No abstract

Anti-human immunodeficiency virus type 1 (Anti-HIV-1) antibody response was compared in four groups of mice following inoculation with HIV-1 gp160, with live recombinant vaccinia virus expressing HIV-1 envelope glycoproteins, or with both immunogens in alternate orders for primary or secondary immunizations. Both subunit and recombinant virus immunogens induced similar levels of antibody response following primary immunization. However, after secondary immunization, mice primed with live recombinant virus and then boosted with subunit gp160 immunogen showed significantly higher antibody response than those in the other three groups. Neutralizing antibodies were generated only in this group of mice and were shown to neutralize both the homologous virus (BRU) and a divergent isolate (SF2) of HIV-1. On the other hand, their reactivities to peptide sequences from the principal neutralizing determinant (PND) of gp120 were limited to the BRU isolate, not SF2 or MN, indicating that the cross-neutralizing activities were directed against determinants other than the linear epitope(s) within the PND. These results also indicate that combined immunization by priming with liver recombinant virus and boosting with subunit immunogen may be more effective than immunization by either immunogen alone.

No abstract

A recombinant vaccinia virus in which the transcription of the human immunodeficiency virus type 1 (BRU isolate) env gene is driven by the 11K late vaccinia promoter yields about 10-fold higher amounts of gp160 env protein upon infection of monkey cells than does a recombinant in which gp160 is expressed using the 7.5K early-late promoter. The gp160 was purified from detergent lysates of infected cells by lentil lectin affinity chromatography followed by immunoaffinity chromatography, and was obtained in yields of 1-2 mg/10(9) cells of material estimated to be about 70% pure. Pairs of rabbits were immunized with purified gp160 using either one of five different adjuvants or an immunostimulating complex. In all cases a substantial humoral immune response was obtained after boosting, including an activity that neutralized the homologous (BRU) isolate of HIV-1. In some cases, this activity also neutralized two distantly related isolates, SF2 and MN.

An immunoglobulin M (IgM) antibody capture enzyme immunoassay (MAC-EIA) was developed for the rapid and early diagnosis of LaCrosse (LAC) virus infections. The MAC-EIA was a sensitive and specific technique for the detection of IgM antibodies to LAC virus in cerebrospinal fluid specimens and in acute-phase serum specimens. In a retrospective study, cerebrospinal fluid and acute-phase serum paired samples from 108 patients were tested by the MAC-EIA and by an IgM immunofluorescence assay. The results were compared with the original diagnosis, which was made by using a variety of classical serological tests including serum neutralization, hemagglutination inhibition, and complement fixation. Thirty patients were confirmed as having LAC virus infections; of these, 30 (100%) were diagnosed as positive by serum MAC-EIA, and 27 (90%) were positive by cerebrospinal fluid MAC-EIA. The MAC-EIA was more sensitive than the IgM immunofluorescence assay. Two patients who were not previously confirmed as positive cases were diagnosed as having LAC virus infections by the MAC-EIA. One patient who was subsequently diagnosed as having a Jamestown Canyon virus infection and two patients who were previously infected with Jamestown Canyon virus were not falsely identified as having LAC virus infections by the MAC-EIA.