|
A viral Antigen is an antigen with multiple antigenicities that is protein in nature, strain-specific, and closely associated with the virus particle. A viral antigen is a protein encoded by the viral genome.A viral protein is an antigen specified by the viral genome that can be detected by a specific immunological response.
Viruses are infectious pathogens that cause serious diseases & major threats for global public health, such as influenza, hepatitis, & AIDS. Virus is a sub-micrometer particle that has DNA or RNA packed in a shell called capsid. Viral antigens protrude from the capsid and often fulfill important function in docking to the host cell, fusion, and injection of viral DNA/RNA. Antibody-based immune responses form a first layer of protection of the host from viral infection; however, in many cases a vigorous cellular immune response mediated by T-cells and NK-cells is required for effective viral clearance. When cellular immunity is unable to clear the virus, the infection can become chronic, and serum antibodies to the viral pathogen are used as first indicator for the diagnosis of the disease.
ELISAs provide a valuable tool in the detection and diagnosis of virus infection. The ability to produce recombinant viral proteins will ensure that future ELISAs are safe, specific and rapid. Even when a virus cannot be cultured, provided gene sequence is available, it is possible to rapidly respond to emerging viruses and new viral strains of existing pathogens.
Recombinant viral antigens contain part of viral sequence meaning that the recombinant antigen contains a region which can be recognized by different antibodies produced by different individuals. This reduces the risk of false negatives which can occur with synthetic peptides, which contain only a small portion of the entire protein. If an individual infected with a viral antigen makes antibodies to a part of the protein not included in the synthetic peptides, a false negative results.
Recombinant viral protein usually contains a fusion protein/partner which produces superior attachment to assay surfaces such as wells. For this reason, smaller amounts of recombinant protein will produce the same results as larger amounts of unfused protein. The choice of fusion partner prevents false positives, allowing superior adhesion without incorrect results.
Recombinant Viral proteins are expressed in bacteria, yeast, mammalian cells, and viruses. E. Coli cells were first to be used for this purpose but the expressed proteins were not glycosylated, which was a major drawback since many of the immunogenic proteins of viruses such as the envelope glycoproteins, were glycosylated. Nevertheless, in many instances, it was demonstrated that the non-glycosylated protein backbone was just as immunogenic. The obvious advantage of recombinant viral antigens is that they are available in unlimited quantities and the production and quality control processes is simple.
Advantages of defined using recombinant viral antigens:
1. Production and quality control is simple.
2. No nucleic acids or other viral or external proteins, therefore less toxic.
3. Safer in cases where viruses are oncogenic or establish a persistent infection.
4. Feasible even if virus cannot be cultivated
Disadvantages:
1. May be less immunogenic than conventional inactivated whole-virus vaccines.
2. Requires adjuvant .
3. Fails to elicit CMI.
1. A Viral Protein Mimics its Way into cells.
2. Viral Protein Helps Infected T Cells Stick To Uninfected Cells.
3. The Viral Protein A238L Inhibits Cyclooxygenase-2 Expression through a Nuclear Factor of Activated T Cell-dependent Trans-activation Pathway.
4. Viral Protein is an effective preventative against ear infection.
5. HIV-1 Viral Protein R Induces Apoptosis via a Direct Effect on the Mitochondrial Permeability Transition Pore.
6. The Level of Viral Antigen Presented by Hepatocytes Influences CD8 T-Cell Function.
7. Antigen-presenting cells from calves persistently infected with bovine viral diarrhea virus, a member of the Flaviviridae, are not compromised in their ability to present viral antigen.
8. There is a difference in the distribution and spread of a viral antigen, development of lesions and correlation between presence of viral antigen and lesions.
9. The absence of viral antigens on the surface of equine herpesvirus-1-infected peripheral blood mononuclear cells is a strategy to avoid complement-mediated lysis.
10. Viral Protein Influences Key Cell-signaling Pathway.
11. A viral protein produced by cancer-causing virus influences a key signaling pathway in the immune cells that the virus infects. This stimulates the cells to divide, helping the virus spread through the body.
12. Protection by recombinant viral proteins against a respiratory virulent avian metapneumovirus has been achieved.
13. Viral O-acetylesterases are found in influenza C viruses and Corona-viruses. Viral O-acetylesterases remove cellular receptors from the surface of target cells which destroys the receptor. Recombinant viral O-acetylesterases derived from Sf9 insect cells as chimeric proteins fused to eGFP specifically hydrolyze 9-O-acetylated sialic acids, while that of sialodacryoadenitis virus, a rat coronavirus related to mouse hepatitis virus, is specific for 4-O-acetylated sialic acid. The recombinant esterases were shown to specifically de-O-acetylate sialic acids on glycoconjugates. The recombinant viral proteins can be used to unambiguously identify O-acetylated acids.
