Document Type

Thesis - University Access Only

Award Date

2003

Degree Name

Master of Science (MS)

Department / School

Veterinary and Biomedical Sciences

First Advisor

Christopher C. L. Chase

Abstract

Bovine herpesvirus 1 (BHV-1 ), also known as infectious bovine rhinotracheitis virus (IBR), causes upper respiratory and reproductive diseases in cattle and is a member of the herpesvirus family. Bovine herpesvirus 4 (BHV-4) has been associated in cattle with symptoms that include weight loss, reproductive diseases, cancers, and infections from other opportunistic microorganisms that cause additional illnesses and complications. The role of BHV -1 and BHV -4 on innate and acquired immunity remains unclear. This study focused on the effects ofBHV-1 wildtype strains (Cooper and LA), BHV-1 mutant strains (BHV-1 V20, BHV-1 Vk25, BHV-1 Vk36, and BHV-1 gE􀁙3.l IBRP), or BHV-4 strains (Movar, DN599, and Georgia) on the functional characteristics (phagocytic and microbicidal activity, nitric oxide (NO) production) and surface marker expression ofmonocyte-derived macrophages (M DM), which_play a key role in the immune system. MDM are present in almost all tissues in the body and have multiple roles that include engulfing damaged cells or pathogens, presenting antigens to T cells, and activating the immune system. Our investigations showed that BHV-1 and BHV-1 mutants significantly reduced the inflammatory functions of MDM. BHV-1 infected MDM, replicated, and released virions. BHV-1 decreased the phagocytic activity by ~37-46%, fungicidal activity by ~48-69%, and bactericidal activity by ~48-59%. BHV-1 also decreased the expression of CD 14 by ~50-64%, MHC class I by ~48-60%, CDI l b by ~38-46%, MHC class II by ~31-38%, and CDl l c by ~15-21 %. Significant differences were also observed among the BHV-1 wildtype strains, gff mutant strains, and gr mutant strains. For all functional characteristics tested, BHV-1 wildtype strain, Cooper, had the most profound effect on MDM while BHV-1 V20, a mutant strain lacking gE and gl, had the least effect on MDM. Compared to BHV-1 Cooper strain, BHV-1 V20 had ~7-10% less effect on phagocytic activity, ~9-21 % less effect on fungicidal activity, and ~5-11 % less effect on bactericidal activity. BHV-1 V20 also had ~7-14% less effect on CD14, ~9-13% less effect on MHC class I, ~7-8% less effect on CDl l b, ~6-7% less effect on MHC class II, and ~4-7% less effect on CD 11 c. Our investigations with BHV-4 showed that MDM were not susceptible to BHV- 4 infection and that the functional characteristics of MDM were not altered by BHV-4. Further investigations into a bovine macrophage cell line (BOMAC), previously shown to be susceptible to BHV-4 infection, revealed that the BOMAC cell line did not express surface markers normally expressed on macrophages - MHc· class II, CD 11 b, CD 11 c, and CD14. The results from our investigations provide additional insight into the effects of BHV -1 or BHV -4 on the inflammatory functions and surface marker expression of MDM, help determine the viral pathogenesis of BHV-1 and BHV-4, and help clarify the role of BHV-1 and BHV-4 on innate and acquired immunity.

Library of Congress Subject Headings

Cattle -- Virus diseases.
Herpesvirus diseases in animals.
Infectious bovine rhinotracheitis.
Immune response.
Monocytes.
Macrophages.

Publisher

South Dakota State University

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Rights Statement

In Copyright