Administration of aerosolized SARS-CoV-2 to K18-hACE2 mice uncouples respiratory infection from fatal neuroinvasion.

The development of a tractable small animal model faithfully reproducing human coronavirus disease 2019 pathogenesis would arguably meet a pressing need in biomedical research. Thus far, most investigators have used transgenic mice expressing the human ACE2 in epithelial cells (K18-hACE2 transgenic mice) that are intranasally instilled with a liquid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) suspension under deep anesthesia. Unfortunately, this experimental approach results in disproportionate high central nervous system infection leading to fatal encephalitis, which is rarely observed in humans and severely limits this model's usefulness. Here, we describe the use of an inhalation tower system that allows exposure of unanesthetized mice to aerosolized virus under controlled conditions. Aerosol exposure of K18-hACE2 transgenic mice to SARS-CoV-2 resulted in robust viral replication in the respiratory tract, anosmia, and airway obstruction but did not lead to fatal viral neuroinvasion. When compared with intranasal inoculation, aerosol infection resulted in a more pronounced lung pathology including increased immune infiltration, fibrin deposition, and a transcriptional signature comparable to that observed in SARS-CoV-2­infected patients. This model may prove useful for studies of viral transmission, disease pathogenesis (including long-term consequences of SARS-CoV-2 infection), and therapeutic interventions.

COVID-19 and the Eye: Ocular Manifestations, Treatment and Protection Measures.

The novel pandemic coronavirus disease 2019 (COVID-19) leading to health and economic problems worldwide is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although COVID-19 mainly occurs as a lower respiratory tract infection, there is multiorgan involvement in infected patients. The disease is transmitted from person to person through air droplets or contact with contaminated surfaces. SARS-CoV-2 leads to this systemic involvement by attaching to angiotensin-converting enzyme 2 (ACE2) receptors located on several human cells. Since SARS-CoV-2 RNA has been found in tears of infected patients, ocular surface may allow the virus to transmit to nasopharynx via the nasolacrimal duct. This narrative review aims to sum up all segmental ocular complications, ocular adverse effects of COVID-19 treatment, and preventive measures suggested to minimize the SARS-CoV-2 transmission between patients and ophthalmologists by reviewing currently available literature.

Identification and Characterization of Rift Valley Fever Virus-Specific T Cells Reveals a Dependence on CD40/CD40L Interactions for Prevention of Encephalitis.

Rift Valley fever virus (RVFV) is an arbovirus found throughout Africa. It causes disease that is typically mild and self-limiting; however, some infected individuals experience severe manifestations, including hepatitis, encephalitis, or even death. Reports of RVFV encephalitis are notable among immunosuppressed individuals, suggesting a role for adaptive immunity in preventing this severe complication. This phenomenon has been modeled in C57BL/6 mice depleted of CD4 T cells prior to infection with DelNSs RVFV (RVFV containing a deletion of nonstructural protein NSs), resulting in late-onset encephalitis accompanied by high levels of viral RNA in the brain in 30% of animals. In this study, we sought to define the specific type(s) of CD4 T cells that mediate protection from RVFV encephalitis. The viral epitopes targeted by CD4 and CD8 T cells were defined in C57BL/6 mice, and tetramers for both CD4 and CD8 T cells were generated. RVFV-specific CD8 T cells were expanded and of a cytotoxic and proliferating phenotype in the liver following infection. RVFV-specific CD4 T cells were identified in the liver and spleen following infection and phenotyped as largely Th1 or Tfh subtypes. Knockout mice lacking various aspects of pathways important in Th1 and Tfh development and function were used to demonstrate that T-bet, CD40, CD40L, and major histocompatibility complex class II (MHC-II) mediated protection from RVFV encephalitis, while gamma interferon (IFN-γ) and interleukin-12 (IL-12) were dispensable. Virus-specific antibody responses correlated with protection from encephalitis in all mouse strains, suggesting that Tfh/B cell interactions modulate clinical outcome in this model. IMPORTANCE The prevention of RVFV encephalitis requires intact adaptive immunity. In this study, we developed reagents to detect RVFV-specific T cells and provide evidence for Tfh cells and CD40/CD40L interactions as critical mediators of this protection.

