Nat E. HIV-1 infection causes a steady state imbalance between congenital lymphocytes and natural killer cells.

In this paper, we will discuss the role of innate lymphoid cells (ILCs) and natural killer (NK), NK cells constitute the first line of defense of human immune system. IL-22 secreted by type III ILC (ilc3) plays an important role in blocking intestinal microbial infection, while NK cells play a key role in immune regulation, clearance of virus infected cells and cancer cells by secreting cytokines and mediating target cell killing.at present, the interaction between HIV-1 infection and ilc3 and NK cells is not clear.on February 17, 2020, Jeremy Luban team of UMass School of Medicine (the first author is Yetao Wang) published an article in the journal Nature Immunology on HIV-1-induced cytochemics decepte homeostatic innate ymphoid cells and expand tcf7 dependent memory NK cells.this study systematically tested HIV-1 negative (HIV-1 negative), HIV-1 positive people without drug treatment with viremia (HIV-1 + viral), HIV-1 positive people receiving drug treatment (HIV-1 + Art) and HIV-1 + sporadic controller (HIV-1 + sporadic controller) Compared with HIV-1 negative people, all HIV-1 infected people showed a decrease in ILC levels.by further testing the level of ilc3 in the intestinal tract of HIV-1 negative and HIV-1 positive people receiving drug treatment, it was found that even if the HIV-1 positive people were not detected with HIV-1 virus, and had the same level of CD4 + T cells, ILC as the HIV-1 negative population The level of ilc3 was still significantly decreased in this group, indicating that the continuous decline of ilc3 was associated with chronic inflammation prevalent in HIV-1 infected people.consistent with this conclusion, the concentration of sCD14 in blood was negatively correlated with ILC, while the number of CD4T cells and the ratio of CD4 / CD8 were positively correlated with ILC. The number of inflammatory related molecules MX1 and MPO positive cells in the gut were significantly increased in HIV-1 infected patients, indicating that ILC plays an important role in avoiding systemic inflammation caused by intestinal microorganisms. NK cells play an important role in the control of HIV-1 infection. Although NK cells are generally considered as innate immune cells, more and more experiments have shown that hapten or cytokine stimulation can make NK cells produce immune memory, and when they encounter similar stimuli again, they will stimulate NK cells to produce stronger cytotoxicity or IFN - γ secretion.these NK cells with immune memory function are called memory NK cells (memory NK or adaptive NK).based on different experimental systems, different types of memory NK cells express different surface molecules, and the mechanism of these cell formation is still unclear.by analyzing the transcriptome and epigenetic characteristics of human peripheral blood NK cells, it was found that NK cells with high expression of CD56 (cd56hi) were highly similar to memory cd8t cells.single cell transcriptome analysis also showed that these cells highly expressed memory T cell molecular marker tcf7, independent of other NK cell groups. In vitro experiments showed that NK cells with low expression of CD56 (cd56dim) differentiated into tcf7 + cd56hink cells after stimulation by cytokines, thus obtaining immune memory.further studies showed that the number of tcf7 + memory NK cells increased significantly in HIV-1 infected patients, suggesting that the immune activation caused by HIV-1 infection may be the reason for the increase of tcf7 + memory NK cells.in conclusion, this study suggests that in-depth understanding of the persistent decrease of ilc3 caused by HIV-1 infection and the increase of memory NK cells may have clinical significance for the treatment of chronic inflammation and related diseases related to HIV-1 infection.original link: plate maker: Qi sauce