Low pathogenic avian influenza virus infection increases the staining intensity of KUL01+ cells including macrophages yet decrease of the staining intensity of KUL01+ cells using clodronate liposomes did not affect the viral genome loads in chickens

Abstract

The effect of depletion of macrophages using clodronate liposomes as well as macrophage response following viral infections have been studied in various mouse-virus infection models, but they have not been extensively studied in chickens relevant to virus infections. When we infected day 6 chickens with H4N6 low pathogenic avian influenza virus (LPAIV), we observed that H4N6 LPAIV infection increased the staining intensity of KUL01+ cells in trachea, lungs and duodenum of chickens at 3 days post-infection. Then, we used clodronate liposomes intra-abdominally in 5 day-old chickens and found significant reduction of staining intensity of KUL01+ cells in trachea and duodenum but not in lungs at 4 days post-treatment. When we infected the clodronate liposome and PBS liposome treated chickens with H4N6 LPAIV intra-nasally at day 6, we found no effect on H4N6 LPAIV genome loads in trachea, lungs and duodenum of chickens. This study indicates that although KUL01+ cell intensity are increased in respiratory and gastrointestinal tissues in chickens following H4N6 LPAIV infection, the decrease of KUL01+ cell intensity using clodronate liposomes did not change the H4N6 LPAIV genome loads in any of the examined tissues suggesting that KUL01+ cells may not be critical during H4N6 LPAIV infection in chicken.

Few Amino Acid Mutations in H6 Influenza A Virus From South American Lineage Increase Viral Replication Efficiency in Poultry

“…Furthermore, an increase in the percentages of CD3 + TCRγδ + lymphocytes in the ileum of chickens inoculated with 20Ch557/H6N2 virus was observed ( Figure 3B , p < 0.05), being in part due to an increase in CD3 + TCRγδ + CD8a + subpopulation. Besides, the macrophage population positive for staining of KUL01 marker showed a trend to increase in proportion in lamina propria from ileum from 20Ch557/H6N2 chickens ( Figure 3C ), as described during LPAIV infection ( Abdul-Cader et al, 2018 ). The percentages of other subsets analyzed from ileum did not show differences between groups (data not shown).…”

Few amino acid mutations in H6 influenza A virus from South American lineage increase pathogenicity in poultry

“…Furthermore, an increase in the percentages of CD3+TCRγδ+ lymphocytes in the ileum of chickens inoculated with 20Ch557/H6N2 virus was observed (Fig 3B, p < 0.05), being in part due to an increase in CD3+TCRγδ+ CD8a+ subpopulation. Besides, macrophage population positive for staining of KUL01 marker showed a trend to increase in proportion in lamina propria from ileum from 20Ch557/H6N2 chickens (Fig 3C ), as described during LPAIV infection 13 . The percentages of other subsets analyzed from ileum did not show differences between groups (data not shown).…”

Effect of CpG-Oligonucleotide in Enhancing Recombinant Herpes Virus of Turkey-Laryngotracheitis Vaccine-Induced Immune Responses in One-Day-Old Broiler Chickens

“…Our immunophenotyping analysis also found two distinct populations of KUL-01+ cells, of which both KUL-01 hi and KUL-01 Lo populations were found to be significantly higher in the CpG-ODN (10 μg) adjuvant vaccinated chickens. A previous study also noted a similar distinction in the KUL-01+ cell population while investigating anti-AIV responses [ 43 ], and furthermore, another study indicated that KUL-01 hi cells possess enhanced phagocytic and tissue migratory activity in chickens [ 44 ]. However, it remains to be investigated if these two phenotypically distinct populations of macrophages induced in response to CpG-ODN stimulation have any biologically distinct functions in chickens.…”