Characterization of protective immune response elicited by a trimeric envelope protein from an Indian clade C <scp>HIV</scp>‐1 isolate in rhesus macaques

et al. 2020

Preprint

ADJ induces inflammasome activation in DCs, but deficiency for NLRP3, ASC or caspase 1 did not affect ADJ-mediated cross-presentationNext, we examined the effects of ADJ on the expression profiles of cytokines, chemokines and canonical cell surface markers of DC activation. Compared to untreated DCs, ADJ-treated DCs showed statistically significant, yet modest increases in expression of CD40, CD80, and CD86; no significant differences in expression were observed for MHC-I, MHC-II, or CCR7 (Fig. 1C).ADJ-treated DCs produced higher levels of IL-12 (p70), TNF-, IL-1, CCL3, CCL4, CXCL1, and RANTES, as compared to untreated DCs; no significant differences in expression were observed for IL-6, IL-10, and IFN- (Fig. 1D). Particularly, ADJ-stimulated DCs also produced significantly elevated levels of IL-1 and IL-18 (Fig. 1D), which is suggestive of inflammasome activation. Since inflammasome activation has been implicated in modulation of antigen presentation by DCs (Sokolovska et al., 2013, Li et al., 2019, we performed B3Z assays using DCs deficient in NLRP3, ASC, or caspase 1 to interrogate whether inflammasome activation is required for ADJ-induced cross-presentation in BMDCs. Surprisingly, loss of NLRP3, ASC or caspase 1 activity did not affect ADJ-induced cross-presentation by DCs, in vitro (Fig. 1E). To validate whether caspase 1 is required for cross-presentation in vivo, we immunized cohorts of wild type (WT) and caspase 1-deficient mice with ADJ+OVA, and quantified OVA SIINFEKLspecific CD8 T cells in spleens using MHC I tetramers at day 8 after immunization. Consistent with our results from B3Z assays, caspase 1 deficiency did not significantly affect the activation of SIINFEKL-specific CD8 T cells in spleens (Fig. 1F), suggesting that caspase 1 is not essential for ADJ-driven cross-presentation to CD8 T cells in vivo.

Section: Introductionmentioning

confidence: 99%

Carbomer-based Nano-Emulsion Adjuvant Enhances Dendritic Cell Cross-presentation via Lipid Body Formation Independent of Glycolysis

Suresh

et al. 2020

Preprint

“…Insights from such studies might aid in the rational development of adjuvants that can drive potent vaccine-induced T cell responses by engaging monocytes in the lungs. Adjuplex (ADJ) is a carbomer-based nano-emulsion adjuvant that is known to elicit robust neutralizing antibodies to malarial and HIV envelope glycoproteins in mice and nonhuman primates (36,37). We have previously reported that subunit protein formulated in ADJ protects against vaccinia virus and IAV in mice by enhancing DC cross-presentation (38,39).…”

