Arrayed imaging reflectometry (air) sensor chip comprising influenza hemagglutinin (HA) polypeptides suitable for the detection of antiviral immune responses
A sensor chip for detecting an immune response against an influenza virus, the sensor chip including a substrate having a surface and a plurality of hemagglutinin polypeptides bound to discrete locations on the surface of the substrate, each hemagglutinin polypeptide having a hemagglutinin epitope. Detection devices containing the sensor chip and methods of detecting influenza immune responses are also described herein.
1. An arrayed imaging reflectometry (AIR) sensor chip suitable for the detection of influenza immune responses comprising:
a multilayer substrate comprising a surface and hemagglutinin polypeptides from different influenza strains or isolates, wherein said hemagglutinin polypeptides from each individual influenza strain or isolate comprise a hemagglutinin epitope and are covalently attached to the chip surface at different locations;
wherein said hemagglutinin polypeptides retain conformational epitopes that are capable of binding to anti-influenza antibodies;
wherein said surface with hemagglutinin polypeptides covalently attached at the different locations forms a coating on the chip surface that results in destructive interference of polarized light illuminating said surface at an appropriate incident angle and wavelength in the absence of antibody binding; and
wherein exposure of the surface to a sample comprising anti-influenza antibodies produces a detectable change in reflectance at a location upon antigen-antibody binding.
2. The sensor chip according to claim 1 , wherein the hemagglutinin polypeptides are full length hemagglutinin proteins.
3. The sensor chip according to claim 1 , wherein the hemagglutinin polypeptides are fragments of full length hemagglutinin proteins.
4. The sensor chip according to claim 3 , wherein the hemagglutinin polypeptide fragments each comprise an immunodominant hemagglutinin epitope of their respective native influenza strain.
5. The sensor chip according to claim 1 , wherein the hemagglutinin polypeptides are covalently attached to the substrate via a glutaraldehyde linker.
6. The sensor chip according to claim 1 , wherein each of said locations comprises a concentration of hemagglutinin polypeptide of about 100 fg/mm 2 to about 100 ng/mm 2 .
7. The sensor chip according to claim 1 further comprising:
neuraminidase polypeptides from different influenza strains or isolates, wherein said neuraminidase polypeptides from each individual strain or isolate comprise a neuraminidase epitope and are covalently attached to the chip surface at different locations;
wherein said neuraminidase polypeptides retain conformational epitopes that are capable of binding to anti-influenza antibodies; and
wherein said surface with neuraminidase polypeptides covalently attached at the different locations forms a coating on the chip surface that results in destructive interference of polarized light illuminating said surface at an appropriate incident angle and wavelength in the absence of antibody binding.
8. The sensor chip according to claim 7 , wherein the neuraminidase polypeptides are full length neuraminidase proteins.
9. The sensor chip according to claim 7 , wherein the neuraminidase polypeptides are fragments of full length neuraminidase proteins.
10. The sensor chip according to claim 9 , wherein the neuraminidase polypeptide fragments each comprise an immunodominant neuraminidase epitope of their respective native influenza strain.
11. A method for detecting anti-influenza antibodies using arrayed imaging reflectometry (AIR), said method comprising:
providing a sensor chip according to claim 1 ;
contacting the sensor chip with a sample under conditions that permit specific anti-influenza antibody binding to the hemagglutinin polypeptides present on the chip surface;
rinsing the sensor chip to remove any unbound antibody; and
detecting light reflected off the surface of the chip under conditions effective to identify anti-influenza antibody-antigen binding.
12. The method according to claim 11 , wherein the sample is obtained from a human, a non-human primate, a domesticated animal, or a wild animal.
13. The method according to claim 11 , wherein said detecting comprises:
measuring light reflected from the chip and
providing an output identifying the hemagglutinin polypeptides bound by an antibody of the sample based on the measured reflected light.
14. The method according to claim 13 , wherein the measuring the reflected light further comprises capturing an image of at least a substantial portion of the surface of the chip.