Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: 1. To characterize monocyte-derived DCs in cattle morphologically and functionally. 2. To investigate the role of bovine peripheral blood monocytes and monocyte-derived DCs in peripheral B cell differentiation and immunoglobulin secretion. 3. To compare the susceptibility of bovine antigen presenting cells, monocytes and DCs to infection by CP and NCP BVDVs in vitro. 4. Evaluate the role of BVDV variants on antigen presentation of the peripheral blood monocytes and monocyte-derived DCs in order to stimulate T cell immune responses. PARTICIPANTS: Individuals who worked on the project: Dr. Lesya Pinchuk: Principle investigator. Dr. Pinchuk is the PhD advisor and supervisor of Mr. Sang-Ryul Lee; Sang-Ryul Lee: Ph.D. candidate; Collaborators and contacts: Dr. Bindu Nanduri: Collaborator in the Department of Basic Sciences, College of Veterinary Medicine, MSU Dr. Todd Pharr: Collaborator in the Department of Basic Sciences, College of Veterinary Medicine, MSU Dr. George Pinchuk: Collaborator in the Department of Sciences and Mathematics, Mississippi University for Women TARGET AUDIENCES: The target audience includes undergraduate and graduate stuidents, members of the scientific community working in the area of viral immunology. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We have identified 47 bovine proteins, involved in immune function of professional antigen presenting cells (APC) that have been significantly altered after cytopathic (cp) bovine viral diarrhea virus (BVDV) infection. In particular, proteins related to immune responses such as cell adhesion, apoptosis, antigen uptake, processing and presentation, acute phase response proteins, MHC class I- and II- related proteins and other molecules involved in immune function of professional antigen presentation have been significantly altered after BVDV infection. Our data suggest that by modulating expression levels in multiple proteins related to immune responses BVDV could significantly compromise immune defense mechanisms resulting in uncontrolled immune activation or suppression.
Publications
- Lee, S.-R., Pharr, G. T., Boyd, B. L., Pinchuk, L. M.* 2008. Bovine viral diarrhea viruses modulate type I IFN and pro-inflammatory cytokines production via toll-like receptor-dependent mechanisms. Comp. Immunol. Microbiol. Inf. Dis. 31(5):403-18
- Pinchuk, G.V.# , Lee, S.-R.#, Nanduri, B., Honsinger, K. L., Stokes, J. V., Pinchuk, L. M.* 2008. Bovine viral diarrhea viruses differentially alter the expression of the protein kinases and related proteins affecting the development of infection and anti-viral mechanisms in bovine monocytes. Biochim. Biophys. Acta. 1784:1234-47
- Lee, S.-R.#, Nanduri, B.#, Pharr, G. T., Stokes, J. V. Pinchuk, L. M.* 2009. Bovine Viral Diarrhea Virus infection affects the expression of proteins related to professional antigen presentation in bovine monocytes. Biochim. Biophys. Acta. 1794:14-22
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Progress 07/01/02 to 06/30/08
Outputs
OUTPUTS: 1. To characterize monocyte-derived DCs in cattle morphologically and functionally. 2. To investigate the role of bovine peripheral blood monocytes and monocyte-derived DCs in peripheral B cell differentiation and immunoglobulin secretion. 3. To compare the susceptibility of bovine antigen presenting cells, monocytes and DCs to infection by CP and NCP BVDVs in vitro. 4. Evaluate the role of BVDV variants on antigen presentation of the peripheral blood monocytes and monocyte-derived DCs in order to stimulate T cell immune responses. PARTICIPANTS: Individuals who worked on the project: Dr. Lesya Pinchuk: Principle investigator. Dr. Pinchuk is the PhD advisor and supervisor of Mr. Sang-Ryul Lee; Sang-Ryul Lee: Ph.D. candidate; Bobbie Boyd, Senior Research Associate; Emily. F. Kruger, MS student supervised by Dr. Pinchuk Collaborators and contacts: Dr. Bindu Nanduri: Collaborator in the Department of Basic Sciences, College of Veterinary Medicine, MSU Dr. Todd Pharr: Collaborator in the Department of Basic Sciences, College of Veterinary Medicine, MSU Dr. George Pinchuk: Collaborator in the Department of Sciences and Mathematics, Mississippi University for Women Dr. Fiona McCarthy: Collaborator in the Department of Basic Sciences, College of Veterinary Medicine, MSU TARGET AUDIENCES: The target audience includes undergraduate and graduate stuidents, members of the scientific community working in the area of viral immunology. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
