HspBP1 and anti-HspBP1 levels in the serum of HIV-infected individuals are associated to the disease progression

Expression of HSPA14 in patients with acute HIV-1 infection and its effect on HIV-1 replication

Introduction

Heat shock protein (HSPs) are important intracellular factors, which are often involved in the regulation of viral replication including HIV-1 in infected individuals as molecular chaperone proteins. Heat shock proteins 70 (HSP70/HSPA) family play important roles in HIV replication, but this family contain many subtypes, and it is unclear how these subtypes participate in and affect HIV replication.

Methods

To detect the interaction between HSPA14 and HspBP1 by CO-IP. Simulating HIV infection status in vitro to detect the change of intracellular HSPA14 expression after HIV infection in different cells. Constructing HSPA14 overexpression or knockdown cells to detect intracellular HIV replication levels after in vitro infection. Detecting the difference of HSPA expression levels in CD4+ T cells of untreated acute HIV-infected patients with different viral load.

Results

In this study, we found that HIV infection can lead to changes in the transcriptional level of many HSPA subtypes, among which HSPA14 interacts with HIV transcriptional inhibitor HspBP1. The expression of HSPA14 in Jurkat and primary CD4+T cells infected with HIV were inhibited, overexpression of HSPA14 inhibited HIV replication, while knocking down HSPA14 promoted HIV replication. We also found that the expression level of HSPA14 is higher in peripheral blood CD4+T cells of untreated acute HIV infection patients with low viral load.

Conclusion

HSPA14 is a potential HIV replication inhibitor and may restrict HIV replication by regulating the transcriptional inhibitor HspBP1. Further studies are needed to determine the specific mechanism by which HSPA14 regulates viral replication.

Identification of 5' upstream sequence involved in HSPBP1 gene transcription and its downregulation during HIV-1 infection

The Human Immunodeficiency Virus-1 (HIV-1) is known to modulate the host environment for successful replication and propagation like other viruses. The virus utilises its proteins to interact with or modulate host factors and host signalling pathways that may otherwise restrict the virus. A previous study from our lab has shown that the host heat shock protein 70 (HSP70) binding protein (HSPBP1) is a co-chaperone that inhibits viral replication. We have also shown that the virus downregulates HSPBP1 during infection. However, the mechanism of downregulation remains to be elucidated. In the present study, we hypothesized that the HSPBP1 promoter may be repressed during infection leading to its downmodulation at the RNA and protein levels. The 5' upstream region of the HSPBP1 gene was first mapped and it was identified that a fragment comprising of a ∼600 bp upstream region of the transcription start site show the highest promoter-like activity. Further, the Sp1 transcription factor was shown to be essential for normal promoter activation. Our results further demonstrate that HIV-1 downregulates the activity of the identified promoter. It was seen that the viral transactivator protein, Tat, was responsible for the downmodulation of the HSPBP1 promoter. HIV-1 Tat is known to bind and regulate several cellular promoters during infection, thereby making the environment conducive for establishment of the virus. Our results further show that Tat is recruited to the HSPBP1 promoter and in the presence of Tat, recruitment of Sp1 on HSPBP1 promoter was decreased, which explains the suppression of HSPBP1 during HIV-1 infection. Therefore, this study further adds to the list of cellular promoters that are modulated by Tat during HIV-1 infection either directly or indirectly.

Bioinformatics analyses of significant genes, related pathways, and candidate diagnostic biomarkers and molecular targets in SARS-CoV-2/COVID-19

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infection is a leading cause of pneumonia and death. The aim of this investigation is to identify the key genes in SARS-CoV-2 infection and uncover their potential functions. We downloaded the expression profiling by high throughput sequencing of GSE152075 from the Gene Expression Omnibus database. Normalization of the data from primary SARS-CoV-2 infected samples and negative control samples in the database was conducted using R software. Then, joint analysis of the data was performed. Pathway and Gene ontology (GO) enrichment analyses were performed, and the protein-protein interaction (PPI) network, target gene - miRNA regulatory network, target gene - TF regulatory network of the differentially expressed genes (DEGs) were constructed using Cytoscape software. Identification of diagnostic biomarkers was conducted using receiver operating characteristic (ROC) curve analysis. 994 DEGs (496 up regulated and 498 down regulated genes) were identified. Pathway and GO enrichment analysis showed up and down regulated genes mainly enriched in the NOD-like receptor signaling pathway, Ribosome, response to external biotic stimulus and viral transcription in SARS-CoV-2 infection. Down and up regulated genes were selected to establish the PPI network, modules, target gene - miRNA regulatory network, target gene - TF regulatory network revealed that these genes were involved in adaptive immune system, fluid shear stress and atherosclerosis, influenza A and protein processing in endoplasmic reticulum. In total, ten genes (CBL, ISG15, NEDD4, PML, REL, CTNNB1, ERBB2, JUN, RPS8 and STUB1) were identified as good diagnostic biomarkers. In conclusion, the identified DEGs, hub genes and target genes contribute to the understanding of the molecular mechanisms underlying the advancement of SARS-CoV-2 infection and they may be used as diagnostic and molecular targets for the treatment of patients with SARS-CoV-2 infection in the future.