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Selvaraj R.K.,Ohio Agricultural Research and Development Center
Developmental and Comparative Immunology | Year: 2013

Regulatory T cells (Tregs) are a subset of T cells that specialize in immune suppression. CD4+CD25+FoxP3+ T cells have been characterized as Tregs and extensively studied in mammals. In the absence of a putative FoxP3 ortholog in avians, CD4+CD25+ cells is characterized as Tregs in avians. Avian CD4+CD25+ cells produce high amounts of IL-10, TGF-β, CTLA-4, and LAG-3 mRNA; lack IL-2 mRNA; and suppress T cell proliferation in vitro through both contact-dependent and -independent pathways. Depleting avian CD4+CD25+ cells increases the proliferation of, IL-2 amount, and IFNγ mRNA amount of CD4+CD25- cells. Avian CD4+CD25+ cells lose their suppressive properties immediately after inflammation and acquire supersuppressive properties once inflammation subsides. Although Treg activity could be beneficial to the host, Tregs simultaneously inhibit host immunity and cause persistent infections of certain pathogens. Therapy targeted toward alleviating Treg mediated immune suppression can improve host immunity against those persistent pathogens and benefit poultry production. © 2013 Elsevier Ltd. Source


Shanmugasundaram R.,Ohio Agricultural Research and Development Center | Sifri M.,Archer Daniels Midland ANI | Selvaraj R.K.,Ohio Agricultural Research and Development Center
Poultry Science | Year: 2013

This experiment studied the effects of whole yeast cell product supplementation on broiler production parameters, fecal coccidial oocyst counts, and local and systemic immune parameters following an experimental coccidial infection. Birds were fed 0, 0.1, or 0.2% whole yeast cell product (CitriStim). At 21 d of age, birds were challenged with live coccidial oocysts. Supplementation with whole yeast cell product increased BW gain between 0 and 12 d (P = 0.01) postcoccidial challenge. Birds supplemented with 0.2% Citristim had better (P = 0.01) feed efficiency between 0 and 12 d postcoccidial infection. Supplementation with whole yeast cell product decreased (P = 0.01) the fecal coccidial oocyst count at 7 d postcoccidial challenge. Citristim supplementation at 0.2% increased (P < 0.01) macrophage nitric oxide production by 93 and 193% at 5 and 12 d postcoccidial challenge. Supplementation with whole yeast cell product at 0.2% increased cecal tonsil interleukin-1 mRNA amounts approximately 4.5- and 3.7-fold at 5 and 12 d postcoccidial challenge, respectively, over the group with no whole yeast cell product supplementation. Citristim supplementation downregulated cecal tonsil interleukin-10 mRNA amounts compared with the unsupplemented groups at both 5 (P = 0.01) and 12 d (P < 0.01) postcoccidial challenge. Supplementation with whole yeast cell product did not alter (P > 0.05) serum anticoccidial IgG contents or cecal tonsil CD4This experiment studied the effects of whole yeast cell product supplementation on broiler production parameters, fecal coccidial oocyst counts, and local and systemic immune parameters following an experimental coccidial infection. Birds were fed 0, 0.1, or 0.2% whole yeast cell product (CitriStim). At 21 d of age, birds were challenged with live coccidial oocysts. Supplementation with whole yeast cell product increased BW gain between 0 and 12 d (P = 0.01) postcoccidial challenge. Birds supplemented with 0.2% Citristim had better (P = 0.01) feed efficiency between 0 and 12 d postcoccidial infection. Supplementation with whole yeast cell product decreased (P = 0.01) the fecal coccidial oocyst count at 7 d postcoccidial challenge. Citristim supplementation at 0.2% increased (P < 0.01) macrophage nitric oxide production by 93 and 193% at 5 and 12 d postcoccidial challenge. Supplementation with whole yeast cell product at 0.2% increased cecal tonsil interleukin-1 mRNA amounts approximately 4.5- and 3.7-fold at 5 and 12 d postcoccidial challenge, respectively, over the group with no whole yeast cell product supplementation. Citristim supplementation downregulated cecal tonsil interleukin-10 mRNA amounts compared with the unsupplemented groups at both 5 (P = 0.01) and 12 d (P < 0.01) postcoccidial challenge. Supplementation with whole yeast cell product did not alter (P > 0.05) serum anticoccidial IgG contents or cecal tonsil CD4+ and CD8+ cell percentages at 5 and 12 d postcoccidial infection. It could be concluded that supplementing whole yeast cell product (CitriStim) to broiler diets can improve production parameters, decrease fecal oocyst count, and increase inflammatory cytokine production postcoccidial infection.+ and CD8+ cell percentages at 5 and 12 d postcoccidial infection. It could be concluded that supplementing whole yeast cell product (CitriStim) to broiler diets can improve production parameters, decrease fecal oocyst count, and increase inflammatory cytokine production postcoccidial infection. © 2013 Poultry Science Association Inc. Source


