title: Low-level exposure to HIV induces virus-specific T cell responses and immune activation in exposed HIV-seronegative individuals.
abstract: HIV-specific T cells response and T cell activation are frequently seen in exposed seronegative individuals (ESN). In this study, we report HIV-specific response and level of T cell activation in ESN partners of HIV-infected patients presenting low or undetectable levels of HIV-RNA. We evaluated 24 HIV-serodiscordant couples. ESN were classified into three categories of exposure to HIV (very low, low, and moderate-high), considering levels of HIV-RNA in their infected partner and frequency of sexual high-risk practices within the last 12 mo. HIV-specific T cell responses and activation levels in T cell subsets were evaluated by flow cytometry. We reported that 54% of ESN had detectable HIV-specific T cells response, being the highest prevalence seen in the low exposure group (64%). Several T cell subsets were significantly increased in ESN when compared with controls: CD4(+)CD38(+) (p = 0.006), CD4(+)HLA-DR(-)CD38(+) (p = 0.02), CD4(+)CD45RA(+)CD27(+)HLA-DR(-)CD38(+) (p = 0.002), CD8(+)CD45RA(+)CD27(+)CD38(-)HLA-DR(+) (p = 0.02), and CD8(+)CD45RA(+)CD27(-)CD38(+)HLA-DR(+) (p = 0.03). Activation of CD8(+) T cells was increased in ESN with detectable HIV T cell responses compared with ESN lacking these responses (p = 0.04). Taken together, these results suggest that persistent but low sexual HIV exposure is able to induce virus-specific T cells response and immune activation in a high proportion of ESN, suggesting that virus exposure may occur even in conditions of maximal viral suppression in the HIV-infected partner.
authors.affiliation: Infectious Diseases Department, Hospital Carlos III, Madrid, Spain. clararestrepog@gmail.com
authors.forename: Clara
authors.initials: C
authors.lastname: Restrepo
authors.forename: Norma I
authors.initials: NI
authors.lastname: Rallón
authors.forename: Jorge
authors.initials: J
authors.lastname: del Romero
authors.forename: Carmen
authors.initials: C
authors.lastname: Rodríguez
authors.forename: Victoria
authors.initials: V
authors.lastname: Hernando
authors.forename: Mariola
authors.initials: M
authors.lastname: López
authors.forename: Alejandra
authors.initials: A
authors.lastname: Peris
authors.forename: Sara
authors.initials: S
authors.lastname: Lozano
authors.forename: José M
authors.initials: JM
authors.lastname: Sempere-Ortells
authors.forename: Vincent
authors.initials: V
authors.lastname: Soriano
authors.forename: José M
authors.initials: JM
authors.lastname: Benito
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000097:blood; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D054407:Chemokine CCL4 / Q000097:blood; D005260:Female; D005434:Flow Cytometry; D006678:HIV / Q000276:immunology*; D015658:HIV Infections / Q000097:blood / Q000276:immunology; D018023:HIV Seronegativity / Q000276:immunology*; D006684:HLA-DR Antigens / Q000097:blood; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
chemical_list: C066507:CCL4 protein, human; D054407:Chemokine CCL4; D006684:HLA-DR Antigens; D007371:Interferon-gamma; D051997:ADP-ribosyl Cyclase 1