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PubMed2003

Route of administration is the prime determinant of IgA and IgG2a responses in the respiratory tract of mice to the cold-adapted live attenuated influenza A donor strain A/Leningrad/134/17/57.

Serum antibody and antibody secretory cell (ASC) responses to the cold-adapted (CA) live attenuated influenza A donor strain A/Leningrad/134/17/57 in BALB/c mice were determined in the lungs and mediastinal lymph nodes after administration by the intranasal, subcutaneous and intramuscular routes. Both types of response were greatest when an inoculum consisting of 10(6.5) 50% egg infectious doses (EID(50)) was administered twice intranasally at an interval of 3 weeks. Serum responses by the intramuscular route were much higher than by the subcutaneous route but, at doses of 10(6.5-7.5) EID(50), were still lower than that obtained with two doses of an intranasal inoculum of 10(6.5) EID(50). Virus-specific ASC responses for IgA and IgG2a were obtained in the lungs and mediastinal lymph nodes of mice inoculated with 10(6.5) EID(50) by the intranasal route. However, ASC responses after inoculation by either the subcutaneous or intramuscular routes were barely detectable, even at doses as high as 10(7.5) EID(50). These results confirm that intranasal administration of live vaccines induces far higher virus-specific IgA and IgG2a responses in the respiratory tract of mice than can be achieved by parenteral administration and that serum antibody levels induced by parenteral vaccination are unrelated to the respiratory ASC response.

Administration, Intranasal↗
PubMed2002

Safety of the trivalent, cold-adapted influenza vaccine in preschool-aged children.

OBJECTIVE: To provide additional information on the safety of trivalent, cold-adapted influenza vaccine (CAIV-T) in children. METHODS: Children 15 to 71 months of age were enrolled in a multicenter, prospective, randomized, double-blind, and placebo-controlled trial to receive by nasal spray CAIV-T or placebo. In year 1 (1996-1997), 1314 were enrolled in the 2-dose cohort and 288 were enrolled in the 1-dose cohort. In year 2 (1997-1998), 1358 of the original participants received 1 dose of vaccine or placebo according to their original treatment group assignment. In year 3 (1998-1999) and year 4, the trial continued as an open-label safety trial of CAIV-T. A total of 642 and 549 children enrolled in years 3 and 4, respectively, received their third and fourth sequential annual doses of CAIV-T. Measured were 1) the occurrence of specific respiratory, gastrointestinal and systemic symptoms, unexpected symptoms (not specified in the diary card), and use of medications within the first 10 days after vaccination; 2) the occurrence of an acute illness and use of medication within 11 to 42 days after vaccination; and 3) the occurrence of serious adverse events within 42 days after vaccination. RESULTS: The adjusted odd ratios of specific respiratory and gastrointestinal symptoms during the 10 days after vaccination were determined in years 1 and 2. Runny nose or nasal congestion, vomiting, muscle aches, and fever were significantly associated with the first dose of CAIV-T. With the second dose, runny nose was the only symptom that was associated with CAIV-T. In year 2, CAIV-T did not cause excess in any of the specific respiratory and gastrointestinal symptoms. In years 3 and 4, specific respiratory and gastrointestinal symptoms were comparable to that observed in year 2. A CAIV-T-associated symptom was most likely to occur on day 2 with the first dose of vaccine. The occurrence of unexpected symptoms was primarily of the gastrointestinal system. Approximately 6% of CAIV-T and 3.6% of placebo recipients had a gastrointestinal symptom. CAIV-T seemed to be associated with a mild excess in abdominal pain and vomiting only with the first vaccine dose. A statistically significant increase in the use of analgesics/antipyretics was detected only with the first dose in CAIV-T vaccinees compared with placebo recipients (23.5% vs 16.6%). Between days 11 and 42, CAIV-T use was not associated with an excess of illness, otitis media, or use of medication. None of the 6 serious adverse events in CAIV-T recipients in years 1 to 4 was attributed to the vaccine. CONCLUSIONS: CAIV-T was safe in children. Mild respiratory, gastrointestinal, and systemic symptoms of short duration were observed in a minority of children and primarily with the first vaccine dose. Sequential annual doses of CAIV-T were well tolerated.

