Commercially available rabbit anti-human polyclonal antisera as a useful tool for immune system studies in veterinary species

Multiple myeloma in a captive lion (Panthera leo)

Multiple myeloma is a rare, systemic proliferation of neoplastic plasma cells. A case was reported in an 11-year-old male captive lion (Panthera leo) at the National Zoological Gardens of South Africa, Pretoria. The classic features of symptomatic multiple myeloma were all evident in this case; namely osteolytic lesions, monoclonal gammopathy in the serum with excretion of monoclonal proteins in the urine, neoplastic plasma cells in the bone marrow and associated renal failure and anaemia. In addition, similar to the common pattern of this disease in domestic felids, at least three extramedullary tumours were found and several organs were infiltrated by neoplastic plasma cells. The cytoplasm of approximately 50%of the neoplastic round cells, including a few giant myeloma cells, stained weakly to strongly using immunohistochemical stains for B-lymphocytes (CD79a). The normal haematological parameters and lack of any osteolytic lesions in the lion at the time of the first evaluation suggest that the primary neoplastic cells could have originated from one of the extramedullary tumour sites. Only two cases of multiple myeloma have previously been reported in captive wild felids. To the authors’ knowledge, there are no case reports of multiple myeloma in lions.

γδ T lymphocytes are recruited into the inflamed uterus of bitches suffering from pyometra

Very little is known about the occurrence of immune system cells in the canine uterus. The aim of this study was to generate information about lymphocyte subsets that are present in the healthy canine uterus and that are recruited under inflammatory conditions caused by pyometra. Using immunohistochemistry and flow cytometry, a significant influx of γδ T lymphocytes was found in pyometra samples mainly due to recruitment of γδ(+)/CD8(-) T lymphocytes. The relative expression of genes encoding selected cytokines/chemokines was evaluated in samples from healthy and pyometra-affected uteri. Expression of pro-inflammatory cytokines (including IL-1β, TNF-α, IL-8, IL-17 and IFN-γ) and chemokines (including CXCL10, CCL4 and CCL5) was upregulated in pyometra samples confirming the presence of inflammation. In contrast, the expression of the homeostatic chemokine CCL25 and of the anti-inflammatory cytokine IL-10 was downregulated and unchanged, respectively.

Characterization of monoclonal antibodies against canine P-selectin glycoprotein ligand-1 (PSGL-1)

Thirteen different monoclonal antibodies against canine P-selectin glycoprotein ligand-1 (cPSGL-1) were obtained by immunization of rats with cells of a canine lymphoma cell line (Ema). O-sialoglycoprotein endopeptidase treatment of Ema cells showed that all of these antibodies recognized O-glycosylated peptides of canine PSGL-1. Experiments using deletion or point mutants of cPSGL-1 indicated that these antibodies could be categorized into several groups based on their cPSGL-1 recognition characteristics. These anti-cPSGL-1 monoclonal antibodies will be useful for analysis of the canine P-selectin and PSGL-1 system.

Lactoferrin in canine sera: a pyometra study

The concentration of lactoferrin was measured in canine sera from groups of healthy male dogs as well as pregnant and non-pregnant female dogs and was compared with that of bitches with pyometra. Lactoferrin concentrations were higher in bitches with pyometra. The role of elevated lactoferrin concentrations in the suppression of lymphocyte activity was examined in sera from bitches with pyometra in a series of investigations. Although the sera from bitches with pyometra were capable of suppressing lymphocyte activity, lactoferrin was not found to be involved in this action.