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. 2012 Mar;86(6):3327-36.
doi: 10.1128/JVI.06676-11. Epub 2012 Jan 11.

Alpha interferon and HIV infection cause activation of human T cells in NSG-BLT mice

Brian R Long  1 , Cheryl A Stoddart
Affiliations

Alpha interferon and HIV infection cause activation of human T cells in NSG-BLT mice

Brian R Long et al. J Virol. 2012 Mar.

Abstract

The development of small animal models for the study of HIV transmission is important for evaluation of HIV prophylaxis and disease pathogenesis. In humanized bone marrow-liver-thymus (BLT) mice, hematopoiesis is reconstituted by implantation of human fetal liver and thymus tissue (Thy/Liv) plus intravenous injection of autologous liver-derived hematopoietic stem progenitor cells (HSPC). This results in reconstitution of human leukocytes in the mouse peripheral blood, lymphoid organs, and mucosal sites. NOD-scid interleukin-2 receptor-negative (IL-2Rγ(-/-)) (NSG)-BLT mice were inoculated intravaginally with HIV and were monitored for plasma viremia by a branched DNA assay 4 weeks later. T-cell activation was determined by expression of CD38 and HLA-DR on human CD4(+) and CD8(+) T cells in mouse peripheral blood at the time of inoculation and 4 weeks later. Additional BLT mice were treated with human alpha interferon 2b (IFN-α2b) (intron A) and assessed for T-cell activation. Productive HIV infection in BLT mice was associated with T-cell activation (increases in CD38 mean fluorescence intensity and both the frequency and absolute number of CD38(+) HLA-DR(+) T cells) that correlated strongly with plasma viral load and was most pronounced in the CD8(+) T-cell compartment. This T-cell activation phenotype was recapitulated in NSG-BLT mice treated with intron A. HIV susceptibility correlated with the number of HSPC injected, yet a number of mice receiving the Thy/Liv implant alone, with no HSPC injection, were also susceptible to intravaginal HIV. These results are consistent with studies linking T-cell activation to progressive disease in humans and lend support for the use of NSG-BLT mice in studies of HIV pathogenesis.

