Proceedings of the 10th International Colloquium on Paratuberculosis

#82 Oral vaccination <strong>of</strong> mice with Mycobacterium bovis BCG vaccine in a lipid matrix protects
against infection with M. avium subsp. paratuberculosis
Valérie Rosseels, Virginie Roupie, Mat<strong>the</strong>w Lambeth, Frank E. Aldwell, Kris Huygen
WIV-ex Pasteur Institute Brussels, Belgium; University <strong>of</strong> Otago, New Zealand
Objective: Existing vaccines against MAP, based on whole killed or live attenuated bacteria, can delay <strong>the</strong> onset
<strong>of</strong> clinical symptoms but not <strong>the</strong> actual infection. Moreover, vaccinated cattle develop antibodies that interfere
with serodiagnosis <strong>of</strong> Johne’s disease and <strong>the</strong>y become reactive in <strong>the</strong> PPD skin-test, used for <strong>the</strong> control
<strong>of</strong> bovine tuberculosis. Fur<strong>the</strong>rmore, <strong>the</strong> intramuscular administration <strong>of</strong> <strong>the</strong>se vaccines in oily adjuvant induces
local granulomas at <strong>the</strong> injection site and poses a risk for <strong>the</strong> veterinarian. Here we have analyzed <strong>the</strong> potential
<strong>of</strong> oral vaccination to overcome <strong>the</strong>se hurdles.
Materials and Methods: MAP susceptible BALB.B10 mice [1] were taken <strong>of</strong>f food but not water for five
hours before placing <strong>the</strong>m individually in a cage with water, minimal bedding and <strong>the</strong> lipid vaccine (M. bovis
BCG Danish 1331, 107 CFU in lipid PK) in a cup as described before [2] . Control animals were fed with
cups containing only lipid PK. Each animal was left overnight to consume <strong>the</strong> vaccine. After <strong>the</strong> paste was
eaten, animals were returned to group cages with normal mouse food available. Mycobacteria specific IFN-g
responses were analyzed 5 weeks post immunisation. Fifteen weeks post immunisation, mice were challenged
with 1.6 x106 RLU <strong>of</strong> luminescent MAP ATCC 19698 and bacterial replication was monitored in spleen and liver
for 12 weeks.
Results: Although only weak mycobacteria-specific IFN-g and lymphoproliferative immune responses
were detected in spleen and maxillary lymph nodes <strong>of</strong> mice fed with <strong>the</strong> lipid-formulated BCG vaccine, bacterial
numbers (as detected by luminometry) were significantly lower in spleen and particularly in liver at four and
eight weeks post challenge.
Conclusion: Lipid based, orally delivered mycobacterial vaccines may be a safe and practical method <strong>of</strong>
controlling paratuberculosis.
References: 1: Roupie V et al Infect.Immun. 2008. 76: 2099-2105. 2: Clark S et al Infect Immun. . 2008. 76:
3771-3776.
#92 Differential expression <strong>of</strong> CD5 on B lymphocytes in cattle infected with Mycobacterium
avium subsp. paratuberculosis
Judith R. Stabel, Mohammad S. Khalifeh, USDA-ARS-NADC, USA; Jordan University <strong>of</strong> Science and Technology,
Jordan
CD5 is a cell surface molecule involved in antigen recognition and is present on all T lymphocytes and a subset
<strong>of</strong> B lymphocytes. The purpose <strong>of</strong> this study was to examine CD5 + expression on peripheral blood B cells from
healthy, noninfected cattle and cattle with subclinical and clinical paratuberculosis. Peripheral blood mononuclear
cells (PBMC) were freshly isolated or cultured for 7 days in <strong>the</strong> presence or absence <strong>of</strong> live Mycobacterium
avium subsp. paratuberculosis (M. avium subsp. paratuberculosis), and <strong>the</strong>n analyzed by flow cytometry
for CD5 expression within <strong>the</strong> B cell subpopulation. Analysis demonstrated a significant increase (P < 0.01)
in B cells in clinical animals as compared to healthy control cows and subclinically infected cows. In addition,
three subpopulations within <strong>the</strong> CD5 + B cell population were identified: CD5dim, CD5bright, and a minor
population that was characterized as CD5extra bright. A decrease in <strong>the</strong> CD5dim B cell population along with a
concomitant increase in CD5bright B cells was observed in infected cows, an effect that was highly significant
(P < 0.01) for subclinically infected cows in cultured PBMC. In vitro infection with live M. avium subsp. paratuberculosis
did not affect CD5 + expression patterns on B cells, regardless <strong>of</strong> animal infection status. Addition
<strong>of</strong> exogenous IL-10 to PBMC cultures resulted in decreased numbers <strong>of</strong> CD5bright B cells for healthy control
cows, whereas, a synergistic effect <strong>of</strong> IL-10 and infection with live M. avium subsp. paratuberculosis resulted in
increased CD5bright B cells for subclinically infected cows. These results suggest that differential expression
<strong>of</strong> CD5bright and CD5dim subpopulations on B cells in animals with paratuberculosis may reflect a shift in host
immunity during <strong>the</strong> disease process.
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