Age Factors↗
PubMedDate not supplied

[Steroid hormone dynamics in cold adaptation of rats of different inbred strains].

In experiments on WAG, Sprague-Dawley and August rats the significance of genetic differences in the adrenocortical and gonadal response to long-term cold adaptation was demonstrated. The highest blood corticosterone level in WAG rats and the lowest one in August rats were seen following the 4-week exposure to 10 degrees C. A decreased blood testosterone concentration under cold conditions was observed only in August rats. Aldosterone excretion with the urine diminished during the cold exposure in WAG and Sprague-Dawley rats, being enhanced in August rats. The relationship is discussed between hormonal and metabolic changes under prolonged exposure to cold.

11-Hydroxycorticosteroids↗
PubMed1980

Cold adaptation in the rat: increased brown fat peroxisomal beta-oxidation relative to maximal mitochondrial oxidative capacity.

Brown fat hypertrophy in the rat resulting from cold adaptation is shown here to involve increased mitochondrial, peroxisomal, and lysosomal enzyme activities. Mitochondrial activity in homogenates of brown fat was estimated as cytochrome c oxidase. After 4 wk in the cold (+5 C), the total activity was 3-fold higher than in control rats, although the specific activity was somewhat lower. Peroxisomal activity was followed as cyanide-insensitive palmitoyl-CoA-dependent NAD+ reduction (palmitoyl-CoA oxidase) and as catalase. The total activity of both palmitoyl-CoA oxidase and catalase was more than 10-fold higher than in controls and the specific activity about 3-fold higher. Acid phosphatase, used as a lysosomal marker, showed a 6-fold higher total activity and almost twice as high specific activity. The relatively greater increase in peroxisomes and lysosomes compared with mitochondria indicates an involvement in thermogenesis also for these organelles.

Acid Phosphatase↗
PubMed1991

Further studies on cold adapted variants of human influenza virus A/Krasnodar/101/59 (H2N2) with special reference to genetic stability of attenuation markers.

A previously described cold adapted (ca) attenuated virus, K/25, derived from parent strain A/Krasnodar/101/59 (H2N2), was further modified by 35 additional passages in chick embryos at suboptimal temperature. The virus obtained had retained a distinct ts and ca phenotype and some other markers of attenuation but differed from formerly isolated ca variants by its higher genetic stability connected with an increased growth capacity in chick embryos.

Animals↗
PubMed2004

Imparting temperature sensitivity and attenuation in ferrets to A/Puerto Rico/8/34 influenza virus by transferring the genetic signature for temperature sensitivity from cold-adapted A/Ann Arbor/6/60.

The four temperature-sensitive (ts) loci identified in the PB1 and PB2 gene segments of cold-adapted A/Ann Arbor/6/60 influenza virus, the master donor virus for influenza A virus (MDV-A) FluMist vaccines, were introduced into a divergent A/Puerto Rico/8/34 influenza virus strain. Recombinant A/Puerto Rico/8/34 virus with these four introduced ts loci exhibited both ts and att phenotypes similar to those of MDV-A, which could be used as a donor virus for manufacturing large quantities of inactivated influenza virus vaccine against potential pandemic strains.

Animals↗
PubMed2006

Expression and purification of a cold-adapted group III trypsin in Escherichia coli.

The recently classified group III trypsins include members like Atlantic cod (Gadus morhua) trypsin Y as well as seven analogues from other cold-adapted fish species. The eight group III trypsins have been characterized from their cDNAs and deduced amino acid sequences but none of the enzymes have been isolated from their native sources. This study describes the successful expression and purification of a recombinant HP-thioredoxin-trypsin Y fusion protein in the His-Patch ThioFusion Escherichia coli expression system and its purification by chromatographic methods. The recombinant form of trypsin Y was previously expressed in Pichia pastoris making it the first biochemically characterized group III trypsin. It has dual substrate specificity towards trypsin and chymotrypsin substrates and demonstrates an increasing activity at temperatures between 2 and 21 degrees C with a complete inactivation at 30 degrees C. The aim of the study was to facilitate further studies of recombinant trypsin Y by finding an expression system yielding higher amounts of the enzyme than possible in our hands in the P. pastoris system. Also, commercial production of trypsin Y will require an efficient and inexpensive expression system like the His-Patch ThioFusion E. coli expression system described here as the enzyme is produced in very low amounts in the Atlantic cod.

