Martin S. Finkelstein

Antibody Response to Bacteriophage ΦX 174 in Non-Mammalian Vertebrates.

Discussion and Summary After a single injection of 108–10 bacteriophage ΦX 174, the chicken, frog and goldfish were shown to produce approximately the same levels of neutralizing, rapidly sedimenting, γ-globulin antibodies as those previously obtained in analogously immunized mammals(5,6). Repeated injections of bacteriophage in the frog and goldfish, at intervals of 2–4 weeks, did not elicit an anamnestic antibody response. However, higher levels of antibody, mainly in the slowly sedimenting γ-globulin fraction were produced after immunization with bacteriophage in complete Freunds adjuvant, and, in the case of the goldfish, after further elevation of the environmental temperature to 32°C. Thus, in 3 classes of non-mammalian vertebrates a change was observed in the sedimentation properties of antibody γ-globulins produced during immunization. This change appeared similar to the replacement of 19S by 7S antibodies in the circulation of immunized mammals. These findings suggest that the mechanisms responsible for this phenomenon were present in the most recent common ancestors of terrestrial vertebrates and bony fish and that formation of rapidly sedimenting antibody is an integral and important part of the immune mechanism.

Salivary and serum IgA levels in a geriatric outpatient population.

In two separate studies, specimens of saliva from 57 individuals over the age of 65 years (mean age, 76.7 years) and 37 persons under the age of 40 years (mean age, 28.8 years) were examined for concentrations of IgA as functions of volume, total protein, and electrolyte conductivity; some were also tested for IgG and IgM content. The results show that older persons have higher concentrations of these solutes in their saliva than do younger controls. This suggests that the ability to secrete IgA into saliva does not diminish significantly with aging.

Passage of bacteriophage phi X 174 across the placenta in guinea pigs.

Discussion and summary These studies indicate that a virus particle, bacteriophage φX 174, incapable of infecting mammalian cells, can cross the placenta and gain access to the foetal circulation. The possibility of in vitro contamination of foetal blood samples during cardiac puncture of the foetus can be excluded since: a) the washing procedure of the foetus was shown to be effective after deliberate contamination of the foetuss skin; b) after injection of phage into pregnant guinea pigs, separate bleedings of 0.5 ml and 0.1 ml from the foetal heart usually showed a 5-fold difference in amount of φX in the 2 samples; this difference was not observed in deliberately contaminated foetuses from pregnant guinea pigs not injected with φX. It is unlikely that endotoxin contamination of phage preparations was responsible for the transplacental passage of virus because of virtual absence of biologically detectable endotoxin in the preparations of phage employed and the failure of an injection of endotoxin with phage to increase the amount of phage found in the foetal circulation. There was no apparent difference in phage transfer between foetuses of markedly different weights, 56–120 g. The route of transplacental passage of phage is as yet uncertain. The failure to find a gradient in concentration from amniotic fluid to foetal blood (the latter sometimes had a higher phage concentration) suggests that phage is not transferred by this route. Previous studies of placental transfer of large proteins indicate that the splanchnopleure is the principal transfer organ in guinea pigs(7). The question arises as to whether the placenta is an effective barrier in preventing intrauterine viral infections. The following findings are relevant to this question: a) in the guinea pig, the difference between maternal and foetal blood virus concentrations was approximately 1055–106 and transfer usually was not demonstrated when maternal φX concentration was below 107/ml; b) the φX particle is an unusually small virus (approximately 250 angstroms in diameter).

Effects of plant lectins on virus growth in nonlymphoid cells

Abstract Several plant lectins markedly reduce the numbers of virus plaque-forming units released by cultures of different cell types, treated either before or after infection. Antiviral activity, which is not due to activation of the interferon system, is long lived and is demonstrable against a variety of enveloped and nonenveloped cytocidal RNA and DNA viruses. Although several mechanisms are responsible for the total antiviral effect, depending upon the virus studied, major effects seem to be the blocking of virus release, agglutination of cell-associated as well as liberated virus, and, possibly, diminished production of virus.