AEGiS-07IAC: HIV envelope contains a structural MHC class II homology consistent with an alloepitope.

7th International AIDS Conference


Florence, Italy — June 16-21, 1991

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HIV envelope contains a structural MHC class II homology consistent with an alloepitope.

Int Conf AIDS 1991 Jun 16-21; 7:25 (abstract no. M.A.15)
Dalgleish A, Habeshaw J, Manca F, Hounsell E; MRC Clinical Research Centre Harrow HA1 3UJ UK

OBJECTIVE: 1) To show that gp120 contains an alloepitope which would be available to interact with the T cell receptor (TCR), and to explore if this interaction is with a specific V-alpha/beta region of the TCR. 2) To determine if T cell responses against HIV are T cell restricted at the V-alpha/beta level.

METHODS: Modelling of gp120 carboxyterminal region incorporating homologies with IgG variable regions, predictions of protein secondary structure (Chou-Fasman and Garnier et al algorithms), molecular dynamics and energy minimisation. Raising and characterisation of T cell clones to gp120 and gp160.

RESULTS: HIV has a surface accessible alpha helical forming sequence which can exist in close proximity to a region of homology with the minor alpha helix of MHC class I and regions of beta strand motif of class I and class II. This model represents a conformation for part of gp120 which mimics the binding domain for the TCR on MHC molecule. In addition it has been shown that in vitro T cell lines against gp120 and 160 are restricted in their use o TCR genes.

DISCUSSION: These results are consistent with HIV acting as an alloepitope which could lead to chronic immune activation and T cell deletion similar to that seen in graft versus host disease. Treatment and vaccines should therefore be directed at GVHD as well as the virus. Specific treatment should be targeted at the specific responsive TCR gene, using well known strategies based on T cell vaccination and idiotypy. This approach may also lead to novel drugs designed to inhibit this interaction.

Keywords: AEGIS, HIV, Receptors, Antigen, T-Cell, T-Lymphocytes, HIV Envelope Protein gp120, Epitopes, Receptors, HIV, HIV Envelope Protein gp160, Clone Cells, HIV Envelope Protein gp41, Myosin Heavy Chains, Graft vs Host Disease, In Vitro, ICA7KWDaegis,hiv,receptors,antigen,t-cell,t-lymphocytes,hivenvelopeproteingp120,epitopes,receptors,hiv,hivenvelopeproteingp160,clonecells,hivenvelopeproteingp41,myosinheavychains,graftvshostdisease,invitro,ica7
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Copyright © 1991 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.