Effect of a Fermented Soy Product on Cognition, Immune Status and Vaccine (IS)

Immune status measurements will be performed using both static and functional tests on whole blood, serum and peripheral blood mononuclear cells (PBMC). Phlebotomy to obtain the needed samples will be performed at baseline (week 0) and at 16 weeks. Changes in immune status include changes in: (a) lymphocyte activity and cytokine production (b) natural killer cells activity, (c) lymphocyte subsets, and (d) inflammatory markers and cytokines.

Lymphocyte activity and cytokine production will be measured using enzyme-linked immunoassay (ELISA) and flow cytometry. Peripheral blood mononuclear cells (PBMCs) will be incubated and stimulated with or without phytohemagglutinin (PHA) or Lipopolysaccharide (LPS) and the culture supernatant fluids collected and assayed using ELISA for the following cytokines: granulocyte macrophage colony- stimulating Factor (GM-CSF), tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin 1 beta (IL-1β), interleukin 2 (IL-2), interleukin 6 (IL-6), and interleukin 10 (IL-10).

The NK degranulation assay will be performed on blood samples. The test will be conducted using a modified flow cytometry method that measures the expression of CD107a.

Immunophenotyping will be performed on cryopreserved PBMCs using a flow cytometry. The following markers will be measured: T cytotoxic cells (Tc; CD3+CD8+), T helper cells (Th; CD3+CD4+), B cells (CD19+), NK cells (NK; CD3-CD16+), and regulatory T cells (Treg; CD3+CD4+CD25+Foxp3+).

Inflammatory markers in serum will be measured by ELISA and will include C-reactive protein (CRP), E-selectin, Pentraxin 3, Rantes, MCP-1 and Eotaxin. Immunophenotyping will be performed on cryopreserved PBMCs using a flow cytometry. The following markers will be measured: T cytotoxic cells (Tc; CD3+CD8+), T helper cells (Th; CD3+CD4+), B cells (CD19+), NK cells (NK; CD3-CD16+), and regulatory T cells (Treg; CD3+CD4+CD25+Foxp3+). Additional characterization of T cells based on naive and memory phenotypes will be determined by corresponding patterns in the expression of CD45RA, CD45RO and CD62L, while different subpopulations of Tregs will be further differentiated by expressions of GITR, CTLA-4 and LAG-3

CBC and the differential counts will be performed on whole blood with the use of an automated hematology analyzer at a certified clinical facility. Immunophenotyping will be performed on cryopreserved PBMCs using a flow cytometry. The following markers will be measured: T cytotoxic cells (Tc; CD3+CD8+), T helper cells (Th; CD3+CD4+), B cells (CD19+), NK cells (NK; CD3-CD16+), and regulatory T cells (Treg; CD3+CD4+CD25+Foxp3+). Additional characterization of T cells based on naive and memory phenotypes will be determined by corresponding patterns in the expression of CD45RA, CD45RO and CD62L, while different subpopulations of Tregs will be further differentiated by expressions of GITR, CTLA-4 and LAG-3

Neutralizing antibody titers in the serum against the hemagglutinin and neuraminidase of the vaccine strain will be measured using the standard commercial ELISA kits.

Viral load in blood will be measured using a quantitative polymerase chain reaction (qPCR) protocol as described by Ward CL, et al. (2004).

The composite score will be calculated using the scores from the tests listed below. We will calculate the standardized scores of each test as the score of each participant minus the group mean and divide by its standard deviation. The composite score is the mean of the standardized scores. The 12 tests are: Rey Auditory Verbal Learning Test (RAVLT), Rey-Osterrieth Complex Figure (ROCF), Semantic Fluency (Animals), Boston Naming Test (BNT), Visual Object and Space Perception Battery (VOSP), Block Design section from the Wechsler Adult Intelligence Scale (WAIS-III), Trail Making Test (TMT), FAS Word Fluency, Stroop Color Word Test, Symbol Digit Modalities Test (SMDT) Digit Span from the WAIS-III and Conners Continuous Performance Test (CPT-II).

Upper respiratory tract infections will be tracked using the Jackson and Dowling questionnaire as adapted and published by Martineau et al. (2015). The questionnaire will be completed daily by participants, either manually or electronically, throughout the 20-week study period