Although generalized T-cell activation is an important factor in chronic HIV disease pathogenesis, its role in primary infection remains poorly defined. To investigate the effect of immune activation on T-cell changes in subjects with early HIV infection, and to test the hypothesis that an immunologic activation "set point" is established early in the natural history of HIV disease, a prospective cohort of acutely infected adults was performed. The median density of CD38 molecules on CD4 ؉ and CD8 ؉ T cells was measured longitudinally in 68 antiretroviral-untreated individuals and 83 antiretroviraltreated individuals. At study entry, T-cell activation was positively associated with viremia, with CD8 ؉ T-cell activation levels increasing exponentially at plasma HIV RNA levels more than 10 000 copies/mL. Among untreated patients, the level of CD8 ؉ T-cell activation varied widely among individuals but often remained stable within a given individual. CD8 ؉ T-cell activation and plasma HIV RNA levels over time were independently associated with the rate of CD4 ؉ T-cell loss in untreated individuals. These data indicate that immunologic activation set point is established early in HIV infection, and that this set point determines the rate at which CD4 ؉ T cells are lost over time. IntroductionUntreated HIV-1 infection is associated with a gradual loss of peripheral CD4 ϩ T cells. Although the direct cytopathic effect of HIV-1 on CD4 ϩ T cells almost certainly contributes to this gradual depletion, 1 most cells destined to die in vivo as a consequence of HIV infection are not productively infected with HIV. 2 This observation has led to the hypothesis that progressive CD4 ϩ T-cell depletion occurs due to indirect effects of viral replication. [3][4][5][6] The mechanism for these indirect effects of HIV replication on CD4 ϩ T-cell depletion is not understood.One widely accepted model postulates that HIV causes accelerated proliferation, expansion, and death of T cells, and that this heightened T-cell turnover eventually results in depletion or exhaustion of the regenerative capacity of the immune system. 4,5 Multiple studies have shown that HIV infection results in a state of high T-cell turnover (ie, the rates of T-cell proliferation and death are increased). For example, in vivo labeling of T cells indicates that HIV infection results in increased numbers of rapidly cycling CD4 ϩ and CD8 ϩ T cells. 7,8 These cells are primarily of memoryeffector phenotype, and are destined to proliferate and die rapidly. 9 The rate at which HIV recruits cells into this rapid turnover state is directly proportional to the level of viremia, 8 which in turn is directly related to the rate at which CD4 ϩ T cells are lost. 10 In the absence of antiretroviral treatment, markers of T-cell activation and T-cell turnover predict the rate of disease progression 11-14 and the rate of CD4 ϩ T-cell loss. 15 When antiretroviral therapy is initiated, the rate of T-cell turnover and the degree of generalized T-cell activation both decrease, suggest...
Dendritic cells play a pivotal role in host immune defense, such as elimination of foreign pathogen and inhibition of tumorigenesis. In this paper, we report that [Gd@C 82 (OH) 22 ] n could induce phenotypic maturation of dendritic cells by stimulating DC production of cytokines including IL-12p70, upregulating DC costimulatory (CD80, CD83, and CD86) and MHC (HLA-A,B,C and HLA-DR) molecules, and switching DCs from a CCL5-responsive to a CCL19-responsive phenotype. We found that [Gd@C 82 (OH) 22 ] n can induce dendritic cells to become functionally mature as illustrated by their capacity to activate allogeneic T cells. Mice immunized with ovalbumin in the presence of [Gd@C 82 (OH) 22 ] n exhibit enhanced ovalbumin-specific Th1-polarized immune response as evidenced by the predominantly increased production of IFNγ, IL-1β, and IL-2. The [Gd@C 82 (OH) 22 ] n nanoparticle is a potent activator of dendritic cells and Th1 immune responses. These new findings also provide a rational understanding of the potent anticancer activities of [Gd@C 82 (OH) 22 ] n nanoparticles reported previously.
Graves’ disease (GD) is one of the most common autoimmune diseases. The immune dysfunction in GD involves the generation of thyroid-stimulating hormone receptor (TSHR) autoantibodies that presumably arise consequent to interactions among dendritic cells (DCs), T cells, and regulatory T (Treg) cells. However, the immunological mechanisms of interactions between them that lead to the induction and regulation of this autoimmune disease are poorly defined. In this study, we investigated whether DCs are the main cause of the defective activity of Treg cells in GD patients. We found a significant decrease in the percentage of circulating CD4+CD25+FOXP3+ Treg cells in untreated GD patients (uGD), which was negatively correlated with the concentration of TSHR autoantibodies. uGD-derived DCs were polarized to increase the number of plasmacytoid DCs (pDCs) and conferred the ability to abrogate the suppressive function of Treg cells through inducing apoptosis of CD4+CD25+ Treg cells in an IFN-α–dependent manner, and elevated thyroid hormones further exacerbated the effect. The nucleotide UDP, which inhibits IFN-α secretion of pDCs through P2Y6 receptor signaling, restored the suppressive function of CD4+CD25+ Treg cells. Collectively, uGD-derived DCs through pDC polarization and elevated thyroid hormones act in concert to impair the regulatory capacity of Treg cells, facilitating the production of TSHR autoantibodies in the pathogenesis of GD.
