The Expression of IL6 and 21 in Crossbred Calves Upregulated by Inactivated Trivalent FMD Vaccine

Foot and mouth disease (FMD) is an economically important disease and a whole-virus inactivated trivalent virus vaccine is the mainstay for controlling the disease in India. The protective humoral immune response to FMD vaccination is a complex, but, tightly regulated process mediated by the interplay of interleukins (IL). Based on the specific role of IL6 and 21 in adaptive immune response, we hypothesized that inactivated trivalent FMD vaccine would stimulate IL6 and 21 expression in the circulating lymphocytes. The expressions of IL6 and 21 were assayed on 0, 28, 60, 90, and 120 d post-vaccination (DPV) by quantitative PCR (qPCR) with simultaneous assessment of FMDV antibody titer by liquid phase blocking ELISA. The results revealed that the peak expression of IL6 and 21 was on DPV 28 which correlated well with the FMDV antibody titer and plummeted to the prevaccination titer level by 60 DPV. As IL21 is the final effector of antibody production as compared to IL6, we investigated the expression of IL21 in calves that had protective titer (>1.8) with the unprotected group (<1.8). Expression of IL21 on 28 DPV was numerically higher in the protected than that of the unprotected group of calves.     

Evaluation of a genetically modified foot-and-mouth disease virus vaccine candidate generated by reverse genetics

ABSTRACT: BACKGROUND: Foot-and-mouth disease (FMD) is the most economically important and highly contagious disease of cloven-hoofed animals worldwide. Control of the disease has been mainly based on large-scale vaccinations with whole-virus inactivated vaccines. In recent years, a series of outbreaks of type O FMD occurred in China (including Chinese Taipei, Chinese Hong Kong) posed a tremendous threat to Chinese animal husbandry. Its causative agent, type O FMDV, has evolved into three topotypes (East-South Asia (ME-SA), Southeast Asia (SEA), Cathay (CHY)) in these regions, which represents an important obstacle to disease control. The available FMD vaccine in China shows generally good protection against ME-SA and SEA topotype viruses infection, but affords insufficient protection against some variants of the CHY topotype. Therefore, the choice of a new vaccine strain is of fundamental importance. RESULTS: The present study describes the generation of a full-length infectious cDNA clone of FMDV vaccine strain and a genetically modified virus with some amino acid substitutions in antigenic sites 1, 3, and 4, based on the established infectious clone. The recombinant viruses had similar growth properties to the wild O/HN/CHA/93 virus. All swine immunized with inactivated vaccine prepared from the O/HN/CHA/93 were fully protected from challenge with the viruses of ME-SA and SEA topotypes and partially protected against challenge with the virus of CHA topotype at 28 days post-immunization. In contrast, the swine inoculated with the genetically modified vaccine were completely protected from the infection of viruses of the three topotypes. CONCLUSIONS: Some amino acid substitutions in the FMDV vaccine strain genome did not have an effect on the ability of viral replication in vitro. The vaccine prepared from genetically modified FMDV by reverse genetics significantly improved the protective efficacy to the variant of the CHA topotype, compared with the wild O/HN/CHA/93 virus. Thus, the full-length cDNA clone of FMDV can be a useful tool to develop genetically engineered FMDV vaccine candidates to help control porcinophilic FMD epidemics in China.     

Immune response of various animals to Akabane disease live virus vaccine

When various animals and routes of inoculation were examined for antibody response to Akabane disease live virus vaccine, the intracerebral (ic) inoculation of mice induced a better antibody response than the subcutaneous (sc) inoculation of calves, guinea pigs, hamsters, mice, or rats. Immunogenicity was compared among lots of this vaccine by performing ic inoculation of mice and sc inoculation of calves and guinea pigs. As a result, there was no distinct significant difference between any two lots of the vaccine, regardless of the animal species used. There was a tendency that the larger the dose of inoculation of the virus, the earlier the production of neutralizing (NT) antibody took place in calves inoculated with the vaccine, and the higher the antibody titer and the rate of taking a turn for positivity for antibody became in these calves. When calves immunized with the vaccine and cows in the field possessing NT antibody were given booster inoculation with the vaccine, the antibody titer showed a significant increase in almost all the calves and cows that exhibited an NT antibody titer of 4 or less at the time of booster inoculation. There were, however, no changes in antibody titer in such calves and cows as presenting an NT antibody titer of 8 or more. Calves and pregnant cows immunized with the vaccine were prevented from viremia and fetal infection when challenged by inoculation with virulent virus.     