Peripheral Injection of Tim-3 Antibody Attenuates VSV Encephalitis by Enhancing MHC-I Presentation.

Viral encephalitis is the most common cause of encephalitis. It is responsible for high morbidity rates, permanent neurological sequelae, and even high mortality rates. The host immune response plays a critical role in preventing or clearing invading pathogens, especially when effective antiviral treatment is lacking. However, due to blockade of the blood-brain barrier, it remains unclear how peripheral immune cells contribute to the fight against intracerebral viruses. Here, we report that peripheral injection of an antibody against human Tim-3, an immune checkpoint inhibitor widely expressed on immune cells, markedly attenuated vesicular stomatitis virus (VSV) encephalitis, marked by decreased mortality and improved neuroethology in mice. Peripheral injection of Tim-3 antibody enhanced the recruitment of immune cells to the brain, increased the expression of major histocompatibility complex-I (MHC-I) on macrophages, and as a result, promoted the activation of VSV-specific CD8+ T cells. Depletion of macrophages abolished the peripheral injection-mediated protection against VSV encephalitis. Notably, for the first time, we found a novel post-translational modification of MHC-I by Tim-3, wherein, by enhancing the expression of MARCH9, Tim-3 promoted the proteasome-dependent degradation of MHC-I via K48-linked ubiquitination in macrophages. These results provide insights into the immune response against intracranial infections; thus, manipulating the peripheral immune cells with Tim-3 antibody to fight viruses in the brain may have potential applications for combating viral encephalitis.

Recombinant bovine IL17A acts as an adjuvant for bovine herpesvirus vaccine.

The Bovine herpes virus type 5 glycoprotein D (gD) is essential for viral penetration into host permissive cells. The Herpes virus gD glycoprotein has been used for bovine immunization, being efficient in reduction of viral replication, shedding and clinical signs, however sterilizing immunity is still not achieved. Recombinant subunit vaccines are, in general, poorly immunogenic requiring additional adjuvant components. Interleukin 17A (IL17A) is a pro-inflammatory cytokine produced by T helper 17 cells that mediate mucosal immunity. IL17 production during vaccine-induced immunity is a requirement for mucosal protection to several agents. In this study, we investigated the potential of a recombinant IL17A to act as an adjuvant for a recombinant BoHV-5 glycoprotein D vaccine in cattle. Three cattle groups were divided as: group 1) rgD5 + alumen + rIL-17A; 2) rgD5 + alumen; and 3) PBS + alumen. The cattle (3 per group) received two doses of their respective vaccines at an interval of 21 days. The group that received rIL17 in its vaccine formulation at the 7th day after the prime immunization had significant higher levels of specific rgD-IgG than the alumen group. Addition of rIL17 also led to a significant fold increase in specific anti-rgD IgG and neutralizing antibodies to the virus, respectively, when compared with the alumen group. Cells stimulated with rIL17A responded with IL17 transcription, as well IL2, IL4, IL10, IL15, Bcl6 and CXCR5. Our findings suggest that the rIL17A has adjuvant potential for use in vaccines against BoHV-5 as well as potentially other pathogens of cattle.

Epidemiology, management, and graft outcomes after West Nile virus encephalitis in kidney transplant recipients.

