Altered Natural Killer Cell Function in HIV-Exposed Uninfected Infants

Frontiers in Immunology

卷:8

Laurel L. Lenz¹  Christiana Smith²  Emilie Jalbert²  Adriana Weinberg²  Jennifer Canniff²  Marisa M. Mussi-Pinhata³  Fabiana R. Amaral³  Jorge Pinto⁴  Volia de Almeida⁵  Jorge O. Alarcon⁶  George Siberry⁷  Rachel A. Cohen⁸  Qilu Yu⁸ 

[1] Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA;

[2] Department of Pediatric Infectious Diseases, University of Colorado School of Medicine, Aurora, CO, USA;

[3] Department of Pediatrics, Ribeirão Preto School of Medicine, University of São Paulo, São Paulo, Brazil;

[4] Federal University of Minas Gerais, Belo Horizonte, Brazil;

[5] Federal University of Sao Carlos Biological and Health Sciences Center, Sao Carlos, Brazil;

[6] Instituto de Medicina Tropical “Daniel A. Carrión” de la Universidad Nacional Mayor de San Marcos, Lima, Perú;

[7] Maternal and Pediatric Infectious Disease Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, USA;

[8] Westat, Rockville, MD, USA;

关键词: HIV-1;    infant;    natural killer cells;    K562 cells;    interleukin-12;    respiratory tract infections;   

DOI  :  10.3389/fimmu.2017.00470

来源: DOAJ

【 摘 要 】

ObjectivesHIV-exposed uninfected (HEU) infants have higher rates of severe and fatal infections compared with HIV-unexposed (HUU) infants, likely due to immune perturbations. We hypothesized that alterations in natural killer (NK) cell activity might occur in HEU infants and predispose them to severe infections.DesignCase–control study using cryopreserved peripheral blood mononuclear cells (PBMCs) at birth and 6 months from HEU infants enrolled from 2002 to 2009 and HUU infants enrolled from 2011 to 2013.MethodsNK cell phenotype and function were assessed by flow cytometry after 20-h incubation with and without K562 cells.ResultsThe proportion of NK cells among PBMCs was lower at birth in 12 HEU vs. 22 HUU (1.68 vs. 10.30%, p < 0.0001) and at 6 months in 52 HEU vs. 72 HUU (3.09 vs. 4.65%, p = 0.0005). At birth, HEU NK cells demonstrated increased killing of K562 target cells (p < 0.0001) and increased expression of CD107a (21.65 vs. 12.70%, p = 0.047), but these differences resolved by 6 months. Stimulated HEU NK cells produced less interferon (IFN)γ at birth (0.77 vs. 2.64%, p = 0.008) and at 6 months (4.12 vs. 8.39%, p = 0.001), and showed reduced perforin staining at 6 months (66.95 vs. 77.30%, p = 0.0008). Analysis of cell culture supernatants indicated that lower NK cell activity in HEU was associated with reduced interleukin (IL)-12, IL-15, and IL-18. Addition of recombinant human IL-12 to stimulated HEU PBMCs restored IFNγ production to that seen in stimulated HUU cultures.ConclusionNK cell proportion, phenotype, and function are altered in HEU infants. NK cell cytotoxicity and degranulation are increased in HEU at birth, but HEU NK cells have reduced IFNγ and perforin production, suggesting an adequate initial response, but decreased functional reserve. NK cell function improved with addition of exogenous IL-12, implicating impaired production of IL-12 by accessory cells. Alterations in NK cell and accessory cell function may contribute to the increased susceptibility to infection in HEU infants.

【 授权许可】

Unknown