Project description:We sought to test whether vaccine-induced immune responses could protect rhesus macaques (RMs) against upfront heterologous challenges with an R5 simian-human immunodeficiency virus, SHIV-2873Nip. We immunized the RMs with recombinant Env proteins heterologous to the challenge virus. For induction of immune responses against Gag, Tat, and Nef, we explored a strategy of immunization with overlapping synthetic peptides (OSP). The immune responses against Gag and Tat were finally boosted with recombinant proteins. The vaccinees and a group of ten control animals were given five low-dose intrarectal (i.r.) challenges with SHIV-2873Nip. All controls and seven out of eight vaccinees became systemically infected; there was no significant difference in viremia levels of vaccinees vs. controls. Prevention of viremia was observed in one vaccinee which showed strong boosting of virus-specific cellular immunity during virus exposures. The protected animal showed no challenge virus-specific neutralizing antibodies in the TZM-bl or A3R5 cell-based assays and had low level ADCC activity after the virus exposures. Microarray data strongly supported a role for cellular immunity in the protected animal. Our study represents a case of protection against heterologous tier 2 SHIV-C by vaccine-induced, virus-specific cellular immune responses. For the protected RM, blood was collected before vaccination, on the day of first virus exposure and six weeks after last virus challenge. Lymph node and rectal pinch biopsies were performed before vaccination and six weeks after last virus challenge. Blood was collected in tempus tubes and processed immediately according to the manufacturer’s instructions and stored at -80C. The biopsy specimens were cut into small pieces and immediately placed into RNAlater solution (Qiagen, Valencia, CA) and also stored at -80C. Total RNA from blood, lymph node and rectal biopsies was extracted using RNAeasy extraction kits (Qiagen, Valencia, CA). cDNA labeling, hybridization, staining and scanning were performed according to the manufacturer’s instructions (Affymetrix, Santa Clara, CA) for rhesus gene expression arrays.
Project description:We sought to test whether vaccine-induced immune responses could protect rhesus macaques (RMs) against upfront heterologous challenges with an R5 simian-human immunodeficiency virus, SHIV-2873Nip. We immunized the RMs with recombinant Env proteins heterologous to the challenge virus. For induction of immune responses against Gag, Tat, and Nef, we explored a strategy of immunization with overlapping synthetic peptides (OSP). The immune responses against Gag and Tat were finally boosted with recombinant proteins. The vaccinees and a group of ten control animals were given five low-dose intrarectal (i.r.) challenges with SHIV-2873Nip. All controls and seven out of eight vaccinees became systemically infected; there was no significant difference in viremia levels of vaccinees vs. controls. Prevention of viremia was observed in one vaccinee which showed strong boosting of virus-specific cellular immunity during virus exposures. The protected animal showed no challenge virus-specific neutralizing antibodies in the TZM-bl or A3R5 cell-based assays and had low level ADCC activity after the virus exposures. Microarray data strongly supported a role for cellular immunity in the protected animal. Our study represents a case of protection against heterologous tier 2 SHIV-C by vaccine-induced, virus-specific cellular immune responses.
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:Bacille Calmette-Guérin (BCG) vaccination can confer non-specific protection against heterologous pathogens. However, the underlying mechanisms remain mysterious. We used scRNA-seq in this study to identify transcriptional changes in the immune and epithelial cells in the lungs following BCG vaccination in mice
Project description:After a century of the Bacillus Calmette-Guérin (BCG) vaccine, our understanding of its protection against homologous (Mycobacterium tuberculosis) or heterologous (e.g. influenza virus) infections is still limited. Here we show that systemic (intravenous) BCG vaccination (BCG-iv) provides significant protection against subsequent influenza A virus (IAV) infection in mice. We further demonstrate that the BCG-mediated cross-protection against IAV is largely due to the enrichment of conventional CD4+ αβ effector memory T cells that express high levels of CX3CR1hi in circulation trafficking into the lung parenchyma. Importantly, pulmonary CX3CR1hi T cells limit early viral infection in an antigen-independent manner via potent IFNγ production, which subsequently enhances long-term antimicrobial activity of the innate immune system like alveolar macrophages. Similarly, we uncover a prominent IFNγ signature in which its increased basal production was associated with enhanced BCG-mediated heterologous innate memory responses in BCG-vaccinated humans. These results offer insight into the unknown mechanism by which BCG has persistently displayed broad protection against non-tuberculous infections via a crosstalk between adaptive and innate memory responses.
