C.84-AIDS Vaccine Thai RV 144 Correlate Of Protection: Envelope gp120 V2 Loop, Which Induces Protect

Présentation Poster au 5°congrès européen de virologie ( Lyon, Septembre 2013)

REF 058         Category: 04. Adaptive immunity and Vaccines

Publié dans Virologie Septembre 2013, vol 17, Supplement S 134

Thai RV 144 vaccine efficacy is 31%; protective IgG target the gp120 V1-V2 loops. We analyse the V2 loop (Zolla-Pazner S, 2013) by Amino Acid (AA) sequences comparison by Basic Local Analysis Search Tool Protein (BLASTP) with visual search and three-dimensional (3D) structures of conotoxin (Xue T, 2003) and spider Atrax atracotoxin (Pallaghy PK, 1997). The 2 Thai vaccine strains V2 loops were screened on toxins binding to the voltage-gated Na  channel (NaCh). Result: 1) 3 mu-conotoxin active site AAs (K13, Q14, K16) (Conus Geographicus, Kinoshitai, Striatus, Betulinus chimera) (Ekberg J, 2008) are found in the Thai V2 loop (V172 crucial):

2) The vaccine MN strain V2 loop mimics the scorpion toxin NH2-terminus active site 1-KKEGY-5 (Kharrat R, 1989); its deletion abolishes the toxicity (El Ayeb M, 1986). Interestingly antibodies against scorpion toxin NH2-terminus 1-KKEGY-5 induce broad cross-reactive protection (Devaux C, 1996). The toxin precursor (Cn II-13, AaH, Bot IX chimera) (Possani LD, 2000) is included.

3) V2/V3 loops of HIV-2/SIV PBJ14 (fatal AIDS) were 3D superimposed on spider Atratoxin (Atx)/versustoxin, 2 NaCh ligands. Atrax Robustus is a very dangerous spider from Australia.

V2 loop YxxxWYxxDxxC is conserved in HIV-2.

V3 loop AA sequence is SGLVFH:

CONCLUSION

The scorpion venom concept of AIDS (Tran GMK, 1989, 1993, 1997) is confirmed by the homology between the Thai V2 loop and mu-conotoxin, a NaCh ligand. Omega-3, a NaCh modifier, is efficient in AIDS (Caprani A, 2012). AIDS vaccine should target V2/V3 loop, and avoid mitigating and deleterious IgA directed against the envelope first conserved region C1 (Haynes BF, 2012) (Tran GMK, Eur Conf Virol 2013, Lyon).

An AIDS therapeutic vaccine (as was the case for Pasteur anti-rabies vaccine) would be more rapid to develop, step by step, than a classical prophylactic vaccine: The rapidity of a therapeutic vaccine is calculated in months, whereas for a prophylactic vaccine, each trial would take about a dozen of years. The same therapeutic vaccine, when finally successful, can be then converted in a prophylactic vaccine (following the anti-rabies vaccine example).

The scorpion model of AIDS means that there must at least 6 or 7 different AIDS vaccines, as numerous as the number of different geographical species of scorpions. A mannose-based vaccine must be added to the proteins.

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Acknowledgements: Positifs Association.