A Respiratory Syncytial Virus (RSV) Anti-G Protein F(ab′)<sub>2</sub>Monoclonal Antibody Suppresses Mucous Production and Breathing Effort in RSV rA2-line19F-Infected BALB/c Mice

and may be good candidates for vaccine development. In this study, we examined immunity induced by rMuV⌬SH and rMuV⌬V in mice. Furthermore, we generated recombinant mumps viruses lacking expression of both the V protein and the SH protein (rMuV⌬SH⌬V). Analysis of rMuV⌬SH⌬V indicated that it was stable in tissue culture cell lines. Importantly, rMuV⌬SH⌬V was immunogenic in mice, indicating that it is a promising candidate for mumps vaccine development. Mumps is a human infectious disease characterized by lateral or bilateral nonsuppurative swelling of the parotid glands. In severe cases, mumps can lead to orchitis in postpuberty male patients and damage to the central nervous system. In the prevaccine era, 90% of the population turned seropositive for mumps virus (MuV) by 14 to 15 years of age, reflecting its highly contagious nature. Mumps virus is neurotropic and was one of the most common causes of aseptic meningitis before the implementation of mass mumps vaccination programs.At present, the Jeryl Lynn (JL) vaccine is the most commonly used mumps vaccine, administered as lyophilized live virus with measles and rubella vaccine components. The JL vaccine strain originated from an infectious isolate from a mumps patient in 1963 (1). The virus was attenuated through continuous passages in embryonic hen eggs and chicken embryos/chicken embryo cell cultures (1). The JL vaccine was licensed in the United States in 1967 and has been used for over 40 years. This vaccine has been efficacious and safe overall (2-6). However, several large mumps outbreaks have occurred recently in the United States and worldwide in populations that have been vaccinated with the JL vaccine (7-10). Major mumps outbreaks in the United States include the 2006 multistate mumps outbreak, reporting 6,584 suspected cases originating from the state of Iowa (11, 12) and the 2009 -2010 New York and New Jersey mumps outbreaks with a total of 2,078 suspected cases reported in 2010 (13). Both of the outbreaks occurred among highly vaccinated populations, raising questions about the efficacy of the current vaccination program in the United States. One possible causality is the antigenic differences between the genotype A vaccine strain and the genotype G circulating wild-type mumps viruses.In this study, we seek to develop a mumps vaccine candidate through genetic modification of a clinically isolated mumps virus. Mumps virus is a member of the family Paramyxoviridae, subfamily Paramyxovirinae, and genus Rubulavirus (6,14). It is an enveloped virus enclosing a negative-sense, single-stranded, nonsegmented RNA genome of 15,384 nucleotides in length which encodes 9 viral proteins (15-17). Studies of the function of the Paramyxovirus SH protein reveal that it blocks tumor necrosis factor alpha (TNF-␣) induction, signaling, caspase activation, and NF-B nuclear translocation in transfected and virus-infected cells (18)(19)(20)(21)(22)(23). The V protein is an accessory protein translated from the authentic transcript of the V/P gene (24,25). Mumps V protein...

Section: Discussionsupporting

confidence: 64%

Immunogenicity of Novel Mumps Vaccine Candidates Generated by Genetic Modification

Chen

Phan

et al. 2014

“…Plasmids used to express codon-optimized RSV N, P, M2-1, and L were described (24). DSP [1][2][3][4][5][6][7] and DSP [8][9][10][11] plasmids were a gift from Naoyuki Kondo (25).…”

Section: Methodsmentioning

confidence: 99%

“…Features of A2-line19F pathogenesis in BALB/c mice include high levels of airway goblet cell hyperplasia, a relatively high peak viral load, airway hyperreactivity, and increased breathing effort compared to that caused by the A2 strain and a chimeric virus harboring the F protein of the Long strain in an A2 strain genetic background (3,7). Airway mucin induction leading to airway plugging is considered an important sequelae of RSV disease in infants (8,9).…”

mentioning

confidence: 99%

Identification of Residues in the Human Respiratory Syncytial Virus Fusion Protein That Modulate Fusion Activity and Pathogenesis

