Evaluation of peripheral blood neutrophil function in tumor‐bearing dogs

Abstract

Background: Peripheral blood neutrophils of untreated human cancer patients have been shown to have normal, increased, and decreased phagocytic activity, killing capacity, and/or oxidative burst activities. Objectives: The objectives of this study were to evaluate oxidative burst and phagocytic activities of peripheral blood neutrophils from tumor‐bearing dogs before therapy and compare them with neutrophil function of healthy control dogs. Methods: Heparinized whole blood was obtained from dogs with high‐grade lymphoma (n=23), sarcoma (n=13), or carcinoma (n=11), and healthy control dogs (n=11) for flow cytometric evaluation of oxidative burst and phagocytic activities. Percentage of bursting cells and amount of oxidative burst activity were determined after stimulation with phorbol 12‐myristate 13‐acetate (PMA) or Escherichia coli. Percentage of phagocytic cells and amount of phagocytic activity were determined after incubation with fluorescent E. coli. Results: Compared with control dogs, dogs with sarcoma (P=.004) and carcinoma (P=.05) had a lower percentage of neutrophils exhibiting oxidative burst activity after stimulation with PMA. Phagocytic activity was significantly lower in dogs with sarcomas compared with control dogs (P<.0001) and dogs with lymphoma (P=.01). Conclusions: Untreated carcinomas and sarcomas in dogs may suppress the percentage of neutrophils capable of oxidative burst when stimulated by PMA. Furthermore, sarcomas also may suppress the amount of phagocytic activity per neutrophil. Until further studies can be performed, the clinical significance of these findings is unknown.

Peripheral blood biomarkers of solid tumor angiogenesis in dogs: A polychromatic flow cytometry pilot study

“…As the CHSPCs have been further characterized, we have found that the human markers do not fully correlate with the canine cell subtypes. Interestingly, recent studies utilizing flow cytometry have shown differences in myeloid and lymphoid cells in the diagnosis and successful treatment of canine malignancies (LeBlanc et al, 2010; Tominaga et al, 2010; Comazzi et al, 2011). In a preliminary flow cytometry assessment of therapy with the anti-angiogenic agent ABT-510, there was no significant change in circulating endothelial cells in 10 dogs that experienced early disease progression.…”

Evaluation of immunomodulatory effect of recombinant human granulocyte‐macrophage colony‐stimulating factor on polymorphonuclear cell from dogs with cancer in vitro

“…Additional exclusion criteria were: previously diagnosed immune system disorder (such as immune mediated disease), history of inflammatory disease within 3 months of presentation, non‐measurable tumour burden or breeds with known congenital neutrophil dysfunction disorders (Brittany Spaniel, Weimaraner, Foxhound, Pointer, Irish Setter, Doberman). Dogs with neoplasia were divided into the soft tissue sarcoma (STSA) group or the general neoplasia group, because STSA has been specifically associated with cancer‐induced immunodysfunction in dogs . Dogs in the control group were deemed healthy based on history, physical examination and complete blood count.…”

“…Dogs with spontaneously occurring cancer often have cancer‐associated immunosuppression that is similar to cancer‐associated immunosuppression in humans . Administration of immunosuppressive medications such as chemotherapy exacerbates cancer‐associated immunosuppression, further increasing the risk of sepsis .…”

Resveratrol decreases oxidative burst capacity and alters stimulated leukocyte cytokine production in vitro

“…Propidium iodide was added to stain DNA; this allowed exclusion of aggregation artifacts of bacteria or dead cells during flow cytometry. Oxidative burst activity was also determined using a commercially available test kit (Phagoburst ® , Orpegen Pharma, Heidelberg, Germany) validated for use with canine blood (LeBlanc et al, 2010) according to manufacturer instructions. Heparinized whole blood was incubated with various stimuli (unlabeled opsonized E. coli LE392, PMA, or control solution).…”

“…Following incubation with resveratrol or control, PMN phagocytic and oxidative burst capacity were determined. Canine PMN phagocytic ability was determined using a commercially available test kit (Phagotest ® , Orpegen Pharma, Heidelberg, Germany) previously validated for dogs (LeBlanc et al, 2010) according to manufacturer instructions. Heparinized whole blood was incubated with FITC-labeled opsonized E. coli strain LE392 for 10 min in a 37 • C water bath to stimulate phagocytosis by white blood cells; negative control samples were those incubated without bacteria.…”