strongly associated with protection against chlamydia infection. This study is not driven by a hypothesis.

Study Overview

• Status: Completed
• Conditions: Chlamydia

Detailed Description

With more than 90 million new cases annually, Chlamydia trachomatis is the most common sexually transmitted bacterial disease. Untreated endocervical C. trachomatis infections can cause pelvic inflammatory disease (PID), a disorder of the endometrium, fallopian tubes, and adjacent structures that occurs after ascension of the bacterium from the lower to upper genital tract. Adverse outcomes secondary to C. trachomatis-induced PID include tubal infertility, ectopic pregnancy, and chronic pelvic pain. Vaccine development has been identified as essential for control of C. trachomatis infections, and current evidence suggests that an effective vaccine will likely be based on several C. trachomatis antigens. Experimental models of infection have identified HSP60, major outer-membrane protein (MOMP), outer membrane protein 2 (OMP2), and polymorphic membrane protein D (PmpD) as promising vaccine candidates. A prospective study of Kenyan commercial sex workers found that production of interferon-gamma (IFN-γ) by peripheral blood cells stimulated with chlamydia heat-shock protein (HSP60) strongly correlated with protection against incident C. trachomatis infection. This proposal details an exploratory identification of the antigen-specific cell mediated immune responses associated with antecedent C. trachomatis infection in women.

C. trachomatis is an obligate, intracellular, gram-negative microorganism recognized as the most common bacterial sexually transmitted disease worldwide. The highest rates of infection with this organism are consistently found among adolescents and young adults. Young women are also the group most adversely impacted by the effects of C. trachomatis infection on reproductive health. While approximately 70% of infections with C. trachomatis in young women are asymptomatic, 20% - 40% of these occult infections will progress from endocervical inflammation to the development of PID. In addition to its strong association with PID, C. trachomatis infection is also thought to enhance HIV transmission and contribute to human papilloma virus induced cervical neoplasia. Although data from both experimental models and clinical studies suggest that antigen specific CD4+ and CD8+ T cells are required for optimal control of genital tract chlamydial infections, the current lack of information regarding the specific C. trachomatis antigens eliciting protective immune responses in humans hinders vaccine development.

This is an exploratory investigation in which we will develop the methodology needed to identify the antigen-specific cell mediated immune responses most strongly associated with protection against incident C. trachomatis infection.

• Study Type: Observational
• Enrollment (Actual): 55

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15213
      • Magee-Womens Hospital of UPMC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 15 years to 35 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

• Sampling Method: Non-Probability Sample

Study Population

20 women with history of endocervical chlamydia and 10 women with no history of endocervical chlamydia

Description

Inclusion Criteria:

• Women between 15-35 years of age at the time of enrollment onto this study. Minors between the ages of 1-17 will require parental consent to participate in the study.
• History of, in past 5 years, endocervical C. trachomatis infection (total of 20 women) or no history of endocervical C. trachomatis infection (total of 10 women).

Exclusion Criteria:

• Pregnancy.
• Immunocompromised, by history (including but not limited to known HIV, cancer, autoimmune diseases).

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
history of chlamydia infection; Women who self-reported a history of cervical infection with Chlamydia trachomatis
no history of chlamydia infection; Women who self-reported no history of cervical infection with Chlamydia trachomatis

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
This is an exploratory investigation in which we will develop the methodology needed to identify the antigen-specific cell mediated immune responses most strongly associated with protection against incident C. trachomatis infection.	1 year

Collaborators and Investigators

• Sponsor: University of Pittsburgh
• Collaborators: National Institute of Allergy and Infectious Diseases (NIAID); National Institutes of Health (NIH)

Study record dates

Study Major Dates

• Study Start: December 1, 2009
• Primary Completion (Actual): June 1, 2010
• Study Completion (Actual): June 1, 2010

Study Registration Dates

• First Submitted: August 29, 2009
• First Submitted That Met QC Criteria: September 1, 2009
• First Posted (Estimate): September 2, 2009

Study Record Updates

• Last Update Posted (Actual): April 7, 2017
• Last Update Submitted That Met QC Criteria: April 5, 2017
• Last Verified: April 1, 2017

More Information

Terms related to this study

• Keywords: chlamydia; healthy women; history of endocervical chlamydia; no history of endocervical chlamydia
• Additional Relevant MeSH Terms: Infections; Communicable Diseases; Sexually Transmitted Diseases; Gram-Negative Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Chlamydiaceae Infections; Sexually Transmitted Diseases, Bacterial; Chlamydia Infections
• Other Study ID Numbers: PRO09070184; U19AI084024 (NIH)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No