BACKGROUND: Minimal data exist describing the epidemiology, management, and long-term graft outcomes after West Nile viral disease in kidney transplant recipients (KTRs). METHODS: Single-center observational cohort study of patients who received a kidney transplant between 1/1/1994 and 12/31/2018 and developed WNV at any time point after transplantation. RESULTS: During the 24-year study period, 11 patients had documented WNV infection. Seven patients were recipients of a kidney transplant alone, and four had a simultaneous kidney and pancreas transplant. The mean age at the time of transplant was 44.7 ± 17.1 years, and the mean age at the time of WNV infection was 48 ± 17.2 years. All patients received lymphocyte depleting induction at transplant (alemtuzumab (n = 2), OKT3 (n = 1), or anti-thymocyte globulin (n = 8)). The mean time from transplant to WNV infection was 3.4 ± 5.4 years, and none was suspected of having a donor-derived infection. Three patients were treated for rejection in the 6 months before infection. The most common presenting symptom was altered mental status (n = 7), followed by a combination of fever and headache (n = 4). All patients had detectable serum WNV IgM antibodies at the time of diagnosis. All patients had a reduction in their immunosuppression and received supportive care; only two patients were treated with intravenous immunoglobulins. Nine patients recovered with no residual deficit; however, two suffered permanent neurologic damage. The mean estimated glomerular filtration rate drop at 1 year after the infection was 8.4 ± 13 mL/min/1.73 m2 . Three patients suffered acute rejection within 1 year after the infection episode, likely attributable to aggressive immunosuppressive reduction. The mean follow-up after the infection was 5.1 ± 4.3 years. At last follow-up, two patients lost their kidney allograft, and five patients died. None of the graft losses or deaths occurred within a year of the WNV or were directly attributable to WNV. CONCLUSION: The majority of patients with WNV infection after KTR recovered fully with supportive care and immunosuppressive adjustment without residual neurologic sequelae. Additionally, WNV infection was associated with relatively small reductions in eGFR at 1 year.

Nipah Virus: Past Outbreaks and Future Containment.

Viral outbreaks of varying frequencies and severities have caused panic and havoc across the globe throughout history. Influenza, small pox, measles, and yellow fever reverberated for centuries, causing huge burden for economies. The twenty-first century witnessed the most pathogenic and contagious virus outbreaks of zoonotic origin including severe acute respiratory syndrome coronavirus (SARS-CoV), Ebola virus, Middle East respiratory syndrome coronavirus (MERS-CoV) and Nipah virus. Nipah is considered one of the world's deadliest viruses with the heaviest mortality rates in some instances. It is known to cause encephalitis, with cases of acute respiratory distress turning fatal. Various factors contribute to the onset and spread of the virus. All through the infected zone, various strategies to tackle and enhance the surveillance and awareness with greater emphasis on personal hygiene has been formulated. This review discusses the recent outbreaks of Nipah virus in Malaysia, Bangladesh and India, the routes of transmission, prevention and control measures employed along with possible reasons behind the outbreaks, and the precautionary measures to be ensured by private-public undertakings to contain and ensure a lower incidence in the future.

CpG Oligonucleotides Protect Mice From Alphavirus Encephalitis: Role of NK Cells, Interferons, and TNF.

Arboviruses including alphavirus are responsible for most emerging infectious diseases worldwide. Recent outbreaks of chikungunya virus serve as a stark reminder to their pathogenic potential. There are no vaccines or therapeutics currently available to contain alphavirus outbreaks. In this study we evaluated the effect of immunomodulatory CpG ODN on the clinical progression of neurotropic Sindbis virus infection. Neonatal C57Bl-6 mice challenged with Sindbis virus AR339 (25 PFU Subcutaneous) infect neurons in the CNS leading to the development of ataxia, seizures, paralysis, and death. We show that systemic administration of CpG ODN modulates the cytokine and chemokine gene expression levels in the CNS and ultimately protects neonatal mice from lethal neurotropic infection. The protection conferred by CpG ODN is controlled by innate immune response and T and B cells were dispensable. Further, protection required Type I, Type II interferons, and TNF as well as functional NK cells, but did not involve iNOS. This study confirms that administration of innate immune modulators can be used as a strategy to boost host innate immune responses and protect against neurotropic viruses reducing their pathogenic footprint.

The microbiota protects from viral-induced neurologic damage through microglia-intrinsic TLR signaling.

