Canine peripheral non-conventional TCRαβ CD4CD8α double-negative T cells show T helper 2-like and regulatory properties.

The dog is an important companion animal and also serves as model species for human diseases. Given the central role of T cells in immune responses, a basic understanding of canine conventional T cell receptor (TCR)αβ T cells, comprising CD4 single-positive (sp) T helper (Th) and CD8α sp cytotoxic T cell subsets, is available. However, characterization of canine non-conventional TCRαβ CD4CD8α double-positive (dp) and TCRαβ CD4CD8α double-negative (dn) T cells is limited.

Piroplasms of New Zealand seabirds.

Blood and ectoparasitic ticks were collected from migratory seabirds in New Zealand, including Australasian gannets (n = 13) from two sites and red-billed gulls (n = 9) and white-fronted terns (n = 2) from a third location. Blood smears were screened for parasite presence by microscopy, while DNA from blood samples was subjected to PCR for the presence of tick-transmitted protozoan haemoparasites belonging to the order Piroplasmida. Parasites were identified by comparing small subunit ribosomal RNA (18S rDNA) gene sequences to related sequences on GenBank.