Infections in recipients of liver homografts.

Seventeen patients received liver homografts between 1963 and May, 1968. The eight treated before July, 1967, died within 34 days; seven had progressive infections with gram-negative bacilli, Candida albicans and cytomegalovirus. The infections were similar to but more fulminating than those after renal homotransplantation. In nine later cases, there was more discriminating donor selection, improved immunosuppression, and better organ preservation. In the first five of these nine patients, all infants, lobar hepatic gangrene apparently secondary to delayed right hepatic arterial thrombosis developed. Two died within a few days, two and three and a half months after transplantation. The three who did not die immediately subsequently had multiple bacteremias, fungemias and cytomegalovirus pulmonary infections. One of these children is alive twelve months after transplantation; the others died after four and a half and six months. In contrast, the last four patients, in whom septic liver infarctions were avoided, have been free of serious infections for two to five and a half months

Genomic Expression Libraries for the Identification of Cross-Reactive Orthopoxvirus Antigens

Increasing numbers of human cowpox virus infections that are being observed and that particularly affect young non-vaccinated persons have renewed interest in this zoonotic disease. Usually causing a self-limiting local infection, human cowpox can in fact be fatal for immunocompromised individuals. Conventional smallpox vaccination presumably protects an individual from infections with other Orthopoxviruses, including cowpox virus. However, available live vaccines are causing severe adverse reactions especially in individuals with impaired immunity. Because of a decrease in protective immunity against Orthopoxviruses and a coincident increase in the proportion of immunodeficient individuals in today's population, safer vaccines need to be developed. Recombinant subunit vaccines containing cross-reactive antigens are promising candidates, which avoid the application of infectious virus. However, subunit vaccines should contain carefully selected antigens to confer a solid cross-protection against different Orthopoxvirus species. Little is known about the cross-reactivity of antibodies elicited to cowpox virus proteins. Here, we first identified 21 immunogenic proteins of cowpox and vaccinia virus by serological screenings of genomic Orthopoxvirus expression libraries. Screenings were performed using sera from vaccinated humans and animals as well as clinical sera from patients and animals with a naturally acquired cowpox virus infection. We further analyzed the cross-reactivity of the identified immunogenic proteins. Out of 21 identified proteins 16 were found to be cross-reactive between cowpox and vaccinia virus. The presented findings provide important indications for the design of new-generation recombinant subunit vaccines

Inactivation of respiratory syncytial virus by zinc finger reactive compounds

<p>Abstract</p> <p>Background</p> <p>Infectivity of retroviruses such as HIV-1 and MuLV can be abrogated by compounds targeting zinc finger motif in viral nucleocapsid protein (NC), involved in controlling the processivity of reverse transcription and virus infectivity. Although a member of a different viral family (<it>Pneumoviridae</it>), respiratory syncytial virus (RSV) contains a zinc finger protein M2-1 also involved in control of viral polymerase processivity. Given the functional similarity between the two proteins, it was possible that zinc finger-reactive compounds inactivating retroviruses would have a similar effect against RSV by targeting RSV M2-1 protein. Moreover, inactivation of RSV through modification of an internal protein could yield a safer whole virus vaccine than that produced by RSV inactivation with formalin which modifies surface proteins.</p> <p>Results</p> <p>Three compounds were evaluated for their ability to reduce RSV infectivity: 2,2'-dithiodipyridine (AT-2), tetraethylthiuram disulfide and tetramethylthiuram disulfide. All three were capable of inactivating RSV, with AT-2 being the most potent. The mechanism of action of AT-2 was analyzed and it was found that AT-2 treatment indeed results in the modification of RSV M2-1. Altered intramolecular disulfide bond formation in M2-1 protein of AT-2-treated RSV virions might have been responsible for abrogation of RSV infectivity. AT-2-inactivated RSV was found to be moderately immunogenic in the cotton rats <it>S.hispidus </it>and did not cause a vaccine-enhancement seen in animals vaccinated with formalin-inactivated RSV. Increasing immunogenicity of AT-2-inactivated RSV by adjuvant (Ribi), however, led to vaccine-enhanced disease.</p> <p>Conclusions</p> <p>This work presents evidence that compounds that inactivate retroviruses by targeting the zinc finger motif in their nucleocapsid proteins are also effective against RSV. AT-2-inactivated RSV vaccine is not strongly immunogenic in the absence of adjuvants. In the adjuvanted form, however, vaccine induces immunopathologic response. The mere preservation of surface antigens of RSV, therefore may not be sufficient to produce a highly-efficacious inactivated virus vaccine that does not lead to an atypical disease.</p

