Profiling Atlantic salmon B cell populations: CpG-mediated TLR-ligation enhances IgM secretion and modulates immune gene expression

Profiling Atlantic salmon B cell populations: CpG-mediated TLR-ligation enhances IgM secretion and modulates immune gene expression

Blog Article

Abstract While TLR-activated pathways are key regulators of B cell responses in mammals, their impact on teleost B cells are scarcely addressed.Here, the potential of Atlantic salmon B cells to respond to TLR ligands was shown by demonstrating a constitutive expression of nucleic-acid sensing TLRs in magnetic sorted IgM+ cells.Of the two receptors recognizing CpG in teleosts, tlr9 was the dominating receptor with over ten-fold higher expression than tlr21.Upon CpG-stimulation, IgM secretion increased for head kidney (HK) taylor made p790 for sale and splenic IgM+ cells, while blood B cells were marginally affected.

The results suggest that CpG directly affects salmon B cells to differentiate into antibody secreting cells (ASCs).IgM secretion was also detected in the non-treated controls, again with the highest levels in the HK derived population, signifying that persisting ASCs are present in this tissue.In all tissues, the IgM+ cells expressed high MHCII levels, suggesting antigen-presenting functions.Upon CpG-treatment the co-stimulatory molecules cd83 and cd40 were upregulated, while cd86 was down-regulated under the 3 gallon flat back bucket same conditions.

Finally, ifna1 was upregulated upon CpG-stimulation in all tissues, while a restricted upregulation was evident for ifnb, proposing that salmon IgM+ B cells exhibit a type I IFN-response.