We used non-cytopathic (ncp) and cytopathic (cp) bovine viral diarrhoea viruses (BVDV) to determine how the two biotypes affect mannose receptor (MR)-mediated endocytosis and fluid phase uptake in bovine monocytes. We demonstrated that endocytosis in uninfected monocytes after 1 h of culture was mediated by the MR and fluid phase uptake. After 24 h of culture it was mediated via fluid phase uptake only. Both cp and ncp BVDV affected the mechanisms of antigen uptake in monocytes. Endocytosis in BVDV infected monocytes was MR-independent and mediated by fluid phase uptake after 1 h of infection. The 24 h BVDV infection changed the antigen uptake mechanisms to become MR- and fluid phase uptake-dependent. We conclude that antigen uptake is affected in the early stage of BVDV infection during the first 24 h, with both BVDV biotypes, cp and ncp, having similar effects on monocyte antigen uptake in cattle. BVDV might disrupt the function of monocytes as professional APC and contribute to the specific immunotolerance to BVDV. Professional antigen presenting cells (APC), dendritic cells (DC) and their myeloid progenitors, monocytes/macrophages are critical controllers of innate and adaptive immunity. We show that differential detergent fractionation (DDF) analysis of bovine monocytes reveals proteins related to antigen pattern recognition, uptake and presentation to immunocompetent lymphocytes. We identify 53 bovine proteins involved in immune function of professional APC. 13 adhesion molecules, three toll-like receptors (TLR1, 6 and 8), three antigen uptake-related proteins (including mannose receptor [MR] precursor), and eight actin-like proteins involved in active endocytosis were identified. MHC class I and II-related proteins, cytokines, active substances and growth factors have been identified. We conclude that the DDF approach can provide interpretable and meaningful functional information concerning protein expression profiles associated with monocyte activation, transformation into macrophages and/or immature DC, and maturation of monocyte-derived DC in the presence of multiple bovine pathogens. We used noncytopathic (ncp) and cytopathic (cp) Bovine Viral Diarrhea Viruses (BVDV) to determine the expression levels of TLR genes, type I IFN, pro-inflammatory and Th1/Th2 cytokine gene expression in bovine monocytes. Both BVDV strains had similar effects. We found some significant differences that could be due to biological differences between cp and ncp BVDV strains. TLR3 was significantly up-regulated in 1h ncp, but not in cp BVDV- infected monocytes, whereas TLR7 expression dominated in 24h infection with both BVDV strains. Type I IFN and IL-12 gene expression was also significantly up-regulated in 1h ncp, but not cp BVDV infection that correlated with the enhanced TLR3 gene expression. Both BVDV biotypes suppressed pro-inflammatory cytokines TNF-alpha, IL-1beta, and IL-6, co-stimulatory molecules CD80 and CD86, but did not change Th1 type cytokine IL-12 and INF-gamma, gene expression after 24h infection. We hypothesize that BVDV may escape immune responses by altering the expression of TLR 3 and 7 and their signaling pathways.
Publications
- B. L. Boyd, T. M. Lee, E. F. Kruger and L. M. Pinchuk. 2004. Cytopathic and Noncytopathic Bovine Viral Diarrhoea Virus Biotypes affect Fluid Phase Uptake and Mannose Receptor-Mediated Endocytosis in Bovine Monocytes. Vet. Immunol. Immunopathol. 102:53-65
- Lee, S.-R., Pharr, G. T., Cooksey, A. M., McCarthy, F. M., Boyd, B. L., Pinchuk, L. M. 2006. Differential detergent fractionation for non-electrophoretic bovine peripheral blood monocyte proteomics reveals proteins involved in professional antigen presentation. Development. Comp. Immunol. 30:1070-1083
- Lawrence M., Pinchuk, L. M., Bridges S., Pharr, G. T., McCarthy F, Nanduri, B., Burgess, S. 2007. The NC-107 (National Committee- 107) Technical Committee sponsored by USDA: Department of Large Animal Medicine, Mississippi Station, Vancuver, British Columbia, September 19-20, 2007.