Immunogenicity and Protective Capacity of a Virosomal Respiratory Syncytial Virus Vaccine Adjuvanted with Monophosphoryl Lipid A in Mice

Respiratory Syncytial Virus (RSV) is a major cause of viral brochiolitis in infants and young children and is also a significant problem in elderly and immuno-compromised adults. To date there is no efficacious and safe RSV vaccine, partially because of the outcome of a clinical trial in the 1960s with a formalin-inactivated RSV vaccine (FI-RSV). This vaccine caused enhanced respiratory disease upon exposure to the live virus, leading to increased morbidity and the death of two children. Subsequent analyses of this incident showed that FI-RSV induces a Th2-skewed immune response together with poorly neutralizing antibodies. As a new approach, we used reconstituted RSV viral envelopes, i.e. virosomes, with incorporated monophosphoryl lipid A (MPLA) adjuvant to enhance immunogenicity and to skew the immune response towards a Th1 phenotype. Incorporation of MPLA stimulated the overall immunogenicity of the virosomes compared to non-adjuvanted virosomes in mice. Intramuscular administration of the vaccine led to the induction of RSV-specific IgG2a levels similar to those induced by inoculation of the animals with live RSV. These antibodies were able to neutralize RSV in vitro. Furthermore, MPLA-adjuvanted RSV virosomes induced high amounts of IFNγ and low amounts of IL5 in both spleens and lungs of immunized and subsequently challenged animals, compared to levels of these cytokines in animals vaccinated with FI-RSV, indicating a Th1-skewed response. Mice vaccinated with RSV-MPLA virosomes were protected from live RSV challenge, clearing the inoculated virus without showing signs of lung pathology. Taken together, these data demonstrate that RSV-MPLA virosomes represent a safe and efficacious vaccine candidate which warrants further evaluation

Adverse Events Post Smallpox-Vaccination: Insights from Tail Scarification Infection in Mice with Vaccinia virus

Adverse events upon smallpox vaccination with fully-replicative strains of Vaccinia virus (VACV) comprise an array of clinical manifestations that occur primarily in immunocompromised patients leading to significant host morbidity/mortality. The expansion of immune-suppressed populations and the possible release of Variola virus as a bioterrorist act have given rise to concerns over vaccination complications should more widespread vaccination be reinitiated. Our goal was to evaluate the components of the host immune system that are sufficient to prevent morbidity/mortality in a murine model of tail scarification, which mimics immunological and clinical features of smallpox vaccination in humans. Infection of C57BL/6 wild-type mice led to a strictly localized infection, with complete viral clearance by day 28 p.i. On the other hand, infection of T and B-cell deficient mice (Rag1−/−) produced a severe disease, with uncontrolled viral replication at the inoculation site and dissemination to internal organs. Infection of B-cell deficient animals (µMT) produced no mortality. However, viral clearance in µMT animals was delayed compared to WT animals, with detectable viral titers in tail and internal organs late in infection. Treatment of Rag1−/− with rabbit hyperimmune anti-vaccinia serum had a subtle effect on the morbidity/mortality of this strain, but it was effective in reduce viral titers in ovaries. Finally, NUDE athymic mice showed a similar outcome of infection as Rag1−/−, and passive transfer of WT T cells to Rag1−/− animals proved fully effective in preventing morbidity/mortality. These results strongly suggest that both T and B cells are important in the immune response to primary VACV infection in mice, and that T-cells are required to control the infection at the inoculation site and providing help for B-cells to produce antibodies, which help to prevent viral dissemination. These insights might prove helpful to better identify individuals with higher risk of complications after infection with poxvirus

Study protocol: Determinants of participation and quality of life of adolescents with cerebral palsy: a longitudinal study (SPARCLE2)

