Chandranaik Marinaik | bioRxiv Science

bioRxiv2020

Polymeric Pathogen-like Particles-Based Combination Adjuvants Elicit Potent Mucosal T Cell Immunity to Influenza A Virus

Eliciting durable and protective T cell-mediated immunity in the respiratory mucosa remains a significant challenge. Polylactic-co-glycolic acid (PLGA)-based cationic pathogen-like particles (PLPs) loaded with TLR agonists mimic biophysical properties of microbes and hence, simulate pathogen-pattern recognition receptor interactions to safely and effectively stimulate innate immune responses. We generated micro particle PLPs loaded with TLR4 (glucopyranosyl lipid adjuvant, GLA) or TLR9 (CpG) agonists, and formulated them with and without a mucosal delivery enhancing carbomer-based nanoemulsion adjuvant (ADJ). These adjuvants delivered intranasally to mice elicited high numbers of influenza nucleoprotein (NP)-specific CD8+/ CD4+ effector and tissue-resident memory T cells (TRMs) in lungs and airways. PLPs delivering TLR4 versus TLR9 agonists drove phenotypically and functionally distinct populations of effector and memory T cells. While PLPs loaded with CpG or GLA provided immunity, combining the adjuvanticity of PLP-GLA and ADJ synergistically enhanced the development of airway and lung TRMs and protective immunity to pathogenic influenza A virus. Further, balanced CD8 (Tc1/Tc17) and CD4 (Th1/Th17) recall responses were linked to effective influenza virus control in the lungs. These studies provide mechanistic insights into vaccine-induced T cell immunity in the respiratory tract and pave the way for the development of a universal influenza vaccine.

immunology↗

bioRxiv2020

Programming Multifaceted Pulmonary T-Cell Immunity by Combination Adjuvants

Induction of protective mucosal T-cell memory remains a formidable challenge to vaccinologists. Using a novel adjuvant strategy that elicits unusually potent CD8 and CD4 T-cell responses, we have defined the tenets of vaccine-induced pulmonary T-cell immunity. An acrylic acid-based adjuvant (ADJ), in combination with TLR agonists glucopyranosyl lipid adjuvant (GLA) or CpG promoted mucosal imprinting but engaged distinct transcription programs to drive different degrees of terminal differentiation and disparate polarization of TH1/TC1/TH17/TC17 effector/memory T cells. Combination of ADJ with GLA, but not CpG, dampened TCR signaling, mitigated terminal differentiation of effectors and enhanced the development of CD4 and CD8 TRM that protected against H1N1 and H5N1 influenza viruses. Mechanistically, vaccine-elicited CD4 T cells played a vital role in optimal programming of CD8 TRM and anti-viral immunity. Taken together, these findings provide new insights into vaccine-induced multi-faceted mucosal T-cell immunity with significant implications in the development of vaccines against respiratory pathogens. One Sentence SummaryAdjuvants Induce Multipronged T-Cell Immunity in the Respiratory Tract.

immunology↗