Symbiotic microbes impact the function and development of the central nervous system (CNS); however, little is known about the contribution of the microbiota during viral-induced neurologic damage. We identify that commensals aid in host defense following infection with a neurotropic virus through enhancing microglia function. Germfree mice or animals that receive antibiotics are unable to control viral replication within the brain leading to increased paralysis. Microglia derived from germfree or antibiotic-treated animals cannot stimulate viral-specific immunity and microglia depletion leads to worsened demyelination. Oral administration of toll-like receptor (TLR) ligands to virally infected germfree mice limits neurologic damage. Homeostatic activation of microglia is dependent on intrinsic signaling through TLR4, as disruption of TLR4 within microglia, but not the entire CNS (excluding microglia), leads to increased viral-induced clinical disease. This work demonstrates that gut immune-stimulatory products can influence microglia function to prevent CNS damage following viral infection.

Compartmentalization of a Multidrug-Resistant Cytomegalovirus UL54 Mutant in a Stem Cell Transplant Recipient with Encephalitis.

We report a case of cytomegalovirus encephalitis in a hematopoietic stem cell transplant recipient. A previously uncharacterized V787E mutation in UL54 was identified in cerebrospinal fluid but not plasma specimens. For the V787E recombinant virus, the half maximal effective concentrations for ganciclovir, foscarnet, and cidofovir were 8.6-, 3.4- and 2.9-fold higher than for wild-type virus, and the replicative capacity was lower. The introduction of a bulkier and negatively charged glutamate residue at position 787 could destabilize the finger domain of UL54 DNA polymerase. Viral genotyping of cerebrospinal fluid is warranted in subjects with cytomegalovirus encephalitis, owing to the low penetration of antivirals in this compartment.

CD4 T Cells, CD8 T Cells, and Monocytes Coordinate To Prevent Rift Valley Fever Virus Encephalitis.

Rift Valley fever virus (RVFV) is an arbovirus that causes disease in livestock and humans in Africa and the Middle East. While human disease is typically mild and self-limiting, some individuals develop severe manifestations, such as hepatitis, hemorrhagic fever, or encephalitis. Encephalitis occurs 2 to 3 weeks after acute illness; therefore, we hypothesized that it was a result of an inadequate adaptive immunity. To test this hypothesis in vivo, we used an attenuated virus (DelNSsRVFV) that does not typically cause disease in mice. We first characterized the normal immune response to infection with DelNSsRVFV in immunocompetent mice and noted expansion of natural killer cells and monocytes, as well as activation of both CD8 and CD4 T cells. Depleting C57BL/6 mice of CD4 T cells prior to DelNSsRVFV infection resulted in encephalitis in 30% of the mice; in encephalitic mice, we noted infiltration of T cells and inflammatory monocytes into the brain. CD4 and CD8 codepletion in C57BL/6 mice, as well as CD4 depletion in CCR2 knockout mice, increased the frequency of encephalitis, demonstrating that these cell types normally contributed to the prevention of disease. Encephalitic mice had similar viral RNA loads in the brain regardless of which cell types were depleted, suggesting that CD4 T cells, CD8 T cells, and inflammatory monocytes did little to control viral replication in the brain. CD4-depleted mice exhibited diminished humoral and T cell memory responses, suggesting that these immune mechanisms contributed to peripheral control of virus, thus preventing infection of the brain.IMPORTANCE RVFV is found in Africa and the Middle East and is transmitted by mosquitos or through contact with infected animals. Infected individuals can develop mild disease or more severe forms, such as hepatitis or encephalitis. In order to understand why some individuals develop encephalitis, we first need to know which immune functions protect those who do not develop this form of disease. In this study, we used a mouse model of RVFV infection to demonstrate that CD4 T cells, CD8 T cells, and monocytes all contribute to prevention of encephalitis. Their likely mechanism of action is preventing RVFV from ever reaching the brain.

Lipid-Coated Mesoporous Silica Nanoparticles for the Delivery of the ML336 Antiviral to Inhibit Encephalitic Alphavirus Infection.