- Pinchuk, L. M.*, Nanduri, B., Pharr, G. T., Pinchuk, G. V. 2008. Comparative protein profiling approach to elucidate the mechanisms involved in BVDV interference of monocyte and DC antigen presentation to avoid effective recognition and elimination by innate and adaptive immune responses (Technical report and abstract). The NC-107 (National Committee- 107) Technical Committee sponsored by USDA: Department of Large Animal Medicine, Mississippi Station, Charlotte, North Carolina, September 24-25, 2008.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: 1. To characterize monocyte-derived DCs in cattle morphologically and functionally. 2. To investigate the role of bovine peripheral blood monocytes and monocyte-derived DCs in peripheral B cell differentiation and immunoglobulin secretion. 3. To compare the susceptibility of bovine antigen presenting cells, monocytes and DCs to infection by CP and NCP BVDVs in vitro. 4. Evaluate the role of BVDV variants on antigen presentation of the peripheral blood monocytes and monocyte-derived DCs in order to stimulate T cell immune responses. PARTICIPANTS: Individuals who worked on the project: Dr. Lesya Pinchuk: Principle investigator. Dr. Pinchuk is the PhD advisor and supervisor of Mr. Sang-Ryul Lee; Sang-Ryul Lee: Ph.D. candidate. Collaborators and contacts: Dr. Bindu Nanduri: Collaborator in the Department of Basic Sciences, College of Veterinary Medicine, MSU Dr. Todd Pharr: Collaborator in the Department of Basic Sciences, College of Veterinary Medicine, MSU Dr. George Pinchuk: Collaborator in the Department of Sciences and Mathematics, Mississippi University for Women TARGET AUDIENCES: The target audience includes undergraduate and graduate students, members of the scientific community working in the area of viral immunology. PROJECT MODIFICATIONS: No Project Modifications information reported.
Impacts
We have made a detailed characterization of the proteins related to professional antigen presentation in bovine monocytes infected with cp BVDV by the DDF-MudPIT approach. We conclude that the DDF approach can provide interpretable and meaningful functional information concerning protein expression profiles associated with monocyte activation, transformation into macrophages and/or immature DC, and maturation of monocyte-derived DC in the presencxe of multiple bovine pathogens. The semi-quantitation of protein by DDF-MudPIT approach was used to characterize bovine proteins in infected and uninfected bovine monocytes for the first time. Using a proteomics approach, we compared the expression of protein kinases in bovine peripheral monocytes infected with cp and ncp BVDV. Proteins were isolated from membrane and cytosolic fractions with the DDF method and identified with 2D LC ESI MS2. Of approximately 10,000 proteins identified by this approach, 378 proteins had amino acid sequence homology with known protein kinases. Twenty-three kinases were significantly altered in bovine monocytes infected with BVDV strains. In particular, the expression of urokinase-type plasminogen activator receptor (u-PAR), a protein similar to myristoilated alanin-rich C kinase substrate (MARCKS), nucleoside diphosphate kinase B (NDKB) was increased, while the expression of Rho-associated protein kinase 1 (ROK1) and hexokinase type 3 (HK3) was decreased in cells infected with both BVDV strains. The expression of predicted proteins similar to doublecortin kinase 2 (DKK2) and to kinase suppressor of Ras 2 (KSR2) was significantly increased in cells infected with the cp strain of BVDV compared to uninfected cells. The expression of predicted proteins similar to the receptor of activated C kinase (RACK), galactokinase 1 (GK1), and pyridoxal kinase (PK) was increased, and the expression of predicted proteins similar to proto-oncogene tyrosine kinase FGR, spleen tyrosine kinase (STK), pyruvate kinase isozymes M1 and M2 (PS-PK-M1/M2) and mitogen-activated protein tyrosine kinase kinase kinase (PS-MAPKKK) was decreased in cells infected with the ncp strain of BVDV compared to uninfected monocytes.
