Comparative Immunogenicities of Chikungunya Vaccines Propagated in Monkey Kidney Monolayers and Chick Embryo Suspension Cultures

A comparative study was made of Formalin-inactivated Chikungunya vaccines prepared from the virus propagated in African green monkey kidney monolayers and concentrated chick embryo suspension cultures. The vaccine prepared in the chick embryo suspension cultures was significantly more protective to mice against a live homologous virus challenge and stimulated the production of 4 to 5 times more circulating antibodies than the vaccine prepared with virus grown in African green monkey kidney monolayer cultures.     

Chorioallantoic Membrane Measles: Development and Clinical Evaluation of a New Further Attenuated Measles Vaccine

A new, further attenuated measles vaccine, developed by propagation of Edmonston B measles virus in the chorioallantoic membrane in ovo, has been clinically evaluated in children and found to compare favorably with a commercially available product. The vaccine is prepared in chick embryo tissue culture and appears to possess noteworthy stability at 4 C.     

Goat serum: an alternative to fetal bovine serum in biomedical research

Serum is frequently added to the defined basal medium as a source of certain nutritional and macromolecular growth factors essential for cell growth. Although a number of synthetic media have been prepared serum continues to be used in cell culture by many investigators. The best supplementation to a basal medium is fetal bovine serum (FBS) that is most frequently used for all types of cell cultures. During last four decades National Institute of Virology, Pune, has been working on isolation and identification of viruses from clinical specimens, employing tissue culture. Initially FBS was used for this purpose. However, due to its prohibitive cost and uncertain supply an alternative was sought. Commercially available sera from newborn calf, sheep, horse, human and serum obtained from goat blood (available from local abattoir) were tried. Goat serum (GS) was found to be suitable for most of the cell lines and primary cultures. Primary cultures from guinea pig embryo, monkey kidney, chick embryo, mouse peritoneal macrophages, and established cell lines were prepared and grown in growth media supplemented with GS. These cultures were studied for their morphology and growth in comparison with cultures grown in FBS containing media, and were used for mass cultivation of cells, quantitation and susceptibility of various virus strains, studies on effects of different nutrients and natural substances on cellular metabolism and virus replication, epitope analysis of various strains of Japanese encephalitis (JE) virus, strain differentiation studies, studies on antibody dependent plaque enhancement, assay of murine migration inhibition factor. Monoclonal antibodies against JE virus adapted to GS were characterised for their retention of functionalities. The results were comparable to those of cell cultures grown in FBS containing media. Similar results on chromosome studies were obtained from patient's whole blood cultures prepared in GS and FBS containing growth media. Organ cultures from mammalian, reptile and avian hosts; successfully grown in GS supplemented growth media, were used for different virological studies. Growth media supplemented with GS were used for in vitro cultivation of malarial parasites. Thus since the last three decades many scientists are using GS in place of FBS, in various fields of biomedical research. The present article reviews an account of the same.     

Persistently infected cultures as a source of hepatitis A virus.

Primary African green monkey kidney, continuous African green monkey kidney cell line BS-C-1, and buffalo green monkey kidney cultures were infected with a uniform inoculum of hepatitis A virus (HAV). Although both the cell line BS-C-1 and primary African green monkey kidney cultures produced useful amounts of virus, HAV was detected earlier and in greater quantities in primary African green monkey kidney cultures. A persistently infected primary African green monkey kidney culture was developed. The influence of incubation time (4 to 40 days) and concentration (2 to 15%) of fetal calf serum in the maintenance medium on production of HAV by this culture was examined. An incubation period of 24 to 28 days was found to be optimal; reducing this period led to decreased yields of HAV. No significant difference in the amount of HAV produced was observed with differing concentrations of fetal calf serum. Three different methods of extraction and the effect of multiple extractions on the recovery of HAV from cell lysates were examined. Sonication was a critical factor. Two extractions yielded more than 90% recoverable virus. Yields in excess of 10(11) physical particles of HAV per 850-cm2 roller bottle were routine. The total yield could be increased by concentrating the HAV present in spent maintenance medium by using bentonite or organic flocculation.     