Adaptation, Physiological↗
PubMed1993

[ts-Mutations in the genomes of cold-adapted variants of influenza A/Hong Kong/1/68(H3N2) and A/Victoria/35/72(H3N2) viruses].

The phenotype and localization of ts mutations in genomes of the influenza A/Victoria/30-ir (A/Vic/30-ir) and A/Hong Kong/17-ir (A/HK/17-ir) cold-adapted (ca) viruses were studied. Using the recombination analysis in chick embryo fibroblasts (CEF) we determined that influenza A/HK/17-ir ca virus carries ts mutations in three "internal" genes, i.e., PB1, NP and M, and influenza A/Vic/30-ir ca virus carries ones in four genes, i.e., PA, NP, M and NS. We have revealed ts mutations for NA gene in none of these viruses. Prior to the analysis of ts mutations in HA gene of influenza A/HK/17-ir and A/Vic/30-ir ca viruses, three cloning steps were performed in chick embryos (CE) by the method of limiting dilutions at 34 degrees C followed by selection of some strains with the most prominent ts phenotype. The cloned strains with such phenotypes were shown to repeat stable results within the recombination analysis in CE, i.e., none from the cloned strains of A/HK/17-ir ca virus recombined in CE at 40 degrees C with the 46 ts mutant, while recombination of this mutant with the cloned A/Vic/30-ir ca strains led to formation of the ts progeny. Thereafter our data result in conclusion that ts mutations in the PA gene must lead to some insignificant contribution for the expression of general ts phenotype among the ca strains as far as this sign is clearly displayed by both viruses, although only one of them, i.e., A/HK/17-ir carries ts mutation in the HA gene.

Adaptation, Physiological↗
PubMed1975

The influence of the social thermoregulation on the cold-adaptive growth of BAT in hairless and furred mice.

When mice were living in groups they developed less brown adipose tissue (BAT) during cold adaptation as compared with single mice. This effect of social aggregation was more pronounced in genetically hairless mice than in furred mice. In both races of mice the most significant difference in BAT growth was found between single mice and pairs of mice, indicating that the formation of pairs causes the relatively most effective improvement of thermal balance.

Adaptation, Physiological↗
PubMed2004

Safety of cold-adapted live attenuated influenza vaccine in a large cohort of children and adolescents.

OBJECTIVE: To determine the safety of cold-adapted trivalent intranasal influenza virus vaccine (CAIV) in children and adolescents. STUDY DESIGN: A randomized, double blind, placebo-controlled safety trial in healthy children age 12 months to 17 years given CAIV (FluMist; MedImmune Vaccines, Inc.) or placebo (randomization, 2:1). Children <9 years of age received a second dose of CAIV or placebo 28 to 42 days after the first dose. Enrolled children were then followed for 42 days after each vaccination for all medically attended events. Prespecified outcomes included 4 prespecified diagnostic groups and 170 observed individual diagnostic categories. The relative risk and the 2-sided 90% confidence interval were calculated for each diagnostic group and individual category by clinical setting, dose and age. More than 1500 relative risk analyses were performed. RESULTS: A total of 9689 evaluable children were enrolled in the study. Of the 4 prespecified diagnostic categories (acute respiratory tract events, systemic bacterial infection, acute gastrointestinal tract events and rare events potentially associated with wild-type influenza), none was associated with vaccine. Of the biologically plausible individual diagnostic categories, 3, acute gastrointestinal events, acute respiratory events and abdominal pain, had different analyses that demonstrated increased and decreased relative risks, making their association with the vaccine unlikely. For reactive airway disease a significant increased relative risk was observed in children 18 to 35 months of age with a relative risk of 4.06 (90% confidence interval, 1.29 to 17.86) in this age group. The individual diagnostic categories of upper respiratory infection, musculoskeletal pain, otitis media with effusion and adenitis/adenopathy had at least one analysis that achieved a significant increased risk ratio. All of these events were infrequent. CONCLUSION: CAIV was generally safe in children and adolescents. The observation of an increased risk of asthma/reactive airway disease in children <36 months of age is of potential concern. Further studies are planned to evaluate the risk of asthma/reactive airway disease after vaccine.

