In Vitro Analysis of Myd88-mediated Cellular Immune Response to West Nile Virus Mutant Strain Infection

The overall goal of this study is to introduce two flow cytometry based immunological assays for measuring the cell mediated immune response to West Nile virus infection in the in vitro T-cell priming assay dendritic cells, or dcs purified from West Nll virus infected mice. A co-culture with naive CFSE labeled T cells purified from OT two transgenic mice in the presence of ova peptide. The proliferation response of the T cells is then analyzed by flow cytometry in a biosafety level two laboratory in the modified intracellular cytokine staining assay PLE cytes from West Nile virus infected mice, A stimulated ex vivo with West Nile specific peptides in a micro centrifuge tube and then the cell sustain for intracellular cytokine production and analyzed in the tube by flow cytometry in the biosafety level two laboratory.

Ultimately, these methods can be used to examine the role of specific signaling pathways in the activation of T cells in West Nile virus infected animals, and they significantly reduce the performance time inside biosafety level three facilities. Though this method can provide insight into western N virus cellular immunity, it can also be applied to other biosafety level three pathogen For the in vitro T-cell priming assay. Begin by isolating splenic dendritic cells from wild type C 57 black six A, my D eight eight knockout mice inoculated with West Nile virus and control uninfected animals with anti CD 11 C magnetic beads according to the manufacturer's instructions.

Then to isolate the T cells, homogenize the spleen dissected from an OT two mouse with the frosted ends of two slides, transfer the cell suspension into a 15 milliliter conical tube, then add RPMI medium to a final volume of 40 milliliters. Let the cells settle for five minutes and then transfer 30 milliliters of the sup nascent to a new 50 milliliter conical tube. Next, use a CD four positive T-cell isolation kit according to the manufacturer's instructions to sort the CD four positive T-cell and then transfer the collected cells into a 50 milliliter conical tube followed by two washes in PBS After the second wash, incubate the cells in PBS with 0.5%bovine serum albumin at one time cent of the six cells per milliliter and 0.5 micromolar per milliliter of CFSE at 37 degrees Celsius protected from light after 10 minutes, incubate the cells in five milliliters of cold, complete medium on ice for five minutes.

Then after another PBS wash, fix 0.2 times 10 to the six CFSE labeled CD four positive T cells in 2%PFA and determine the basal level of CFSE expression of the T-cell by flow cytometry. Re suspend the rest of the CFSE labeled cells, incomplete, medium, and then culture two times 10 to the five purified ot two CD four positive T cells alone or with two times 10 to the four purified wild type or my D eight eight knockout dcs in a 24 well plate with or without one microgram per milliliter over residue 3 23 3 39 in one milliliter of complete medium per well at 37 degrees Celsius after five days, harvest the cells and wash them twice in facts buffer and fix the pellets in 0.25 milliliters of 2%PFA and immediately vortex the samples for flow cytometry data acquisition. Double click the flow cytometry software and select channels zero to 200, 000 on forward scatter and zero to 200, 000 on side scatter to generate a density plot.

Then create a gate on the live wells to analyze the fluorescent intensity of the CFSE. Open the histogram for the FL one channel and acquire 20, 000 events on the gated population. Then set up a marker on the samples for the OT two cells cultured alone.

Acquire data for the OT two cells co-culture with wild type or my D eight eight knockout dcs in a similar way for the intracellular cytokine staining assay. After generating a single cell suspension from spleens harvested from West Nile virus, infected mice at the appropriate time points count the cells and then dilute them with complete medium to a 2.5 times cent of the six cells per milliliter concentration. Next Eloqua one milliliter of the cytes into a 1.5 milliliter micro centri tube.

And then to stimulate the CD eight positive T cells, add 10 microliters of freshly diluted Western specific peptides followed by one microliter of feld. In a solution, mix the cell suspensions carefully and then punch two holes in the cap of the tube with an 18 gauge needle and incubate the cells at 37 degrees Celsius for five hours. After the transfer the cells into a new micro centrifuge tube and spin them down after a washing one milliliter of fax buffer, re suspend the second pellet in 120 microliters of fax buffer.

Then block the nonspecific binding sites with FC block and label the tubes with the appropriate experimental and control antibodies as outlined in the table. Next, incubate the cells in fixation and permeation buffer and then transfer the cells to a biosafety level to laboratory for labeling with control or anti interferon gamma antibodies according to the table. To measure the intracellular cytokine production, set up a forward by side scatter plot as just demonstrated, and then gate the live cells using the compensation tubes to adjust the voltages as necessary.

Create one dot plot to display the data collected for the CD eight positive versus interferon gamma positive cells, followed by another for the CD four positive versus interferon gamma positive cells and acquire 50, 000 events for the gated population of each sample. In this experiment, the total C cells were gated to determine the basal T-cell proliferation rate. In the absence of co-culture with dcs.

When the T cells were co-culture with DC isolated from West Nile virus infected animals, the CFSE positive T cells exhibited an 87%proliferation CFSE labeled T cells Co-culture with DCS from my D eight eight knockout mice in the presence of over exhibited a 74.5%proliferation rate, suggesting that the deficiency in the my D eight eight signaling pathway leads to an impaired antigen presenting capacity by the dcs during a mutant West null virus infection. The percentages of splenic CD four positive interferon gamma positive and CD eight positive interferon gamma positive T cells isolated from West Nile virus infected wild-type mice in this representative figure was 0.4%and 1.7%respectively. While the percentages of double positive splenic T cells isolated from West Nile virus infected my D eight eight knockout mice were only 0.2%and 0.6%Similar analyses were performed with cytes isolated from non-infected mice with no difference observed in the percentage of double positive populations T cells between the two groups.

Moreover, the single positive populations of the CD four positive and CD eight positive T cells from the infected wild-type mice were 21%and 13.3%of the total gated SP cytes, whereas they were determined to be only 15.9%and 11.2%of the my D eight eight knockout SP cytes compared to the infected groups, both CD four positive and CD eight positive T-cell responses were reduced in my D eight eight knockout mice compared to the wild type group at day eight post mutant west snail virus infection. In summary, my D eight eight signaling is involved in the initial T-cell activation of both populations and contributes to CD four positive T-cell responses at a later stage of infection. The flu cytometry based in vitro tcell primase using in CFSE labeled OT two T cells provides a more accurate determination of the percentage of proliferating CD4 positive T-cell with the significant improved overall sensitivity than current standard protocols.

The micro field tube, ICS Math third does not require any special instruments, which offers both some more economical and more flexible choice for researchers.