HIV-1 gp120 N-linked glycosylation differs between plasma and leukocyte compartments
1 Retroviral Genetics Laboratory, Centre for Virus Research, Westmead Millennium Institute, Westmead Hospital, University of Sydney, Westmead NSW. 2145 Sydney. Australia
2 Clinical and Epidemiological Virology, Rega Institute for Medical Research, Leuven, Belgium
3 Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR, Westmead Hospital, Westmead NSW 2145, Australia
4 School of Information Technologies, University of Sydney, Camperdown NSW 2006, Australia
Virology Journal 2008, 5:14 doi:10.1186/1743-422X-5-14Published: 23 January 2008
N-linked glycosylation is a major mechanism for minimizing virus neutralizing antibody response and is present on the Human Immunodeficiency Virus (HIV) envelope glycoprotein. Although it is known that glycosylation changes can dramatically influence virus recognition by the host antibody, the actual contribution of compartmental differences in N-linked glycosylation patterns remains unclear.
Methodology and Principal Findings
We amplified the env gp120 C2-V5 region and analyzed 305 clones derived from plasma and other compartments from 15 HIV-1 patients. Bioinformatics and Bayesian network analyses were used to examine N-linked glycosylation differences between compartments. We found evidence for cellspecific single amino acid changes particular to monocytes, and significant variation was found in the total number of N-linked glycosylation sites between patients. Further, significant differences in the number of glycosylation sites were observed between plasma and cellular compartments. Bayesian network analyses showed an interdependency between N-linked glycosylation sites found in our study, which may have immense functional relevance.
Our analyses have identified single cell/compartment-specific amino acid changes and differences in N-linked glycosylation patterns between plasma and diverse blood leukocytes. Bayesian network analyses showed associations inferring alternative glycosylation pathways. We believe that these studies will provide crucial insights into the host immune response and its ability in controlling HIV replication in vivo. These findings could also have relevance in shielding and evasion of HIV-1 from neutralizing antibodies.