Tuberculosis diagnostic test
View Patent ↗A method of diagnosing in a host infection by or exposure to a mycobacterium which expresses ESAT-6 comprising (i) contacting a population of T cells from the host with one or more peptides or analogues selected from the peptides represented by SEQ ID NO:1 to 11 and analogues thereof which can bind a T cell receptor which recognizes any of the said peptides, and (ii) determining whether the T cells of said T cell population recognize the peptide(s) and/or analogue(s). The method may performed in vivo. Peptides and a kit which enable the method to be carried out are provided.
1. A method of in vitro diagnosis which distinguishes between (a) exposure of a human host to Mycobacterium tuberculosis and (b) vaccination of the human host with BCG, comprising determining whether T cells isolated from said host show a recognition response to a peptide panel comprising one or more epitopes contained within peptide SEQ ID NO: 1, wherein the presence of T cells that show said recognition response indicates that the host has been exposed to Mycobacterium tuberculosis , and wherein T cells from a host vaccinated with BCG but not exposed to Mycobacterium tuberculosis lack the recognition response.
2. The method of claim 1 , wherein the peptide panel further comprises one or more epitopes contained within one or more peptides selected from the group consisting of: peptide SEQ ID NO: 2, peptide SEQ ID NO: 3, peptide SEQ ID NO: 4, peptide SEQ ID NO: 5, peptide SEQ ID NO: 6, peptide SEQ ID NO: 7, peptide SEQ ID NO: 8, peptide SEQ ID NO: 9, peptide SEQ ID NO: 10 and peptide SEQ ID NO: 11.
3. The method of claim 1 , wherein the method yields a diagnostic sensitivity of at least 50%.
4. The method of claim 1 , wherein the T cells are incubated with the peptide panel for between 4 and 24 hours prior to determining the recognition response.
5. The method of claim 1 wherein the T cells are freshly isolated.
6. The method of claim 1 , wherein the T cells are isolated from blood.
7. The method of claim 1 , wherein the T cells comprise CD4+ and CD8+ T cells.
8. The method of claim 1 , wherein the T cells comprise CD4+ immediate effector T cells.
9. The method of claim 1 , wherein the recognition response is measured by detecting IFNγ secretion from the T cells.
10. The method of claim 2 , wherein the method yields a diagnostic sensitivity of at least 50%.
11. The method of claim 2 , wherein the T cells are incubated with the peptide panel for between 4 and 24 hours prior to determining the recognition response.
12. The method of claim 2 , wherein the T cells are freshly isolated.
13. The method of claim 2 , wherein the T cells are isolated from blood.
14. The method of claim 2 , wherein the T cells comprise CD4+ and CD8+ T cells.
15. The method of claim 2 , wherein the T cells comprise CD4+ immediate effector T cells.
16. The method of claim 2 , wherein the recognition response is measured by detecting IFNγ secretion from the T cells.
17. A kit for in vitro diagnosis which distinguishes between (a) exposure of a human host to Mycobacterium tuberculosis and (b) vaccination of the human host with BCG, comprising a peptide panel, wherein the peptide panel comprises peptide SEQ. ID. No: 1.
18. The kit of claim 17 , wherein the peptide panel further comprises one or more peptides selected from the group consisting of: peptide SEQ ID NO: 2, peptide SEQ ID NO: 3, peptide SEQ ID NO: 4, peptide SEQ ID NO: 5, peptide SEQ ID NO: 6, peptide SEQ ID NO: 7, peptide SEQ ID NO: 8, peptide SEQ ID NO: 9, peptide SEQ ID NO: 10 and peptide SEQ ID NO: 11.
19. The kit of claim 17 , wherein the diagnosis has a sensitivity of at least 50%.
20. The kit of claim 18 , wherein the diagnosis has a sensitivity of at least 50%.
21. The kit of claim 17 , further comprising an apparatus to detect a recognition response to the peptide panel by T cells.
22. The kit of claim 18 , further comprising an apparatus to detect a recognition response to the peptide panel by T cells.