Persistently infected cultures as a source of hepatitis A virus

Primary African green monkey kidney, continuous African green monkey kidney cell line BS-C-1, and buffalo green monkey kidney cultures were infected with a uniform inoculum of hepatitis A virus (HAV). Although both the cell line BS-C-1 and primary African green monkey kidney cultures produced useful amounts of virus, HAV was detected earlier and in greater quantities in primary African green monkey kidney cultures. A persistently infected primary African green monkey kidney culture was developed. The influence of incubation time (4 to 40 days) and concentration (2 to 15%) of fetal calf serum in the maintenance medium on production of HAV by this culture was examined. An incubation period of 24 to 28 days was found to be optimal; reducing this period led to decreased yields of HAV. No significant difference in the amount of HAV produced was observed with differing concentrations of fetal calf serum. Three different methods of extraction and the effect of multiple extractions on the recovery of HAV from cell lysates were examined. Sonication was a critical factor. Two extractions yielded more than 90% recoverable virus. Yields in excess of 10(11) physical particles of HAV per 850-cm2 roller bottle were routine. The total yield could be increased by concentrating the HAV present in spent maintenance medium by using bentonite or organic flocculation.     

Western equine encephalomyelitis vaccine produced in chick embryo cell cultures

A method was developed for production of a freeze-dried Western equine encephalomyelitis vaccine from virus propagated in chick embryo cell culture monolayers maintained with a serum-free medium. A sufficient concentration of virus accumulated in the cell culture fluids prior to the occurrence of viral cytopathology to permit the production of a vaccine relatively free from serum and cellular proteins. Inoculation with two mouse ld₅₀ doses of virus per 100 tissue culture cells was found to yield reproducible high virus titers at a convenient harvest time. These harvests were inactivated at 22 C by 0.05% formalin within 48 hr. Potency test results, as measured by the protection of immunized guinea pigs against an intracerebral virus challenge, indicated that the vaccine produced from the virus propagated in cell culture was equal in potency to a lot of whole chick embryo vaccine used to immunize laboratory and field workers subject to a high risk of infection.     

Isolation and identification of Marek's disease virus by fluorescent antibody technique.

Cell-associated herpesvirus related to Marek's disease (MD) was isolated from the direct culture of kidney cells of naturally infected chickens at Taoyuan or by inoculation of clinical specimens to chick kidney (CK) and chick embryo fibroblast cells. The virus isolates replicated in CK or chick embryo kidney cell cultures were identified to be MD by the fluorescent-antibody technique.     

Susceptibility of cell lines of primate and nonprimate origin to certain human viruses

A comparative study was made of the susceptibility of 11 cell lines of human and animal origin, the WI-38 cell strain and fresh cultures of human thyroid, monkey kidney and hamster embryo tissues to certain human viruses. The animal cell lines were derived from monkey, rabbit, mouse, pig and calf tissues. The viruses used were strains of influenza A₂ and B viruses, parainfluenza viruses types 1, 2 and 3, RS virus, adenoviruses types 3, 4 and 21, poliovirus type 1 and Coxsackie A type 21 and Coxsackie B type 3 viruses. Cell lines derived from nonprimate tissues were generally less susceptible than cell cultures of human and simian origin. The combined use of fresh cultures of human thyroid and monkey kidney tissues and of a human cell line seems to provide a satisfactory indicator system for the viruses employed in this study.     

Development of a new live attenuated mumps virus vaccine in human diploid cells

A new live attenuated mumps vaccine was developed in human diploid cells. The S-12 virus was isolated from a 10-year-old girl showing typical symptoms of mumps infection, the diagnosis was confirmed by a pediatrician. The virus was isolated in green monkey kidney cells, without passage in chick embryo cavity or chick embryo fibroblasts. Attenuation of the wild virus was performed by serial passages in human diploid cells (MRC-5). The attenuated virus was characterized by identity tests, as well as by a reduction in plaque size, as marker tests. The virus was free from adventitious agents and safe for laboratory animals as well as for monkeys. The reactogenicity and immunogenicity of the S-12 virus for man was investigated by administration of a monovalent vaccine to 20 seronegative adult male volunteers and 30 children aged 1 to 5 years without history of mumps infection or vaccination. Seroconversion was obtained in 95% of the vaccinees. The new vaccine has the advantage of not requiring specific pathogen-free eggs, and being free from avian proteins and therefore can be used in sensitized patients.     

Chromosome breaks and changes in the mitotic regime of human and animal cells under the influence of a measles virus vaccinal strain (L-16)]

The vaccine strain of the Leningrad-16 measles virus is capable of inducing lesions in the structure and chromosome quantity and of increasing the frequency of cells with pathologic mitosis in human fibroblast embryo culture. The measles virus produced the same effect on genetic structures in marrow cells and testicles of infected mice. No increase of cell frequency with chromosome lesions was observed in the healthy children immunized against measles.     

