Long-term culture of human immunodeficiency virus type 1 resulting in loss of glycosylation sites.

Cultures of human immunodeficiency virus type 1 (HIV-1) provided a model for the study of mutations in the absence of host antibodies. Replicate cultures of biological and molecular clones of HIV-1 were passaged weekly for 30 or 34 weeks. Eight regions of HIV-1 genomic RNA were analyzed by means of single-strand conformation polymorphism analysis and nucleotide sequencing. Six mutations were detected in the biological clones. Two were GA substitutions. The frequency of mutations was higher in V1 compared to that in other regions (P = 0.01). Three mutations involved loss of potential glycosylation sites in V1. These results show that mutations in the viral genome may result from selection by factors other than host immune pressures. J. Med. Virol. 63:197–202, 2001. © 2001 Wiley-Liss, Inc.