Venezuelan equine encephalitis virus (VEEV) poses a major public health risk due to its amenability for use as a bioterrorism agent and its severe health consequences in humans. ML336 is a recently developed chemical inhibitor of VEEV, shown to effectively reduce VEEV infection in vitro and in vivo. However, its limited solubility and stability could hinder its clinical translation. To overcome these limitations, lipid-coated mesoporous silica nanoparticles (LC-MSNs) were employed. The large surface area of the MSN core promotes hydrophobic drug loading while the liposome coating retains the drug and enables enhanced circulation time and biocompatibility, providing an ideal ML336 delivery platform. LC-MSNs loaded 20 ± 3.4 µg ML336/mg LC-MSN and released 6.6 ± 1.3 µg/mg ML336 over 24 hours. ML336-loaded LC-MSNs significantly inhibited VEEV in vitro in a dose-dependent manner as compared to unloaded LC-MSNs controls. Moreover, cell-based studies suggested that additional release of ML336 occurs after endocytosis. In vivo safety studies were conducted in mice, and LC-MSNs were not toxic when dosed at 0.11 g LC-MSNs/kg/day for four days. ML336-loaded LC-MSNs showed significant reduction of brain viral titer in VEEV infected mice compared to PBS controls. Overall, these results highlight the utility of LC-MSNs as drug delivery vehicles to treat VEEV.

Protective efficacy of monovalent and trivalent recombinant MVA-based vaccines against three encephalitic alphaviruses.

The three encephalitic alphaviruses, western, eastern, and Venezuelan equine encephalitis viruses (WEEV, EEEV, and VEEV) are potential biothreat agents due to high infectivity through aerosol exposure, ease of production in large amounts, and relative stability in the environment. Currently, there is no licensed vaccine for human use to these three encephalitic alphaviruses, and efforts to move vaccine candidates forward into clinical trials have not been successful. In this study, the modified vaccinia Ankara-Bavarian Nordic (MVA-BN®) vaccine platform was used to construct and produce three monovalent recombinant MVA-BN-based encephalitic alphavirus vaccines, MVA-BN-W, MVA-BN-E, and MVA-BN-V. Additionally, a MVA-BN-based construct was designed to produce antigens against all three alphaviruses, the trivalent vaccine MVA-BN-WEV. The protective efficacy of these vaccines was evaluated in vivo. Female BALB/c mice were immunized with two doses of each monovalent MVA-BN-based alphavirus vaccine, a mixture of the three monovalent vaccines, MVA-BN-W + E + V, or the trivalent vaccine MVA-BN-WEV at a four-week interval. Two weeks after the booster immunization, the mice were instilled intranasally with 5 × 103 to 1 × 104 plaque forming units of WEEV, EEEV, or VEEV. All mice immunized with monovalent vaccines survived the respective virus challenge without any signs of illness or weight loss, while all the control mice died. The triple mixture of vaccines or the trivalent vaccine also provided 90 to 100% protection to the mice against WEEV and VEEV challenges, and 60% to 90% protection against EEEV challenge. These data suggest that each monovalent MVA-BN-W, MVA-BN-E, and MVA-BN-V is a potential vaccine candidate against respective encephalitic alphavirus and the three monovalent vaccines can be given in a mixture (MVA-BN-W + E + V) or the trivalent vaccine MVA-BN-WEV can serve as a true multivalent vaccine without significantly reducing efficacy against WEEV and VEEV despite slightly reduced efficacy against EEEV challenge.

Effects of Prophylactic Foscarnet on Human Herpesvirus-6 Reactivation and Encephalitis in Cord Blood Transplant Recipients: A Prospective Multicenter Trial with an Historical Control Group.

