Cytotoxic T lymphocyte responses to vaccinia virus antigens but not HIV-1 subtype E envelope protein seen in HIV-1 seronegative Thais.

The HIV-1 prime boost phase I/II vaccine trial using a recombinant canarypox vector, vCP1521, containing subtype E env (gp120), and subtype B env (gp41), gag and protease has started in Thailand. We have demonstrated that although 4 from 15 human immunodeficiency virus type 1 (HIV-1) seronegative Individuals showed cytotoxic T lymphocyte (CTL) responses to vaccinia virus antigens, none of them showed specific CTL responses to subtype E Env after in vitro stimulation. This preliminary study suggests that specific CTL responses to subtype E envelope detected in HIV-1 seronegative Individuals after vaccination should be considered as specific responses to the immunization.

DTH responsiveness of HIV-infected Thai adults.

A study was carried out in Thailand to determine the frequency of reactivity to delayed-type hypersensitivity (DTH) skin tests used for the staging of HIV patients in the United States. A four-antigen panel which included tetanus toxoid (1:10), Candida (1:10), mumps and Trichophyton antigens was assessed in 221 adult subjects from across the full immunological spectrum of HIV disease. Complete anergy was found in 38 per cent of 73 subjects with CD4 counts of 0-200 cells/ml and in 6 per cent of 78 subjects with 201-400 cells/ml. Partial anergy (response to 1 of 4 antigens) was found in 26 per cent of the 0-200 cell/ml group and decreased progressively with increasing CD4 cell count. Results suggested that a 3-member recall antigen panel would provide nearly all the clinically useful information gained by the more standard 4-member panel. In conclusion, DTH skin testing was confirmed to provide a method of assessing the integrity of cellular immune function of HIV-infected Thai adults which correlated with disease progression.