<p>Abstract</p> <p>Background</p> <p>Children and adults with impairments such as cerebral palsy have lower participation in life situations than able-bodied people. Less is known about their subjective perception of their lives, called their quality of life.</p> <p>During adolescence, rapid physical and psychological changes occur; although these may be more difficult for disabled than for able-bodied adolescents, little research has examined the lives of disabled adolescents.</p> <p>In 2003-4 a European Union funded project, SPARCLE, visited 818 children aged 8-12 years with cerebral palsy, sampled from population-based registers in nine European regions. The quality of life reported by these disabled children was similar to that of the general population but their participation was lower; levels of participation varied between countries even for children with similar severity of cerebral palsy.</p> <p>We are currently following up these children, now aged 13-17 years, to identify (i) to what extent contemporaneous factors (pain, impairment, psychological health and parental stress) predict their participation and quality of life, (ii) what factors modify how participation and quality of life at age 8-12 years are associated with participation and quality of life in adolescence, and (iii) whether differences between European countries in participation and quality of life can be explained by variations in environmental factors.</p> <p>Methods/Design</p> <p>Trained researchers will visit families to administer questionnaires to capture the adolescents' type and severity of impairment, socio-demographic characteristics, participation, quality of life, psychological health, pain, environmental access and parental stress. We will use multivariable models (linear, logistic or ordinal) to assess how adolescent participation, quality of life, psychological health, pain, environmental access and parental stress, vary with impairment and socio-demographic characteristics and, where possible, how these outcomes compare with general population data. For participation and quality of life, longitudinal analyses will assess to what extent these are predicted by corresponding levels in childhood and what factors modify this relationship. Structural equation modelling will be used to identify indirect relationships mediated by other factors.</p

Pre-Clinical Evaluation of a Replication-Competent Recombinant Adenovirus Serotype 4 Vaccine Expressing Influenza H5 Hemagglutinin

Influenza virus remains a significant health and social concern in part because of newly emerging strains, such as avian H5N1 virus. We have developed a prototype H5N1 vaccine using a recombinant, replication-competent Adenovirus serotype 4 (Ad4) vector, derived from the U.S. military Ad4 vaccine strain, to express the hemagglutinin (HA) gene from A/Vietnam/1194/2004 influenza virus (Ad4-H5-Vtn). Our hypothesis is that a mucosally-delivered replicating Ad4-H5-Vtn recombinant vector will be safe and induce protective immunity against H5N1 influenza virus infection and disease pathogenesis.The Ad4-H5-Vtn vaccine was designed with a partial deletion of the E3 region of Ad4 to accommodate the influenza HA gene. Replication and growth kinetics of the vaccine virus in multiple human cell lines indicated that the vaccine virus is attenuated relative to the wild type virus. Expression of the HA transgene in infected cells was documented by flow cytometry, western blot analysis and induction of HA-specific antibody and cellular immune responses in mice. Of particular note, mice immunized intranasally with the Ad4-H5-Vtn vaccine were protected against lethal H5N1 reassortant viral challenge even in the presence of pre-existing immunity to the Ad4 wild type virus.Several non-clinical attributes of this vaccine including safety, induction of HA-specific humoral and cellular immunity, and efficacy were demonstrated using an animal model to support Phase 1 clinical trial evaluation of this new vaccine

T Cell-Dependence of Lassa Fever Pathogenesis

Lassa virus (LASV), the causative agent of Lassa fever (LF), is endemic in West Africa, accounting for substantial morbidity and mortality. In spite of ongoing research efforts, LF pathogenesis and mechanisms of LASV immune control remain poorly understood. While normal laboratory mice are resistant to LASV, we report that mice expressing humanized instead of murine MHC class I (MHC-I) failed to control LASV infection and develop severe LF. Infection of MHC-I knockout mice confirmed a key role for MHC-I-restricted T cell responses in controlling LASV. Intriguingly we found that T cell depletion in LASV-infected HHD mice prevented disease, irrespective of high-level viremia. Widespread activation of monocyte/macrophage lineage cells, manifest through inducible NO synthase expression, and elevated IL-12p40 serum levels indicated a systemic inflammatory condition. The absence of extensive monocyte/macrophage activation in T cell-depleted mice suggested that T cell responses contribute to deleterious innate inflammatory reactions and LF pathogenesis. Our observations in mice indicate a dual role for T cells, not only protecting from LASV, but also enhancing LF pathogenesis. The possibility of T cell-driven enhancement and immunopathogenesis should be given consideration in future LF vaccine development

The Role of Research in Viral Disease Eradication and Elimination Programs: Lessons for Malaria Eradication

Using their experiences from, and analysis of, global campaigns to eradicate smallpox, poliomyelitis, and measles, Myron Levine and colleagues derive lessons for malaria eradication