Project description:This study aims to under the characteristics and diversitification of Dengue speicific immunoglobulin repertoires after different immunization strategies in mouse. We propose two different immunization strategies in dengue vaccine development, one is repeated strategy, which DENV1 virus and administrated three times. The other one is epitope-decreased sequential strategy, which sequetially administrated DENV1 virus, DENV1 E protein and DENV1 E protein domain III subunit.
Project description:This study aims to understand the characteristics and diversification of Dengue specific immunoglobulin repertoires after different immunization strategies in mouse. We propose two different immunization strategies in dengue vaccine development. One is tetravalent strategy, which pre-mixed four serotype dengue DNA vaccine and administrated four times. The other one is sequential strategy, which sequentially administrated four time, each serotype vaccine for each dose as sequences of Den1, Den2, Den3 and Den4.
Project description:We performed single-cell transcriptome and antibody repertoire sequencing of bone marrow plasma cells following protein (OVA and TNFR2) immunizations or infection with high dose LCMV clone 13.
Project description:We performed single-cell transcriptome and antibody repertoire sequencing of bone marrow and splenic B cells from mice of different age following protein (TNFR2) immunizations
Project description:Clonal expansion is a hallmark of adaptive immunity, and appears to be driven by high antigen-specific receptor avidity as shown by research using murine in vivo models. In humans, however, the functionality of antigen-specific T cell clonotypes that are recruited into primary and recall immune responses remains surprisingly elusive. In this regard, the vaccination program during the SARS-CoV-2 pandemic represented a unique research opportunity by provision of highly standardized cohorts of healthy human individuals receiving immunizations against a previously unseen antigen. Here, we analyzed 30 HLA-typed individuals before, short-term and long-term after three mRNA vaccinations against SARS-CoV-2. We performed an in-depth characterization of the magnitude, phenotype, clonal composition and functionality of antigen-specific CD8 T cell responses by ELISPOT, flow cytometry and single-cell RNA sequencing, including CITE seq of 130 surface antigens and 16 T cell epitope specificities. 89 T cell receptors (TCRs) covering three complete epitope-specific repertoires were re-expressed by CRISPR/Cas9-mediated orthotopic TCR replacement and tested for their avidity. TCR repertoires underwent continuous tailoring, with high TCR avidity being linked to both clonal persistence and expansion. However, epitope-specific repertoires also maintained diversity by concomitant contraction and new emergence of functional T cell clones over time. These data on the phenotype and clonal selection within human antigen-specific T cell responses instruct our understanding of human T cell biology and may guide the development of enhanced or novel vaccines.
Project description:Clonal expansion is a hallmark of adaptive immunity, and appears to be driven by high antigen-specific receptor avidity as shown by research using murine in vivo models. In humans, however, the functionality of antigen-specific T cell clonotypes that are recruited into primary and recall immune responses remains surprisingly elusive. In this regard, the vaccination program during the SARS-CoV-2 pandemic represented a unique research opportunity by provision of highly standardized cohorts of healthy human individuals receiving immunizations against a previously unseen antigen. Here, we analyzed 30 HLA-typed individuals before, short-term and long-term after three mRNA vaccinations against SARS-CoV-2. We performed an in-depth characterization of the magnitude, phenotype, clonal composition and functionality of antigen-specific CD8 T cell responses by ELISPOT, flow cytometry and single-cell RNA sequencing, including CITE seq of 130 surface antigens and 16 T cell epitope specificities. 89 T cell receptors (TCRs) covering three complete epitope-specific repertoires were re-expressed by CRISPR/Cas9-mediated orthotopic TCR replacement and tested for their avidity. TCR repertoires underwent continuous tailoring, with high TCR avidity being linked to both clonal persistence and expansion. However, epitope-specific repertoires also maintained diversity by concomitant contraction and new emergence of functional T cell clones over time. These data on the phenotype and clonal selection within human antigen-specific T cell responses instruct our understanding of human T cell biology and may guide the development of enhanced or novel vaccines.
Project description:Route of immunization can markedly influence the quality of immune response. Here, we show that intradermal (ID) but not intramuscular (IM) modified vaccinia Ankara (MVA) vaccinations provide protection from acquisition of intravaginal tier2 SHIV challenges in female macaques. Both routes of vaccination induced comparable levels of serum IgG with neutralizing and non-neutralizing activities. The protection in MVA-ID group correlated positively with serum neutralizing and antibody-dependent phagocytic activities, and envelope-specific vaginal IgA; while the limited protection in MVA-IM group correlated only with serum neutralizing activity. MVA-ID immunizations induced greater germinal center Tfh and B cell responses, reduced the ratio of Th1 to Tfh cells in blood and showed lower activation of intermediate monocytes and inflammasome compared to MVA-IM immunizations. This lower innate activation correlated negatively with induction of Tfh responses. These data demonstrate that the MVA-ID vaccinations protect against intravaginal SHIV challenges by modulating the innate and T helper responses.
Project description:We developed an improved library prep protocol and standardized the data analysis pipeline for accurate repertoire profiling. In addition, two metrics were implemented to assess repertoire clone properties. We then studied systemically the effects of two adjuvants, CpG and Alum, on the Ig heavy chain repertoire using the ovalbumin (OVA) challenged mouse model. Ig repertoires of different tissues (spleen and bone marrow) and isotypes (IgG and IgM) were examined and compared in terms of sequence mutation frequency, IGHV gene usage, CDR3 length, rescaled Hill numbers for clonal diversity, and clone selection strength. As a result, Ig repertoires of different tissues or isotypes exhibited distinguishable profiles at the non-immunized steady state. Adjuvanted immunizations further resulted in statistically significant alterations in Ig repertoire compared with PBS or OVA alone immunized groups. Lastly, we applied unsupervised machine learning techniques – multiple factor analysis and clustering – to identify Ig repertoire signatures in different compartments and under varying immunizations.