Project description:In an unbiased transcriptomic screen we observed reduced NK cell activation phenotypes in HLA-B*46 positive people with HIV. These findings show that contemporaneous treated cohorts can be used to analyze host genetic effects in HIV disease, and support a role for NK cells in HIV control revealed by unique properties of the recombinant HLA-B*46 allele which is frequent only in Asia.
Project description:Unlike HIV infection, which progresses to AIDS absent suppressive anti-retroviral therapy (ART), nonpathogenic infections in natural hosts, such African green monkeys (AGMs), are characterized by a lack of gut microbial translocation and robust secondary lymphoid Natural Killer (NK) cell responses resulting in absence of chronic inflammation and limited SIV dissemination in lymph nodes (LN) B-cell-follicles, respectively. In a pathogenic infection model (i.e. ART-treated, SIVmac239-infected rhesus macaques; RMs), sequential Interleukin (IL)-21 and interferon (IFN)-alpha therapy generated terminally-differentiated blood NK cells (NKG2a/clowCD16+) with potent HLA-E-restricted activity in response to SIV-ENV peptides in contrast to control RMs, where less differentiated, IFN-gamma+ NK cells predominated. The frequency and cytolytic activity of NKG2a/clowCD16+ NK cells correlated with a reduction of replication-competent SIV in LN during ART and viral rebound delay following analytical treatment interruption. These data demonstrate that AGM-like NK cell differentiation profiles can be rescued in RMs to promote viral clearance in tissues.
Project description:Unlike HIV infection, which progresses to AIDS absent suppressive anti-retroviral therapy (ART), nonpathogenic infections in natural hosts, such African green monkeys (AGMs), are characterized by a lack of gut microbial translocation and robust secondary lymphoid Natural Killer (NK) cell responses resulting in absence of chronic inflammation and limited SIV dissemination in lymph nodes (LN) B-cell-follicles, respectively. In a pathogenic infection model (i.e. ART-treated, SIVmac239-infected rhesus macaques; RMs), sequential Interleukin (IL)-21 and interferon (IFN)-alpha therapy generated terminally-differentiated blood NK cells (NKG2a/clowCD16+) with potent HLA-E-restricted activity in response to SIV-ENV peptides in contrast to control RMs, where less differentiated, IFN-gamma+ NK cells predominated. The frequency and cytolytic activity of NKG2a/clowCD16+ NK cells correlated with a reduction of replication-competent SIV in LN during ART and viral rebound delay following analytical treatment interruption. These data demonstrate that AGM-like NK cell differentiation profiles can be rescued in RMs to promote viral clearance in tissues.
Project description:Unlike HIV infection, which progresses to AIDS absent suppressive anti-retroviral therapy (ART), nonpathogenic infections in natural hosts, such African green monkeys (AGMs), are characterized by a lack of gut microbial translocation and robust secondary lymphoid Natural Killer (NK) cell responses resulting in absence of chronic inflammation and limited SIV dissemination in lymph nodes (LN) B-cell-follicles, respectively. In a pathogenic infection model (i.e. ART-treated, SIVmac239-infected rhesus macaques; RMs), sequential Interleukin (IL)-21 and interferon (IFN)-alpha therapy generated terminally-differentiated blood NK cells (NKG2a/clowCD16+) with potent HLA-E-restricted activity in response to SIV-ENV peptides in contrast to control RMs, where less differentiated, IFN-gamma+ NK cells predominated. The frequency and cytolytic activity of NKG2a/clowCD16+ NK cells correlated with a reduction of replication-competent SIV in LN during ART and viral rebound delay following analytical treatment interruption. These data demonstrate that AGM-like NK cell differentiation profiles can be rescued in RMs to promote viral clearance in tissues.
Project description:Natural killer (NK) cells are lymphocytes that participate in immune responses through their cytotoxic activity and secretion of cytokines and chemokines. They can be activated by interaction with ligands on target cells or by soluble mediators such as cytokines. In addition, soluble HLA-G, a major histocompatibility complex molecule secreted by fetal trophoblast cells during early pregnancy, stimulates resting NK cells to secrete proinflammatory and proangiogenic factors. Human NK cells are abundant in uterus, where they remain after implantation. Soluble HLA-G is endocytosed into early endosomes of NK cells where its receptor, CD158d, initiates a signaling cascade through DNA-PKcs, Akt and NF-kB3. The physiological relevance of this endosomal signaling pathway, and how the fate and function of NK cells during early pregnancy is regulated, is unknown. Here we show that soluble agonists of CD158d trigger DNA damage response signaling and p21 (CIP1/WAF1) expression to promote senescence in primary NK cells. CD158d engagement resulted in morphological alterations in cell size and shape, chromatin remodeling, and survival in the absence of proliferation, all hallmarks of senescence. Microarray analysis revealed a senescence signature of upregulated genes upon sustained activation through CD158d. The proinflammatory and proangiogenic factors secreted by these metabolically active NK cells are part of a senescence associated secretory phenotype (SASP) that promoted tissue remodeling and angiogenesis as assessed by functional readouts of vascular permeability and endothelial cell tube formation. We propose that ligand-induced senescence is a molecular switch for the sustained activation of NK cells in response to soluble HLA-G for the purpose of remodeling the maternal vasculature in early pregnancy. Time series (4 hr, 16 hr, 64 hr) of NK cells treated with agonist (anti-CD158d mAb) or control. NK cells were from 4 donors.
