HIV-1 infects ILC1 cells.

<p>(<b>A</b>) Representative histograms indicate the expression of the HIV-1 co-receptors CCR5 and CXCR4 on CD4⁺ and CD4^- ILC1s from the spleen of humanized mouse and human peripheral blood. (<b>B</b>) Summary data show the expression of CCR5 and CXCR4 by CD4⁺ ILC1s from human PBMCs (n = 6) and the spleen (n = 14), BM (n = 4), mLN (n = 4) and PBL (n = 3) of humanized mice. BM, bone marrow; mLN, mesenteric lymph node; pLN, popliteal lymph node. (<b>C-D</b>) Representative dot plots (<b>C</b>) and summarized data (<b>D</b>) indicate the p24⁺ ILC1s present <i>in vitro</i> of HIV-1 stock. The numbers (<b>C</b>) indicate the percentages of p24⁺ cells within ILC1s. Human fresh PBMCs were infected with HIV-1 (R3A and NL4-3) <i>in vitro</i> without or with anti-HIV-1 neutralizing antibody. *<i>p</i> < 0.05 and **<i>p</i> < 0.01, two-tailed paired Student’s <i>t</i>-test. (<b>E-F</b>) Activation enhances HIV-1 infection in ILC1 cells. (<b>E</b>) Representative dot plots indicate p24 expression within ILC1s present <i>in vitro</i> of mock or HIV-1 NL4-3 stock with or without activation (PHA pre-stimulation for 24 hours). (<b>F</b>) Summarized data indicate the percentages of p24⁺ cells within ILC1s in various conditions. Human PBMCs were first incubated with PHA for 24 hours in the presence of IL-2 (50 IU/ml) and IL-7 (20 ng/ml). The cells were then incubated with HIV/NL4-3 stock or mock stock for additional 4 days. **<i>p</i> < 0.01 and ***<i>p</i> < 0.001, two-tailed paired Student’s <i>t</i>-test. (<b>G</b>) Summarized data show the levels of cell-associated HIV-1 DNA in purified CD4⁺ T cells, CD4⁺ ILC1s and CD8+ T cells from the PBMCs of HIV-1 infected patients (n = 5) detected by real time-PCR. (<b>H</b>) Representative dot plots show that HIV-1 infects ILC1s <i>in vivo</i> in humanized mice. The numbers indicate the percentages of p24⁺ mCD24⁺ cells within CD3⁺ T cells or ILC1s. At 3 weeks of HIV-1 infection (R3A-HAS virus), bone marrow cells were stained with surface markers, and this was followed by staining of the HIV-1 p24 protein and mCD24. The numbers indicate the percentage of p24 and mCD24 on CD3 T cells and ILC1s in humanized mice (n = 3). (<b>B</b>, <b>D</b> and <b>E</b>) Data represent the mean ± s.e.m. values.