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Figures

Fig 1
Fig 1
Experimental design, HIV inoculation, and loss of CD4+ T cells in HIV-infected BLT mice. (A) Fourteen cohorts of BLT mice (Table 1) were inoculated intravaginally with HIV JR-CSF at 0 weeks (12 weeks after HSPC injection). Peripheral blood of BLT mice was evaluated for human cell reconstitution by Trucount analysis 0 weeks and 4 weeks after inoculation. bDNA, branched DNA assay. (B) Total numbers of peripheral blood leukocytes (CD45+), lymphocytes (Ly), monocytes (Mo), CD4+ T cells (CD4+), CD8+ T cells (CD8+), and B cells (B) were determined for each cohort by Trucount analysis at the time of inoculation. (C) Significant differences were observed in the number of CD4+ T cells and the change in CD4+ T-cell number between HIV-negative (n = 58) and HIV-positive (n = 79) mice at the time of inoculation and 4 weeks after inoculation. The Mann-Whitney U test was used to test the differences between the means.
Fig 2
Fig 2
Overall lack of correlation within cohorts between human CD4+ T-cell reconstitution at the time of inoculation (0 weeks) and the plasma HIV load obtained 4 weeks later. Trend lines from linear regression analysis are shown, and the two-tailed Spearman correlation coefficient (r) was calculated, with resulting P values at 95% confidence.
Fig 3
Fig 3
Numbers of fetal liver-derived CD34+ cells (top left) and HSPC (Lin-1− CD38− CD45RA− CD45+ CD34+ c-kit+ CD90+) (top right) injected into each mouse (−12 weeks) (see Fig. 1A), with the frequency of HIV-viremic mice 4 weeks after inoculation, for the 14 cohorts of BLT mice. The mean number of CD4+ T cells/μl in each cohort at the time of inoculation (0 weeks) correlated with the frequency with which BLT mice became viremic (bottom left). The frequency with which BLT mice that did not receive injected HSPC became infected with HIV following intravaginal inoculation (bottom right) correlated with the frequency with which HSPC-injected BLT mice became infected. Trend lines from linear regression analysis are shown, and the two-tailed Spearman correlation coefficient (r) was calculated, with resulting P values at 95% confidence.
Fig 4
Fig 4
T-cell activation in HIV-infected BLT mice. Peripheral blood was collected from BLT mice at the time of inoculation (0 weeks) (middle row) and 4 weeks later (bottom row). Human peripheral blood was used as a staining and gating control (top row). Blood was immunophenotyped for the presence of human leukocytes and further analyzed for the expression of activation markers. Human CD45+ leukocytes were gated by side scatter into lymphocytes (not shown) and further subdivided into CD3+ (T cells) and CD19+ cells (B cells). CD3+ cells were separated into CD4+ and CD8+ T cells and evaluated for CD38 and HLA-DR expression. Shown in the middle and bottom rows are data for the same BLT mouse at the 0-week and 4-week time points (4.5 log10 copies HIV RNA per 100 μl), where an increase in the frequency of CD38+ HLA-DR+ cells was observed in the CD4+ T-cell and CD8+ T-cell compartments.
Fig 5
Fig 5
Increased expression of cellular activation markers on lymphocytes from HIV-infected BLT mice. (A) The geometric MFI of CD38 (left), as well as the frequency (center) and absolute number per μl (right) of CD38+ HLA-DR+ cells, was determined for CD4+ and CD8+ T cells from a subset of HIV-positive (n = 46) BLT mice at 0 weeks (the time of inoculation) and 4 weeks. P values are shown for the two-tailed, nonparametric Mann-Whitney U test. (B) Activation marker data for HIV-infected mice were correlated with plasma HIV load 4 weeks after inoculation. The MFI of CD38 (left) on CD4+ and CD8+ T cells correlated strongly with viral load, as did the frequency (center) and absolute number (right) of CD38+ HLA-DR+ cells. Trend lines from linear regression analysis are shown, and the two-tailed Spearman correlation coefficient (r) was calculated, with resulting P values at 95% confidence. Data are from cohorts BLT-1012, BLT-1013, BLT-1014, BLT-1015, BLT-1016, BLT-1017, BLT-1018, BLT-1020, BLT-1022, and BLT-1023 (described in Table 1).
Fig 6
Fig 6
Treatment with intron A causes increased expression of CD38 and HLA-DR. (A) Groups of 6 BLT mice from the same cohort were treated with 3 different doses of intron A (106, 105, and 104 IU), beginning 12 weeks after HSPC injection. One group was treated with sterile water. Mice were dosed once daily by intraperitoneal injection for 6 days. On day 7, peripheral blood was phenotyped and examined for expression of CD38 and HLA-DR. (Left) The numbers of CD4+ and CD8+ T cells per μl of whole blood were elevated only slightly in the treated groups. The MFI of CD38 and both the frequency and absolute number per μl of CD38+ HLA-DR+ cells (center left, center right, and right panels, respectively) were determined for CD4+ T cells (top row) and CD8+ T cells (bottom row). (B) Spleens were collected from groups of intron A-treated mice as described for panel A and were processed to produce single-cell suspensions for immunophenotyping by flow cytometry. The MFI of CD38 was increased significantly, in a dose-dependent manner, on both splenic CD4+ and CD8+ T cells (left), yet there was no difference in the frequency of CD38+ HLA-DR+ cells (right). Statistical significance compared with the water-treated group was determined by the Mann-Whitney U test. *, P < 0.05; **, P < 0.01.
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References

    1. Bentwich Z, Kalinkovich A, Weisman Z, Grossman Z. 1998. Immune activation in the context of HIV infection. Clin. Exp. Immunol. 111:1–2 - PMC - PubMed
    1. Brainard DM, et al. 2009. Induction of robust cellular and humoral virus-specific adaptive immune responses in human immunodeficiency virus-infected humanized BLT mice. J. Virol. 83:7305–7321 - PMC - PubMed
    1. Brenchley JM, et al. 2006. Microbial translocation is a cause of systemic immune activation in chronic HIV infection. Nat. Med. 12:1365–1371 - PubMed
    1. Chang JJ, Altfeld M. 2010. Innate immune activation in primary HIV-1 infection. J. Infect. Dis. 202(Suppl 2):S297–S301 - PMC - PubMed
    1. Choudhary SK, et al. 2009. Suppression of human immunodeficiency virus type 1 (HIV-1) viremia with reverse transcriptase and integrase inhibitors, CD4+ T-cell recovery, and viral rebound upon interruption of therapy in a new model for HIV treatment in the humanized Rag2−/− γc−/− mouse. J. Virol. 83:8254–8258 - PMC - PubMed

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