Immunogenic and protective effects of an oral DNA vaccine against infectious pancreatic necrosis virus in fish

DNA vaccines and oral DNA-based immunotherapy against infectious pancreatic necrosis virus (IPNV) have scarcely been studied in salmonid fish. Here, a vector with the capsid VP2 gene inserted was encapsulated in alginate microspheres to avoid the aggressive gastrointestinal conditions experienced following oral administration. Alginate microspheres were effective to protect the pDNA encoding VP2, which was expressed early in different organs of the vaccinated trout and that persisted for at least 60 days. The vaccine induces innate immune responses, raising the expression of IFN more than 10-fold relative to the fish vaccinated with the empty plasmid, at 7 and 15 days post-vaccination. Likewise, maximal expression of the IFN-induced antiviral Mx protein was recorded 15 days post-vaccination and neutralizing antibodies were also detected after 15 days, although their titre rose further at 21 days post-vaccination. Protection was high in the immunized fish, which showed around an 80% relative survival when challenged 15 and 30 days after vaccine delivery. Very low viral load with respect to the control group was detected in the vaccinated fish that survived 45 days after challenge. Thus, this study demonstrates the potential of the encapsulation technique for IPNV-DNA vaccine delivery and the relevance of the IPNV-VP2 gene for future plasmid constructs.     

Enhancement of DNA vaccine (P12A3C-pcDNA) efficacy against foot-and-mouth disease by coadministration of interleukin-18-expressing (IL18 pcDNA) plasmid in guinea-pigs

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals causing considerable economic loss in the affected countries. The presently used tissue-cultured inactivated vaccine protects the vaccinated animals for a short duration of immunity. As one of the approaches to develop alternative vaccines, P12A3C-pcDNA (containing P12A and 3C coding sequences of foot-and-mouth disease virus) and bovine IL18 pcDNA plasmids were constructed and the immune response of these constructs was evaluated when they were coinoculated in guinea-pigs. The humoral response was analyzed using enzyme-linked immunosorbent assay (for levels of IgG1, IgG2) and a serum neutralization test (SNT), and the cellular response using an MTT assay. Significantly higher humoral and cell-mediated immune responses were seen in the P12A3C and the IL-18 coinoculated group than that in P12A3C-pcDNA alone and inactivated virus vaccine inoculated groups. Similarly, a higher population of CD4(+) , CD8(+) and T-helper type 1 (Th1), and Th2 cytokine levels were seen in the former group in comparison with the other groups. P12A3C+IL-18 protected all the six animals when challenged with a homologous virus compared with five and four in an inactivated virus vaccine and the P12A3C-pcDNA groups, respectively. These results have shown that the plasmid encoding for P12A3C-pcDNA, when coinoculated with IL-18, induced higher responses and protected the animals from a virus challenge.     

Preparation of FMD type A87/IRN inactivated vaccine by gamma irradiation and the immune response on guinea pig

FMD is one of the most economically damaging diseases that affect livestock animals. In this study FMD Virus type A87/IRN was multiplied on BHK21 cells. The virus was titrated by TCID50 method, it was 10^7.5/ml. The FMD virus samples were inactivated by gamma ray from 60Co source at −20°C. Safety test was done by IBRS2 monolayer cell culture method, also antigenicity of irradiated and un-irradiated virus samples were studied by Complement Fixation Test. The Dose/Survival curve for irradiated FMD Virus was drawn, the optimum dose range for inactivation of FMDV type A87/IRN and unaltered antigenicity was obtained 40–44 kGy. The inactivated virus samples by irradiation and ethyleneimine (EI) were formulated respectively as vaccine with Al(OH)3 gel and other substances. The vaccines were inoculated to Guinea pigs and the results of Serum Neutralization Test for the normal vaccine and radio-vaccine showed protective titer after 8 months. The potency test of the inactivated vaccines was done, PD50 Value of the vaccines were calculated 7.06 and 5.6 for inactivated vaccine by EI and gamma irradiation respectively.     

