Keith E. Jensen

The fine structure of influenza A, B and C viruses.

1. The particles of various human and animal strains of influenza A are essentially similar. 2. The particles of influenza B and influenza C are similar to those of influenza A, and different from those of the Newcastle disease-mumpsparainfluenza group. 3. The treatment of particles of strains of influenza A and B with formalin enabled the internal structure to be resolved somewhat more clearly. Treatment with chloroform in addition to formalin made it possible to resolve the internal ribonucleoprotein (soluble antigen) lying coiled within the particle in a regular manner. The particles of various human and animal strains of influenza A are essentially similar. The particles of influenza B and influenza C are similar to those of influenza A, and different from those of the Newcastle disease-mumpsparainfluenza group. The treatment of particles of strains of influenza A and B with formalin enabled the internal structure to be resolved somewhat more clearly. Treatment with chloroform in addition to formalin made it possible to resolve the internal ribonucleoprotein (soluble antigen) lying coiled within the particle in a regular manner.

Antimetabolic antibodies to Mycoplasma pneumoniae measured by tetrazolium reduction inhibition.

Summary The reduction of tetrazolium by M. pneumoniae is inhibited by specific serum. Based on this, a method has been derived for measuring growth inhibiting antibody. This procedure was applied to post-vaccination and convalescent sera from animal and human subjects and compared with CF and IHA antibodies. The presence of TRI antibody correlated well with resistance to disease.

Passive Interferon Protection in Mouse Influenza.

Summary Interferon prepared from influenza virus infected eggs or mouse lungs when intranasally administered protected mice against a mouse-adapted Type B influenza challenge. To be effective, the interferons had to be given before virus, and treatments delayed 24 hours after virus exposure served only to aggravate the infection. The concentration of virus used in the challenge was critical. The effect was best observed when the dosage was approximately 10 LD50.

The syncytial viruses.

August Compte has said, “Each of us is aware, if he looks back upon his own history, that he was a theologian in his childhood, a metaphysician in his youth, and a natural philosopher in his manhood.” Not only is this particular speaker well into his more reflective, and certainly less effective, years, but my assigned subject is one which invites a certain amount of philosophizing. What we euphemistically call the “Syncytial Virus Group” comprises some of the larger myxoviruses, as mumps and Newcastle disease virus (NDV), but it also includes measles, canine distemper, rinderpest, the parainfluenzas, and respiratory syncytial virus. As Plowright’ has pointed out, it does not customarily include agents of the herpes group which can also induce a syncytium in the sense that we are employing it, namely, “a multinucleate mass of protoplasm produced by the merging of cells.” Thus it seems appropriate to open this session by illustrating the typical cytopathic changes produced by these viruses in monolayers of simian and serial human cell lines and also to point out certain features that may eventually provide important differential characteristics within this heterogeneous family. In order to facilitate the digestion of this rather complicated situation, I have summarized certain of the differential growth features in TABLE 1. I t will be noted that canine distemper virus (CDV) and rinderpest are not included and this is because our personal experience with these agents in tissue culture has been restricted to the library. All of these viruses cause inultinucleated “giant cells” when grown in a human serial amnion cell, although the parainfluenza 1 strains did not induce this in monkey kidney tissue cells (MKTC) but rather a rapid type of diffuse degeneration with the appearance of swollen, stellate dendritiform cells. NDV also caused no cytopathogenic effects (CPE) in MKTC, confirming an earlier finding by Brandt.2 Only two viruses produced intranuclear inclusions, namely, measles and less frequently the shipping fever strain of parainfluenza 3 . Cytoplasmic inclusions were produced by four agents; measles, respiratory syncytial, CA strain of parainfluenza 2 and SF strain of parainfluenza 3. I t is interesting that the closely related HA-1 strain of parainfluenza 3 failed to induce inclusion bodies. Mumps and NDV were differentiated by the distribution of inclusions in single or fused cells although this may be a variable and chance observation. It would undoubtedly be profitable to investigate more deeply and with histochemical techniques the mode of formation of virus-induced syncytia. There is considerable reason to believe that much of this change is due to surface phenomena associated with particle attachment alone. In the case of measles, Toyoshima, Hata, and hLiki,3 and SchluederbergP have demonstrated that a noninfectious, hemolytic component of much smaller size than intact virus, can rapidly cause the formation of “giant” cells in primate cell monolayers without formation of complete virus. There is also suggestive

Concentration of Adenoviruses by Isoelectric Precipitation

Summary and conclusions The isoelectric optimum of 6 types of human adenoviruses in undialyzed monkey kidney harvest fluids has been established as pH 3.15 ± 0.15. Live and formalin-inactivated viruses were concentrated efficiently by elution of isoelectric precipitates from Celite columns. These observations appear to have several practical applications, as in the preparation of more potent vaccines.

Antibody Response to Influenza Vaccines combined with Hexadecylamine.

Summary Hexadecylamine in levels up to .5 mg/ml is well tolerated by man and animals. A single injection into guinea pigs of influenza vaccines containing this material results in rapid production of antibody levels which exceed those elicited by control vaccines. Preliminary results in man suggest that adjuvants of this nature may be most efficacious in a population receiving primary influenza experience.

Adsorption Characteristics of Influenza Viruses to Cholesterol and Fatty Acids.

Summary Marked differences were noted among strains of influenza with respect to adsorption to powdered cholesterol, palmitic acid and stearic acid. It has been shown that some strains suspended in allantoic fluids adsorb to lipids less efficiently than when suspended in buffered saline. Behavior of type B/GL strain was significantly different from type A strains, especially with cholesterol or palmitic acid as adsorbent. Mixtures of minimal amounts of influenza virus with cholesterol or stearic acid elicited an enhanced antibody response in animals when tested at 3 weeks.