Project description:Heterologous ChAdOx1-BNT162b2 vaccination induces a stronger immune response than two doses of BNT162b2. Yet, the molecular transcriptome, the germline allelic variants of immunoglobulin loci and anti-Omicron antibody levels induced by the heterologous vaccination have not been formally investigated. Moreover, there is a paucity of COVID-19 vaccine studies including diverse genetic populations. Here, we show a robust molecular immune transcriptome and antibody repertoire in 46 office and lab workers from the Republic of Korea after heterologous vaccination, ChAdOx1 followed by BNT162b2. Anti-spike-specific IgG antibody levels against the ancestral SARS-CoV-2 strain increased from 70 AU/ml immediately following the first vaccination to 14,000 U/ml within three days after the second vaccination and 142,000 AU/ml after seven days. Antibody titers against more recent variants, including Omicron, were two- to three-fold lower, yet higher than those obtained after the second dose of a BNT162b2-BNT162b2 homologous vaccination. RNA-seq conducted on peripheral immune cells demonstrated a strong activation of interferon-induced genetic programs in the heterologous cohort and an increase of specific IGHV clonal transcripts encoding neutralizing antibodies was detected. Enrichment of B cell and CD4+ T cell responses was observed following both ChAdOx1-BNT162b2 heterologous and BNT162b2-BNT162b2 homologous vaccination using scRNA-seq, but clonally expanded memory B cells were relatively stronger in the heterologous cohort. In summary, a heterologous vaccination with ChAdOx1 followed by BNT162b2 provides an innate and adaptive immune response exceeding that seen in homologous BNT162b2 vaccination.
Project description:Heterologous ChAdOx1-BNT162b2 vaccination induces a stronger immune response than two doses of BNT162b2. Yet, the molecular transcriptome, the germline allelic variants of immunoglobulin loci and anti-Omicron antibody levels induced by the heterologous vaccination have not been formally investigated. Moreover, there is a paucity of COVID-19 vaccine studies including diverse genetic populations. Here, we show a robust molecular immune transcriptome and antibody repertoire in 46 office and lab workers from the Republic of Korea after heterologous vaccination, ChAdOx1 followed by BNT162b2. Anti-spike-specific IgG antibody levels against the ancestral SARS-CoV-2 strain increased from 70 AU/ml immediately following the first vaccination to 14,000 U/ml within three days after the second vaccination and 142,000 AU/ml after seven days. Antibody titers against more recent variants, including Omicron, were two- to three-fold lower, yet higher than those obtained after the second dose of a BNT162b2-BNT162b2 homologous vaccination. RNA-seq conducted on peripheral immune cells demonstrated a strong activation of interferon-induced genetic programs in the heterologous cohort and an increase of specific IGHV clonal transcripts encoding neutralizing antibodies was detected. Enrichment of B cell and CD4+ T cell responses was observed following both ChAdOx1-BNT162b2 heterologous and BNT162b2-BNT162b2 homologous vaccination using scRNA-seq, but clonally expanded memory B cells were relatively stronger in the heterologous cohort. In summary, a heterologous vaccination with ChAdOx1 followed by BNT162b2 provides an innate and adaptive immune response exceeding that seen in homologous BNT162b2 vaccination.
Project description:Bacillus Calmette-Guérin (BCG) vaccine is one of the most widely-used vaccines worldwide. In addition to protection against tuberculosis, BCG confers a degree of non-specific protection against other infections by enhancing secondary immune responses to heterologous pathogens, an effect termed trained immunity. To better understand BCG-induced immune reprogramming, we performed single-cell transcriptomic measurements before and after BCG vaccination using secondary immune stimulation with bacterial lipopolysaccharide (LPS). We find that BCG vaccination reduces systemic inflammation, and we identify 75 genes with an altered response to LPS, including several inflammatory mediators such as CCL3 and CCL4 which have a heightened response. Co-expression analysis reveals gene modules containing these cytokines lose coordination after BCG vaccination. Others have increased coordination, including several humanin nuclear isoforms which we confirmed induce trained immunity in vitro. Our results link in vivo BCG administration to single cell transcriptomic changes, validated in human genetics experiments, and highlight new genes which may be responsible for the non-specific protective effects of BCG.
Project description:In this study, we show that passive transfer of purified antibodies from vaccinated macaques can protect naïve animals against SIVmac251 challenges. The protective signature included multiple antibody functions and correlated with upregulation of interferon pathways in the vaccinated animals. Adoptive transfer of purified IgG from the vaccinated animals with the most robust protective signatures provided partial protection against SIVmac251 challenges in naïve recipient rhesus macaques. These data demonstrate the protective efficacy of purified vaccine-elicited antiviral antibodies, even in the absence of virus neutralization.