Edwin H. Lennette

Immunological relationship between herpes simplex and varicella-zoster viruses demonstrated by complement-fixation, neutralization and fluorescent antibody tests.

Summary The antigenic relationship between the viruses of varicella-zoster and herpes simplex was studied by complement-fixation, fluorescent antibody staining and neutralization tests. Twenty-three of 75 patients with herpes simplex infections showed significant heterologous increases in complement-fixing antibody titre to varicella-zoster virus. These heterologous increases occurred in patients with serological evidence of a prior infection with varicella-zoster virus, and the greatest proportion occurred in patients in the younger age groups who had probably experienced the most recent varicella-zoster virus infections. Five of 42 patients with varicella-zoster infections showed heterologous complement-fixing antibody responses to herpes simplex virus; all were patients with serological evidence of a prior herpes simplex virus infection. The patients with herpes simplex infection who showed heterologous complement-fixing antibody responses to varicella-zoster virus also showed marked increases in neutralizing antibody and antibody demonstrable by immunofluorescent staining. However, none of the patients with varicella-zoster infection who showed heterologous increases in complement-fixing antibody titre to herpes simplex virus had significant increases in neutralizing antibody.

Electron Microscopic Studies of Coronavirus

Summary Electron-microscopic studies of the morphology and development of a coronavirus (linder strain), isolated in human foetal diploid lung cells from a case of upper respiratory illness, revealed virus particles of diameter 80 to 160 nm. They were initially observed 12 hr after infection. Extracellular and intracytoplasmic virus concentration increased sharply at 18 hr and reached a maximum at 24 hr. The number of particles decreased slightly at 48 hr and by 72 hr many cells were lysed. The particles formed by budding into the cisternae of the endoplasmic reticulum or into an inclusion composed of tubular structures resembling part of the complete virus particle. There were cytoplasmic inclusions of dense particles within a granular matrix and surrounded by a double membrane. The release of particles by lysis is illustrated. Extracellular virus was specifically tagged with ferritin-labelled antibody.

Isolation of rubella virus from brain in chronic progressive panencephalitis.

Rubella virus was isolated from the brain of a congenitally-infected, 12-year-old child in whom progressive mental and motor deterioration became evident at age 8 and 11 years respectively. The virus was initially isolated in a co-culture of CV-I cells with the trypsinized brain tissue; subsequently the culture of the brain tissue also showed evidence of rubella virus infection recognized by indirect fluorescent antibody technique (IFA) using anti-rubella virus antibody prepared in rabbits as intermediate serum. Both isolates interfered with infection of BSC-I cell lines by echovirus type II. The interfering virus was identified as rubella virus by IFA with the specific antiserum, and it is designated as the NTr strain of rubella virus. The complement fixing antibody titre to rubella virus in serum was I:256. The spinal fluid was anticomplementary. Rubella virus haemagglutinating antibody titre (HI) in serum was I:8196 and in the spinal fluid I:128. The HI antibody was of the IgG class. The corresponding HI titres to rubeola virus in serum and spinal fluid were I:8 and less than I:2 respectively.

Intra-erythrocytic Location of Colorado Tick Fever Virus

Summary Although previous studies have shown that Colorado tick fever virus occurs only transiently in the serum, but persists for prolonged periods in the blood cell fraction of man and experimental animals, the exact nature of this cell-associated viraemia was unknown. Using virus isolation, fluorescent antibody staining, histological and electron-microscopic techniques, we have shown that persistent viraemia is predominantly due to virus contained within erythrocytes. Erythrocyte precursor cells are presumably infected in the bone marrow and are subsequently released into the blood stream, persisting for prolonged periods despite the presence of serum antibody. Virus either continues to replicate slowly or is stabilized and remains viable within the erythrocyte. Colorado tick fever virus may be a useful model virus for further study of the mechanism of blood cell infection, with implications for other arboviruses or viruses believed to be involved in leukaemia or other haematological disorders.

A Complement-Fixing Antigen for Varicella-Zoster Derived from Infected Cultures of Human Fetal Diploid Cells.

Summary A procedure is described for preparation of complement-fixing antigens for the varicella-zoster (V-Z) virus in human fetal diploid skin and muscle cell strains. These cells are highly susceptible to the cytopathic effect of the V-Z virus, and can be maintained without a fluid change for the entire period required by the virus to produce complete cellular degeneration. Most of the specific antigen elaborated in the cultures was found to be cell-associated, and relatively high-titered antigens (1:32 and 1:64) were prepared by 50-fold concentration of the cellular phase of infected cultures. Antigens were usually free from anticomplementary activity, but when they were not, the activity could be abolished by treatment with inactivated guinea pig complement.

The Development of Colorado Tick Fever Virus Within Cells of the Haemopoietic System

Electron microscopic examination of haemopoietic liver tissue from mice infected in utero or when newborn showed inclusions of Colorado tick fever virus within erythroblasts, reticulocytes and erythrocytes. Inclusions were also seen within erythroblastoid cells undergoing mitosis. Other evidence of virus replication within erythropoietic cells was the presence of intracytoplasmic and intranuclear fibres, which have been shown to be associated with Colorado tick fever virus replication. The findings reported here support the hypothesis that virus replication within infected erythropoietic cells occurs concurrently with differentiation of the infected cell, resulting in the presence of virions within erythrocytes.

Demonstration of Rubella IgM Antibody by Indirect Fluorescent Antibody Staining, Sucrose Density Gradient Centrifugation and Mercaptoethanol Reduction

Three methods were compared for sensitivity and specificity in detecting rubella IgM antibody in early sera from post-natal infections and in sera from congenital infections. treatment pro-Mercaptoeth

Electron microscopic studies of Rubella virus.

Summary Electron microscopy of BHK-21 and BS-C-1 cells infected with rubella virus revealed spherical particles measuring 50 to 85 nm. in diameter and some elongated forms, predominantly in the budding stage, up to 240 nm. in length. The sequential steps in the development of the virion, beginning with the initial budding stage to the completion of the mature form, were studied. In addition, ferritin-labelled rubella antibodies were used to tag virus particles in various stages of maturation. Surface membranes of infected cells which had undergone antigenic changes without morphological alteration were also tagged; presumably such areas are the sites of haemadsorption of pigeon red blood cells to a seemingly normal-appearing cell membrane. Haemadsorption with and without virus particles functioning as bridges between cells is illustrated.

The Complement-Fixing Antigen of Rubella Virus.

Summary A complement-fixing antigen for rubella virus has been produced by concentration of infected RK-13 cell culture fluids 100-fold by dialysis against polyethylene glycol. The antigen was shown to be separable from the intact viral particle by centrifugation (soluble antigen), and could be rendered non-infectious by ether treatment without undergoing a change in specific reactivity. The complement fixation test was found to be comparable to the neutralization test for detecting significant increases in antibody level in rubella virus infections. Individuals showing significant rises in antibody titer to myxo-virus antigens or Mycoplasma pneumoniae did not show antibody rises with the rubella complement-fixing antigen.

Hemagglutination and Hemagglutination-Inhibition with Adenovirus Type 12.

Summary Hemagglutmation has been demonstrated with the prototype Huie strain and two nonprototype strains of adenovirus type 12. This viral type resembles those classified in Group 3 in that hemagglutination occurred with rat cells in the presence of hetero-typic immune serum. Hemagglutination was specifically inhibited by immune serum to adenovirus type 12, but not immune serum to other adenoviruses. The identity of the hemagglutinating virus as adenovirus type 12 was confirmed by both hemagglutination–inhibition and neutralization tests with reference immune sera prepared in other laboratories.