Diagnostics method
View Patent ↗Method of diagnosing in an individual recent exposure to an agent which is a pathogen, vaccine or any other moiety which induces a cellular response, said method comprising determining in vitro whether the T cells of the individual recognise a protein from said agent having a length of at least 30 amino acids, to a greater extent than one or more peptide epitopes from the agent, a greater extent of recognition of the protein indicating that the individual has recently been exposed to the agent.
1. A method of diagnosing in an individual a recent exposure to M. tuberculosis , said method comprising:
(a) providing a T cell-containing sample from said individual;
(b) contacting different aliquots of said sample separately with antigen compositions comprising either whole ESAT-6, or peptide epitopes derived from ESAT-6 that are 8 to 29 amino acids in length, in ELISPOT assays in order to determine the frequency of antigen-responsive T cells which have been induced to secrete a cytokine; and
(c) evaluating the responsive T cells in each separate ELISPOT assay, wherein a positive response using whole ESAT-6 and a negative response using said peptide epitopes indicates that the individual has recently been exposed to M. tuberculosis.
2. A method according to claim 1 , wherein said peptide epitopes are 12 to 25 amino acids in length.
3. A method according to claim 1 , wherein a pool of at least four different peptide epitopes is employed.
4. A method according to claim 1 , wherein said peptide epitopes represent all possible peptide epitopes derived from ESAT-6.
5. A method according to claim 1 , wherein antigen presenting cells are present in said sample.
6. A method according to claim 1 , wherein said peptide epitopes are selected from the group consisting of:
MTEQQWNFAGIEAAA,
(SEQ ID NO:1)
WNFAGIEAAASAIQG,
(SEQ ID NO:2)
IEAAASAIQGNVTSI,
(SEQ ID NO:3)
SAIQGNVTSIHSLLD,
(SEQ ID NO:4)
NVTSIHSLLDEGKQS,
(SEQ ID NO:5)
HSLLDEGKQSLTKLA,
(SEQ ID NO:6)
EGKQSLTKLAAAWGG,
(SEQ ID NO:7)
LTKLAAAWGGSGSEA,
(SEQ ID NO:8)
AAWGGSGSEAYQGVQ,
(SEQ ID NO:9)
SGSEAYQGVQQKWDA,
(SEQ ID NO:10)
YQGVQQKWDATATEL,
(SEQ ID NO:11)
QKWDATATELNNALQ,
(SEQ ID NO:12)
TATELNNALQNLART,
(SEQ ID NO:13)
NNALQNLARTISEAG,
(SEQ ID NO:14)
NLARTISEAGQAMAS,
(SEQ ID NO:15)
ISEAGQAMASTEGNV,
(SEQ ID NO:16)
and
QAMASTEGNVTGMFA.
(SEQ ID NO:17)