Publications
- Lawrence M., Pinchuk, L. M., Bridges S., Pharr, G. T., McCarthy F, Nanduri, B., Burgess, S. 2007. The NC-107 (National Committee- 107) Technical Committee sponsored by USDA: Department of Large Animal Medicine, Mississippi Station, Vancuver, British Columbia, September 19-20, 2007.
- Lee, S.-R., Nanduri, B., Pharr, G. T., Pinchuk, L. M. 2007. Bovine Viral Diarrhea Virus infection affects the expression of proteins related to professional antigen presentation in bovine monocytes. 1st annual College Research Day at Mississippi State University.
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Progress 01/01/06 to 12/31/06
Outputs
We have used noncytopathic (ncp) and cytopathic (cp) Bovine Viral Diarrhea Viruses (BVDV) to determine the mechanisms of TLR-mediated control of type I IFN and pro-inflammatory cytokine gene expression in bovine monocytes. In general, both BVDV strains had similar effects. However, we found some significant differences that could be due to biological differences between cp and ncp BVDV strains. TLR3 was significantly up-regulated in 1h ncp, but not in cp BVDV- infected monocytes, whereas TLR7 expression dominated in 24h infection with both BVDV strains. Type I IFN gene expression was also significantly up-regulated in 1h ncp, but not cp BVDV infection suggesting TLR3-mediated control of the type I IFN production in BVDV. Both BVDV biotypes suppressed pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 gene expression after 24h infection. We hypothesize that BVDV may escape immune responses by altering the expression of TLR 3 and 7 and their signaling pathways.
We have demonstrated for the first time by using flow cytometry that bovine monocytes use macropinocytosis for a bulk-flow uptake of soluble antigens. Furthermore, we have showed that selective mannose receptor-mediated (MR) endocytosis was significantly down-regulated in bovine monocytes by both BVDV biotypes after 24 h of infection; while macropinocytosis, a potent non-selective antigen uptake, was not affected in infected antigen presenting cells (APC). Moreover, only cp BVDV inhibited macropinocytosis in 1h post infected monocytes. In contrast, after 24h infection, MR-mediated endocytosis was inhibited by ncp BVDV. Therefore, we conclude that cp and ncp BVDV differentially affect an early step of professional antigen presentation in bovine monocytes that might result in variable immune responses in BVDV infection.
Impacts
The proposed research will elucidate the key immune effector mechanisms in BVDV with an emphasis on the TLR-dependendent cytokine polarization in monocytes infected with BVDV. These mechanisms involve the initiation and control of antiviral innate and specific immune responses.
Publications
- Lee, S.-R., Pharr, G. T., Boyd, B. L., Pinchuk, L. M*. 2006. Bovine viral diarrhea viruses modulate type I IFN and pro-inflammatory cytokines gene expression". Vet. Immunol. Immunopathol., in review.
- Pinchuk, L. M., Pharr, G. T., McCarthy F, Nanduri, B., Burgess, S. 2006. Comparative protein profiling approach to elucidate the mechanisms involved in BVDV interference of monocyte and DC antigen presentation to avoid effective recognition and elimination by innate and adaptive immune responses.The NC-107 (National Committee- 107) Technical Committee sponsored by USDA: Department of Large Animal Medicine, Mississippi Station, St. Paul, Minnesota, September 20-21, 2006.
- S.-R. Lee, G. T. Pharr, L. M. Pinchuk. Bovine Viral Diarrhea Viruses Modulate Type I IFN and Pro-Inflammatory Cytokines Production via Toll-Like Receptor-Dependent Mechanisms. Oral presentation at CRWAD, Chicago, IL, Dec.3-5, 2006.