Recombinant Borrelia p41
Recombinant Chagas TcF Antigen
Recombinant Chlamydia Trachomatis HSP70 (462-503)
Recombinant Chlamydia Trachomatis HSP70 (549-660)
Recombinant Chlamydia Trachomatis PGP3-D
Recombinant Chlamydia Trachomatis W2
Recombinant Chlamydia Trachomatis W3-W6
Recombinant Chlamydia Trachomatis W4
Recombinant Chlamydia Trachomatis W4-W5
Recombinant Chlamydia Trachomatis W5
Recombinant Chlamydia Trachomatis W5-W6
Recombinant Cytomegalo Virus gB
Recombinant Cytomegalo Virus Mosaic
Recombinant Cytomegalo Virus Pp150 (UL32)
Recombinant Cytomegalo Virus Pp28 (UL99)
Recombinant Cytomegalo Virus Pp38 (UL80a)
Recombinant Cytomegalo Virus Pp52 (UL44)
Recombinant Cytomegalo Virus Pp65 (UL83)
Recombinant Dengue Virus NS1 c-end Type 2
Recombinant Dengue Virus NS1 n-end Type 2
Recombinant Dengue Virus NS3 Type 1
Recombinant Epstein-Barr Virus (HHV-4) Early Antigen
Recombinant Epstein-Barr Virus (HHV-4) Mosaic EBNA1
Recombinant Epstein-Barr Virus (HHV-4) Mosaic p18
Recombinant Epstein-Barr Virus (HHV-4) p18
Recombinant Epstein-Barr Virus (HHV-4) p23
Recombinant Hemagglutinin-Influenza A Virus H1N1 New Caledonia 20/99
Recombinant Hemagglutinin-Influenza A Virus H1N1 Solomon Island 03/2006
Recombinant Hemagglutinin-Influenza A Virus H1N1 Texas 36/91
Recombinant Hemagglutinin-Influenza A Virus H3N2 New York 55/04
Recombinant Hemagglutinin-Influenza A Virus H3N2 Wisconsin 67/05
Recombinant Hemagglutinin-Influenza A Virus H3N2 Wyoming 3/03
Recombinant Hemagglutinin-Influenza A Virus H5N1 Indonesia 05/2005
Recombinant Hemagglutinin-Influenza A Virus H5N1 Vietnam 1203/04
Recombinant Hemagglutinin-Influenza A Virus H7N7 Netherlands 219/03
Recombinant Hemagglutinin-Influenza A Virus H9N2 Hong Kong 1073/99
Recombinant Hemagglutinin-Influenza B Virus Hong Kong 330/01
Recombinant Hemagglutinin-Influenza B Virus Jilin 20/03
Recombinant Hemagglutinin-Influenza B Virus Malaysia 2506/04
Recombinant Hemagglutinin-Influenza B Virus Ohio 01/05
Recombinant Hepatitis B Surface Antigen adr subtype, CHO
Recombinant Hepatitis B Surface Antigen adr subtype, Saccharomyces Recombinant Hepatitis B Surface Antigen Adw subtype
Recombinant Hepatitis B Surface Antigen Adw subtype, Saccharomyces
Recombinant Hepatitis B Surface Antigen ayw subtype, pichia
Recombinant Hepatitis B Surface Antigen ayw subtype, Saccharomyces
Recombinant Hepatitis B Surface Antigen preS1
Recombinant Hepatitis B Surface Antigen preS2
Recombinant Hepatitis C Virus NS3 (1450-1643)
Recombinant Hepatitis C Virus NS3 Genotype-1a (1356-1459)
Recombinant Hepatitis C Virus NS3 Genotype-1a(1192-1459)
Recombinant Hepatitis C Virus NS3 Genotype-1b (1356-1459)Recombinant Hepatitis C Virus NS3 Genotype-1b(1192-1459)
Recombinant Hepatitis C Virus NS3 Genotype-1c
Recombinant Hepatitis C Virus NS3 Genotype-2b (1356-1459)
Recombinant Hepatitis C Virus NS3 Genotype-2b(1192-1459)
Recombinant Hepatitis C Virus NS3 Genotype-2c (1192-1459)
Recombinant Hepatitis C Virus NS3 Genotype-2c (1356-1459)
Recombinant Hepatitis C Virus NS3 Genotype-3 (1356-1459)
Recombinant Hepatitis C Virus NS3 Genotype-4 (1356-1459)
Recombinant Hepatitis C Virus NS3 Genotype-5 (1356-1459)
Recombinant Hepatitis C Virus NS3 Genotype-5 (1192-1459)
