Alfred A. Tytell’s research while affiliated with Merck & Co. and other places

A highly purified and inactivated vaccine was made of hepatitis B virus surface antigen. The vaccine was tested exhaustively for safety by ordinary procedures and additionally in chimpanzees and marmosets. It was highly potent and induced antibody in guinea pigs, grivet monkeys, and chimpanzees after three doses of vaccine were given subcutaneously. Chimpanzees given three doses of vaccine were protected against challenge with 1,000 chimpanzee-infectious doses of live human hepatitis B virus given intravenously in controlled studies. Tests of the vaccine for control of hepatitis B in man are to be carried out.

A highly purified and inactivated Vaccine was made of hepatitis B virus surface antigen. The vaccine was tested exhaustively for safety by ordinary procedures and additionally in chimpanzees and marmosets. It was highly potent and induced antibody in guinea pigs, grivet monkeys, and chimpanzees after three doses of vaccine were given subcutaneously. Chimpanzees given three doses of vaccine were protected against challenge with 1,000 chimpanzee-infectious doses of live human hepatitis a virus given intravenously in controlled studies, Tests of the vaccine for control of hepatitis a in man are to be carried out.

A highly purified and inactivated vaccine was made of hepatitis B virus surface antigen. The vaccine was tasted exhaustively for safety by ordinary procedures and additionally in chimpanzees and marmosets. It was highly potent and induced antibody in guinea pigs, grivet monkeys, and chimpanzees after three doses of vaccine were given subcutaneously. Chimpanzees given three doses of vaccine were protected against challenge with 1,000 chimpanzee-infectious doses of live human hepatitis B virus given intravenously in controlled studies. Tests of the vaccine for control of hepatitis B in man are to be carded out.

A soluble complex of poly I:C and poly-L-lysine (poly I:C/poly-L-lysine) has been prepared that induces high titers of circulating interferon in monkeys. By limiting the molar ratio of lysine to nucleotide to 0.5, a complex was formed that was soluble up to 2.0 mg poly I:C/ml of phosphate-buffered saline. Complexes of poly I:C with poly-L-lysine of various molecular weights, and in a constant ratio (0.5) of lysine to nucleotide, were evaluated for capacity to induce serum interferon in grivet monkeys. Substantial enhancement (10- to 100-fold) of the capacity of poly I:C to induce interferon in grivet monkeys was observed using poly I:C complexed with poly-L-lysines of molecular weight 10(4) daltons or greater. The poly I:C/poly-L-lysine as an effective inducer of interferon in grivet monkeys, rhesus monkeys, chimpanzees and marmosets. A high interferon titer (greater than 100 units/ml blood) was maintained in grivet monkeys by repeated daily administration of the complex. No long-term hyporesponsiveness was noted following repeat inductions over a period of months. The serum interferon produced in monkeys in response to poly I:C/poly-L-lysine resembled human leukocyte interferon in its biological characteristics.

Growth and interferon production by human lymphoblastoid cells (Namalva) have been achieved by using medium with a complete substitution of human albumin for fetal bovine serum. Medium containing 0.3% human albumin supported exponential cell growth (minimum doubling time, 20 h) in Bilthoven 10-liter fermentors. Interferon induction with Sendai virus resulted in interferon yields of 0.5 x 10(4) to 1.0 x 10(4) interferon units per 10(6) Namalva cells per ml in RPMI 1640 medium containing 0.15 to 0.3% human albumin. Both cell growth and interferon production in medium containing human albumin were comparable to growth and interferon production in the same medium containing 10 and 5% fetal bovine serum, respectively.

A sensitive enzyme-linked immunosorbent assay (ELISA) for antibodies to double-stranded RNA has been developed using polyinosinic acid . polycytidylic acid (InCn) as antigen. Bound antibody was detected using alkaline phosphatase-conjugated goat antiimmunoglobulin and ρ-nitrophenylphosphate as substrate. The assay, as demonstrated for rabbit, NZB/NZW mouse, and grivet monkey sera, was far more sensitive and reproducible than quantitative complement fixation. In Cn complexed with poly-L-lysine and adsorbed to polystyrene tubes resulted in optimal uptake of antibodies to double-stranded RNA. In-Cn without added poly-L-lysine or with other cationic substances adsorbed poorly, as measured by reduced antibody uptake. Specificity of the assay for antibodies to double-stranded RNA was demonstrated by reduction of antibody binding to antigen-coated tubes following adsorption of sera with double-stranded, but not single-stranded RNAs. Similar adsorption studies indicated that this method could be used also to assay for double-stranded RNA. Therefore, a simple ELISA can be used for quantitative determination of either antibodies to double-stranded RNA or double-stranded RNA antigen.

The relative contribution of thymus-derived lymphocytes (T-cells) and of macrophages to resistance to primary infection with herpes simplex virus type 1 (HSV-1) was studied in C58 mice. Resistance was dependent on macrophage competence, but was relatively independent of T-lymphocyte competence. Although aging mice became progressively more deficient in functional T-cells, as demonstrated by a decreasing resistance to transplanted line Ib leukemia and by declining responses to T-cell nitogens (concanavalin A and phytohemagglutinin), their resistance to HSV-1 increased with increasing age. Moreover, in mice that were made selectively deficient in T-cells by the combination of adult thymectomy and treatment with anti-thymocyte serum, resistance to HSV-1 did not correlate spleen and mesenteric lymph nodes. However, selective reduction of macrophages by intraperitoneal injection of silica resulted in enhanced susceptibility to HSV-1. Furthermore, in vitro suppression of HSV-1 plaque formation in mouse embryo fibroblast cells was obtained by cocultivation of infected fibroblast monolayers with peritoneal macrophages, but not with splenic lymphocytes, from adult mice. Macrophages from weanling mice failed to suppress the development of plaques, indicating that the increase in resistance to HSV-1 with age is a result of increased macrophage competence.

The etiology of immune polioencephalomyelitis (IPE) and the mechanisms of resistance to IPE induction were investigated in C58 mice. IPE was found to be induced by a lipid-solvent-sensitive, filterable replicating agent present in line Ib leukemic cell suspensions. IPE was serially transmitted in immunosuppressed mice with filtered extracts of spleens from diseased animals. The IPE-inducing activity of Ib cell extracts was abolished by chloroform or deoxycholate. Gel filtration of Ib cell extracts showed that the IPE agent has a molecular weight of at least 10(7). Electron microscopy of the active fractions from columns and of spinal cord extracts from mice with IPE revealed a virus-like particle, 40 nm in diameter, which is probably the IPE revealed a virus-like particle, 40 nm in diameter, which is probably the IPE agent. Administration of cyclophosphamide at various times after challenge increased the incidence of IPE in mice, suggesting that IPE is not autoimmune mediated. Immunosuppression resulted in maintenance of high levels of IPE agent in the central nervous system tissue, while immunization resulted in low levels. Moreover, immunized mice produced neutralizing antibodies. These data suggest that antibodies help restrict the amount of IPE agent in the nervous tissue, and that this restriction is required for resistance to IPE induction in C58 mice.