The protective activity of preparations made from the tick-borne encephalitis virus grown using different cell cultures]

The preparations of tick-borne encephalitis (TBE) virus grown in swine embryo kidney cell culture have been shown to possess pronounced protective activity per unit of virion protein E in comparison with TBE virus preparations derived from cell culture 4647 and chick embryo cell culture. The antigenic activity of all virus preparations under study has proved to be practically the same. The role of post-translation modifications of TBE virus protein E in the manifestation of some of its biological properties is discussed.     

Hypotheses and facts

The book, The river, is based on assumptions and not facts. Oral polio vaccine was produced entirely in rhesus monkey kidney cell cultures. Allegations that it was produced in chimpanzee kidneys at the Wistar Institute in Philadelphia or, alternatively, that the vaccine was made in the then Belgian Congo in chimpanzee kidney has no basis in fact. As the only witness to the historical events leading to the development of oral polio vaccine, I have demonstrated in this paper the truthful facts excluding any link between oral polio vaccine and human immunodeficiency virus.     

Use of a Clonal Line of Porcine Kidney Cell Cultures for Primary Isolation and Vaccine Studies with Adenoviruses

The clonal line (Y15) of porcine kidney stable cells provided a recovery system for adenovirus T4 from specimens from adults with respiratory illnesses that was as sensitive as human embryo kidney cultures. Adenoviruses T7 from adults, and T1, 2, 3, and 5 from children could be readily isolated in porcine kidney cell cultures. The latter were useful for adenovirus vaccine studies in that infectivity titers of live virus vaccine and neutralization antibody responses after vaccination were equal to those obtained in human embryo kidney cultures.     

A single-blind, placebo-controlled comparison of the reactivity and antigenicity of trivalent oral poliomyelitis vaccine prepared in monkey kidney or human diploid cell substrates

Vaccination with a single dose of trivalent oral poliomyelitis vaccine elicited fourfold or greater antibody responses to one or more poliomyelitis virus types in 59% of volunteers (16/27) receiving vaccine prepared from virus grown in monkey kidney cells and in 69% of volunteers (16/23) receiving vaccine prepared from virus grown in MRC5 human diploid cells. Type for type the antibody titres and percentages of volunteers responding to the two vaccines were broadly equivalent. The clinical reactivities of both vaccines were similar to that of a placebo in terms of the overall incidence, duration and severity of reactions. The nature of the reactions observed did, however, vary, in that headaches were more frequently reported by recipients of vaccine prepared from virus grown in monkey kidney cells. This difference was not, however, statistically significant.     

Molecular hybridization of nucleic acids as a method for the laboratory diagnosis of influenza in model experiments on cell cultures and in research on nasopharyngeal smears obtained from patients

DNA probes containing the nucleotide sequences of the conservative genes of influenza A virus (matrix, nucleoprotein and acidic polymerase genes) show their specificity with respect to the RNA of influenza A viruses in mammal tissue cell cultures (continuous spaniel kidney cell culture and primary calf kidney cell culture). The minimal amount of infected monolayer cells, permitting the detection of viral RNA, is 10(3). The results obtained in the study of nasopharyngeal washings make it possible to recommend the method of molecular hybridization for use in the epidemiological analysis in addition to virological and serological tests. The method of hybridization permits the detection of virus-specific RNA in the allantoic fluid of chick embryos in subculturing the materials under study even in those cases when hemagglutinating influenza virus cannot be isolated.     

Cell growth optimization in microcarrier culture

Three monkey kidney cell lines and primary chicken embryo cells were grown in microcarrier culture. The carrier support was DEAE-Sephandex gel beads at low anion exchange capacity prepared according to a protocol developed at the Massachusetts Institute of Technology. The growth rate of the cells and the final cell density in microcarrier culture was dependent on the concentration of the beads in culture and on the size of the initial cell inoculum. A bead concentration of 1.0 to 2.0 mg of beads/ml of tissue culture medium and a cell inoculum of 20,000 cells/cm2 of bead surface appeared to be optimal. The efficiency of the microcarrier culture system was compared to that of stationary and roller bottle cultures. Stationary flasks gave cell densities about twofold higher than maximal densities in roller bottles and about threefold and twofold higher than cell densities in microcarrier culture at a bead concentration of 2.5 and 1.0 mg/ml, respectively. In terms of cell yield per milliliter of tissue culture medium, the microcarrier culture was superior to roller bottle and stationary cultures. An advantage of the microcarrier culture system is its suitability for scale up into large volume production units.     

