Canine macrophages can like human macrophages be in vitro activated toward the M2a subtype relevant in allergy

Abstract

The M2a subtype of macrophages plays an important role in human immunoglobulin E (IgE-mediated allergies) and other Th2 type immune reactions. In contrast, very little is known about these cells in the dog. Here we describe an in vitro method to activate canine histiocytic DH82 cells and primary canine monocyte-derived macrophages (MDMs) toward the M2a macrophages using human cytokines. For a side-by-side comparison, we compared the canine cells to human MDMs, and the human monocytic cell line U937 activated towards M1 and M2a cells on the cellular and molecular level. In analogy to activated human M2a cells, canine M2a, differentiated from both DH82 and MDMs, showed an increase in CD206 surface receptor expression compared to M1. Interestingly, canine M2a, but not M1 derived from MDM, upregulated the high-affinity IgE receptor (FcεRI). Transcription levels of M2a-associated genes (IL10, CCL22, TGFβ, CD163) showed a diverse pattern between the human and dog species, whereas M1 genes (IDO1, CXCL11, IL6, TNF-α) were similarly upregulated in canine and human M1 cells (cell lines and MDMs). We suggest that our novel in vitro method will be suitable in comparative allergology studies focussing on macrophages.

P2Y2 and P2X4 Receptors Mediate Ca2+ Mobilization in DH82 Canine Macrophage Cells

“…However, studies have demonstrated that these cell lines can be polarised towards a more specialised macrophage phenotype, in which the expression of P2 receptors, such as P2X4 and P2X7 receptors, are commonly upregulated [34,38,74]. A study has recently demonstrated that DH82 canine macrophage cells could be polarised towards the M1 or M2a subtype through cytokine stimulation [20]. However, the DH82 cells utilised throughout this study remained unpolarised (M0) and, thus, it remains to be determined if cytokine stimulation influences P2 receptor expression or function.…”

“…The DH82 cell line is a canine macrophage cell line isolated from a 10 year old Golden Retriever with malignant histiocytosis [ 19 ]. This cell line has recently been demonstrated as a useful model of canine macrophage physiology, bearing similarities to an M0 macrophage subtype with demonstrated potential for polarisation to either M1 or M2a subtypes through cytokine stimulation [ 20 ]. Studies have demonstrated that DH82 cells express a number of macrophage markers, such as CD11c and CD18 [ 21 ], and can secrete tumour necrosis factor (TNF)-α and interleukin (IL)-6 similar to that observed in lipopolysaccharide (LPS)-stimulated canine monocytes [ 22 ].…”

A caninein vitromodel for evaluation of marrow‐derived mesenchymal stromal cell‐based bone scaffolds

“…First, the current work focused solely on hMSCs and cMSCs and did not investigate potential species differences among supporting cell types (for example, osteoblasts osteoclasts, osteocytes, and macrophages) that are also important for regeneration. It should be noted, however, that although some species differences have been found for human versus canine MSCs 38,95 and macrophages, 96 the overall degree of similarity between bone composition, 97 cell and tissue response to stimuli, [98][99][100][101][102][103][104][105][106] and pathological outcomes [107][108][109][110] between these two species highlights a significant overlap in behaviors. Furthermore, evaluation of additional hMSC and cMSC donors may be needed for definitive conclusions to be made regarding interspecies similarity in the osteoinductive effects of PEG-PDMS scaffolds.…”

Peripheral mechanisms of arthritic pain: A proposal to leverage large animals for in vitro studies

“…With regard to examining the roles of non-neuronal cells in large animal models of arthritis, successful culture of FLS from synovium punch or synovial fluid has been conducted in horses ( Ghasemi et al, 2017 , Warnock et al, 2014 ), sheep ( Smith et al, 2008 ) and dogs ( Pelletier et al, 1997 ). Macrophages and lymphocytes have also been cultured from large animals such as, sheep, pigs and dogs ( Beya et al, 1986 , Herrmann et al, 2018 , Jungi et al, 1992 , Saalmüller et al, 1994 ). These results thus demonstrate that non-neuronal/neuronal co-culture studies can also be set up with cells derived from large animals.…”