Natural killer (NK) cells play a pivotal role in the immune response against infections and malignant transformation, and adopted transfer of NK cells is thought to be a promising therapeutic approach for cancer patients. Previous reports describing the phenotypic features of canine NK cells have produced inconsistent results. Canine NK cells are still defined as non-B and non-T (CD3−CD21−) large granular lymphocytes. However, a few reports have demonstrated that canine NK cells share the phenotypic characteristics of T lymphocytes, and that CD3+CD5dimCD21− lymphocytes are putative canine NK cells. Based on our previous reports, we hypothesized that phenotypic modulation could occur between these two populations during activation. In this study, we investigated the phenotypic and functional differences between CD3+CD5dimCD21− (cytotoxic large granular lymphocytes) and CD3−CD5−CD21− NK lymphocytes before and after culture of peripheral blood mononuclear cells isolated from normal dogs. The results of this study show that CD3+CD5dimCD21− lymphocytes can be differentiated into non-B, non-T NK (CD3−CD5−CD21−TCRαβ−TCRγδ−GranzymeB+) lymphocytes through phenotypic modulation in response to cytokine stimulation. In vitro studies of purified CD3+CD5dimCD21− cells showed that CD3−CD5−CD21− cells are derived from CD3+CD5dimCD21− cells through phenotypic modulation. CD3+CD5dimCD21− cells share more NK cell functional characteristics compared with CD3−CD5−CD21− cells, including the expression of T-box transcription factors (Eomes, T-bet), the production of granzyme B and interferon-γ, and the expression of NK cell-related molecular receptors such as NKG2D and NKp30. In conclusion, the results of this study suggest that CD3+CD5dimCD21− and CD3−CD5−CD21− cells both contain a subset of putative NK cells, and the difference between the two populations may be due to the degree of maturation.

No abstract

No abstract

BackgroundPrevious surveys in dogs from Korea indicated that dogs are exposed to a variety of vector- borne pathogens, but perception for a nation-wide canine vector-borne disease (CVBD) occurrence has been missing. We report here results of both serological and molecular prevalence studies for major CVBDs of dogs from all over the South Korean Peninsula except for Jeju Island.ResultsSerological survey of 532 outdoor dogs revealed the highest prevalence for Dirofilaria immitis (25.2%), followed by Anaplasma phagocytophilum (15.6%), Ehrlichia canis (4.7%) whereas Borrelia burgdorferi showed the lowest prevalence (1.1%). The number of serologically positive dogs for any of the four pathogens was 216 (40.6%). Concurrent real-time PCR assay of 440 dogs in the study indicated that DNA of “Candidatus M. haematoparvum”, Mycoplasma haemocanis, Babesia gibsoni, A. phagocytophilum, and Hepatozoon canis was identified in 190 (43.2%), 168 (38.2%), 23 (5.2%), 10 (2.3%) and 1 (0.2%) dogs, respectively. DNA of Bartonella spp., Ehrlichia spp., Leishmania spp., Rickettsia spp. and Neorickettsia risticii was not identified. Analysis of questionnaires collected from owners of 440 dogs showed that the number of dogs with heartworm preventive medication was 348 (79.1%) among which dogs still positive to D. immitis infection were 60 (17.2%), probably due to the mean months of heartworm preventive medication being only 6.5. The high prevalence rates of both “Ca. M. haematoparvum” and Mycoplasma haemocanis in dogs from Korea indicate that these organisms may be transmitted by vectors other than Rhipicephalus sanguineus because this tick species has rarely been found in Korea. This is the first nationwide survey for canine haemotropic mycoplasma infections in Korea.ConclusionsThis study showed that the risk of exposure to major vector-borne diseases in dogs is quite high throughout all areas of South Korean Peninsula. Since achieving full elimination of many pathogens causing CVBDs from infected animals is often impossible even when they are clinically cured, dogs once exposed to CVBDs can remain as lifetime reservoirs of disease for both other animals and humans in the close vicinity, and should therefore be treated with preventative medications to minimise the risk of pathogen transmission by the competent vectors.

Antibiotics continue to be used as growth promoters in the poultry industry. Honeybee (Apis melifera) venom (HBV) possesses a number of beneficial biological activities, particularly for regulating the immune system. The aim of the present study was to evaluate the immunoprophylactic effects of HBV against Salmonella Gallinarum in broiler chicks as an initial step towards developing eco-friendly alternatives to reduce antibiotic use. HBV was administered using a spray technique. HBV improved body weight gain, particularly in the presence of infection. Moreover, HBV enhanced antibody production activity against formalin-killed S. Gallinarum. The CD4+:CD8+ T lymphocyte ratio, relative mRNA expression levels of interleukin-18 and interferon-γ, and serum lysozyme activity also increased following HBV administration before the infection period as well as during infection. HBV reinforced bacterial clearance and increased survivability against S. Gallinarum. Corresponding pathological analyses demonstrated that the HBV-sprayed group displayed mild and less severe abnormal changes compared with those in the control group. It was presumed that the prophylactic effects of HBV against S. Gallinarum were associated with its non-specific immune response stimulating activity. Thus, HBV may provide an alternative to reduce antibiotic use in the poultry industry.