Adeno-associated viral vectors for functional intravenous gene transfer throughout the non-human primate brain

Crossing the blood-brain barrier in primates is a major obstacle for gene delivery to the brain. Adeno-associated viruses (AAVs) promise robust, non-invasive gene delivery from the bloodstream to the brain. However, unlike in rodents, few neurotropic AAVs efficiently cross the blood-brain barrier in non-human primates. Here we report on AAV.CAP-Mac, an engineered variant identified by screening in adult marmosets and newborn macaques, which has improved delivery efficiency in the brains of multiple non-human primate species: marmoset, rhesus macaque and green monkey. CAP-Mac is neuron biased in infant Old World primates, exhibits broad tropism in adult rhesus macaques and is vasculature biased in adult marmosets. We demonstrate applications of a single, intravenous dose of CAP-Mac to deliver functional GCaMP for ex vivo calcium imaging across multiple brain areas, or a cocktail of fluorescent reporters for Brainbow-like labelling throughout the macaque brain, circumventing the need for germline manipulations in Old World primates. As such, CAP-Mac is shown to have potential for non-invasive systemic gene transfer in the brains of non-human primates.

Intravenous functional gene transfer throughout the brain of non-human primates using AAV

Adeno-associated viruses (AAVs) promise robust gene delivery to the brain through non-invasive, intravenous delivery. However, unlike in rodents, few neurotropic AAVs efficiently cross the blood-brain barrier in non-human primates (NHPs). Here we describe AAV.CAP-Mac, an engineered variant identified by screening in adult marmosets and newborn macaques with improved efficiency in the brain of multiple NHP species: marmoset, rhesus macaque, and green monkey. CAP-Mac is neuron-biased in infant Old World primates, exhibits broad tropism in adult rhesus macaques, and is vasculature-biased in adult marmosets. We demonstrate applications of a single, intravenous dose of CAP-Mac to deliver (1) functional GCaMP for ex vivo calcium imaging across multiple brain areas, and (2) a cocktail of fluorescent reporters for Brainbow-like labeling throughout the macaque brain, circumventing the need for germline manipulations in Old World primates. Given its capabilities for systemic gene transfer in NHPs, CAP-Mac promises to help unlock non-invasive access to the brain.

Quantitation of influenza vaccine hemagglutinin by immunoelectrophoresis

A technique for the quantitation of hemagglutinin (HA) in influenza vaccines by immunoelectrophoresis (IEP) is described. This method gives accurate, and reproducible results and requires approximately 9 h to complete. The HA content of four manufacturers' vaccines correlated with the chick cell agglutination (CCA) values for each manufacturers' vaccine. However, when comparisons were made between vaccines produced by different manufacturers, up to a four-fold difference in HA content was observed. Comparison with single radial immunodiffusion (SRID) gave comparable results for vaccines produced by three of four manufacturers; the fourth manufacturers' vaccine gave 1.6-fold higher results by SRID. Human seroconversion rates in seronegative individuals correlated better with IEP determined HA content than the current assay of vaccine potency using CCA.

Comparative trial of influenza vaccines. II. Adverse reactions in children and adults

Commercially prepared zonally and chromatographically purified bivalent (A/England-B/Mass) and monovalent (B/Hong Kong) inactivated influenza vaccines were given to 438 individuals 6-33 years old. The vaccines had been examined for antigen content by chick cell agglutination (CCA) tests and electron microscopic particle count determinations. Endotoxin and pyrogen content were determined by limulus amebocyte lysate (LAL) and rabbit pyrogenicity assays; and egg-associated protein contamination was estimated by total protein and single radial immunodiffusion assays. Although great differences (10-200-fold) were found in the amount of endotoxin or pyrogen in the vaccines, no significant differences were found in the febrile responses they induced. Both bivalent and monovalent vaccines induced fever of greater than or equal to 38 C at a rate of approximately 3 1/2-4% above background. The febrile responses were most frequent at 24 hours after inoculation and a higher rate was observed in children than adults. Local reactions consisting of tenderness, erythema or induration were seen in from 20-57% of the recipients and also were unrelated to the pyrogenic or host-derived materials in the vaccines. Adults had higher local reaction rates than children and some vaccines containing larger amounts of viral antigen induced significantly higher rates of reactivity than did vaccines containing smaller amounts of antigen. Although 37-51% of all recipients experienced either a local and/or febrile reaction to influenza immunization, the reactions were in general mild and would not consitute a significant disadvantage in the immunization of children over 6 years and adults to prevent influenza infection and its sequelae.

Comparative trial of influenza vaccines. I. Immunogenicity of whole virus and split product vaccines in man

Groups of about 100 persons aged 6 to 88 years were given 1 of 6 commercially prepared whole virus or split-product bivalent (A/England-B/Mass) influenza vaccines and 6 weeks later were given 1 of 5 monovalent (B/Hong Kong) vaccines. Hemagglutination-inhibiting (HI) antibody titers in serum specimens taken 6 and 12 weeks after inoculation were compared to those obtained before immunization. Overall antibody responses in all groups were adequate, yielding HI titers that are associated with relatively good levels of protection from infection. No differences were noted among the vaccines in their ability to boost pre-existing antibody. The tributyl phosphate (TBP) split-product vaccine, however, induced significantly lower homologous seroconversion and geometric mean antibody titers (GMT) to A/England and heterologous antibody titers to A/Aichi in persons without pre-existing antibody than did equivalent whole virus vaccines. Both the TBP and the ether-treated monovalent B/Hong Kong vaccines also induced lower heterologous GMT's to B/Mass in initially seronegative individuals. These data agree with previous observations that the primary response to influenza and other viral vaccines prepared from disrupted virions results in lower levels of antibody than does that to equivalent whole virus preparations. Studies are underway to determine whether the lesser immune response induced by these vaccines in seronegative persons is the result of smaller amounts of antigen in such preparations or because the antigen may be processed less efficiently by humoral or cellular immune mechanisms.