Serum Proteome Changes following Human Immunodeficiency Virus Infection

Background: Quantification of viral RNA levels and CD4 cell count determinations are the most widely used laboratory assays employed in monitoring HIV patients. However, these tests are expensive, complex to perform, and require advanced laboratory infrastructure and highly skilled laboratory technicians. For these reasons, alternative ways to monitor the progression of HIV have been sought. The aim of this study was to compare the serum proteome of asymptomatic HIV-positive subjects to HIV-negative controls in order to identify novel protein changes that are induced in the human serum proteome following HIV infection. It is hoped that monitoring changes in these protein could be used as a cheaper biomarker for the progression of HIV infection. Methods: Blood was collected from volunteers undergoing HIV testing at a primary health clinic. Samples were separated into HIV-positive and HIV-negative groups, and subjected to two-dimensional gel electrophoresis. The gels were silver-stained and analyzed to detect significant differences between protein spots. Significant spots were digested with trypsin and subjected to analysis using MALDI-TOF mass spectrometry. Results: Eleven spots were found to be significantly different between the two groups. Nine spots were significantly decreased and two spots were significantly increased in the HIV-positive group compared to the HIV-negative group. The proteins found to be decreased were identified as abnormal spindle-like microcephaly-associated protein, type II cytoskeletal keratin, alpha-l-acid glycoprotein, haptoglobin, apolipoprotein A-I, zinc finger CCCH domain-containing protein 13 and haemoglobin beta subunit. The proteins found to be increased were identified as pre-mRNA-splicing factor CWC25 homolog and 60S ribosomal protein L4. Conclusions: Significant differences were found between HIV-positive and HIV-negative samples. This information could be used to develop immunoassays to analyse protein changes as an additional method of monitoring changes in HIV infection in the clinical laboratory.