Adolescent↗
PubMed2006

The role of a zinc finger-containing glycine-rich RNA-binding protein during the cold adaptation process in Arabidopsis thaliana.

The mechanistic role of a glycine-rich RNA-binding protein designated atRZ-1a that contributes to enhance cold tolerance in Arabidopsis was investigated. Overexpression of atRZ-1a did not affect the expression of various cold-responsive genes such as COR6.6, COR15a, COR47, RD29A, RD29B and LTI29. Proteome analyses revealed that overexpression of atRZ-1a modulated the expression of several stress-responsive genes, and the transcript levels and RNA stability of these target genes were not affected by atRZ-1a. atRZ-1a successfully complements the cold sensitivity of Escherichia coli lacking four cold shock proteins. These results strongly suggest that atRZ-1a plays a role as an RNA chaperone during the cold adaptation process.

Acclimatization↗
PubMed1975

[Role of thyroid hormone in cold adaptation. 1. Requirement of thyroxine during the course of cold acclimation as estimated by noradrenaline sensitivity (author's transl)].

The amount of thyroxine required for the development and maintenance of cold acclimation was investigated in the rat. Warm-adapted thyroidectomized rats could not survive at 5 degrees C. When thyroxine was replaced, these rats could survive and responded to noradrenaline with increased oxygen consumption in proportion to the dose of replaced thyroxine. Judged from the amount of thyroxine in thyroidectomized rats necessary to restore noradrenaline sensitivity to the same level as seen in intact controls, 30 degrees C-adapted rats were found to require 3.3 mug thyroxine/100 g b.w./day, while 5 degrees C-adapted rats required only 1.2 mug. It is concluded that the amount of thyroxine necessary to produce cold acclimation is much larger than that for the maintenance of cold acclimation.

Acclimatization↗
PubMed1997

Factors affecting the yield of cold-adapted influenza virus vaccine.

Various manipulations to production procedures have been investigated in order to discover methods to attain adequate or augmented titers of cold-adapted influenza virus (CAIV) vaccine. The methods modified include those used for reassortant selection and the determination of virus growth parameters. Increased infectivity titers were achieved through selection of high-yielding mutants by isolating multiple plaques during plaque purification of reassortant clones, as well as through optimization of egg incubation times, age, and lot for individual strains. Up to 6-fold increases in virus yield were obtained by selecting high yielding mutants, up to 9-fold increases were achieved by modifying egg incubation times, and a nearly 1 log increase was realized by determining the ideal egg age for individual strains.

Adaptation, Physiological↗
PubMed1984

Advantage of live attenuated cold-adapted influenza A virus over inactivated vaccine for A/Washington/80 (H3N2) wild-type virus infection.

The efficacy of live attenuated cold-adapted (ca) reassortant influenza virus vaccine against experimental challenge with homologous wild-type virus 5 to 8 weeks after vaccination was compared with that of licensed inactivated vaccine in 81 seronegative (haemagglutination-inhibition antibody titre less than or equal to 1:8) college students. At a dose of 10(7.5) 50% tissue culture infectious dose (TCID50) (70 HID50, human 50% infectious doses) the live virus vaccine, given intranasally, completely protected against illness caused by wild-type virus, whereas the inactivated vaccine, administered intramuscularly, provided 72% protection. Wild-type virus was recovered from only 13% of live virus vaccinees (10(7.5) TCID50 dose of ca virus) compared with 63% of inactivated virus vaccinees and the few infected live virus vaccinees shed 1000 times less wild-type virus than did infected inactivated virus vaccinees or unvaccinated controls. This striking reduction in virus shedding suggests that influenza transmission may be more efficiently interrupted with live than with inactivated virus vaccination.