The role of IgM in paratyphoid immunity

The authors analyze the results of studies on the effect produced by the immunization of calves with paratyphoid vaccine on the production of agglutinins, changes in the blood serum immunoglobulin levels, and the specificity of IgM to Salmonella dublin and Salmonella typhimurium antigens. The highest level of agglutinins to paratyphoid antigens in the blood sera of the immunized calves was registered on days 14-21 after immunization, changes in the levels of different immunoglobulin classes being insignificant. The agglutination test and the enzyme immunoassay have revealed that antibodies to S. dublin anb S. typhimurium antigens belong to IgM.     

The Effect of Bovine IFN-α on the Immune Response in Guinea Pigs Vaccinatedwith DNA Vaccine of Foot-and-Mouth Disease Virus

Foot-and-mouth disease virus (FMDV) belongs to thegenus Aphthovirus of the family Picornavidae. The FMDVgenome is a copy of positive-sense, single-stranded RNA,which contains one large open reading frame (ORF). TheORF is translated into a polypeptide, which undergoesautoproteolytic cleavage to produce the structural and non-structural proteins and ultimately forms mature viral pro-teins [1,2]. FMD is caused by the FMDV, which is a highly conta-gious vesicular disease of cloven-hoofe…     

Immune responses of mice to influenza subunit vaccine in combination with CIA07 as an adjuvant

CIA07 is an immunostimulatory agent composed of E. coli DNA fragments and modified LPS lacking the lipid A moiety. In this study, we investigated whether CIA07 promotes immune responses as an adjuvant to the influenza subunit vaccine. Balb/c mice were immunized intramuscularly once or twice at a 4-week interval with the trivalent influenza subunit vaccine antigen alone or in combination with CIA07 as adjuvant. Antigen-specific serum antibody titers and hemagglutination-inhibition (HI) antibody titers were assessed. At 4 weeks after each immunization, the antigen-specific total serum IgG antibody titer in mice receiving CIA07 was 2 to 3 times higher than that in animals administered antigen alone (P<0.05). The CIA07-treated group additionally displayed higher HI antibody titers against each of the 3 vaccine strains, compared to the antigen group. Animals receiving antigen alone displayed barely detectable antigen-specific serum IgG2a antibody titers. In contrast, coadministration of CIA07 with antigen led to significantly enhanced IgG2a antibody responses, suggesting that CIA07 stimulates a Th1-type immune response. Moreover, the CIA07-treated group displayed a marked increase in the number of interferon gamma-producing CD8(+) T cells in splenocytes. These data collectively demonstrate that CIA07 has the ability to induce both Th1-type cellular and Th2-type humoral immune responses to the influenza subunit vaccine, and support its potential as an effective adjuvant to the influenza vaccine.     

Development and characterization of monoclonal antibodies to foot and mouth disease virus type 'C'

Five fusion experiments were conducted with spleen cells from Balb/c mice immunized with purified 146S antigen of foot and mouth disease virus type 'C' (vaccine strain). Monoclones (31) thus developed were isotyped as IgM (3), IgG1 (6), IgG2a (5), IgG2b (3) and IgG3 (14). Eleven clones isotyped as IgM, IgG2a and IgG2b showed neutralizing activity in virus neutralization and plaque reduction tests. Six of the neutralizing clones precipitated 146S virus in Ouchterlony reaction. On the basis of location of MAb reactive epitopes in relation to intact virus (146S), 12S particles and VP1 in ELISA test, the clones were classified as Class II (6), Class III (11) and Class IV (14). These clones may be useful for purposes of antigen detection from field isolates and for estimation of antibody titres in vaccinated animals.     

