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Fatou, B.

Publications and source records attributed to Fatou, B..

3 recordsLinked to original sources

Epigenetic Memory of COVID-19 in Innate Immune Cells and Their Progenitors

Severe coronavirus disease 2019 (COVID-19) is characterized by systemic inflammation and can result in protracted symptoms. Robust systemic inflammation may trigger persistent changes in hematopoietic cells and innate immune memory through epigenetic mechanisms. We reveal that rare circulating hematopoietic stem and progenitor cells (HSPC), enriched from human blood, match the diversity of HSPC in bone marrow, enabling investigation of hematopoiesis and HSPC epigenomics. Following COVID-19, HSPC retain epigenomic alterations that are conveyed, through differentiation, to progeny innate immune cells. Epigenomic changes vary with disease severity, persist for months to a year, and are associated with increased myeloid cell differentiation and inflammatory or antiviral programs. Epigenetic reprogramming of HSPC may underly altered immune function following infection and be broadly relevant, especially for millions of COVID-19 survivors. One Sentence SummaryTranscriptomic and epigenomic analysis of blood reveal sustained changes in hematopoiesis and innate immunity after COVID-19. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=197 HEIGHT=200 SRC="FIGDIR/small/479588v1_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@1ffe42dorg.highwire.dtl.DTLVardef@dd4868org.highwire.dtl.DTLVardef@1bcae8borg.highwire.dtl.DTLVardef@674e85_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

Determinants of precocious B-cell aging in European adolescences living with perinatally acquired HIV-1 after over 10 years of suppressive therapy

HIV infection results in a state of chronic immune activation leading to premature immune aging, B-cells dysfunction, that persists despite prolonged virological suppression. In this scenario, adolescence living with perinatally acquired HIV (PHIV), deserve a peculiar attention since potentially exposed for their entire life to chronic immune activation. Here we identified determinants of precocious aging B cells in 40 PHIV undergoing suppressive antiretroviral therapy (ART) for median 13.5 years. All individuals started ART by 2nd year of life and achieved virus suppression within the 1st year of ART, with majority of patient maintaining suppression until analysis and 5/40 experiencing viral Spike (transient elevation of HIV-1 VL, 50-999 copies/ml). We employed a multiomics approach including deep immunological B and T cell phenotype in PBMC, with aging B cells defined by the expression of T-bet and CD11c; plasma proteomics analysis by mass spectrometry and serum level of anti-measles antibodies as correlates of humoral response. We found that individuals with expansion of aging B cell, defined by the expression of T-bet+CD11c+, were those starting treatment later, presenting detectable levels of cell-associated HIV-1 RNA, history of Spikes, and a higher frequency of exhausted T-cells, including those expressing PD-1, LAG3, TIGIT. Accordingly, the proteomic analysis revealed that subjects with expansion of aging B cells and exhausted T cells had enrichment of proteins involved in immune inflammation and complement activation pathways, such as CLU and APCS which are also involved in tumor progression. Signs of precocious aging were associated with a reduced capacity to maintain virological memory against measles vaccination. To our knowledge, this is the first study focusing on precocious B-cell aging and dysfunctionality in PHIV with long-term virological suppression. Our experimental strategy enabled identification of clinical, viral, cellular and plasma soluble markers associated with B-cells aging. Our results pave the way to further define risk of disease progression or lymphoproliferative disorders in PHIV. Author summaryDespite a successful antiretroviral therapy (ART), adolescence living with perinatally acquired HIV (PHIV) experience B-cells dysfunction, including loss of vaccine-induced immunological memory and higher risk of developing B-cells associated tumors. It is thus paramount to define novel and precise correlates of precious aging B cell for the definition of novel therapeutic strategies. Here, we studied 40 PHIV who started treatment by 2nd year of life and maintain virological suppression for 13.5 years, with 5/40 patients experiencing transient elevation of the HIV-1 load in the plasma (Spike). We applied a multi-omics approach including immunological B and T cell phenotype, plasma proteomics analysis and serum level of anti-measles antibodies as functional correlates of vaccine-induced immunity. We found that levels of aging B cells were positively associated with age at ART start, cell associated HIV-1 RNA (caHIV-1 RNA) and the presence of Spikes. Individuals with increased proportions of aging B cells had concomitant expansion of exhausted T cells and were unable to maintain vaccine-induced immunity over time. B-cell aging, and T-cell exhaustion were also associated with proteins involved in immune inflammation. The factors found here to be associated with aging B-cell could inform further therapeutic studies.

immunology↗

Proteomics on longitudinal serum samples differentiates localized and disseminated Lyme disease

Lyme disease (LD) is the most prevalent vector-borne disease in North America, with ~300,000 new cases annually in the USA alone. LD is most often recognized by the appearance of the skin lesion erythema migrans (EM) at the tick bite site but also can present with signs of disseminated infection manifesting as multiple EM lesions and/or involvement of the heart, nervous system or joints. In this study, we examined the serum proteome of study participants presenting with either a single EM (localized LD) or early disseminated infection (disseminated LD). Samples collected at the time of diagnosis and at convalescent time points were assessed using our in-house developed MStern blotting-based serum proteomics platform. After technical validation of our platform, the temporal analysis from diagnosis to clinical resolution of the infection demonstrates LD stage-associated pathways activation such as a temporary upregulation of acute phase response specific to the participants with disseminated LD. In addition, we identified the members of the serum amyloid A protein family as potentially promising candidate biomarkers to identify those with disseminated LD. The results of this pilot study demonstrate the feasibility of using our time- and cost-effective sample sparing MStern blotting-based serum proteomics platform to efficiently interrogate proteome changes over time in those suffering infections such as LD. These observations establish a new approach to human serum proteomics, provide fresh insight into the host immune responses associated with disease severity (localized versus disseminated infection) and suggest novel biomarker candidate panels for LD stages. ImportanceWe investigated the proteome changes of Borrelia burgdorferi-infected participants with either a single erythema migrans or early disseminated Lyme disease infection. Using our in-house time-and cost-effective proteomics platform, the temporal analysis from diagnosis to clinical resolution of the infection shows a temporary upregulation of the acute phase response specific to the participants with disseminated infection. Finally, specific protein panels were identified as possible biomarker candidates to categorize those having an initial diagnosis of disseminated manifestation using a reference cohort of acute localized infection and a clinically resolved convalescent phase disease samples from the same Lyme disease participants.

immunology↗