Neutrophil subtypes shape HIV-specific CD8 T-cell responses after vaccinia virus infection

Mauro Di Pilato,Santiago F Gonzalez,Miguel Palomino-Segura,Patricia Pérez,Alberto Benguría,Ernesto Mejías-Pérez,Mariano Esteban,Ana Dopazo,Raphael Kfuri-Rubens,Carlos Oscar S Sorzano,Diego Ulisse Pizzagalli,Andrés Hidalgo,Rocco D’Antuono,Iván Ballesteros,Andrea Rubio-Ponce,Carmen E Gómez

doi:10.1038/s41541-021-00314-7

Abstract

Neutrophils are innate immune cells involved in the elimination of pathogens and can also induce adaptive immune responses. Nα and Nβ neutrophils have been described with distinct in vitro capacity to generate antigen-specific CD8 T-cell responses. However, how these cell types exert their role in vivo and how manipulation of Nβ/Nα ratio influences vaccine-mediated immune responses are not known. In this study, we find that these neutrophil subtypes show distinct migratory and motility patterns and different ability to interact with CD8 T cells in the spleen following vaccinia virus (VACV) infection. Moreover, after analysis of adhesion, inflammatory, and migration markers, we observe that Nβ neutrophils overexpress the α4β1 integrin compared to Nα. Finally, by inhibiting α4β1 integrin, we increase the Nβ/Nα ratio and enhance CD8 T-cell responses to HIV VACV-delivered antigens. These findings provide significant advancements in the comprehension of neutrophil-based control of adaptive immune system and their relevance in vaccine design.

Highlights

Neutrophils are innate immune effector cells that form the first line of defense against microbial pathogens[1]
Intraperitoneal (i.p.) injection of 107 plaque-forming units (PFU) of Compared to 2 h p.i., the ratio Nβ/Nα significantly increased in vaccinia virus (VACV) strain NYVAC-C ΔA52RΔB15RΔK7R deletion mutant and we identified by flow cytometry Ly6G+CD11b+ neutrophils (Fig. 1a)
To after infection (Supplementary Fig. 1g–i), suggesting that the time window between 2 and 10 h represents an opportunity for Nβ to determine how neutrophil trafficking occurs from the primary site of infection to the spleen, we quantified neutrophils in peritoneal cavity (PEC), spleen, and blood at 2, 6, and 10 h post infection (p.i.) (Fig. 1b–d)

Summary

Introduction

Neutrophils are innate immune effector cells that form the first line of defense against microbial pathogens[1]. They immediately migrate to the inflammation site and neutralize the insult in a process termed microbial sterilization[2], which is characterized by the engulfing of pathogens, infected and apoptotic cells[3,4], the disarming of microorganisms through neutrophil extracellular traps[5], the generation of reactive oxygen intermediates[6], and the release of lytic enzymes from their granules[2]. Neutrophils polarize to distinct phenotypes in response to environmental signals[10], and in the presence of granulocyte macrophage-colony stimulating factor (GM-CSF) and interferon (IFN)-γ, neutrophils can acquire antigen-presenting cell (APC) functions and trigger CD8 T-cell activation[11]. In the presence of transforming growth factor (TGF)-β, TAN polarize from the antitumoral N1 to the pro-tumoral N2 phenotype, characterized by impaired ability to activate CD8 T cells[16]

Methods

Results

Conclusion