Method for simultaneously detecting an antigen of, and an antibody against, an infectious microorganism
The invention relates to a method for detecting, in vitro, an infection with a microorganism, such as the hepatitis C virus, in a biological sample, by simultaneously detecting an antigen of this microorganism and the antibodies against this same antigen, and also to the reagents and kits implementing this method.
1. A kit which is of use for detecting an infection with human immunodeficiency virus (HIV) in a biological sample, comprising:
a) a capture or detection antigen which comprises an antigenic fragment of a gag protein of HIV, said fragment comprising at least one destroyed epitope, while at the same time conserving the ability to bind the antibodies directed against HIV possibly present in the biological sample; and
b) a capture or detection antibody directed against said epitope, which is intact, of said gag protein of HIV;
wherein the antigenic fragment comprises sequence FRGYVGRFYKTLRAEQAGQGVKNFMTETLLVQNANPDCKTILKALGPAATLEEMMTAC SEQ ID NO: 22.
2. The kit as claimed in claim 1 , in which the antibody is an antibody for capturing the HIV antigen present in the biological sample.
3. The kit as claimed in claim 1 , in which the antibody recognizes an epitope of sequence QASQEVKNWMTETLL (SEQ ID NO: 24).
4. The kit as claimed in claim 1 further comprising, besides the capture antigen, means of detecting the anti-HIV antibodies present in the biological sample, the detecting means forming complexes with the capture antigen.
5. The kit as claimed in claim 4 , wherein the detecting means is a labeled anti-immunoglobulin or anti-isotype antibody.
6. The kit as claimed in claim 1 , wherein the capture antibody and the capture antigen are present in a form immobilized on a solid phase.
7. The kit as claimed in claim 6 , further comprising:
c1) a labeled detection antibody directed against another of the epitopes, which are intact, of the HIV protein; and
c2) optionally a labeled detection antigen which is an antigenic fragment of the gag protein of HIV, the fragment comprising at least one other destroyed epitope, while at the same time conserving the ability to bind the anti-HIV antibodies possibly present in a biological sample.
8. The kit as claimed in claim 1 , also comprising at least one detergent of the nonionic type.
9. The kit as claimed in claim 8 , wherein the at least one detergent is NP40.