5A, anti-BARF1 serum IgG antibodies were not detected in any of the EBV-negative donors but were detected in 66% of the healthy EBV-seropositive individuals and in 70% of the NPC patients

5A, anti-BARF1 serum IgG antibodies were not detected in any of the EBV-negative donors but were detected in 66% of the healthy EBV-seropositive individuals and in 70% of the NPC patients. (NPC). The macaque data accurately predicted that serum antibodies against BARF1 are a normal response to EBV contamination when human serum samples are analyzed. The rhesus macaque animal provides a unique perspective on humoral responses to EBV contamination in humans and can be a valuable model for EBV vaccine development. INTRODUCTION Epstein-Barr virus (EBV) encodes over 60 different proteins during lytic virus replication, including (i) immediate-early (IE) proteins that act principally as transcriptional activators to initiate the cascade of lytic gene expression, (ii) early (E) proteins directed at a variety of functions, MT-802 including gene regulation, immune evasion, nucleotide metabolism, and DNA replication, and (iii) late (L) proteins, most of which are virion proteins (26). Serum antibody responses to lytic contamination proteins are commonly used to diagnose EBV contamination. Induction of humoral immune responses to EBV lytic contamination proteins is also important for EBV vaccines. Antibodies against gp350, the major MT-802 membrane glycoprotein (BLLF1), are capable of neutralizing EBV contamination (24), and recent clinical trials showed that a gp350 subunit vaccine can induce EBV-neutralizing antibodies (7, 22) and protect humans from EBV-induced infectious mononucleosis (IM) (31). Protection was not complete, but this ground-breaking trial provided proof of theory for a vaccine strategy against EBV-induced disease. Since antibody responses are the foundation of most successful virus vaccines, it is not unreasonable to speculate that induction of better humoral immune responses against EBV gp350 or induction of antibody MT-802 responses against other EBV lytic contamination proteins may enhance efficacy of an EBV vaccine. However, testing these hypotheses in human studies can be prohibitive. Rhesus macaques are naturally infected with an EBV-related herpesvirus, or lymphocryptovirus (LCV), that encodes a repertoire of viral proteins identical to that of EBV and which biologically mimics EBV infection in humans with, e.g., oral transmission, asymptomatic persistent latent infections in peripheral blood B cells, lytic replication and viral shedding from the oral cavity, and association with malignant disease (38). EBV-related herpesviruses are found only in humans and nonhuman primates, and infection is tightly restricted to primate cells (19). Thus, models in other small laboratory animals require reconstitution of a human immune system for EBV infection (16), use of more distantly related gammaherpesviruses (32), or injection of EBV-infected B cells with tumor engraftment as the endpoint (21). Naive rhesus macaques can be experimentally infected by oral inoculation with rhesus lymphocryptovirus (rhLCV), providing a highly accurate experimental model for vaccine development and pathogenesis studies. The rhesus macaque model provides a distinct advantage due to a genome that bears a repertoire of viral genes identical to that of EBV (28), experimental infection of a natural host by the normal route of transmission (20), reproduction of a natural host-pathogen relationship resulting in persistent infection (20), and the potential for virus-induced malignancies (27). We have previously demonstrated that the small viral capsid antigen (sVCA; rhBFRF3) is strongly immunogenic in rhLCV-infected macaques, as in EBV-infected humans, and can be used in serologic assays to distinguish between rhLCV-infected and -naive animals (25). In the current study, we evaluate a range of rhLCV lytic infection proteins in order to better understand the repertoire of immunogenic lytic infection proteins in rhLCV-infected macaques. These studies provide a comprehensive picture of humoral immune responses to Rabbit polyclonal to ERCC5.Seven complementation groups (A-G) of xeroderma pigmentosum have been described. Thexeroderma pigmentosum group A protein, XPA, is a zinc metalloprotein which preferentially bindsto DNA damaged by ultraviolet (UV) radiation and chemical carcinogens. XPA is a DNA repairenzyme that has been shown to be required for the incision step of nucleotide excision repair. XPG(also designated ERCC5) is an endonuclease that makes the 3 incision in DNA nucleotide excisionrepair. Mammalian XPG is similar in sequence to yeast RAD2. Conserved residues in the catalyticcenter of XPG are important for nuclease activity and function in nucleotide excision repair lytic infection proteins in a natural, nonhuman primate host infected with an EBV-related herpesvirus. A comparison of humoral immune responses in LCV-infected macaques and humans provides insight into EBV serologic tests and the soundness of the rhesus macaque model for EBV vaccine development. MATERIALS AND METHODS Animals. Rhesus macaques were housed at the New England Primate Research Center (NEPRC). Serum samples were collected from 38 rhesus macaques between 1 and 18 years of age from a conventional colony and from 10 animals from a specific-pathogen-free colony. Stored serum samples from 3 rhLCV-naive macaques experimentally infected by oral rhLCV inoculation 8 years prior to the study were also available. Results of experimental rhLCV infection have been previously reported (27). All animal work was performed with approval from the Committee on Animals for Harvard Medical School, and all animals were maintained in compliance with federal and institutional guidelines for animal care. Natural and experimental rhLCV infections were confirmed by serum immunoassay for positive IgG responses against the sVCA (rhBFRF3) (25). Human sera. Deidentified serum samples were obtained from 15 EBV-seronegative and 35 EBV-seropositive human donors whose EBV statuses were determined by serologic assays for serum antibodies against EBNA and the viral capsid antigen in a clinical diagnostic laboratory. Serum samples were.