Chinese tongue sole is a marine fish with ZW sex determination. Genome sequencing suggested that the Z-linked dmrt1 is a putative male determination gene, but direct genetic evidence is still lacking. Here we show that TALEN of dmrt1 efficiently induced mutations of this gene. The ZZ dmrt1 mutant fish developed ovary-like testis, and the spermatogenesis was disrupted. The female-related genes foxl2 and cyp19a1a were significantly increased in the gonad of the ZZ dmrt1 mutant. Conversely, the male-related genes Sox9a and Amh were significantly decreased. The dmrt1 deficient ZZ fish grew much faster than ZZ male control. Notably, we obtained an intersex ZW fish with a testis on one side and an ovary on the other side. This fish was chimeric for a dmrt1 mutation in the ovary, and wild-type dmrt1 in the testis. Our data provide the first functional evidence that dmrt1 is a male determining gene in tongue sole.
BackgroundOvarian cancer (OC) is a gynecological malignancy with a high mortality. Cisplatin-based treatment is the typical treatment regimen for OC patients; however, it may cause unfavorable resistance. The current study intends to explore the function of cancer-associated fibroblast (CAF)-derived exosomal microRNA-98-5p (miR-98-5p) in cisplatin resistance in OC, and the participation of CDKN1A.MethodsBioinformatics analysis was employed in order to obtain cisplatin resistance-related differential genes in OC as well as possible upstream regulatory miRs. After gain- and loss-of-function assays in OC cells, RT-qPCR and western blot analysis were employed to measure CDKN1A and miR-98-5p expression. Dual luciferase reporter assay was applied to verify the targeting relationship between miR-98-5p and CDKN1A. CAFs were treated with miR-98-5p inhibitor, and then exosomes were isolated and co-cultured with OC cells. CCK-8, colony formation and flow cytometry assays were conducted to assess cell proliferation, cell colony formation, cell cycle distribution and cell apoptosis, respectively. At last, xenograft tumor in nude mice was carried out to test whether exosomal miR-98-5p could affect cisplatin resistance in OC in vivo.ResultsCDKN1A was highly expressed in cisplatin-sensitive OC cell lines, and silencing CDKN1A significantly promoted proliferation and cell cycle entry but decreased apoptosis in cisplatin-sensitive OC cells. miR-98-5p targeted CDKN1A to inhibit CDKN1A expression. CAF-derived exosomal miR-98-5p increased OC cell proliferation and cell cycle entry, but suppressed cell apoptosis. Furthermore, exosomal miR-98-5p promoted cisplatin resistance and downregulated CDKN1A in nude mice.ConclusionCollectively, CAF-derived exosomes carrying overexpressed miR-98-5p promote cisplatin resistance in OC by downregulating CDKN1A.
Mice transgenic for the E7 tumor Ag of human papillomavirus type 16, driven from a keratin 14 promoter, express E7 in keratinocytes but not dendritic cells. Grafted E7-transgenic skin is not rejected by E7-immunized mice that reject E7-transduced transplantable tumors. Rejection of recently transplanted E7-transgenic skin grafts, but not of control nontransgenic grafts or of established E7-transgenic grafts, is induced by systemic administration of live or killed Listeria monocytogenes or of endotoxin. Graft recipients that reject an E7 graft reject a subsequent E7 graft more rapidly and without further L. monocytogenes exposure, whereas recipients of an E7 graft given without L. monocytogenes do not reject a second graft, even if given with L. monocytogenes. Thus, cross-presentation of E7 from keratinocytes to the adaptive immune system occurs with or without a proinflammatory stimulus, but proinflammatory stimuli at the time of first cross-presentation of Ag can determine the nature of the immune response to the Ag. Furthermore, immune effector mechanisms responsible for rejection of epithelium expressing a tumor Ag in keratinocytes are different from those that reject an E7-expressing transplantable tumor. These observations have implications for immunotherapy for epithelial cancers.
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