Cord blood transplantation (CBT) is a distinct risk factor for human herpesvirus-6 (HHV-6) reactivation and HHV-6 encephalitis. In a prospective multicenter trial we investigated the effects of prophylactic foscarnet (90 mg/kg i.v. infusion from days 7 to 27 after CBT) on the occurrence of HHV-6 reactivation, HHV-6 encephalitis, and acute graft-versus-host disease (aGVHD) in CBT recipients. Between 2014 and 2016, 57 patients were included in a foscarnet-prophylaxis group. Outcomes were compared with an historical control group who received CBT between 2010 and 2014 (standard-treatment group, n = 63). The cumulative incidence of high-level HHV-6 reactivation, defined as plasma HHV-6 DNA ≥ 104 copies/mL, at 60 days after CBT was significantly lower in the foscarnet-prophylaxis group than in the standard-treatment group (18.3% versus 57.3%, P < .001). Multivariate analysis revealed that myeloablative preconditioning and standard treatment were significant risk factors for high-level HHV-6 reactivation. The cumulative incidence of HHV-6 encephalitis at 60 days after CBT was not different between the groups (foscarnet-prophylaxis group, 12.4%; standard-treatment group, 4.9%; P = .14). The cumulative incidences of grades II to IV and grades III to IV aGVHD at 60 days after CBT were not different between the groups (grades II to IV aGVHD: foscarnet-prophylaxis group, 42.0%; standard-treatment group, 40.5%; P = .96; grades III to IV aGVHD: foscarnet-prophylaxis group, 14.5%; standard-treatment group, 14.5%; P = 1.00). In the setting of this study foscarnet significantly suppressed systemic HHV-6 reactivation in CBT recipients but failed to prevent the development of HHV-6 encephalitis. Suppression of HHV-6 reactivation by foscarnet did not show any effects against the incidence of aGVHD.

IFNγ inhibits G-CSF induced neutrophil expansion and invasion of the CNS to prevent viral encephalitis.

Emergency hematopoiesis facilitates the rapid expansion of inflammatory immune cells in response to infections by pathogens, a process that must be carefully regulated to prevent potentially life threatening inflammatory responses. Here, we describe a novel regulatory role for the cytokine IFNγ that is critical for preventing fatal encephalitis after viral infection. HSV1 encephalitis (HSE) is triggered by the invasion of the brainstem by inflammatory monocytes and neutrophils. In mice lacking IFNγ (GKO), we observed unrestrained increases in G-CSF levels but not in GM-CSF or IL-17. This resulted in uncontrolled expansion and infiltration of apoptosis-resistant, degranulating neutrophils into the brainstem, causing fatal HSE in GKO but not WT mice. Excessive G-CSF in GKO mice also induced granulocyte derived suppressor cells, which inhibited T-cell proliferation and function, including production of the anti-inflammatory cytokine IL-10. Unexpectedly, we found that IFNγ suppressed G-CSF signaling by increasing SOCS3 expression in neutrophils, resulting in apoptosis. Depletion of G-CSF, but not GM-CSF, in GKO mice induced neutrophil apoptosis and reinstated IL-10 secretion by T cells, which restored their ability to limit innate inflammatory responses resulting in protection from HSE. Our studies reveals a novel, complex interplay among IFNγ, G-CSF and IL-10, which highlights the opposing roles of G-CSF and IFNγ in regulation of innate inflammatory responses in a murine viral encephalitis model and reveals G-CSF as a potential therapeutic target. Thus, the antagonistic G-CSF-IFNγ interactions emerge as a key regulatory node in control of CNS inflammatory responses to virus infection.

A MVA construct expressing a secretable form of the Dengue virus 3 envelope protein protects immunized mice from dengue-induced encephalitis.

Dengue is no longer restricted to tropical developing countries, but is now a major global public health problem. Despite the recent license approval of the CYD-TDV vaccine in some countries, efforts to develop a more efficient vaccine against Dengue virus (DENV) continue. Herein, we evaluate the immunogenicity and level of protection of two potential vaccines against DENV based on recombinant modified vaccinia virus Ankara (rMVA). The vaccine addressing the Envelope protein from DENV serotype 3 to the endoplasmic reticulum elicited neutralizing antibodies titers which correlate with protection, and also confers protection upon challenge in a mouse model. Our results support the development of a tetravalent dengue vaccine with the further construction of rMVAs expressing proteins from the other DENV serotypes.

EV-A71 vaccine licensure: a first step for multivalent enterovirus vaccine to control HFMD and other severe diseases.

