Owen Owns up

[Thomas Daniel <danielt@u.washington.edu>]

Colleagues,

Owen Hammel returns to Mathbio with the following talk.   Remember, 114
Kincaid 1230 on Wed and Friday.


The Management.



Bacterial Kidney Disease in Snake River Spring Chinook

Bacterial kidney disease (BKD) is one the most problematic diseases
affecting wild, hatchery and farmed salmonids in the Pacific Northwest.
It
is especially of concern for Snake River spring chinook salmon. Attempts

at controlling BKD have been ongoing for decades, and recent advances in

detection techniques have allowed for more detailed studies of disease
dynamics.

Renibacterium salmoninarum (RS), the causative agent of BKD, is
transmitted both horizontally (between salmon) and vertically (from
female
spawner to offspring). Stress and temperature affect the ability of
salmon
to fight off the disease. No consistent method of control for BKD has
been
found.

The antigen p57, a surface protein of RS that is also secreted by the
bacterium, has immunosuppressive effects on lymphocytes, and may cause
immunotolerance in progeny of infected female spawners. RS can reproduce

within phagocytic cells and also induce uptake by non-phagocytic cells,
and thus can hide out from the immune response. Phagocytes activated by
helper T cells do kill bacteria residing within them. Low temperatures,
stress and p57 can suppress helper T cell action.

I will present data analysis and re-analysis which suggest the
importance
of immunotolerance and temperature effects. I will also present models
which address the internal dynamics of bacteria within the host and the
immune response, the effect of the disease on survivorship throughout
the lifecycle and the induction of immunotolerance in the next
generation.


Owen Hamel
Quantitative Ecology and Resource Management
owen@cbr.washington.edu
685-1132