High-Dimensional Phenotyping of B-Cells Responding to Rhinovirus Infection
Monday, March 5, 2018: 2:00 PM
S220EF (Convention Center)
Jacob D. Eccles, ,

RATIONALE: Human rhinoviruses (RV) cause roughly half of the one-billion colds experienced annually within the US, while simultaneously precipitating life-threatening respiratory distress in asthmatic populations. Meanwhile, for reasons that remain unclear, adaptive immunity does not promote long-term protection from infection despite each instance of viral clearance generally coinciding with the development of serum neutralizing antibodies. To better understand these responses at a cellular level, we have implemented methods to appreciate fluctuations in peripheral blood B-cells during RV infection.

METHODS: Six human subjects were nasally inoculated with RV strain A39, and peripheral blood mononuclear cells were drawn and isolated at days 0, 5, and 21 post-infection. Cells were barcoded with palladium-labeled anti-CD45 antibodies, and combined for subsequent processing steps. Next, B-cells were magnetically enriched by negative selection against CD3, CD14, and CD16, and then stained with a 40-marker mass cytometry antibody panel. After collection on a CyTOF2, multiplexed sample data were debarcoded and subjected to FlowSOM clustering analysis.

RESULTS: At day 5, a variety of memory phenotype clusters exhibited modest decreases in frequency. In contrast, the expansion of a singular plasmablast phenotype was more pronounced (p < 0.05). These nascent cells demonstrated classical plasmablast markers (CD19low, CD20low, CD38hi), displayed an activated phenotype (CD27hi, CD95hi, CD80/6hi, CD40low), expressed inflamed airway homing receptors (CCR5+, CXCR3+, Itgα4β1+), and bore indicators of an early, short-lived response (IgM+, Bcl-2low, Ki-67+).

CONCLUSIONS: Our high-dimensional approach highlights the early adaptive response to RV, suggesting that initial humoral contributions during acute infection are mediated by IgM-secreting plasmablasts acting at the site of infection.