Project description:Langerhans cells (LC) represent one of the first lines of contact between the immune system and sexually transmitted pathogens, and in the human epidermis LCs have been thought to represent the only mononuclear phagocyte (MNP) population. Here we show an additional epidermal MNP subset that can be distinguished from LCs phenotypically as CD11chi, CD1c+ MR+ (epidermal CD11c+ DCs). These cells are transcriptionally similar to dermal cDC2 but express higher levels of costimulatory markers and are more efficient at T cell stimulation. Importantly, compared to LC, epidermal CD11c+ DCs are i) enriched in the epithelium of anogenital tissues where they preferentially interact with HIV, ii) express the higher levels of the HIV entry receptor CCR5, iii) support the higher levels of HIV uptake and replication and iv) are more efficient at transferring virus to CD4 T cells. Importantly these findings were observed using both a lab-adapted and transmitted/founder strain of HIV. We also describe a cell population that can be discerned from LCs by their lower surface expression of CD45, HLA-DR and CD33 (epidermal CD33low cells). These are transcriptionally similar to LCs but do not appear to function as APCs as do not secrete cytokines, express negligible amounts of costimulatory molecules and are very weak inducers of T cell proliferation. They also do not act as HIV target cells. Our findings reveal a new subset of epidermal DCs in skin and anogenital tissues with a potential key role in sexual transmission of HIV.
Project description:CD11c+ Myeloid Dendritic Cells (mDCs) were isolated from the peripheral blood mononuclear cells (PBMCs) of HIV uninfected and HIV infected subjects. The expression of CD11c+ mDCs was accessed to determine how HIV infection may play a role on the expression profiles of these cells. mDCs are known to play a role in antigen presentation, and thus are pivotal in immune sensing and priming of the adaptive immune response. We wanted to see if the change in immune system function during chronic HIV infection may be due to defects in this cell subtype. We used microarray analysis to detail the global program of gene expression underlying changes in mDC function during HIV infection. PBMCs were isolated from HIV uninfected and HIV infected blood samples. CD11c+ cells were sorted from the whole PBMC population by magnetic bead sorting (anti-CD11c antibody bound to a magnetic bead inclubated with whole PBMCs). RNA was isolated from this sorted population to get the gene expression of this subtype of cells.
Project description:CD11c+ Myeloid Dendritic Cells (mDCs) were isolated from the peripheral blood mononuclear cells (PBMCs) of HIV uninfected and HIV infected subjects. The expression of CD11c+ mDCs was accessed to determine how HIV infection may play a role on the expression profiles of these cells. mDCs are known to play a role in antigen presentation, and thus are pivotal in immune sensing and priming of the adaptive immune response. We wanted to see if the change in immune system function during chronic HIV infection may be due to defects in this cell subtype. We used microarray analysis to detail the global program of gene expression underlying changes in mDC function during HIV infection.
Project description:We cultured bone marrow derived dendritic cells from WT and CD11c KO mice. Then, a group of bone marrow dendritic cells were stimulated with LPS overnight. We obtained bone marrow derived dendritic cells with or without LPS stimulation and analyzed proteomics profiles.
Project description:Transcriptome analysis of dentritic cells from the spleen (CD11c+) or MLN (CD11c+CD103+) of mice with DC-specific deletion of TGFBR2 gene, or their control littermates. TRGFR2 gene was deleted in dendritic cells using Cre/lox approach. Mice with this deletion develop spontaneous multi-organ autoimmune inflammation and die by 15 weeks of age. Splenic CD11c+ Dc were isolated by magetic cell sorting. MLN CD11c+CD103+ DC were flow sorted. RNA was isolated using RNAqueous-Micro kit (Ambion) and analyzed using Affymetrix Mouse Exon 1.0 ST Array
Project description:Spleen and lymph node dendritic cells have a differential capacity do induce and retain iTreg cells. Therefore we performed a comparative analysis of the dendritic cells derived from these two compartments to identify the responsible genes CD11c+ conventional dendritic cells were facs sorted from spleens and lymph nodes of BALB/c animals for RNA extraction and hybridization on Affymetreix microarray
Project description:Transcriptome analysis of dentritic cells from the spleen (CD11c+) or MLN (CD11c+CD103+) of mice with DC-specific deletion of TGFBR2 gene, or their control littermates. TRGFR2 gene was deleted in dendritic cells using Cre/lox approach. Mice with this deletion develop spontaneous multi-organ autoimmune inflammation and die by 15 weeks of age.
Project description:Tissue mononuclear phagocytes (MNP) are specialised in pathogen detection and antigen presentation. They are the first cells of the immune system to encounter HIV and play a key role in transmission as they deliver the virus to CD4 T cells, which are the primary HIV target cell in which the virus undergoes replication. Most studies have investigated the role that epithelial MNPs play in HIV transmission but, as mucosal trauma and inflammation are strongly associated with HIV transmission, it is also important to examine the role that sub-epithelial MNPs play. Sub-epithelial MNPs are present in a diverse array of subsets which differ in their function and the pathogens they detect. Understanding how specific subsets interact with HIV and deliver the virus to CD4 T cells is therefore of key importance to vaccine and microbicide development. In this study we have shown that, after topical application, HIV can penetrate to interact with sub-epithelial resident myeloid cells in anogenital explants and defined the full array of MNP subsets that are present in all the human anogenital and colorectal sub-epithelial tissues that HIV may encounter during sexual transmission. In doing so we have identified two subsets that preferentially take up HIV, become infected and transmit the virus to CD4 T cells; CD14+CD1c+CD11c+ monocyte-derived dendritic cells and langerin-expressing conventional dendritic cells 2 (cDC2).