共表达H5N1流感病毒M1和HA基因的DNA疫苗与腺病毒载体疫苗的小鼠免疫评价

为评价在小鼠体内表达流感病毒M1和HA基因诱导的免疫反应,制备共表达H5N1亚型禽流感病毒 (A/Anhui/1/2005) 全长基质蛋白1 (M1) 基因和血凝素 (HA) 基因的重组DNA疫苗pStar-M1/HA和重组腺病毒载体疫苗Ad-M1/HA,将其按初免-加强程序免疫BALB/c小鼠,共免疫4次,每次间隔14 d。第1、3次用DNA疫苗,第2、4次用重组腺病毒载体疫苗,每次免疫前及末次免疫后14 d采集小鼠血清用于检测体液免疫应答,末次免疫后14 d采集小鼠脾淋巴细胞用于检测细胞免疫应答。血凝     

Single immunization with MF59-adjuvanted inactivated whole-virion H7N9 influenza vaccine provides early protection against H7N9 virus challenge in mice

H7N9 influenza infection in humans would result in severe respiratory illness. Vaccination is the best way to prevent influenza virus. In this paper, we investigated the effect of early protection provided by inactivated whole-virion H7N9 influenza vaccine in a mouse model.Mice were immunized intramuscularly once with different doses of inactivated whole-virion H7N9 influenza vaccine alone or in combination with MF59 adjuvant. Specific IgM and IgG antibody titers in sera of mice were detected by ELISA 3, 5 and 7days after immunization. To evaluate the early protection provided by the vaccine, mice were challenged with lethal dose (40LD₅₀) of homologous virus 3, 5 and 7 days after immunization respectively. The survival rate and body weight change of mice during 21 days after challenge and the residual lung virus titer on 3rd day after challenge were determined. The results demonstrated that mice could obtain effective protection 3 days after immunization with the vaccine at a high dose, and 5–7 days after immunization even at a low dose. Thus early immune responses induced by inactivated whole-virion H7N9 vaccine could provide effective protection.     

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.     

Delayed-type hypersensitivity and in vitro lymphocyte response in guinea pigs immunized with a live varicella vaccine

The relation of delayed type hypersensitivity (DTH) assessed by the Varicella-Zoster virus (VZV) skin test and lymphocyte transformation (LTF) with VZV antigen was investigated in guinea pigs immunized with live varicella vaccine virus, or heat-inactivated vaccine virus. Guinea pigs immunized with live varicella vaccine virus showed positive DTH and LTF responses to viral antigen as well as a neutralizing (NT) antibody response, while those immunized with heat-inactivated vaccine virus showed only an NT antibody response of the same degree as that to live vaccine virus. These results show the reliability of the skin test in assessing cell-mediated immunity (CMI) to VZV and the advantage of the live varicella vaccine over the inactivated one in immunizing guinea pigs.     

Early kinetics of antibody response to inactivated influenza vaccine

The aim was to examine the rapidity of haemagglutination inhibiting (HI) antibody response induced by immunization with a current inactivated trivalent influenza vaccine. Five to six sequential serum samples collected in autumn 1992 from each of 68 vaccinees in three age groups were studied for HI antibodies to ten influenza virus strains representing vaccine and epidemic viruses. Geometric mean titres, response rates and protection rates are presented. Response rates of > 70% were overall, but not until two weeks after the vaccination. Significant two- and four-day post-vaccination antibody responses were detected only occasionally. In previously vaccinated persons, average antibody titres to some of the viruses decreased during the first days after the vaccination. In the subsequent samples, the titres remained lower than in persons who were not vaccinated against influenza in preceding years. Protection against influenza infection may be frequently developed not until two weeks after vaccination. This has relevance to prophylactic administration of amantadine and rimantadine when an influenza A outbreak is imminent and the vaccination is late.     

Clinical trial with inactivated hepatitis A vaccine and recommendations for its use.

