Project description:How tissue resident memory CD4 T cell differ from circulating memory CD4 T cells and how such differences impact functional recall responses to pathogens is unknown. We used microarrays to detail the global programme of gene expression underlying differences between sort purified circulating memory CD4 T cells from the lung and spleen, which are labelled with flourescent antibody following intravenous administration, and lung tissue resident memory CD4 T cells, which are not labelled with flourescent antibody following intravenous administration, on day 28 post influenza infection.
Project description:This data is from a murine model established to study the lasting impact of allergic airway sensitization on subsequent anti-viral memory T cell responses and the ability to develop protective immunity to reinfection. Animals were either sensitised by exposure to HDM or PBS and then subsequently exposed to influenza virus. Samples were collected at various time points for analysis of both CD8 and C4 positive tissue resident memory T cells.
Project description:Long-lived, tissue-resident memory B cells (BRM) are established in the lungs of mice after pulmonary influenza infection. Influenza-specific BRM were localised within inducible bronchus-associated lymphoid tissues (iBALT) and displayed phenotypic and transcriptional signatures reminiscent of tissue-resident T cells, distinct from classical memory B cells in the blood or secondary lymphoid sites.
Project description:Tissue-resident memory T cells (TRM) are a non-circulating subset of memory that are maintained at sites of pathogen entry and mediate optimal protection against reinfection. Lung TRM can be generated in response to respiratory infection or vaccination, however, the molecular pathways involved in CD4+TRM establishment have not been defined. Here, we performed transcriptional profiling of influenza-specific lung CD4+TRM following influenza infection to identify pathways implicated in CD4+TRM generation and homeostasis. Lung CD4+TRM displayed a unique transcriptional profile distinct from spleen memory, including up-regulation of a gene network induced by the transcription factor IRF4, a known regulator of effector T cell differentiation.
Project description:We have defined naïve, central memory, effector memory and terminally differentiated porcine CD8 T cells, using CD45RA and CCR7 mAbs. We analyzed the phenotype of CD8 T cells specific for three influenza nucleoprotein (NP) epitopes using tetramers after influenza infection or immunization in lymphoid and respiratory tissues. The hierarchy of response to the three epitopes changes during the response in different tissues. Most NP-specific CD8 T cells in broncho-alveolar lavage (BAL) and lung are tissue resident memory cells (TRM), that express CD69 and have an effector memory or terminally differentiated phenotype. NP-specific cells isolated from BAL express genes characteristic of TRM, but gene expression differs at 7, 21 and 63 days post infection. The frequency of NP-specific cells declines over 63 days in all tissues but is best maintained in BAL. The pig is a powerful model for understanding how best to induce and harness local immunity.
Project description:To evaluate the transcriptional responses of effector and memory virus-specific CD8 T cell subsets after primary and secondary influenza infection, we sorted subsets of FluNP 366-374/Db+ CD8+ T cells from the BAL, lung, and spleen at the peak of primary x31 influenza infection (day 10), resting memory (day 30), or 3 days after secondary PR8 influenza challenge (Day 30+3). Cells from the circulation were excluded from BAL and lung based on intravital labeling with anti-CD45. Memory cells from the lung were further separated in TRM and TEM subsets based on expression of CD69 at the day 30 and day 30+3 timepoints. Memory cells from the BAL were separated into long-term airway resident versus recently-recruited cells based on CD11a expression at the day 30 and days 30+3 timepoints. The results show that virus-specific BAL and lung TRM cells, but not lung TEM cells or spleen TEM cells, rapidly alter their transcriptional program and increase expression of effector molecules within 3 days of a secondary influenza challenge.
Project description:Pre-existing immunity impacts vaccine responses to endemic respiratory viruses such as influenza, but directly connecting influenza infections early in life with immune responses decades later is difficult. However, H2N2 stopped circulating in the human population in 1968, creating the opportunity to directly evaluate the impact of early H2N2 exposure on vaccine responses 50 years later. Here, we vaccinate individuals born before (H2 Exposed) or after (H2 Naïve) 1968 with an H2 HA DNA plasmid and/or a ferritin nanoparticle vaccine. H2 Exposed individuals generated a rapid B cell recall response that differed in potency, cross-reactivity, immunoglobulin repertoire, epitope targeting and phenotype from the de novo response in H2 Naïve individuals. Furthermore, vaccinating with a DNA versus a protein nanoparticle vaccine altered the response in H2 Naïve but not H2 Exposed individuals. This study clearly establishes and describes the life-long impact of influenza HA-specific memory B cells formed early in life on vaccine responses decades later.
