Analysis of murine neonatal Germinal Center (GC) B cells transcriptome (RNA-Seq) following HA/CAF01 immunization in the presence or absence of maternal antibodies

Purpose: the goals of this study are to characterize GC B cells elicited by neonatal immunization with HA/CAF01 at the transcriptome level (RNA-seq) and study whether and how maternal antibodies affect GC B cell differentiation in early life Methods: transcriptomic analysis of highly pure GC B cells and the corresponding non-GC B cells isolated from draining lymph nodes of immunized neonatal mice were generated by HiSeq 4000 sequencing, using Illumina Technology. The sequence reads that passed quality filters were analyzed using the package edgeR: the fold-change and the Benjamini-Hochberg corrected p-value thresholds were set to 2 and 0.05 respectively. Main results: 1) we identified the differentially expressed genes (DEGs) in GC B cells versus non-GC B cells in murine neonates born to naive or influenza-immune mothers and observed that the canonical changes reflecting the acquisition of a GC B cell phenotype and state after neonatal immunization are not affected by high titers of maternal antibodies. 2) 39 DEGs distinguished GC B cells elicited in the presence or absence of MatAbs. GC B cells elicited in presence or absence of MatAbs used different VH and Vk genes and showed differences in genes associated with B cell differentiation and isotype switching. Overall design: Transcriptomic analysis of neonatal GC B cells at day 18 post HA/CAF01 immunization in the presence or absence of maternal antibodies were generated by deep sequencing, in triplicate, using Illumina Technologies.