OBJECTIVE--To compare the reactogenicity and immunogenicity of an inactivated hepatitis A vaccine in two different immunisation schedules. DESIGN--Randomised trial. SETTING--One London teaching hospital. SUBJECTS--104 healthy adult volunteers (71 men, 33 women aged 19-60). INTERVENTIONS--Hepatitis A vaccine to group 1 (54 volunteers) at 0, 1, and 2 months and to group 2 (50) at 0, 1, and 6 months. MAIN OUTCOME MEASURES--Symptoms at and after each dose; liver function, hepatitis A virus specific serum immune response; and responses in saliva and parotid fluid in immunised volunteers and subjects with natural immunity. RESULTS--The vaccine was well tolerated; 97% (96/99) and 100% of those immunised developed serum antibody after one and two doses of vaccine respectively. Geometric mean titres increased progressively after each dose and were significantly higher in men but not women in group 2 after the third dose (ratio between geometric mean titres 0.265, 95% confidence interval 0.18 to 0.39; p less than 0.001). At one year this group-sex interaction was absent; geometric mean titres for both sexes were significantly higher in group 2 (ratio 0.330, 0.227 to 0.478; p less than 0.0001). Antibody responses were not significantly different between the groups at two years. Compared with naturally infected subjects immunised volunteers developed poor or undetectable virus specific IgG and IgA responses in saliva and parotid fluid. CONCLUSIONS--The vaccine was safe and highly immunogenic, and the differences in the immune responses in saliva and parotid fluid are unlikely to affect its efficacy.     

Chimeric yellow fever virus 17D-Japanese encephalitis virus vaccine: dose-response effectiveness and extended safety testing in rhesus monkeys

ChimeriVax-JE is a live, attenuated recombinant virus prepared by replacing the genes encoding two structural proteins (prM and E) of yellow fever 17D virus with the corresponding genes of an attenuated strain of Japanese encephalitis virus (JE), SA14-14-2 (T. J. Chambers et al., J. Virol. 73:3095-3101, 1999). Since the prM and E proteins contain antigens conferring protective humoral and cellular immunity, the immune response to vaccination is directed principally at JE. The prM-E genome sequence of the ChimeriVax-JE in diploid fetal rhesus lung cells (FRhL, a substrate acceptable for human vaccines) was identical to that of JE SA14-14-2 vaccine and differed from sequences of virulent wild-type strains (SA14 and Nakayama) at six amino acid residues in the envelope gene (E107, E138, E176, E279, E315, and E439). ChimeriVax-JE was fully attenuated for weaned mice inoculated by the intracerebral (i.c.) route, whereas commercial yellow fever 17D vaccine (YF-Vax) caused lethal encephalitis with a 50% lethal dose of 1.67 log(10) PFU. Groups of four rhesus monkeys were inoculated by the subcutaneous route with 2.0, 3.0, 4.0, and 5. 0 log(10) PFU of ChimeriVax-JE. All 16 monkeys developed low viremias (mean peak viremia, 1.7 to 2.1 log(10) PFU/ml; mean duration, 1.8 to 2.3 days). Neutralizing antibodies appeared between days 6 and 10; by day 30, neutralizing antibody responses were similar across dose groups. Neutralizing antibody titers to the homologous (vaccine) strain were higher than to the heterologous wild-type JE strains. All immunized monkeys and sham-immunized controls were challenged i.c. on day 54 with 5.2 log(10) PFU of wild-type JE. None of the immunized monkeys developed viremia or illness and had mild residual brain lesions, whereas controls developed viremia, clinical encephalitis, and severe histopathologic lesions. Immunized monkeys developed significant (>/=4-fold) increases in serum and cerebrospinal fluid neutralizing antibodies after i.c. challenge. In a standardized test for neurovirulence, ChimeriVax-JE and YF-Vax were compared in groups of 10 monkeys inoculated i.c. and analyzed histopathologically on day 30. Lesion scores in brains and spinal cord were significantly higher for monkeys inoculated with YF-Vax. ChimeriVax-JE meets preclinical safety and efficacy requirements for a human vaccine; it appears safer than yellow fever 17D vaccine but has a similar profile of immunogenicity and protective efficacy.     