Cell growth optimization in microcarrier culture

Summary Three monkey kidney cell lines and primary chicken embryo cells were grown in microcarrier culture. The carrier support was DEAE-Sephadex gel beads at low anion exchange capacity prepared according to a protocol developed at the Massachusetts Institute of Technology. The growth rate of the cells and the final cell density in microcarrier culture was dependent on the concentration of the beads in culture and on the size of the initial cell inoculum. A bead concentration of 1.0 to 2.0 mg of beads/ml of tissue culture medium and a cell inoculum of 20,000 cells/cm² of bead surface appeared to be optimal. The efficiency of the microcarrier culture system was compared to that of stationary and roller bottle cultures. Stationary flasks gave cell densities about twofold higher than maximal densities in roller bottles and about threefold and twofold higher than cell densities in microcarrier culture at a bead concentration of 2.5 and 1.0 mg/ml, respectively. In terms of cell yield per millitier of tissue culture medium, the microcarrier culture was superior to roller bottle and stationary cultures. An advantage of the microcarrier culture system is its suitability for a scale up into large volume production units.     

Inactivated Eastern Equine Encephalomyelitis Vaccine Propagated in Rolling-Bottle Cultures of Chick Embryo Cells

A method was developed for the production of Eastern equine encephalomyelitis vaccine from virus grown in rolling-bottle cultures (840 cm(2) growth area) of chick embryo cells. The PE-6 strain of virus was propagated in chick embryo cell roller cultures maintained on serum-free medium 199 containing 0.25% human serum albumin and antibiotics (MM). A multiplicity of inoculum of 0.005 yielded acceptable titers of virus at a convenient harvest time of 18 to 24 hr and reduced the carry-over of extraneous material from the virus seed. Growth studies in which 100, 200, or 300 ml of MM was used showed that use of 300 ml of MM offered two advantages: (i) cytopathic effects were less at the 18- to 24-hr harvest time, thereby decreasing cellular material in the final product, and (ii) total virus yield was not substantially reduced, thus permitting large-scale production of virus for further processing. Studies on formalin inactivation at 37 C indicated that the virus was inactivated by 0.05% formalin within 12 to 16 hr and with 0.1% formalin within 6 to 8 hr. Antigen extinction tests in hamsters revealed excellent potency (e.g., median-effective-dose values of 0.069 to 0.012 ml) for both fluid and freeze-dried products. The advantages of the roller-bottle technique in vaccine production are discussed.     

Studies with bovine parainfluenza - 3 virus in u.a.R. (Egypt)

A bovine strain of myxovirus parainfluenza-3 (MP3) virus, designated S virus, was isolated from lung tissue collected from cattle with respiratory illness in 1963. The virus agglutinates mammalian and avian erythrocytes, and is sensitive to ether, sodium desoxycholate and trypsin. It grows in primary calf kidney, buffalo kidney, dog kidney, camel kidney and MS cell cultures. The S virus forms well-defined plaques in buffalo and calf kidney cells on the 5th or 6th day after inoculation. Examination of cell cultures following inoculation with S virus revealed giant cell formation, and introcytoplasmic and intranuclear inclusions. At 37 degrees C the virus titer dropped from 10(10.4) to 10(2.6) in 3 days. Virus was completely inactivated at 56 degrees C within 15 minutes. Growth-curve studies in tissue culture monolayer cells revealed a latent period of 10 hours. The intracellular virus titer was slightly lower than that of extracellular virus. The isolate was identified as MP3 virus by serum neutralization and hemagglutination-inhibition tests. Antibodies (HI) to S virus were shown to be present in a significant proportion of Egyptian cattle. The epidemiological significance of MP3 (bovine strain) virus in U.A.R. is discussed.     

The morphology of cell lines suitable for vaccine production studied by scanning electron microscopy]

Five nontumorogenic cell lines suitable for vaccine production were studied by SEM. It was shown that diploid cell line 41 originated from sheep embryo kidney and also two heteroploid cell lines, line 4921 originated from embryo skin and muscles of the African green young monkey and line 4647 from kidney of the adult monkey, maintained normal cell morphology and normal growth pattern in early and in later passages in cultures. Some alterations in epithelial dense monolayer formation were revealed in the heteroploid cell lines: in line 455 originated from spleen of the adult African green monkey, and in line 4184 originated from line 41. The revealed alterations can be considered as the early morphological signs of the transformation of epithelial cells in culture. These cell lines also retained the stability of their morphological characteristics at the earlier and later passages. All the studied cell lines were free of contaminating agents.