Neutrophils play a key role in initiating an innate immune response, being the first type of immune cell arriving at the site of injury or
infection. These cells are able to mount a direct anti-bactericidal response by the production of reactive
oxygen or
reactive nitrogen species (ROS/RNS). An important component of the host innate immune response is recognition of
pathogen-associated molecular patterns (
PAMPs) by
pattern recognition receptors (
PRRs).
Toll-like receptors (TLRs) are an important family of
PRRs and, are a key component in activation of innate immune mechanisms. In the present study we described the presence of
mRNA transcripts for TLR1, TLR2, TLR4, TLR6, TLR7 and TLR10 in bovine neutrophils. In contrast, the presence of
mRNA transcripts for TLR3 varied between animals, whereas no transcripts were detected for TLR5, TLR8, TLR9 or the
C-type lectin receptor dectin-1 in neutrophils isolated from bovine blood. Additionally,
zymosan, a dectin-1/TLR2
ligand, induced ROS, but not RNS production in a CD11b-, but not dectin-1-dependent manner. This effect was dependent on Store Operated
Calcium Entry (SOCE), and partially inhibited using
monoclonal antibodies to CD11b. Taken together, our data describe the presence of specific
PRRs transcripts in the
mRNA isolated from bovine neutrophil and show a CD11b-/Ca(2+) dependent ROS production by these cells.