Are the receptor occupancy tests flow cytommetry?
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Posted On: 03/13/2021 11:17:31 AM
Are the receptor occupancy tests flow cytommetry?
A 2010 PRO140 HIV article (google "lalezari pro140"
describes a receptor occupancy test which I could not understand.
For certain that 2010 test was not what Patterson is doing. But I can't tell exactly how
I thought flow cytommetry was used for sorting cells from one another.
You put the cells through a narrow tube, only one cell at a time can fit.
Before going into the narrow tube, the cell solution is treated with flourescent antibodies.
Before goint into the narrow tube, the antibodies bind to the cells in the solution.
Before going into the narrow tube, some cells have antibodies on them and others cells have no antibodies attached to them.
At the end of th narrow tube is a mechanical gate that is controlled by an optical flouresence signal from the molecule. If "green" go right, if "dark" go left.
In this fashion flow cytommetry could separate cells that have antibodies bound from cells that do not.
I think what Patterson does goes well beyond this.
For a single cell, Patterson counts not only the number of antibodies bound by Leronlimab but also the number of CCR5 receptors which are free and not bound by Leronlimab.
Patterson quantitates single cells, by themselves, I think. For sure Patterson is an expert in the various single cell high throughput labe tools like 10xGenomics.
I just assume that since Patterson is reporting "receptor occupancy" he must measure both bound and unbound CCR5 receptors.
I suppose that these tests, including Patterson) could assume that every T-cell in every different human has a fixed number of CCR5 receptors.
In that case, the amplitude of the optical signal at the end of the narrow tube might be an indicator of the precentage of CCR5 receptors that are occupied.
In addition, if the T-cells can be sufficiently purified to the point where the density of cells from different samples and different humans can be assumed constant, then an optical flourescent signal could be obtained from a larger number of cells.
I don't know how they do the RO test.
One problem with assuming all humans have the same number of CCR5 receptors on their T-cells is that the quantity of CCR5 receptors on a single human cell is known to vary wildly depending not only on the type of cell but also the environmental conditions that the cell is inside of.
If Patterson and others are assuming that all humans in all RO tests have the same number of CCR5 receptors on their T-cells for the purpose of offering standardized RO tests, that could be a significant weakness in RO testing and that could be a contributing factor to CYDY's struggles with RO testing in HIV.
For HIV, the FDA may feel that RO testing is not sufficiently robust and as a result there is no way to determine the appropriate leronlimab dose for an HIV patient. Admittedly just wild speculation.
A 2010 PRO140 HIV article (google "lalezari pro140"
describes a receptor occupancy test which I could not understand. For certain that 2010 test was not what Patterson is doing. But I can't tell exactly how
I thought flow cytommetry was used for sorting cells from one another.
You put the cells through a narrow tube, only one cell at a time can fit.
Before going into the narrow tube, the cell solution is treated with flourescent antibodies.
Before goint into the narrow tube, the antibodies bind to the cells in the solution.
Before going into the narrow tube, some cells have antibodies on them and others cells have no antibodies attached to them.
At the end of th narrow tube is a mechanical gate that is controlled by an optical flouresence signal from the molecule. If "green" go right, if "dark" go left.
In this fashion flow cytommetry could separate cells that have antibodies bound from cells that do not.
I think what Patterson does goes well beyond this.
For a single cell, Patterson counts not only the number of antibodies bound by Leronlimab but also the number of CCR5 receptors which are free and not bound by Leronlimab.
Patterson quantitates single cells, by themselves, I think. For sure Patterson is an expert in the various single cell high throughput labe tools like 10xGenomics.
I just assume that since Patterson is reporting "receptor occupancy" he must measure both bound and unbound CCR5 receptors.
I suppose that these tests, including Patterson) could assume that every T-cell in every different human has a fixed number of CCR5 receptors.
In that case, the amplitude of the optical signal at the end of the narrow tube might be an indicator of the precentage of CCR5 receptors that are occupied.
In addition, if the T-cells can be sufficiently purified to the point where the density of cells from different samples and different humans can be assumed constant, then an optical flourescent signal could be obtained from a larger number of cells.
I don't know how they do the RO test.
One problem with assuming all humans have the same number of CCR5 receptors on their T-cells is that the quantity of CCR5 receptors on a single human cell is known to vary wildly depending not only on the type of cell but also the environmental conditions that the cell is inside of.
If Patterson and others are assuming that all humans in all RO tests have the same number of CCR5 receptors on their T-cells for the purpose of offering standardized RO tests, that could be a significant weakness in RO testing and that could be a contributing factor to CYDY's struggles with RO testing in HIV.
For HIV, the FDA may feel that RO testing is not sufficiently robust and as a result there is no way to determine the appropriate leronlimab dose for an HIV patient. Admittedly just wild speculation.
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