Identification of AIDS-Associated Kaposi Sarcoma: A Functional Genomics Approach

Peng Zhang; Jiafeng Wang; Xiao Zhang; Xiaolan Wang; Liying Jiang; Xuefeng Gu

doi:10.3389/fgene.2019.01376

Identification of AIDS-Associated Kaposi Sarcoma: A Functional Genomics Approach

Front Genet. 2020 Jan 24:10:1376. doi: 10.3389/fgene.2019.01376. eCollection 2019.

Authors

Peng Zhang^{1

2}, Jiafeng Wang³, Xiao Zhang⁴, Xiaolan Wang⁵, Liying Jiang⁶, Xuefeng Gu⁶

Affiliations

¹ School of Clinical Medicine, Shanghai University of Medicine & Health Sciences, Shanghai, China.
² Department of Public Health, Shanghai General Practice Medical Education and Research Center, Shanghai, China.
³ Stem Cell Research and Cellular Therapy Center, Affiliated Hospital of Guangdong Medical University, Zhanjiang, China.
⁴ Department of Implant Dentistry, Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.
⁵ College of Nursing and Health Management, Shanghai University of Medicine & Health Sciences, Shanghai, China.
⁶ Shanghai Key Laboratory of Molecular Imaging, Collaborative Research Center, Shanghai University of Medicine & Health Sciences, Shanghai, China.

Abstract

Background: Kaposi sarcoma-associated herpes virus (KSHV) is one of the most common causal agents of Kaposi Sarcoma (KS) in individuals with HIV-infections. The virus has gained attention over the past few decades due to its remarkable pathogenic mechanisms. A group of genes, ORF71, ORF72, and ORF73, are expressed as polycistronic mRNAs and the functions of ORF71 and ORF72 in KSHV are already reported in the literature. However, the function of ORF73 has remained a mystery. The aim of this study is to conduct comprehensive exploratory experiments to clarify the role of ORF73 in KSHV pathology and discover markers of AIDS-associated KSHV-induced KS by bioinformatic approaches.

Methods and results: We searched for homologues of ORF-73 and attempted to predict protein-protein interactions (PPI) based on GeneCards and UniProtKB, utilizing Position-Specific Iterated BLAST (PSI-BLAST). We applied Gene Ontology (GO) and KEGG pathway analyses to identify highly conserved regions between ORF-73 and p53to help us identify potential markers with predominant hits and interactions in the KEGG pathway associated with host apoptosis and cell arrest. The protein p53 is selected because it is an important tumor suppressor antigen. To identify the potential roles of the candidate markers at the molecular level, we used PSIPRED keeping the conserved domains as the major parameters to predict secondary structures. We based the FUGE interpretation consolidations of the sequence-structure comparisons on distance homology, where the score for the amino acids matching the insertion/deletion (indels) detected were based on structures compared to the FUGE database of structural profiles. We also calculated the compatibility scores of sequence alignments accordingly. Based on the PSI-BLAST homologues, we checked the disordered structures predicted using PSI-Pred and DISO-Pred for developing a hidden Markov model (HMM). We further applied these HMMs models based on the alignment of constructed 3D models between the known structure and the HMM of our sequence. Moreover, stable homology and structurally conserved domains confirmed that ORF-73 maybe an important prognostic marker for AIDS-associated KS.

Conclusion: Collectively, similar variants of ORF-73 markers involved in the immune response may interact with targeted host proteins as predicted by our computational analysis. This work also suggests the existence of potential conformational changes that need to be further explored to help elucidate the role of immune signaling during KS towards the development of therapeutic applications.

Keywords: AIDS; ORF-73; herpesvirus; immune evasion; protein–protein interactions; sequence homology.