The neurogenic potential of the postnatal neocortex has not been tested previously with a combination of both retroviral and bromodeoxyuridine (BrdU) labeling. Here we report that injections of enhanced green fluorescent protein (eGFP) retrovirus into 134 postnatal rats resulted in GFP labeling of 642 pyramidal neurons in neocortex. GFP-labeled neocortical pyramidal neurons, however, unlike GFP...

The current experiments use the Friend retrovirus model to demonstrate that vaccine-primed B cells are essential for sterilizing immunity, and the results indicate that the requisite function of these cells is the production of virus-neutralizing antibodies rather than priming or reactivation of T cells. B cell-deficient mice were poorly protected by vaccination, but adoptive transfer experimen...

We propose that retroviruses exploit a cell-encoded pathway of intercellular vesicle traffic, exosome exchange, for both the biogenesis of retroviral particles and a low-efficiency but mechanistically important mode of infection. This Trojan exosome hypothesis reconciles current paradigms of retrovirus-directed transmission with the unique lipid composition of retroviral particles, the host cel...

Transgenic modification of sperm before fertilization has distinct advantages over conventional transgenic methods. The primary advantage is that the mosaicism inherent in those other techniques is avoided. A culture system using primary cultures of zebrafish male germ cells, in which the differentiation from spermatogonia to functional sperm can occur in vitro, provides the opportunity for gen...

Cats, as definitive host, play an important role in the transmission of Toxoplasma gondii. This study aimed to establish the seroprevalence of anti-T. gondii immunoglobulins G and M, and determine the frequency of oocysts in the feces of the domestic cat population in Rio de Janeiro, Brazil. We also aimed to study the association between T. gondii infection and age, sex, breed, lifestyle, diet ...

The host restriction factors TRIM5α and TRIMCyp potently inhibit retrovirus infection by binding to the incoming retrovirus capsid. TRIM5 proteins are dimeric, and their association with the viral capsid appears to be enhanced by avidity effects owing to formation of higher-order oligomeric complexes. We examined the stoichiometric requirement for TRIM5 functional recognition by quantifying the...

This report describes the use of a recombinant murine retrovirus encoding beta-galactosidase (PLJ beta-gal retrovirus) to study the antiretroviral activity of zidovudine (AZT) and other nucleoside analogs. The PLJ beta-gal virus permits the rapid and unequivocal identification of individual virus-infected cells arising from a single cycle of viral replication. With this model system, AZT is sho...

Cytotoxic CD8(+) T cells control acute viremia in many viral infections. However, most viruses that establish chronic infections evade destruction by CD8(+) T cells, and regulatory T cells (Treg) are thought to be involved in this immune evasion. We have infected transgenic mice, in which Treg can be selectively depleted, with Friend retrovirus (FV) to investigate the influence of Treg on patho...

APOBEC3G (CEM15 ) deaminates cytosine to uracil in nascent retroviral cDNA. The potency of this cellular defense is evidenced by a dramatic reduction in viral infectivity and the occurrence of high frequencies of retroviral genomic-strand G --> A transition mutations. The overwhelming dinucleotide hypermutation preference of APOBEC3G acting upon a variety of model retroviral substrates is 5'-GG...