Tick-borne Langat/mosquito-borne dengue flavivirus chimera, a candidate live attenuated vaccine for protection against disease caused by members of the tick-borne encephalitis virus complex: evaluation in rhesus monkeys and in mosquitoes

Langat virus (LGT), strain TP21, a naturally avirulent tick-borne flavivirus, was used to construct a chimeric candidate virus vaccine which contained LGT genes for premembrane (preM) and envelope (E) glycoprotein and all other sequences derived from dengue type 4 virus (DEN4). The live virus vaccine was developed to provide resistance to the highly virulent, closely related tick-borne flaviviruses that share protective E epitopes among themselves and with LGT. Toward that end the chimera, initially recovered in mosquito cells, was adapted to grow to high titer in qualified simian Vero cells. When inoculated intraperitoneally (i.p.), the Vero cell-adapted LGT TP21/DEN4 chimera remained completely attenuated for SCID mice. Significantly, the chimera protected immunocompetent mice against the most virulent tick-borne encephalitis virus (TBEV). Subsequently, rhesus monkeys were immunized in groups of 4 with 10(5) or 10(7) PFU of LGT strain TP21, with 10(5) PFU of DEN4, or with 10(3), 10(5), or 10(7) PFU of the chimera. Each of the monkeys inoculated with DEN4 or LGT TP21 became viremic, and the duration of viremia ranged from 1 to 5 days. In contrast, viremia was detected in only 1 of 12 monkeys inoculated with the LGT TP21/DEN4 chimera; in this instance the level of viremia was at the limit of detection. All monkeys immunized with the chimera or LGT TP21 virus developed a moderate to high level of neutralizing antibodies against LGT TP21 as well as TBEV and were completely protected against subsequent LGT TP21 challenge, whereas monkeys previously immunized with DEN4 virus became viremic when challenged with LGT TP21. These observations suggest that the chimera is attenuated, immunogenic, and able to induce a protective immune response. Furthermore, passive transfer of serum from monkeys immunized with chimera conferred significant protection to mice subsequently challenged with 100 i.p. 50% lethal doses of the highly virulent TBEV. The issue of transmissibility of the chimera by mosquitoes was addressed by inoculating a nonhematophagous mosquito, Toxorhynchites splendens, intrathoracically with the chimera or its DEN4 or LGT parent. Neither the LGT TP21/DEN4 vaccine candidate nor the wild-type LGT TP21 virus was able to infect this mosquito species, which is highly permissive for dengue viruses. Certain properties of the chimera, notably its attenuation for monkeys, its immunogenicity, and its failure to infect a highly permissive mosquito host, make it a promising vaccine candidate for use in immunization against severe disease caused by many tick-borne flaviviruses.     

Induction of positive cellular and humoral immune responses by a prime-boost vaccine encoded with simian immunodeficiency virus gag/pol

It is believed likely that immune responses are responsible for controlling viral load and infection. In this study, when macaques were primed with plasmid DNA encoding SIV gag and pol genes (SIVgag/pol DNA) and then boosted with replication-deficient vaccinia virus DIs recombinant expressing the same genes (rDIsSIVgag/pol), this prime-boost regimen generated higher levels of Gag-specific CD4+ and CD8+ T cell responses than did either SIVgag/pol DNA or rDIsSIVgag/pol alone. When the macaques were i.v. challenged with pathogenic simian/HIV, the prime-boost group maintained high CD4+ T cell counts and reduced plasma viral loads up to 30 wk after viral challenge, whereas the rDIsSIVgag/pol group showed only a partial attenuation of the viral infection, and the group immunized with SIVgag/pol DNA alone showed none at all. The protection levels were better correlated with the levels of virus-specific T cell responses than the levels of neutralization Ab responses. These results demonstrate that a vaccine regimen that primes with DNA and then boosts with a replication-defective vaccinia virus DIs generates anti-SIV immunity, suggesting that it will be a promising vaccine regimen for HIV-1 vaccine development.