Recombinant Hepatitis C Virus NS3 Genotype-5a
Recombinant Hepatitis C Virus NS3 Genotype-6 (1356-1459)
Recombinant Hepatitis C Virus NS3 Genotype-6a (1192-1459)
Recombinant Hepatitis C Virus NS3 Genotype-1b
Recombinant Hepatitis C Virus NS3, Biotin Labeled
Recombinant Hepatitis C Virus NS3, Horseradish Peroxidase Labeled
Recombinant Hepatitis C Virus NS4
Recombinant Hepatitis C Virus NS4 a+b
Recombinant Hepatitis C Virus NS4 a+b, Biotin Labeled
Recombinant Hepatitis C Virus NS4 a+b, Fluorescein Labeled
Recombinant Hepatitis C Virus NS4 a+b, Rhodamine Labeled
Recombinant Hepatitis C Virus NS4 Mosaic
Recombinant Hepatitis C Virus NS4, Horseradish Peroxidase Labeled
Recombinant Hepatitis C Virus NS5
Recombinant Hepatitis C Virus NS5 Genotype-1a (2322-2423)
Recombinant Hepatitis C Virus NS5 Genotype-1
Recombinant Hepatitis C Virus NS5 Genotype-1a
Recombinant Hepatitis C Virus NS5 Genotype-1b
Recombinant Hepatitis C Virus NS5 Genotype-2
Recombinant Hepatitis C Virus NS5 Genotype-2a
Recombinant Hepatitis C Virus NS5 Genotype-2b
Recombinant Hepatitis C Virus NS5 Genotype-3
Recombinant Hepatitis C Virus NS5 Genotype-3a
Recombinant Hepatitis C Virus NS5 Genotype-3b
Recombinant Hepatitis C Virus NS5 Genotype-4
Recombinant Hepatitis C Virus NS5 Genotype-5
Recombinant Hepatitis C Virus NS5 Genotype-6
Recombinant Hepatitis C Virus NS5 Genotype-6a
Recombinant Hepatitis C Virus NS5, Biotin Labled
Recombinant Hepatitis C Virus NS5, Horseradish Peroxidase Labled
Recombinant Hepatitis C Virus Nucleocapsid (core) (105-302)
Recombinant Hepatitis C Virus Nucleocapsid (core) 22kDa
Recombinant Hepatitis C Virus Nucleocapsid (core) 22kDa, Biotin
Recombinant Hepatitis C Virus Nucleocapsid (core) 22kDa, Fluorescein Labeled
Recombinant Hepatitis C Virus Nucleocapsid (core) 22kDa, Rhodamine Labeled
Recombinant Hepatitis C Virus Nucleocapsid (core) 24
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-1
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-1a
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-1b
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-2a
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-2b
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-3/10
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-3a
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-3b
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-4
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-5
Recombinant Hepatitis C Virus Nucleocapsid (core) Genotype-6a
Recombinant Hepatitis C Virus Nucleocapsid (core), Biotin Labeled
Recombinant Hepatitis C Virus Nucleocapsid (core), Horseradish Peroxidase Labled
Recombinant Hepatitis C Virus Combined
Recombinant Hepatitis A Virus P2C
Recombinant Hepatitis A Virus P2C-P3A
Recombinant Hepatitis A Virus P2C-P3B
Recombinant Hepatitis A Virus P3C
Recombinant Hepatitis A Virus VP1
Recombinant Hepatitis A Virus VP1-P2A (669-782)
Recombinant Hepatitis A Virus VP1-P2A (722-830)
Recombinant Hepatitis A Virus VP3
Recombinant Hepatitis A Virus VP4-VP2
Recombinant Hepatitis B Virus Core(1-183)
Recombinant Hepatitis B Virus Core(1-186)
Recombinant Hepatitis B Virus Core Delta
Recombinant Hepatitis B Virus HBe