- L. M. Pinchuk, S.-R. Lee, G. T. Pharr, G. V. Pinchuk. BVDV infection affects antigen uptake and cytokine gene expression in bovine monocytes. Poster presentation at CRWAD, Chicago, IL, Dec.3-5, 2006.
- Katie Pruitt, Sang-Ryul Lee, Bobbie Boyd, G. todd Pharr, and Lesya Pinchuk Poster presentation at GSU, July 2006 Cytopathic and Noncytopathic Bovine Viral Diarrhea Infection Induces Macropinocytosis in CD14+ Monocytes.
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Progress 01/01/05 to 12/31/05
Outputs
Cytokine gene expression of IL-4, IL-2, and IFN-gamma was evaluated in control and BVDV-infected monocytes. We have demonstrated that after 24 hr of infection with NCP BVDV (NY) the expression of IFN-gamma and IL-2 in monocytes were inhibited, but at the same time, the expression of IL-4 gene was increased suggesting the Th2 type cytokine polarization. In contrast to NCP strain, the 24 hr CP BVDV infection (NADL) strongly promoted Th1 type cytokine polarization with IFN-gamma and IL-2 cytokine genes predominantly expressed. We have demonstrated that differential detergent fractionation (DDF) analysis of bovine monocytes reveals proteins related to antigen pattern recognition, uptake and presentation to immunocompetent lymphocytes. We found a total of 302 proteins of which 71 proteins were related to immune function (33.6%) and 91 (30.1%) were not annotated. Immune proteins included 23 previously unannotated proteins, which were assigned to this group based on known
literature (Lee et al., in revision). Overall, 12 bovine proteins related to cell adhesion, 3 TLR proteins (bovine TLR1, 6, 8) involved in innate antigen pattern recognition, 3 proteins related to antigen uptake including the MR precursor, and 8 actin-related proteins involved in active endocytosis in monocytes/macrophages and immature DC were identified.
Impacts
The proposed research will elucidate the key immune effector mechanisms in BVDV with an emphasis on the monocyte-dependent cytokine polarization in BVDV. These mechanisms involve the initiation and control of antiviral innate and specific immune responses. We conclude that DDF approach can provide interpretable and meaningful functional information concerning protein expression profiles associated with monocyte activation, transformation into macrophages and/or immature DC, and maturation of monocyte-derived DC in the presence of multiple bovine pathogens.
Publications
- Lee, S.-R., Pharr, G. T., Cooksey, A. M., McCarthy, F. M., Boyd, B. L, and Pinchuk, L. M *. 2005. Differential detergent fractionation for non-electrophoretic bovine peripheral blood monocyte proteomics reveals proteins involved in professional antigen presentation. Development. Comp. Immunol. Revised version submitted.
- Abstract, Oral and Poster Presentations Pinchuk, L. M.* , Pharr, G. T., McCarthy F. 2005. Differential detergent fractionation for non-electrophoretic bovine blood monocyte proteomics reveals proteins involved in professional antigen presentation. The NC-107 (National Committee- 107) Technical Committee sponsored by USDA: Department of Large Animal Medicine, Mississippi Station, September 2005, Athens, Georgia. Abstract.
- Lee, S.-R., Pharr, G. T., Cooksey, A. M., McCarthy, F. M., Boyd, B. L., Pinchuk L. M Cytopathic and Non-cytopathic Bovine Viral Diarrhoea Viruses affect Antigen Presentation in Peripheral Blood Monocytes. Phi Zeta Research Conference, October, 2005. Oral presentation.
- Lee, S.-R., Pharr, G. T., Cooksey, A. M., McCarthy, F. M., Boyd, B. L., Pinchuk L. M. Bovine monocyte proteomics reveals proteins involved in professional antigen presentation. CRWAD, St. Louis, Missouri, Dec. 4-6, 2005. Abstract and oral presentation.
