Limited cross-reactivity between different HIV-1 clades.
BACKGROUND
The past two decades has seen an extensive search for a vaccine to curtail the HIV/AIDS pandemic. The prevailing opinion is that an HIV vaccine should elicit broadly cross-neutralizing antibodies and cellular immune responses against primary isolates from divergent clades. The majority of subunit or protein based vaccines currently in clinical trials are based on HIV-1 envelope proteins mainly derived from subtypes B/A. This has serious implications for developing nations where the pandemic is caused by HIV-1 subtype C. This study was undertaken considering speculation on the potential cross-reactivity between antigens derived from--and immune responses induced by different viral subtypes.


OBJECTIVE
We report our observations after Galanthus nivalis affinity purification of recombinant HIV envelope proteins (CHO gp120/140/160) derived from subtypes B/A and using these purified proteins as antigens in ELISA assays (against subtype C induced antibodies).


CONCLUSIONS
Polyclonal antibodies from HIV-1 subtype C infected HIV/AIDS patients recognized the recombinant antigens at varying antibody titers (100-1000). Prior to ELISA assays, routine SDS-PAGE and N-terminal sequencing confirmed the identity of the purified proteins while their ability to induce apoptosis confirmed their functionality. The purified proteins were also used to elicit polyclonal antibodies in mice, which recognized the immunogens as antigen in ELISA assays at titers of 500-5000, and cross-reacted at lower antibody titers.
Mthunzi
Patience
P
Biochemistry Division, Department of Chemistry and Biochemistry, Rand Afrikaans University, P.O. Box 524, Auckland-Park 2006, Johannesburg, South Africa.
Meyer
Debra
D
D016915:AIDS Vaccines / Q000276:immunology; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D015483:HIV Antibodies / Q000097:blood / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology; D015497:HIV-1 / Q000145:classification / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology
D016915:AIDS Vaccines; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D011994:Recombinant Proteins