Project description:Acute myeloid leukemia (AML) is a heterogeneous group of malignancies which may be sensitive to the natural killer (NK) cell anti-tumor response. However, NK cells are frequently defective in AML. Here, we found in an exploratory cohort (n = 46) that NK-cell status at diagnosis of AML separated patients in two groups with a different clinical outcome. Patients with a deficient NK-cell profile, including reduced expression of some activating NK receptors (e.g. DNAM-1, NKp46 and NKG2D) and decreased IFN-g production, had a significantly higher risk of relapse (P = 0.03) independently of cytogenetic classification in multivariate analysis. Patients with defective NK cells showed a profound gene expression decrease in AML blasts for cytokine and chemokine signaling (e.g. IL15, IFNGR1, IFNGR2, CXCR4), antigen processing (e.g. HLA-DRA, HLA-DRB1, CD74) and adhesion molecule pathways (e.g. PVR, ICAM1). A set of 388 leukemic classifier genes defined in the exploratory cohort was independently validated in a multicentric cohort of 194 AML patients. In total, these data evidenced the interplay between NK-cells and AML blasts at diagnosis allowing an immune-based stratification of AML patients independently of clinical classifications. 5 normal AML cells were compared with 8 NK deficient AML cells.
Project description:Acute myeloid leukemia (AML) is a heterogeneous group of malignancies which may be sensitive to the natural killer (NK) cell anti-tumor response. However, NK cells are frequently defective in AML. Here, we found in an exploratory cohort (n = 46) that NK-cell status at diagnosis of AML separated patients in two groups with a different clinical outcome. Patients with a deficient NK-cell profile, including reduced expression of some activating NK receptors (e.g. DNAM-1, NKp46 and NKG2D) and decreased IFN-g production, had a significantly higher risk of relapse (P = 0.03) independently of cytogenetic classification in multivariate analysis. Patients with defective NK cells showed a profound gene expression decrease in AML blasts for cytokine and chemokine signaling (e.g. IL15, IFNGR1, IFNGR2, CXCR4), antigen processing (e.g. HLA-DRA, HLA-DRB1, CD74) and adhesion molecule pathways (e.g. PVR, ICAM1). A set of 388 leukemic classifier genes defined in the exploratory cohort was independently validated in a multicentric cohort of 194 AML patients. In total, these data evidenced the interplay between NK-cells and AML blasts at diagnosis allowing an immune-based stratification of AML patients independently of clinical classifications. Gene expression analysis were performed on CD56bright and CD56dim NK cells sorted from patients with impaired or normal CD56bright NK cells (n=2 for each patients? group) and from 3 HC
Project description:Despite the introduction of combined antiretroviral therapy (cART), people living with HIV (PLWH) still have an increased risk of EBV-associated B cell malignancies. In the HIV setting, B cell physiology is altered by co-existence with HIV-infected cells and the chronic action of secreted viral proteins, e.g. HIV-1 Tat that, once released, efficiently penetrates non-infected cells. Here we modeled a chronic action of HIV-1 Tat on B cells by ectopically expressing Tat or its mutant version TatC22G deprived of transactivation activity in two EBV-immortalized lymphoblastoid B cell lines. RNA-sequencing analysis revealed that Tat regulated the expression of hundreds of genes, including downregulation of a subset of genes related to MHC class II. Tat-induced transcriptional downregulation of HLA-DRB1, HLA-DRB5 genes was accompanied by a decrease in HLA-DR surface expression; this effect could be reproduced by co-cultivating B cells with Tat-expressing T cells. Notably, HLA-DRB1 expression in B cells was also decreased in PLWH. Chronic Tat presence decreased the NF-ᴋB pathway activity; this downregulated NF-ᴋB-dependent transcriptional targets, including MHC class II genes. Tat-induced HLA-DR downregulation in B cells also impaired EBV-specific CD4+ T cell response, which could contribute to the escape from immune surveillance and eventually promote B cell lymphomagenesis.