We examined the properties of the mouse serum lipoprotein responsible for specific neutralization of the endogenous mouse xenotropic (X-tropic) type C retrovirus. The anti-X-tropic virus activity of the mouse lipoprotein neutralizing factor (NF) could not be blocked by sugars or lectins. Moreover, neutralization did not involve rupture of the virion core. Sucrose density gradient analysis of X-...

An enzyme immunossay (EIA) was adapted for detection of antibody to varicella-zoster virus, and its sensitivity and specificity were compared with those of neutralization, immune adherence hemagglutination (IAHA), and complement fixation tests. Test sera showed little nonspecific reactivity in the EIA system, and valid results could usually be obtained at serum dilutions as low as 1:8. Demonstr...

1. A combination of poliomyelitis virus and specific human serum is effective for the production of active immunity. 2. For each gram of active virus given intradermally as an emulsion, 6 cc. of human immune serum, injected subcutaneously, was required in our experiments to protect a monkey from paralysis. Some degree of active immunity was induced. 3. Immunity, without symptom of the disease, ...

Human immunodeficiency virus type 1 (HIV-1) uses a variety of chemokine receptors as coreceptors for virus entry, and the ability of the virus to be neutralized by antibody may depend on which coreceptors are used. In particular, laboratory-adapted variants of the virus that use CXCR4 as a coreceptor are highly sensitive to neutralization by sera from HIV-1-infected individuals, whereas primary...

Mannose-binding lectin (MBL), a serum lectin that mediates innate immune functions including activation of the lectin complement pathway, binds to carbohydrates expressed on some viral glycoproteins. In this study, the ability of MBL to bind to virus particles pseudotyped with Ebola and Marburg envelope glycoproteins was evaluated. Virus particles bearing either Ebola (Zaire strain) or Marburg ...

In Japan, most pig populations are now free from pseudorabies virus (PRV) due to the recent success of an extensive eradication program. However, PRV infection persists in Japanese wild boars (Sus scrofa leucomystax), representing another potential reservoir for the virus in Japan. In this study, the seroprevalence of PRV in wild boars captured in three different prefectures was ascertained. A ...

Defining the specificities of the anti-human immunodeficiency virus type 1 (HIV-1) envelope antibodies able to mediate broad heterologous neutralization will assist in identifying targets for an HIV-1 vaccine. We screened 70 plasmas from chronically HIV-1-infected individuals for neutralization breadth. Of these, 16 (23%) were found to neutralize 80% or more of the viruses tested. Anti-CD4 bind...