RNA-seq time course analysis of in vitro differentiated antibody-secreting cells
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ABSTRACT: We examined the transcriptional changes that occur as Antibody Secreting Cells (ASC) differentiate and mature using an in vitro culture system. ASC were profiled directly post isolation and at time points weekly out to 48 days in culture. These data reveal how the long-lived ASC transcriptome matures over time.
Project description:We examined the chromatin accessibility changes that occur as antibody-secreting cells (ASC) differentiate and mature using an in vitro culture system. ASC were profiled directly post isolation and at time points weekly out to 14 days in culture. These data reveal how the long-lived ASC accessible chromatin matures over time.
Project description:The CD19 positive antibody secreting cells (ASC) in both bone marrow (BM) have the capacity to provide immune memory in addition to cells traditionally considered long-lived, the CD19-negative BM ASC. We performed flow cytometry (FCM) immunophenotyping, fluorescence-activated cell sorting (FACS) for cell subset isolation, ELISpot assays detecting the isotype of antibody secretion as well as antibodies against vaccine derived antigens, and comparative gene expression analyses of CD19- ASC, CD19+ ASC, CD20- B cells, and CD20+ B cells from BM. The findings may aid in the understanding of the differential cell subsets created through vaccination and lead to improved vaccine strategies and production. FACS sorted tissue B cells and antibody secreting cell subset gene expression.
Project description:Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by multiple autoantibodies, some of which are present in high titers in a sustained, B cell-independent fashion consistent with their generation from long-lived plasma cells (LLPC). Active SLE displays high numbers of circulating antibody-secreting cells (ASC). Understanding the mechanisms of generation and survival of SLE ASC would contribute important insight into disease pathogenesis and novel targeted therapies. We studied the properties of SLE ASC through a systematic analysis of their phenotypic, molecular, structural, and functional features. Our results indicate that in active SLE, relative to healthy post-immunization responses, blood ASC contain a much larger fraction of newly generated mature CD19-CD138+ASC similar to bone marrow (BM) LLPC. SLE ASC were characterized by morphological and structural features of premature maturation. Additionally, SLE ASC express high levels of CXCR4 and CD138, and molecular programs consistent with increased longevity based on pro-survival and attenuated pro-apoptotic pathways.Notably, SLE ASC demonstrate autocrine production of APRIL and IL-10 and experience prolonged in vitro survival. Combined, our findings indicate that SLE ASC are endowed with enhanced peripheral maturation, survival and BM homing potential suggesting that these features likely underlie BM expansion of autoreactive PC.
Project description:Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by multiple autoantibodies, some of which are present in high titers in a sustained, B cell-independent fashion consistent with their generation from long-lived plasma cells (LLPC). Active SLE displays high numbers of circulating antibody-secreting cells (ASC). Understanding the mechanisms of generation and survival of SLE ASC would contribute important insight into disease pathogenesis and novel targeted therapies. We studied the properties of SLE ASC through a systematic analysis of their phenotypic, molecular, structural, and functional features. Our results indicate that in active SLE, relative to healthy post-immunization responses, blood ASC contain a much larger fraction of newly generated mature CD19-CD138+ASC similar to bone marrow (BM) LLPC. SLE ASC were characterized by morphological and structural features of premature maturation. Additionally, SLE ASC express high levels of CXCR4 and CD138, and molecular programs consistent with increased longevity based on pro-survival and attenuated pro-apoptotic pathways.Notably, SLE ASC demonstrate autocrine production of APRIL and IL-10 and experience prolonged in vitro survival. Combined, our findings indicate that SLE ASC are endowed with enhanced peripheral maturation, survival and BM homing potential suggesting that these features likely underlie BM expansion of autoreactive PC.
Project description:Antibody-secreting cells (ASC) circulate after vaccination and infection and migrate to the bone marrow (BM) where a subset known as long-lived plasma cells (LLPC) persist and secrete antibodies for a lifetime. The mechanisms of how circulating ASC become LLPC is not well elucidated. Here, we show that human early-minted blood ASCs have distinct morphology, transcriptomes, and epigenetics compared to human BM LLPC. Compared to blood ASC, BM LLPC have decreased nucleus/cytoplasm ratio but increased endoplasmic reticulum and numbers of mitochondria. Additionally, LLPC acquire transcriptional and epigenetic differences in multiple cellular pathways that include apoptosis. Upregulation of the anti-apoptotic genes MCL1, BCL2, BCL-XL while simultaneously downregulation of pro-apoptotic genes HRK1, CASP3, and CASP8 occurs in LLPC. Consistent with the decrease in gene expression, pro-apoptotic gene loci are less accessible in LLPC. In contrast, anti-apoptotic gene expression is increased but is not always accompanied by changes in accessibility. Importantly, we show that early-minted blood ASCs undergo morphological and transcriptional changes that make these cells resemble ex vivo BM ASCs, suggesting that the BM microniche at least in part promotes LLPC maturation. Overall, our study demonstrates that early-minted blood ASC in the BM microniche must undergo morphological, transcriptional, and epigenetic changes to mature into apoptotic-resistant LLPC.
Project description:Antibody secreting cells (ASC) circulate after vaccination and infection and migrate to the bone marrow (BM) where a subset known as long-lived plasma cells (LLPC) persist and secrete antibodies for a lifetime. The mechanisms of how circulating ASC become LLPC is not well elucidated. Here, we show that human early-minted blood ASCs have distinct morphology, transcriptomes, and epigenetics compared to human BM LLPC. Compared to blood ASC, BM LLPC have decreased nucleus/cytoplasm ratio but increased endoplasmic reticulum and numbers of mitochondria. Additionally, LLPC acquire transcriptional and epigenetic differences in multiple cellular pathways that include apoptosis. Upregulation of the anti-apoptotic genes MCL1, BCL2, BCL-XL while simultaneously downregulation of pro-apoptotic genes HRK1, CASP3, and CASP8 occurs in LLPC. Consistent with the decrease in gene expression, pro-apoptotic gene loci are less accessible in LLPC. In contrast, anti-apoptotic gene expression is increased but is not always accompanied by changes in accessibility. Importantly, we show that early-minted blood ASCs undergo morphological and transcriptional changes that make these cells resemble ex vivo BM ASCs, suggesting that the BM microniche at least in part promotes LLPC maturation. Overall, our study demonstrates that early-minted blood ASC in the BM microniche must undergo morphological, transcriptional, and epigenetic changes to mature into apoptotic-resistant LLPC.
Project description:Here we describe the dynamics underlying the generation of IgE-antibody secreting cells (ASC) in human nasal polyps (NP), mucosal tissues rich in ASC without germinal centers (GC). Using VH next generation sequencing, we identified an extrafollicular (EF) mucosal IgD+ naïve-like intermediate B cell population with high connectivity to the mucosal IgE ASC. Mucosal IgD+ B cells, express germline epsilon transcripts and predominantly co-express IgM. However, a small but significant fraction co-express IgG or IgA instead which also show connectivity to ASC IgE. Phenotypically, NP IgD+ B cells display an activated profile and molecular evidence of BCR engagement. Transcriptionally, mucosal IgD+ B cells reveal an intermediate profile between naïve B cells and ASC. Single cell IgE ASC analysis demonstrates lower mutational frequencies relative to IgG, IgA, and IgD ASC consistent with IgE ASC derivation from mucosal IgD+ B cell with low mutational load. In conclusion, we describe a novel mechanism of GC-independent, extrafollicular IgE ASC formation at the nasal mucosa whereby activated IgD+ naïve B cells locally undergo direct and indirect (through IgG and IgA), IgE class-switch.