Complement fixation inhibiting and complement-fixing antibodies were demonstrated in sera from cats during the acute and convalescent stages, respectively, of feline picornavirus infections. Complement-fixing antibody activity was present in 19S and 7S globulins, whereas complement fixation inhibiting antibody activity was confined to the 7S globulins. Sera with complement-fixing antibody and s...

A method for preparation of soluble feline oncornavirus-induced cell surface antigens was described. This technique relied upon the natural release of antigen(s) from FL-74 feline lymphoblastoid cells during their maintenance at 37 degrees in serum-deficient medium. When concentrated and clarified spent medium from 4-day cultures was tested for its antigen content by inhibition of humoral cytot...

Endogenous retroviruses (ERVs) are widespread in vertebrate genomes and have been loosely grouped into "classes" on the basis of their phylogenetic relatedness to the established genera of exogenous retroviruses. Four of these genera-the lentiviruses, alpharetroviruses, betaretroviruses, and deltaretroviruses-form a well-supported clade in retroviral phylogenies, and ERVs that group with these ...

Retroviruses comprise a large group of enveloped RNA viruses which have been found in a wide range of vertebrate species including fish. To date a number of fish retrovirus genomes have been partially or completely sequenced. Phylogenetic analysis and genome organization indicate a high diversity of fish retroviruses as well as some unique structural features that have not been found in any oth...

Human immunodeficiency virus type 1 (HIV-1) is a more complex retrovirus, coding for several accessory proteins in addition to the structural proteins (Gag, Pol, and Env) that are found in all retroviruses. More complex retroviruses have not been isolated from birds, and simpler retroviruses have not been isolated from humans. However, the proviruses of many endogenous simpler retroviruses are ...

Endogenous retroviruses are integral features of vertebrate genomes. Here, Hayward and Katzourakis offer a glimpse into the fascinating world of these mysterious partners in our evolution.

Endogenous retroviruses are normal constituents in vertebrate genomes. They have been associated with various diseases of presumed autoimmune etiology. However, conclusive evidence of their significance as susceptibility factors in these diseases is still lacking. In our laboratory we have focused attention upon endogenous retroviruses as candidate genes in multiple sclerosis. In this communica...

To develop improved vaccination strategies against feline leukemia virus (FeLV), rats were immunized with the transmembrane envelope protein p15E of FeLV alone or in combination with the commercial vaccine Leucogen comprising the nonglycosylated FeLV surface envelope protein. Binding and neutralizing antibodies were induced in both groups and in the group immunized with Leucogen alone. Higher t...

To develop improved vaccination strategies against feline leukemia virus (FeLV), rats were immunized with the transmembrane envelope protein p15E of FeLV alone or in combination with the commercial vaccine Leucogen comprising the nonglycosylated FeLV surface envelope protein. Binding and neutralizing antibodies were induced in both groups and in the group immunized with Leucogen alone. Higher t...