Peptide Antagonists That Inhibit Sin Nombre Virus and Hantaan Virus Entry through the β ₃ -Integrin Receptor

Abstract

Specific therapy is not available for the treatment of hantavirus cardiopulmonary syndrome caused by Sin Nombre virus (SNV). The entry of pathogenic hantaviruses into susceptible human cells is dependent upon expression of the ␣ v ␤ 3 integrin, and transfection of human ␤ 3 integrin is sufficient to confer infectibility onto CHO (Chinese hamster ovary) cells. Furthermore, pretreatment of susceptible cells with anti-␤ 3 antibodies such as c7E3 or its Fab fragment ReoPro prevents hantavirus entry. By using repeated selection of a cyclic nonamer peptide phage display library on purified ␣ v ␤ 3 , we identified 70 peptides that were competitively eluted with ReoPro. Each of these peptides was examined for its ability to reduce the number of foci of SNV strain SN77734 in a fluorescence-based focus reduction assay according to the method of Gavrilovskaya et al. (I. N. Gavrilovskaya, M. Shepley, R. Shaw, M. H. Ginsberg, and E. R. Mackow, Proc. Natl. Acad. Sci. USA 95:7074-7079, 1998). We found that 11 peptides reduced the number of foci to a greater extent than did 80 g/ml ReoPro when preincubated with Vero E6 cells. In addition, 8 of the 70 peptides had sequence similarity to SNV glycoproteins. We compared all 18 peptide sequences (10 most potent, 7 peptides with sequence similarity to hantavirus glycoproteins, and 1 peptide that was in the group that displayed the greatest potency and had significant sequence similarity) for their abilities to inhibit SNV, Hantaan virus (HTNV), and Prospect Hill virus (PHV) infection. There was a marked trend for the peptides to inhibit SNV and HTNV to a greater extent than they inhibited PHV, a finding that supports the contention that SNV and HTNV use ␤ 3 integrins and PHV uses a different receptor, ␤1 integrin. We then chemically synthesized the four peptides that showed the greatest ability to neutralize SNV. These peptides inhibited viral entry in vitro as free peptides outside of the context of a phage. Some combinations of peptides proved more inhibitory than did individual peptides. In all, we have identified novel peptides that inhibit entry by SNV and HTNV via ␤ 3 integrins and that can be used as lead compounds for further structural optimization and consequent enhancement of activity.

Immunoinformatics Predication and Modelling of a Cocktail of B- and T-cells Epitopes from Envelope Glycoprotein and Nucleocapsid Proteins of Sin Nombre Virus

“…Similar to other viruses that cause HCPS, SNV has a serious potential applicability as a biological weapon because of its high lethality and known aerosol route of transmission [5]. Moreover, it causes a considerable economic harm and stigma to affected communities.…”

“…Moreover, it causes a considerable economic harm and stigma to affected communities. Until now, Specific therapy is not available for the treatment of HCPS caused by SNV [2,3,5]. The main treatment of severe HCPS cases is completely supportive, often in intensive care unit surroundings [2].…”

“…The vascular leakage leads to non-cardiogenic pulmonary edema and in serious cases followed by respiratory failure, multi-organ failure, cardiogenic shock and death [5][6][7][8][9][10]. A different of pathogenic mechanisms have been suggested, including immune cell-mediated injury, cytokinemediated injury and enhanced VEGF responses from intercellular junctions resulting from highly specific virus-integrin interactions [8].…”

“…Hantaviruses (Bunyaviridas, Hantavirus) are rodent-borne emerging viruses [1] which cause over 100,000-200,000 cases per annually worldwide [2][3][4][5]. They are broadly classified into the New World Hantaviruses, which includes those causing hantavirus cardiopulmonary syndrome HCPS, and the Old World Hantaviruses, which are associated with another disease, hemorrhagic fever with renal syndrome (HFRS) [2][3][4][5].…”

“…They are broadly classified into the New World Hantaviruses, which includes those causing hantavirus cardiopulmonary syndrome HCPS, and the Old World Hantaviruses, which are associated with another disease, hemorrhagic fever with renal syndrome (HFRS) [2][3][4][5]. This classification is determined by the geographic distribution of the rodent reservoirs [4].…”