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Alkylglycerols, inflammation products of cancerous tissues, are potent macrophage activating agents. A brief in vitro treatment (30 min) of mouse peritoneal cells with a low concentration (50 ng/mL) of dodecylglycerol (DDG) in 10% foetal calf serum supplemented RPMI-1640 medium (FCS medium) activates macrophages for Fc-receptor mediated ingestion activity. A serum factor(s) was shown to be required for the activation of macrophages. When non-adherent cells were treated with rac-sn-1(3)-dodecylglycerol (DDG) in a serum free-0.1% egg albumin supplemented RPMI medium (EA medium) for 30 min and cultured in FCS medium for 2 h, the resultant conditioned medium contained a signal factor able to activate macrophages (macrophage activating factor). A conditioned medium prepared with electrophoresed serum alpha 2-globulin fraction in EA medium markedly enhanced activation of macrophages. Incubation of DDG-treated non-adherent cell ghosts in EA medium containing alpha 2-globulin also produced the macrophage activating signal factor. Therefore, it is concluded that a serum factor in alpha 2-globulin fraction is processed by pre-existing functions or enzymes of DDG-treated non-adherent cell membrane to yield a macrophage activating signal factor.

One newborn and 24 fetal woodchuck litters from a woodchuck hepatitis virus (WHV) endemic population were examined for serological or hepatic evidence of WHV. In 18 of 24 fetal litters, there was detectable WHV DNA in the livers, either at explant culture or tissue extract. Most of those WHV DNA-positive liver extracts, which were examined by Southern blot, showed integration of WHV. However, WHV DNA replicative forms without integration were demonstrated in livers of two litters from late gestation. Woodchuck hepatitis surface antigen was detected in the sera of two other fetal litters from the late gestation period. WHV DNA was demonstrated in sera of three litters at different stages of ontogeny.

Hepatitis B surface antigen (HBsAg, Australia antigen) was detected by radioimmunoassay in freeze-thaw lysates of washed platelets from HBsAg carriers. Incubation of platelets from an HBsAg-negative person with medium containing HBsAg resulted in the platelets becoming positive for HBsAg. We suggest that platelets may phagocytize HBsAg-coated particles, and this may be an important transport mechanism for the hepatitis B agent.

Antibodies against synthetic peptides derived from the polymerase gene of the hepatitis B virus (HBV) were present in 80% of renal dialysis patients infected with HBV and in woodchucks infected with woodchuck hepatitis virus (WHV). Polymerase antibody (anti-pol) appeared as the earliest marker of both HBV and WHV infections in approximately half of the individuals tested, suggesting that these antibodies were generated following early viral replication in the liver during the incubation period and prior to the appearance of virus in the blood. Many HBV- or WHV-infected individuals negative for surface antigen throughout infection also had anti-pol, but anti-pol appeared only after anti-surface, anti-core and/or anti-e. The presence of anti-pol did not correlate with other serologic markers of HBV or WHV infection, nor did it correlate with histologically confirmed hepatitis in woodchucks. However, there was a significant correlation between the presence of anti-pol and elevated liver enzyme levels in the sera of renal dialysis patients. In several cases, anti-pol was the sole marker of infection, suggesting that underlying infection and low levels of virus replication were present. Most individuals with anti-pol had antibodies to one of the three synthetic peptides, suggesting it may be immunodominant in natural infections. In human populations, groups with a high frequency of HBV infection have a high frequency of polymerase antibodies, and groups with a low frequency of HBV infection have a low frequency of polymerase antibodies. A standard assay for the detection of polymerase antibodies is described, and possible clinical applications are discussed.