Shanmugasundaram R.,Ohio Agricultural Research and Development Center | Selvaraj R.K.,Ohio Agricultural Research and Development Center
PLoS ONE | Year: 2012

Thymic CD4+CD25+ cells have regulatory-T-cell-like properties in chickens. This study examined the ontogeny of CD4+CD25+ cells in the thymus and in peripheral compartments in chickens. CD4+CD25+ cells started to appear in the thymus at day 15 of incubation (E15), although at low percentages. Expressed as a percentage of CD4+ cells, CD4+CD25+ cells increased (P<0.01) from 1.7% at E20 to 7.3% at 0 d post-hatch (D0). CD4+CD25+ cells did not appear in the spleen or cecal tonsils of embryos. Expressed as a percentage of CD4+ cells, CD4+CD25+ cells increased (P<0.01) from 0% at D0 to 27% at D1 in cecal tonsils and from 0% at D0 to 11% at D1 in the spleen. Expressed as a percentage of all mononuclear cells, cecal tonsils at D1 had approximately 3.5-fold higher percentage of CD4+CD25+ cells than the spleen at D1. CD4+CD25+ cells from cecal tonsils of chicks at D1 were suppressive. CD4+CD25+ cells from D0 thymus, when injected back into MHC-compatible chicks, migrated to cecal tonsils and lungs and were detected until 10 d post-injection. CD4+CD25+ cells from cecal tonsils had a higher (P = 0.01) relative amount of CCR9 mRNA than CD4+CD25+ cells from the thymus. It could be concluded that in chickens CD4+CD25+ cells migrate from the thymus immediately post-hatch and preferentially colonize the gut associated lymphoid tissues. CD4+CD25+ cells' preferential migration to cecal tonsils is likely directed through the CCR9 pathway in chickens. © 2012 Shanmugasundaram, Selvaraj. Source


Annamalai T.,Ohio Agricultural Research and Development Center | Selvaraj R.K.,Ohio Agricultural Research and Development Center
Poultry Science | Year: 2012

Two experiments were conducted to study the effects of an in ovo interleukin (IL)-4 plasmid injection in a coccidia infection model. In experiment I, chicks were hatched from eggs that had been injected in ovo with an empty vector or with 10 or 15 μg of IL-4 plasmid, and then challenged posthatch with coccidia. In experiment II, chicks were hatched from eggs that had been vaccinated with coccidia and injected in ovo with an empty vector or with 10 or 15 μg of IL-4 plasmid, and then challenged posthatch with coccidia. In experiment II, the BW gain of birds hatched from eggs vaccinated with live oocysts plus 15 μg of IL-4 plasmid was 25% higher than the BW gain of birds hatched from eggs vaccinated with live oocysts plus empty plasmid. In both experiments I and II, a 15-μg IL-4-plasmid injection decreased fecal oocyst shedding, decreased the number of CD8+ cells in the cecal tonsils, and decreased cecal tonsil lymphocyte cell proliferation postcoccidia challenge. In experiment I, splenic macro-phages of chicks hatched from eggs injected with 15 μg of IL-4 plasmid had higher nitric oxide production than those of chicks hatched from eggs injected with the empty plasmid. In experiment II, a 15-μg IL-4-plasmid injection increased serum anticoccidia IgG postcoccidia challenge. It could be concluded that 15 μg of IL-4 plasmid improved anticoccidia immune responses synergistically with in ovo coccidia vaccination in chickens. © 2012 Poultry Science Association Inc. Source


Shanmugasundaram R.,Ohio Agricultural Research and Development Center | Selvaraj R.K.,Ohio Agricultural Research and Development Center
Poultry Science | Year: 2012

A series of experiments were conducted to study the basal amounts of vitamin D-1α-hydroxylase and vitamin D-24-hydroxylase mRNA amounts in different organs and the effect of immune stimulation on 1α-and 24-hydroxylase mRNA amounts in chickens. At day of hatch, kidneys had an approximately 66-fold higher amount of 1α-hydroxylase and 550-fold higher amount of 24-hydroxylase mRNA, thigh and breast muscles had an approximately 20-fold higher amount of 1α-hydroxylase mRNA, and the thymus had an approximately 41-fold higher amount of 24-hydroxylase mRNA than the liver. An in vivo LPS injection did not alter the amount of 1α-hydroxylase mRNA in the breast muscle (P = 0.60) or in the kidneys (P = 0.39). An in vivo LPS injection decreased (P = 0.01) the amount of 24-hydroxylase mRNA in the breast muscle at 3 d post-LPS injection. An in vivo LPS injection increased (P = 0.01) the amount of 24-hydroxylase mRNA in the kidneys at 2, 3, and 6 d post-LPS injection. An in vitro stimulation altered amounts of 1α-(P = 0.01) and 24-hydroxylase (P = 0.04) mRNA in CD4+ cells. In conclusion, the distribution of 1α-and 24-hydroxylase mRNA amounts was similar to mammals, and an immune stimulation altered the amounts of 1α-and 24-hydroxylase mRNA in chickens. © 2012 Poultry Science Association Inc. Source

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