title: Single-cell cytokine analysis allows detection of cervical T-cell responses against human papillomavirus type 16 L1 in women infected with genital HPV.
abstract: Specific types of human papillomavirus (HPV) are known to play a causal role in the development of cervical cancer, with human papillomavirus type 16 (HPV-16) identified as the predominant type. Despite this, little is known about cervical immune responses to this pathogen. The aim of this study was to assess the feasibility of cervical cytobrush sampling and single-cell cytokine staining to investigate cervical lymphocyte-specific cytokine responses to HPV-16 antigens. Of eighteen women recruited into the study, five were HPV DNA positive at the cervix (current exposure) and a further five had circulating antibodies to HPV-16 (previous exposure). Cervical lymphocytes, isolated from the five HPV DNA-positive women, two HPV DNA-negative controls, and one woman with circulating HPV-16 antibodies were assessed for HPV-specific responses using intracellular staining for interferon-gamma (IFN-gamma) and interleukin-4 (IL-4). We demonstrate that both CD4(+) and CD8(+) cervical T lymphocytes, harvested from noninfected and infected subjects, produce these cytokines in response to nonspecific stimulation. However, antigen-specific (HPV-16 L1) IFN-gamma production by CD4(+) and CD8(+) cervical T lymphocytes is only detectable in women exposed currently or previously to HPV-16. This is the first time that antigen-specific cytokine responses of mucosal lymphocytes, obtained from a site of HPV infection, have been demonstrated. This finding clearly illustrates the use of intracellular cytokine staining for investigation of low precursor frequency single-cell antigen-specific responses in lymphocytes harvested from mucosal sites with HPV infection.
authors: Department of Clinical Laboratory Sciences, Division of Medical Virology, University of Cape Town and Groote Schuur Hospital, Observatory, Cape Town, South Africa.
authors: Jo-Ann S
authors: JA
authors: Passmore
authors: Vanessa C
authors: VC
authors: Burch
authors: Enid G
authors: EG
authors: Shephard
authors: Dianne J
authors: DJ
authors: Marais
authors: Bruce
authors: B
authors: Allan
authors: Patti
authors: P
authors: Kay
authors: Robert C
authors: RC
authors: Rose
authors: Anna-Lise
authors: AL
authors: Williamson
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D036022:Capsid Proteins; D002584:Cervix Uteri / Q000276:immunology* / Q000821:virology; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D009856:Oncogene Proteins, Viral / Q000276:immunology*; D027383:Papillomaviridae / Q000276:immunology*; D030361:Papillomavirus Infections / Q000276:immunology* / Q000821:virology; D013601:T-Lymphocytes / Q000276:immunology*; D014412:Tumor Virus Infections / Q000276:immunology
chemical_list: D036022:Capsid Proteins; D016207:Cytokines; D009856:Oncogene Proteins, Viral; D015847:Interleukin-4; C063317:L1 protein, Human papillomavirus type 16; D007371:Interferon-gamma