Properties and Functions of Feline Herpesvirus Type 1 Glycoproteins.

Abstract

ABSTRACT. Feline herpesvirus type 1 (FHV-1) is a causative agent of feline viral rhinotracheitis and belongs to the subfamily Alphaherpesvirinae of the family Herpesviridae. Since first isolated in 1958 by Crandell and Maurer, FHV-1 is distributed worldwide and is the most clinically significant agent for respiratory infections in cats. In this review, we describe the recent findings with properties and functions of FHV-1 glycoproteins, especially hemagglutinins. -KEY WORDS: feline herpesvirus type 1, glycoprotein, hemagglutinin.J. Vet. Med. Sci. 60(8): 881-888, 1998 negative staining of the virions [16,52,54,88] or ultrathin sectioning of FHV-1-infected cells [11,54], mature virus particles are 120-180 nm in diameter, with various morphologies in shapes and sizes of the envelope surrounding the hexagonal outline of the capsid. The genome of FHV-1 consists of approximately 126-134 kbp. It has a G+C content of approximately 50%. The genome is divided into two unique portions, the unique long (U L ) and unique short (U S ) regions, by inverted repeat segments (IR) (Fig. 1) [24,70]. The U L is 99-104 kbp in size and is composed of unique DNA. The adjacent short segment is approximately 27-30 kbp in size and contains a central portion of Us which is approximately 8-9 kbp in size. The Us region is bounded by inverted repeat sequences of 7-11 kbp.We have already introduced review articles on recombinant viral vector vaccines for the veterinary use [97] and molecular interactions between retroviruses and herpesviruses [30]. Therefore, this review mainly focuses on some of the recent developments regarding properties and functions of FHV-1 glycoproteins including hemagglutinin.

Epidemiological status of felid herpesvirus type-1 and feline calicivirus infections in Brazil

“…FeHV-1 consists of double-stranded DNA of 134 kilobases (Kb) with icosahedral capsids surrounded by a lipid envelope, presence of tegument between envelope and the capsid, and the diameter of virions range from 120 to 300nm (POVEY, 1979;GASKELL et al, 2007). The genome encodes five envelope glycoproteins that are important in the induction of humoral and cellular immunity (MAEDA et al, 1998). Some FeHV-1 isolates may differ in virulence, although all of them belong to one serotype (GASKELL et al, 2007).…”

“…The induction of neutralizing antibodies occurs after infection, primarily against glycoprotein gD (MAEDA et al, 1998). However, the titers of antibodies induced by natural infection are often low and slowly increase, and may be absent until 40 days post-infection (THIRY et al, 2009).…”

The haemagglutination activity of equine herpesvirus type 1 glycoprotein C

“…FHV-1, CHV and ILTV agglutinate RBCs from their respective hosts, and in FHV-1 and CHV the gD proteins serve as the haemagglutinins (Maeda et al, 1994(Maeda et al, , 1997a(Maeda et al, , 1998Prokofieva and Babkin, 1965). Although EHV-1 also possesses HA activity against equine RBCs, we have shown that this activity is associated with gC, not gD.…”

“…Notably, the gCs of FHV-1, CHV, HSV-1, BHV-1 and PRV are able to agglutinate non-host (murine) RBCs (Maeda et al, 1998; Matsuda-Tsuchida et al, 1991;Noda et al, 1993;Okazaki et al, 1991Okazaki et al, , 1993Okazaki et al, , 1994Tetsu et al, 1989;Trepanier et al, 1985;Trybala et al, 1990Trybala et al, , 1993. For each of these published examples, HA of murine RBCs was inhibited by the addition of heparin, suggesting that the heparin-binding domain of gC has structural similarity to the domain for binding to murine RBCs (Inaba et al, 1990;Maeda et al, 1998;Noda et al, 1993;Okazaki et al, 1993;Tetsu et al, 1989;Trybala et al, 1990Trybala et al, , 1993.…”

“…For both FHV-1 and CHV, the glycoprotein D (gD) protein has been identified as the haemagglutinin (Maeda et al, 1994(Maeda et al, , 1997a. However, multiple viruses [including FHV-1, CHV, herpes simplex virus type 1 (HSV-1), bovine herpesvirus type 1 (BHV-1) and pseudorabies virus (PRV] also exhibit HA activity against murine RBCs; for each of these viruses, the murine-specific haemagglutinin has been assigned to glycoprotein C (gC) (Maeda et al, 1998;Matsuda-Tsuchida et al, 1991;Noda et al, 1993;Okazaki et al, 1991Okazaki et al, , 1993Okazaki et al, , 1994Tetsu et al, 1989;Trybala et al, 1990Trybala et al, , 1993. HA activities of these herpesviral gCs can be inhibited by heparin (Maeda et al, 1998;Noda et al, 1993;Okazaki et al, 1991Okazaki et al, , 1993Trybala et al, 1993).…”