Project description:Secondary bacterial pneumonia following influenza infection is a significant cause of mortality worldwide. Upper respiratory tract pneumococcal carriage is important as both determinants of disease and population transmission. The immunological mechanisms that contain pneumococcal carriage are well-studied in mice but remain unclear in humans. Loss of this control of carriage following influenza infection is associated with secondary bacterial pneumonia during seasonal and pandemic outbreaks. We used a human type 6B pneumococcal challenge model to show that carriage acquisition induces early degranulation of resident neutrophils and recruitment of monocytes to the nose. Monocyte function associated with clearance of pneumococcal carriage. Prior nasal infection with live attenuated influenza virus induced inflammation, impaired innate function and altered genome-wide nasal gene responses to pneumococcal carriage. Levels of the cytokine IP-10 promoted by viral infection at the time of pneumococcal encounter was positively associated with bacterial density. These findings provide novel insights in nasal immunity to pneumococcus and viral-bacterial interactions during co-infection.
Project description:The emergence of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) variants and “anatomical escape” characteristics threaten the effectiveness of current coronavirus disease (COVID-19) vaccines. There is an urgent need to understand the immunological mechanism of broad-spectrum respiratory tract protection to guide broader vaccines development. In this study, we investigated immune responses induced by an NS1-deleted influenza virus vectored intranasal COVID-19 vaccine (dNS1-RBD) which provides broad-spectrum protection against SARS-CoV-2 variants. Intranasal delivery of dNS1-RBD induced innate immunity, trained immunity and tissue-resident memory T cells covering the upper and lower respiratory tract. It restrained the inflammatory response by suppressing early phase viral load post SARS-CoV-2 challenge and attenuating pro-inflammatory cytokine (IL-6, IL-1B, and IFN-γ) levels, thereby reducing excess immune-induced tissue injury compared with the control group. By inducing local cellular immunity and trained immunity, intranasal delivery of NS1-deleted influenza virus vectored vaccine represents a broad-spectrum COVID-19 vaccine strategy to reduce disease burden. To investigate the trainned-immunity of alveolar macrophage generated by dNS1-RBD vaccine in C57BL/6 mouse, we vaccinated C57BL/6 mice with dNS1-RBD/dNS1-Vector/PBS and collect the alveolar macrophage samples to sequence for the ATAC-seq data 2 months post vaccinated. Then performed the differential peak and igv track visualization with this dataset.
Project description:The emergence of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) variants and “anatomical escape” characteristics threaten the effectiveness of current coronavirus disease (COVID-19) vaccines. There is an urgent need to understand the immunological mechanism of broad-spectrum respiratory tract protection to guide broader vaccines development. In this study, we investigated immune responses induced by an NS1-deleted influenza virus vectored intranasal COVID-19 vaccine (dNS1-RBD) which provides broad-spectrum protection against SARS-CoV-2 variants. Intranasal delivery of dNS1-RBD induced innate immunity, trained immunity and tissue-resident memory T cells covering the upper and lower respiratory tract. It restrained the inflammatory response by suppressing early phase viral load post SARS-CoV-2 challenge and attenuating pro-inflammatory cytokine (IL-6, IL-1B, and IFN-γ) levels, thereby reducing excess immune-induced tissue injury compared with the control group. By inducing local cellular immunity and trained immunity, intranasal delivery of NS1-deleted influenza virus vectored vaccine represents a broad-spectrum COVID-19 vaccine strategy to reduce disease burden. To investigate the trainned-immunity of alveolar macrophage generated by dNS1-RBD vaccine in Golden Hamster, we vaccinated Golden Hamster with dNS1-RBD/dNS1-Vector/PBS and collect the alveolar macrophage samples to sequence for the ATAC-seq data 2 months post vaccinated. Then performed the differential peak and igv track visualization with this dataset.