Enteroviruses (EVs) are the most common viral agents in humans. Although most infections are mild or asymptomatic, there is a wide spectrum of clinical manifestations that may be caused by EV infections with varying degrees of severity. Among these viruses, EV-A71 and coxsackievirus (CV) CV-A16 from group A EVs attract the most attention because they are responsible for hand, foot and mouth disease (HFMD). Other EV-A viruses such as CV-A6 and CV-A10 were also reported to cause HFMD outbreaks in several countries or regions. Group B EVs such as CV-B3, CV-B5 and echovirus 30 were reported to be the main pathogens responsible for myocarditis and encephalitis epidemics and were also detected in HFMD patients. Vaccines are the best tools to control infectious diseases. In December 2015, China's Food and Drug Administration approved two inactivated EV-A71 vaccines for preventing severe HFMD.The CV-A16 vaccine and the EV-A71-CV-A16 bivalent vaccine showed substantial efficacy against HFMD in pre-clinical animal models. Previously, research on EV-B group vaccines was mainly focused on CV-B3 vaccine development. Because the HFMD pathogen spectrum has changed, and the threat from EV-B virus-associated severe diseases has gradually increased, it is necessary to develop multivalent HFMD vaccines. This study summarizes the clinical symptoms of diseases caused by EVs, such as HFMD, myocarditis and encephalitis, and the related EV vaccine development progress. In conclusion, developing multivalent EV vaccines should be strongly recommended to prevent HFMD, myocarditis, encephalitis and other severe diseases.

Complete genome sequence of mumps viruses isolated from patients with parotitis, pancreatitis and encephalitis in India.

Limited information is available regarding epidemiology of mumps in India. Mumps vaccine is not included in the Universal Immunization Program of India. The complete genome sequences of Indian mumps virus (MuV) isolates are not available, hence this study was performed. Five isolates from bilateral parotitis and pancreatitis patients from Maharashtra, a MuV isolate from unilateral parotitis patient from Tamil Nadu, and a MuV isolate from encephalitis patient from Uttar Pradesh were genotyped by the standard protocol of the World Health Organization and subsequently complete genomes were sequenced. Indian MuV genomes were compared with published MuV genomes, including reference genotypes and eight vaccine strains for the genetic differences. The SH gene analysis revealed that five MuV isolates belonged to genotype C and two belonged to genotype G strains. The percent nucleotide divergence (PND) was 1.1% amongst five MuV genotype C strains and 2.2% amongst two MuV genotype G strains. A comparison with widely used mumps Jeryl Lynn vaccine strain revealed that Indian mumps isolates had 54, 54, 53, 49, 49, 38, and 49 amino acid substitutions in Chennai-2012, Kushinagar-2013, Pune-2008, Osmanabad-2012a, Osmanabad-2012b, Pune-1986 and Pune-2012, respectively. This study reports the complete genome sequences of Indian MuV strains obtained in years 1986, 2008, 2012 and 2013 that may be useful for further studies in India and globally.

Antibodies are not required to a protective immune response against dengue virus elicited in a mouse encephalitis model.

Generating neutralizing antibodies have been considered a prerequisite to control dengue virus (DENV) infection. However, T lymphocytes have also been shown to be important in a protective immune state. In order to investigate the contribution of both humoral and cellular immune responses in DENV immunity, we used an experimental model in which a non-lethal DENV2 strain (ACS46) is used to intracranially prime Balb/C mice which develop protective immunity against a lethal DENV2 strain (JHA1). Primed mice generated envelope-specific antibodies and CD8(+) T cell responses targeting mainly non-structural proteins. Immune sera from protected mice did not confer passive protection to naïve mice challenged with the JHA1 strain. In contrast, depletion of CD4(+) and CD8(+) T lymphocytes significantly reduced survival of ACS46-primed mice challenged with the JHA1 strain. Collectively, results presented in this study show that a cellular immune response targeting non-structural proteins are a promising way in vaccine development against dengue.