Administration, Intranasal↗
PubMed1984

Relative immunogenicity of the cold-adapted influenza virus A/Ann Arbor/6/60 (A/AA/6/60-ca), recombinants of A/AA/6/60-ca, and parental strains with similar surface antigens.

The immunogenicity of several cold-adapted (ca) viruses was compared in CSL mice with that of wild-type parental viruses with similar surface antigens, according to the vaccinating dose required to clear a challenge consisting of 10(4.5) 50% tissue culture infective doses of the wild-type virus. All ca viruses were less immunogenic than their wild-type parental strains by a factor of 10(1.3) to 10(3.4), probably due to the restricted capacity of ca viruses to replicate in the respiratory tracts of mice. However, their immunogenicity was considerably enhanced when two quite small doses were administered 3 weeks apart. The immunogenicity of ca viruses when administered in two doses and wild-type viruses when administered as a single dose varied according to their surface antigens. It was highest for viruses with the H2N2 A/Ann Arbor/6/60 and H3N2 A/Queensland/6/72 surface antigens and lowest for those with H1N1 A/HK/123/77 surface antigens. When two doses consisting of 10(5.0) 50% tissue culture infective doses of A/Ann Arbor/6/60-ca were administered at an interval of 3 weeks, solid immunity was induced against the wild-type A/Ann Arbor/6/60 parental virus, two heterologous H3N2 strains, and an H1N1 strain.

Animals↗
PubMed1981

Analysis of ts mutations of cold-adapted influenza A/Leningrad/134/57 virus variants.

By recombination of ts mutants of fowl plague virus belonging to different complementation groups with two cold-adapted variants of human influenza virus, the number and gene localization of ts mutations occurring in these variants was determined. In the course of passaging of human influenza virus at lowered temperature, the number of genes with ts mutations increased.

Cold Temperature↗
PubMed1992

The attenuation phenotype conferred by the M gene of the influenza A/Ann Arbor/6/60 cold-adapted virus (H2N2) on the A/Korea/82 (H3N2) reassortant virus results from a gene constellation effect.

A single gene reassortant (SGR) virus that derived its M gene from the attenuated influenza A/Ann Arbor/6/60 cold-adapted (CA) donor virus and the remaining genes from the A/Korea/82 (H3N2) wild type (WT) virus (designated A/Korea/82 CA M-SGR) was previously shown to be attenuated in mice, hamsters, ferrets, and humans. The attenuation (ATT) phenotype of this SGR virus could result directly from an altered function of the mutant M gene product of the A/Ann Arbor/6/60 CA virus, which differs from the M gene of the A/Ann Arbor/6/60 WT virus at only one amino acid or, indirectly from a gene constellation effect in which ATT results from an inefficient interaction between the products of the M gene of the A/Ann Arbor/6/60 virus and other genes of the A/Korea/82 virus. Several lines of evidence from the present study are consistent with our interpretation that the ATT phenotype of the A/Korea/82 CA M-SGR results from a gene constellation effect. First, the A/Korea/82 CA M-SGR and an A/Korea/82 SGR containing the A/Ann Arbor/6/60 WT M gene were each restricted in replication in the upper and lower respiratory tract of mice compared with the A/Korea/82 WT virus. Second, an A/Udorn/72 CA M-SGR containing the M gene from the A/Ann Arbor/6/60 CA donor virus in a background of other genes derived from the A/Udorn/72 (H3N2) WT virus was not attenuated in the respiratory tract of mice. These data suggest that the change in the amino acid sequence of the M gene product from the A/Ann Arbor/6/60 WT to CA virus is not responsible for the ATT phenotype of the A/Korea/82 CA M-SGR. In addition, evidence of the genetic instability of the A/Korea/82 CA M-SGR is presented, specifically, an extragenic mutation that results in loss of the ATT phenotype. The implications of these findings for the ATT phenotype of the live attenuated reassortant viruses derived from the A/Ann Arbor/6/60 CA donor virus are discussed.

Adaptation, Physiological↗