Hotard

Lee

Currier

et al. 2015

Self Cite

Human respiratory syncytial virus (RSV) lower respiratory tract infection can result in inflammation and mucus plugging of airways. RSV strain A2-line19F induces relatively high viral load and mucus in mice. The line 19 fusion (F) protein harbors five unique residues compared to the non-mucus-inducing strains A2 and Long, at positions 79, 191, 357, 371, and 557. We hypothesized that differential fusion activity is a determinant of pathogenesis. In a cell-cell fusion assay, line 19 F was more fusogenic than Long F. We changed the residues unique to line 19 F to the corresponding residues in Long F and identified residues 79 and 191 together as responsible for high fusion activity. Surprisingly, mutation of residues 357 or 357 with 371 resulted in gain of fusion activity. Thus, we generated RSV F mutants with a range of defined fusion activity and engineered these into recombinant viruses. We found a clear, positive correlation between fusion activity and early viral load in mice; however, we did not detect a correlation between viral loads and levels of airway mucin expression. The F mutant with the highest fusion activity, A2-line19F-K357T/Y371N, induced high viral loads, severe lung histopathology, and weight loss but did not induce high levels of airway mucin expression. We defined residues 79/191 as critical for line 19 F fusion activity and 357/371 as playing a role in A2-line19F mucus induction. Defining the molecular basis of the role of RSV F in pathogenesis may aid vaccine and therapeutic strategies aimed at this protein. IMPORTANCEHuman respiratory syncytial virus (RSV) is the most important lower respiratory tract pathogen of infants for which there is no vaccine. Elucidating mechanisms of RSV pathogenesis is important for rational vaccine and drug design. We defined specific amino acids in the fusion (F) protein of RSV strain line 19 critical for fusion activity and elucidated a correlation between fusion activity and viral load in mice. Further, we identified two distinct amino acids in F as contributing to the mucogenic phenotype of the A2-line19F virus. Taken together, these results illustrate a role for RSV F in virulence.H uman respiratory syncytial virus (hRSV according to the International Committee on Taxonomy of Viruses; often abbreviated RSV) is a negative-sense, nonsegmented, and singlestranded RNA virus in the Paramyxoviridae family. RSV is the most important viral lower respiratory tract pathogen for infants, causing 16 times more hospitalizations than influenza virus in children under 1 year old (1). There is currently no vaccine licensed to prevent RSV infections; there is also a need for additional therapies, and further knowledge of RSV pathogenesis will enhance efforts toward these goals.Strains of RSV exhibit differential pathogenesis in the BALB/c mouse model of RSV disease (2-4). A strain called line 19 was originally isolated in 1967 and then passaged in primary chick kidney cells, as well as primary chick lung cells, prior to 72 passages in human MRC-5 fibroblast cells (...

“…For example, the G protein is associated with a lower frequency of interferon gamma (IFN-␥) and a higher frequency of interleukin-5 (IL-5)-and IL-6-expressing T cells (29) and alterations in the production of cytokines in infected mice (30). Examples of G-associated host responses that contribute to disease pathogenesis include enhanced inflammation in FI-RSVvaccinated mice challenged with RSV (29,31) and increased pulmonary levels of the tachykinin substance P (32) and mucous production and breathing effort in RSV-challenged mice (33). The G protein also decreased respiratory rates in mice (34).…”

mentioning

confidence: 99%

Prophylaxis with a Respiratory Syncytial Virus (RSV) Anti-G Protein Monoclonal Antibody Shifts the Adaptive Immune Response to RSV rA2-line19F Infection from Th2 to Th1 in BALB/c Mice

Boyoglu-Barnum

Chirkova

Todd

et al. 2014

Self Cite

Respiratory syncytial virus (RSV) is IMPORTANCEThe data in this report suggest that the RSV G protein not only contributes to disease but also dampens the host immune response to infection. Both effects of G likely contribute to difficulties in achieving an effective vaccine. The ability of MAb 131-2G to block these effects of G suggests that inducing antibodies similar to 131-2G should prevent disease and enhance the adaptive immune response with later RSV infection. The fact that 131-2G binds to the 13-amino-acid region conserved among all strains and that flanking sequences are conserved within group A or group B strains simplifies the task of developing a vaccine to induce 131-2G-like antibodies. If our findings in mice apply to humans, then including the 131-2G binding region of G in a vaccine should improve its safety and efficacy.