Section: Introductionmentioning

confidence: 99%

CCR2 Regulates Vaccine-Induced Mucosal T-Cell Memory to Influenza A Virus

Kedl³

et al. 2021

Preprint

Elicitation of lung tissue-resident memory CD8 T cells (TRMs) is a goal of T-cell based vaccines against respiratory viral pathogens such as influenza A virus (IAV). Chemokine receptor 2 (CCR2)-dependent monocyte trafficking plays an essential role in the establishment of CD8 TRMs in lungs of IAV-infected mice. Here, we used a combination adjuvant-based subunit vaccine strategy that evokes multifaceted (TC1/TC17/TH1/TH17) IAV nucleoprotein-specific lung TRMs, to determine whether CCR2 and monocyte infiltration are essential for vaccine-induced TRM development and protective immunity to IAV in lungs. Following intranasal vaccination, neutrophils, monocytes, conventional dendrtitic cells (DCs) and monocyte-derived DCs internalized and processed vaccine antigen in lungs. We also found that Basic Leucine Zipper ATF-Like Transcription Factor 3 (BATF-3)-dependent DCs were essential for eliciting T cell responses, but CCR2 deficiency enhanced the differentiation of CD127HI/KLRG-1LO, OX40+veCD62L+ve and mucosally imprinted CD69+veCD103+ve effector and memory CD8 T cells in lungs and airways of vaccinated mice. Mechanistically, increased development of lung TRMs, induced by CCR2 deficiency was linked to dampened expression of T-bet, but not altered TCF-1 levels or T cell receptor signaling in CD8 T cells. T1/T17 functional programming, parenchymal localization of CD8/CD4 effector and memory T cells, recall T cell responses and protective immunity to a lethal IAV infection were unaffected in CCR2-deficient mice. Taken together, we identified a negative regulatory role for CCR2 and monocyte trafficking in mucosal imprinting and differentiation of vaccine-induced TRMs. Mechanistic insights from this study may aid the development of T-cell-based vaccines against respiratory viral pathogens including IAV and SARS-CoV-2.

CCR2 Regulates Vaccine-Induced Mucosal T-Cell Memory to Influenza A Virus

Kedl

et al. 2021

J Virol

Elicitation of lung tissue-resident memory CD8 T cells (TRMs) is a goal of T-cell based vaccines against respiratory viral pathogens, such as influenza A virus (IAV). Chemokine receptor 2 (CCR2)-dependent monocyte trafficking plays an essential role in the establishment of CD8 TRMs in lungs of IAV-infected mice. Here, we used a combination adjuvant-based subunit vaccine strategy that evokes multifaceted (TC1/TC17/TH1/TH17) IAV nucleoprotein-specific lung TRMs, to determine whether CCR2 and monocyte infiltration are essential for vaccine-induced TRM development and protective immunity to IAV in lungs. Following intranasal vaccination, neutrophils, monocytes, conventional DCs and monocyte-derived dendritic cells internalized and processed vaccine antigen in lungs. We found that Basic Leucine Zipper ATF-Like Transcription Factor 3 (BATF-3)-dependent DCs were essential for eliciting T cell responses, but CCR2 deficiency enhanced the differentiation of CD127HI/KLRG-1LO, OX40+veCD62L+ve and mucosally imprinted CD69+veCD103+ve effector and memory CD8 T cells in lungs and airways of vaccinated mice. Mechanistically, increased development of lung TRMs, induced by CCR2 deficiency was linked to dampened expression of T-bet, but not altered TCF-1 levels or T cell receptor signaling in CD8 T cells. T1/T17 functional programming, parenchymal localization of CD8/CD4 effector and memory T cells, recall T cell responses and protective immunity to a lethal IAV infection were unaffected in CCR2-deficient mice. Taken together, we identified a negative regulatory role for CCR2 and monocyte trafficking in mucosal imprinting and differentiation of vaccine-induced TRMs. Mechanistic insights from this study may aid the development of T-cell-based vaccines against respiratory viral pathogens including IAV and SARS-CoV-2. Importance While antibody-based immunity to influenza A virus (IAV) is type and sub-type specific, lung and airway-resident memory T cells that recognize conserved epitopes in the internal viral proteins are known to provide heterosubtypic immunity. Hence, broadly protective IAV vaccines need to elicit robust T-cell memory in the respiratory tract. We have developed a combination adjuvant-based IAV nucleoprotein vaccine that elicits strong CD4 and CD8 T cell memory in lungs and protects against H1N1 and H5N1 strains of IAV. In this study, we examined the mechanisms that control vaccine-induced protective memory T cells in the respiratory tract. We found that trafficking of monocytes into lungs might limit the development of anti-viral lung-resident memory T cells, following intranasal vaccination. These findings suggested that strategies that limit monocyte infiltration can potentiate vaccine-induced frontline T-cell immunity to respiratory viruses, such as IAV and SARS-CoV-2.