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Progress 01/01/04 to 12/31/04
Outputs
Objectives 1.To characterize monocyte-derived DCs in cattle morphologically and functionally. 2.To investigate the role of bovine peripheral blood monocytes and monocyte-derived DCs in peripheral B cell differentiation and immunoglobulin secretion. 3.To compare the susceptibility of bovine antigen presenting cells, monocytes and DCs to infection by CP and NCP BVDVs in vitro. 4.Evaluate the role of BVDV variants on antigen presentation of the peripheral blood monocytes and monocyte-derived DCs in order to stimulate T cell immune responses. Narrative We have used noncytopathic (ncp) and cytopathic (cp) bovine viral diarrhoea viruses (BVDV) to determine how the two biotypes affect mannose receptor (MR)-mediated endocytosis and fluid phase uptake in bovine monocytes. We have demonstrated that endocytosis in uninfected monocytes after 1 hr of culture was mediated by the MR and fluid phase uptake and after 24 hr of culture it was mediated via fluid phase uptake only. Both
cp and ncp BVDV affected the mechanisms of antigen uptake in monocytes. Endocytosis in BVDV infected monocytes, unlike in uninfected cells, was MR-independent and mediated by fluid phase uptake after 1hr of infection. Twenty-four hour BVDV infection changed the antigen uptake mechanisms to become MR- and fluid phase uptake dependent. Importantly, the infectious dose of the cp BVDV was able to affect the endocytosis but was not sufficient to provide an active viral replication in monocytes. We conclude that antigen uptake, an important antigen presenting cell (APC) function, is affected in the early stage of BVDV infection during the first 24 hrs, with both BVDV biotypes, cp and ncp, having similar effects on monocyte antigen uptake in cattle. By influencing the early antigen uptake function of APC, BVDV might disrupt the function of monocytes as professional APC and contribute to the specific immunotolerance to BVDV.
Impacts
The proposed research will elucidate the key immune effector mechanisms in BVDV with an emphasis on the DC-dependent mechanisms of immunity. These mechanisms involve the initiation and control of antiviral innate and specific immune responses.
Publications
- B. L. Boyd, T. M. Lee, E. F. Kruger and L. M. Pinchuk. 2004. Cytopathic and Noncytopathic Bovine Viral Diarrhoea Virus Biotypes affect Fluid Phase Uptake and Mannose Receptor-Mediated Endocytosis in Bovine Monocytes. Vet. Immunol. Immunopathol. 102:53-65.
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Progress 01/01/03 to 12/31/03
Outputs
OBJECTIVES 1. To characterize monocyte-derived DCs in cattle morphologically and functionally. 2. To investigate the role of bovine peripheral blood monocytes and monocyte-derived DCs in peripheral B cell differentiation and immunoglobulin secretion. 3. To compare the susceptibility of bovine antigen presenting cells, monocytes and DCs to infection by CP and NCP BVDVs in vitro. 4. Evaluate the role of BVDV variants on antigen presentation of the peripheral blood monocytes and monocyte-derived DCs in order to stimulate T cell immune responses. Narrative We have used CP and NCP BVDVs to determine how the two biotypes affect mannose receptor (MR)-mediated endocytosis and fluid phase uptake in bovine monocytes. We have demonstrated that endocytosis in uninfected monocytes after I hr of culture was mediated by the MR and fluid phase uptake and after 24 hr of culture it was mediated via fluid phase uptake only. Both CP and NCP BVDVs affected the mechanisms of antigen uptake
in monocytes. Endocytosis in BVDV infected monocytes, unlike in uninfected cells, was MR-independent and mediated by fluid phase uptake after 1 hr of infection. Twenty-four hour BVDV infection changed the antigen uptake mechanisms to become MR- and fluid phase uptake dependent. Importantly, the infectious dose of the CP BVDV was able to affect the endocytosis but was not sufficient to provide an active viral replication in monocytes. We conclude that antigen uptake, an important APC function, is affected in the early stage of BVDV infection during the first 24 hrs, with both BVDV biotypes, CP and NCP, having the similar effects on monocyte antigen uptake in cattle. By influencing the arly antigen uptake function of APCs, BVDVs might disrupt the function of monocytes as professional APCs and contribute to the specific immunotolerance to BVDVs.
