Development of a Mouse Model to Explore CD4 T Cell Specificity, Phenotype, and Recruitment to the Lung after Influenza B Infection

Abstract

The adaptive T cell response to influenza B virus is understudied, relative to influenza A virus, for which there has been considerable attention and progress for many decades. Here, we have developed and utilized the C57BL/6 mouse model of intranasal infection with influenza B (B/Brisbane/60/2008) virus and, using an iterative peptide discovery strategy, have identified a series of robustly elicited individual CD4 T cell peptide specificities. The CD4 T cell repertoire encompassed at least eleven major epitopes distributed across hemagglutinin, nucleoprotein, neuraminidase, and non-structural protein 1 and are readily detected in the draining lymph node, spleen, and lung. Within the lung, the CD4 T cells are localized to both lung vasculature and tissue but are highly enriched in the lung tissue after infection. When studied by flow cytometry and MHC class II: peptide tetramers, CD4 T cells express prototypical markers of tissue residency including CD69, CD103, and high surface levels of CD11a. Collectively, our studies will enable more sophisticated analyses of influenza B virus infection, where the fate and function of the influenza B-specific CD4 T cells elicited by infection and vaccination can be studied as well as the impact of anti-viral reagents and candidate vaccines on the abundance, functionality, and localization of the elicited CD4 T cells.

R-DOTAP Cationic Lipid Nanoparticles Outperform Squalene-Based Adjuvant Systems in Elicitation of CD4 T Cells after Recombinant Influenza Hemagglutinin Vaccination

“…Many genetically modified strains are uniquely available in the B6 background [ 63 ]. Previous studies by our group identified three major CD4 T cell epitopes in HA-B following the influenza infection of B6 mice [ 60 ], offering a good opportunity to broadly assess CD4 T cell specificity and immunodominance. Figure 1 shows the location of these epitopes in the HA-B protein as well as their degree of conservation across HA-B proteins from historical and contemporary strains of influenza B.…”

“…The 15-mer peptides from HA were obtained from Mimotopes. The sequences are listed in Table 1 [ 60 ]. Hemagglutinin HA recombinant protein made in baculovirus from influenza virus B/Malaysia/2506/2004 (NR-15172) was obtained from BEIR.…”

“…ELISpot assays to detect cytokine-producing cells were performed as previously described [ 60 ]. Briefly, 96-well filter plates were coated with 2 μg/mL purified rat anti-mouse IL-2 or IFN-γ (clone JES6-1A12 and clone AN-18, respectively, BD Biosciences, San Jose, CA, USA) in PBS overnight at 4 °C, washed with media (complete DMEM media with 10% FBS (Gibco, Grand Island, NY, USA)) to remove any unbound antibody and incubated with 100 μL media per well for 1 hr to block non-specific protein binding in subsequent steps.…”

Cross-Protection Induced by Virus-like Particles Derived from the Influenza B Virus

“…In our study, 10-fold or more virus titer reductions were observed in all immunization groups. Recently, it was reported that CD4+ T cells become highly localized in the lung tissues post-infection with IBV [ 45 ]. Partial enrichment of CD4+ T cells in the lungs was observed in our study, thus confirming the findings of the previous work.…”

Live attenuated influenza A virus vaccines with modified NS1 proteins for veterinary use

“…Dendritic cells (DCs) and macrophages are antigen presenting cells (APCs) playing a key role as mediators between innate and the adaptive immune responses (Akira et al, 2006;Trinchieri and Sher, 2007;Borderia et al, 2008;Monteagudo et al, 2019). Moreover, APCs are able to activate adaptive immune responses against the invading pathogens by triggering T cell differentiation (Cuddapah et al, 2010;Topham et al, 2021;Rattan et al, 2022). Importantly, these cells constantly inspect the lungs for pathogens and they are essential to protect the host against invaders.…”