AIDS Vaccine Development
Summary
A group of researchers including Nadeem Sheikh at the Washington
National Primate Research Center are currently performing in depth
research into various aspects of human biology, specializing in
the development and assessment of AIDS vaccine efficacy.
In the study of AIDS, it is important to understand the impact
of viral infection, namely the loss of CD4+ helper T cells which
is an indicator of the onset of AIDS. In their research, the group
determines the absolute number of circulating helper T cells in
blood by a two part process: 1) hematology analysis, which measures
hemoglobin levels, erythrocyte and white blood cell numbers, and
2) flow-cytometry, which identifies specific subsets of white blood
cells.
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Figure 1: In figure 1A, the two-panel graph shows the
long-term loss of circulating CD3/4+ cells in unimmunized
individuals (naïve), whereas immunized subjects show
initial loss and then recovery of helper T cells. The researchers
wanted to know whether the initial loss of cells in the immunized
subjects was as great and rapid as observed with the naïve
individuals and therefore used Origin's statistical features
(Fig. 5) to assess the difference between the two groups (Fig.
1B).
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How Origin Is Used
Origin is used to collate, organize, statistically analyze and
visually display a wide variety of data sets.
Data parameters numbered in the hundreds are generated for each
test subject for every time point assayed. The data generated are
disparate and diverse and include such things as cell immunophenotyping,
clinical parameters, virus loads, and basic body and weight measurements.
The data is collected on a weekly and sometimes daily basis and
is organized into discrete sets or groups using Project Explorer
(Fig. 2).
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Figure 2: Origin's Project Explorer Window
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When plotting, Nadeem finds the Plot Setup dialog (Fig. 3) extremely
useful. The three-pane dialog allows him to add new data sets to
his plots, rescale the XY axis, change plot ranges, as well as merge
data from multiple worksheets into one plot.
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Figure 3: Origin's Plot Setup Dialog
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For analyzing the data, Origin's linear and polynomial regression
options, two population t-test, and area under curve features are
used (Fig 4.).
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Figure 4: Origin's Two Sample t-Test, Polynomial Fit,
and Linear Fit Tools
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Finally, Nadeem relies on Origin's high-quality graphical output
and the ability to easily transport that output into commonly used
graphics packages (e.g. Microsoft® PowerPoint). The Export Page
feature, which allows plots to be exported in a wide variety of
graphical file formats, is a particularly useful feature, especially
since it includes the option of saving graphs in PDF form (Fig.
5).
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Figure 5: Origin's PDF Export Options Dialog
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Biography
Nadeem Sheikh
is an immunologist working on AIDS vaccine development at the Washington
National Primate Research Center, University of Washington.