Impacts
Infection with viral bovine diarrhea virus (BVDV), an economically important pathogen of cattle, causes a wide range of clinical syndromes from a mild latent form to a fatal mucosal disease. The most frequent result of this disease is the birth of persistently infected animals that serve as a natural reservoir for spread of the virus within a herd It is very important to further define the mechanisms that activate monocytes making them efficient in the initiating of T and B cell immune responses and BVDV antigen presentation.
Publications
- Pinchuk LM, Boyd BL, Kruger EF, Roditi I, Furger A. 2003. Bovine dentritic cells generated from monocytes and bone marrow progenitors regulate immunoglobulin production in peripheral blood B cells. Comp Immun Microbiol Infect Dis. 26:233-249.
- Kruger EF, Boyd BL, and L M Pinchuk.2003. Bovine monocytes induce immunoglobulin production in peripheral blood B lymphocytes. Dev Comp Immunol. 27:889-897.
- Boyd BL, Lee TM, Kruger EF, and LM Pinchuk. 2003. Cytopathic and Noncytopathic Bovine Viral Diarrhoea Virus Biotypes affect Fluid Phase Uptake and Mannose Receptor-Mediated Endocytosis in Bovine Monocytes (submitted).
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Progress 01/01/02 to 12/31/02
Outputs
DCs were generated from monocytes in the presence of bovine rGM-CSF and IL-4. DCs derived from monocyte progenitors expressed high levels of CD1, MHC class II, costimulatory molecules CD80/CD86, moderate levels of CD11c and CD14. Monocyte-derived DC populations had few cells that could endocytose FITC-DX. The addition of LPS to 7-8 day DC cultures increased the number of rapidly endocytosing cells. Monocyte-derived DCs were significantly stimulatorier in MLR than monocytes. Monocyte-derived DC populations contained both immature and mature DCs. In vitro culture of bovine monocytes with bovine B cells activated by the anti-CD3 triggered CD4+ T cells or through immunoglobulin (Ig) receptor crosslinking causes cell aggregation and induces B cell Ig secretion. Unlike bovine monocyte-derived DC, monocytes do not promote Ig class switching to IgG and IgA in activated peripheral blood B cells. These results suggest that bovine monocytes are capable of directly inducing Ig
secretion in activated bovine peripheral blood B cells, but do not provide the signals for B cell Ig class switching. Bovine PBMCs were infected with two strains of BVDV, NADL (CP) and NY (NCP) in vitro. Infection with the NY strain decreased the number of endocytosing cells while infection with the NADL strain did not have an effect on the active endocytosis. Endocytosis in NADL infected monocytes as well as in uninfected cultures was inhibited by the addition of EDTA and mannan suggesting the involvement of Mannose receptor. In contrast, the addition of EDTA and mannan to NY infected cultures (1 hour of infection) did not have an effect on active endocytosis. The addition of mannan and EDTA to monocytes infected with the NADL strain for 24 hrs strongly inhibited endocytosis. The addition of the Mannose receptor inhibitors to uninfected monocytes and NY strain down regulated active endocytosis. Using RT-PCR technique, we demonstrated that the NADL, but not NY BVDV transcripts were
detectable in monocytes after 1 hour of infection
Impacts
Infection with viral bovine diarrhea virus (BVDV), an economically important pathogen of cattle, causes a wide range of clinical syndromes from a mild latent form to a fatal mucosal disease. The most frequent result of this disease is the birth of persistently infected animals that serve as a natural reservoir for spread of the virus within a herd It is very important to further define the mechanisms that activate monocytes, immature and mature DCs, making them efficient in the initiating of T and B cell immune responses and BVDV antigen presentation.
Publications
- L. M. Pinchuk, B. L. Boyd, E. F. Kruger, I. Roditi, A. Furger. 2003. Bovine dendritic cells generated from monocytes and bone marrow progenitors regulate immunoglobulin production in peripheral blood B cells. Comparative Immunology Microbiology & Infectious Diseases
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