Cervical Cancer Research – Dr Jo-Ann Passmore
Dr Jo-Ann Passmore
Title of the project
Impact of genital inflammation, HIV co-infection and Human Papillomavirus (HPV)-specific cellular immunity on HPV burden in the female genital tract: Inflammation and HIV co-infection as co-factors for cervical disease progression
Aim of the project
The overall aim of this study will be to investigate the association between inflammation, HPV viral burden and HPV-specific immunity in the genital tract of women dually infected with HIV and HPV. Hypothesis: HIV-infected women will have elevated genital tract inflammation and correspondingly high HPV viral loads despite the presence of HPV-specific cellular immunity. This will contribute to both the persistence of HPV and increased susceptibility to severe cervical disease.
Objective 1: To evaluate the level and composition of genital tract inflammation in HPV-HIV-, HPV-HIV+, HPV+HIV- and HPV+HIV+ women.
Objective 2: To investigate the impact of inflammation on HPV viral load and/or persistence.
Objective 3: To investigate the association between inflammation, HPV viral load and HPV-16-specific T cell immunity in the female genital tract.
What has been achieved to date?
Funding for this project was released by UCT in March 2010.
- Since the project started, we have designed and ordered antibodies for flow cytometric evaluation of HPV-16-specific immunity. Flow cytometry antibodies have been titrated and panels optimized for the study.
- We have enrolled 57 women in the study to date. Of these, 23/57 was HIV-infected while 34/57 was not infected with HIV. Cervical cytobrush samples and blood were taken from each woman and HPV- and HIV-specific immunity in the female genital tract measured ex vivo while PBMC were cryo-preserved and will be processed in batches. Cervical supernatant from these 57 women has been stored at -80oC for later evaluation of inflammatory cytokine concentrations in the genital tract.
- We have optimized an ELISA for measurement of prostate-specific antigen (PSA) as a surrogate marker for the presence of semen in the female genital tract of women enrolled. We have evaluated the concentration of PSA in 33/57 samples collected to date. Of the 33 women evaluated, 5/33 was positive for PSA despite 3/5 reporting 100% condom use at all sexual encounters. This will serve as an indicator of recent unprotected sexual activity.
- The cytokines to be included in the Luminex panel have been selected and kits ordered. Since IL-7, TNF-a, and IL-1b are generally present in very low concentrations in genital fluid, these cytokines will be measured by high sensitivity ELISAs and the kits have been ordered for these cytokines
What is hoped to be achieved in the next year?
During the remainder of 2010 and 2011:
- We will complete recruitment of all women to be enrolled in the study (cross-sectional and longitudinal) and continue to follow 50 women longitudinally. Cervical cytobrush-derived T cell responses to HPV-16 E7 and HPV Gag peptides will continue to be evaluated fresh (since the cell yields do not allow for cryo-preservation) while PBMCs from blood will be stored and processed in batches.
- We will complete analysis of inflammatory cytokine concentrations in cervical supernatant samples stored from cytobrushes processed fresh above.
- In collaboration with Prof Anna-Lise Williamson, we will initiate analysis of HPV types in the genital tract on HIV-infected and uninfected women enrolled in the study.