Recombinant Hepatitis B Virus x
Recombinant Hepatitis D Virus
Recombinant Hepatitis E VirusMosaic ORF2/ORF3 38.5 kDa Recombinant Hepatitis E Virus Mosaic-S ORF2/ORF3 33kDa
Recombinant Hepatitis E VirusORF2 (403-461)
Recombinant Hepatitis E VirusORF2 (452-617)
Recombinant Hepatitis E VirusORF2 (633-659)
Recombinant Hepatitis E VirusORF3
Recombinant Herpes Simplex Virus-1 gD
Recombinant Herpes Simplex Virus-1 gG
Recombinant Herpes Simplex Virus-2 gD
Recombinant Herpes Simplex Virus-2 gG
Recombinant Herpes Simplex Virus-8 Mosaic
Recombinant HIV Type-O Envelope
Recombinant HIV Type-O gp41
Recombinant HIV Type-O gp41, MBP tag
Recombinant HIV-1 p55 gag
Recombinant HIV-1 p66 pol
Recombinant HIV-1 Envelope (233)
Recombinant HIV-1 Envelope (288)
Recombinant HIV-1 Envelope conjugated to HIV-2 gp39
Recombinant HIV-1 Envelope, His Tag
Recombinant HIV-1 gag p17, p24
Recombinant HIV-1 gag p17, p24, gp120
Recombinant HIV-1 gag p17-p24, gp41-gp120
Recombinant HIV-1 gp120 CM
Recombinant HIV-1 gp120 LAV
Recombinant HIV-1 gp120 MN
Recombinant HIV-1 gp120 nef Mosaic
Recombinant HIV-1 gp160 LAV
Recombinant HIV-1 gp160 MN
Recombinant HIV-1 gp41
Recombinant HIV-1 gp41 Long (513-674 a.a.)
Recombinant HIV-1 gp41 Long, Biotin Labeled
Recombinant HIV-1 gp41 Long, Horseradish peroxidase Labeled
Recombinant HIV-1 gp41, Biotin Labeled
Recombinant HIV-1 gp41, His tag
Recombinant HIV-1 gp41, Horseradish Peroxidase Labeled
Recombinant HIV-1 gp41, MBP tag
Recombinant HIV-1 nef
Recombinant HIV-1 p24
Recombinant HIV-1 p24 Core
Recombinant HIV-1 p24 Core, Sf9
Recombinant HIV-1 p24 gag, His Tag
Recombinant HIV-1 p24, Biotin Labeled
Recombinant HIV-1 p24, Horseradish Peroxidase Labeled
Recombinant HIV-1 p31 Integrase
Recombinant HIV-1 pol Integrase
Recombinant HIV-1 TAT
Recombinant HIV-1 TAT Clade-C
Recombinant HIV-1 TAT, Biotin Labeled
Recombinant HIV-2 Envelope
Recombinant HIV-2 gp32
Recombinant HIV-2 gp32, Biotin Labeled
Recombinant HIV-2 gp32, Horseradish Peroxidase Labled
Recombinant HIV-2 gp36
Recombinant HIV-2 gp36 (390-702)
Recombinant HIV-2 gp36, His Tag
Recombinant HIV-2 gp36, MBP tag
Recombinant HIV-I p24 gag
Recombinant HTLV 1+2
Recombinant HTLV-1 Envelope
Recombinant HTLV-1 gp21
Recombinant HTLV-1 gp46
Recombinant HTLV-1 Mosaic
Recombinant HTLV-1 p24 Core
Recombinant Japanese Encephalitis Virus
Recombinant Malaria Cs Mosaic
Recombinant Malaria Protein HSP
Recombinant Measles Virus (399-525)
Recombinant Measles Virus Fusion Mosaic (106-114,519-550)
Recombinant Measles Virus Hemagglutinin Mosaic (1-30,115-150,379-410)
Recombinant Measles Virus Large Polymerase (2059-2183)
Recombinant Measles Virus Large Polymerase (58-149)
Recombinant Measles Virus Non-Structural C-Protein (1-51)
Recombinant Measles Virus Nucleocapsid
Recombinant Mosaic Hepatitis C Virus NS4 Genotype-1
Recombinant Mosaic Hepatitis C Virus NS4 Genotype-2
Recombinant Mosaic Hepatitis C Virus NS4 Genotype-3
Recombinant Mosaic Hepatitis C Virus NS4 Genotype-5
Recombinant Rubella Virus Capsid C
Recombinant Rubella Virus E1 Mosaic
Recombinant Rubella Virus E2
Recombinant SARS Associated Spike Mosaic S(M)
Recombinant SARS Associated Spike Mosaic S(N)
Recombinant SARS Associated Spike Mosaic S©
Recombinant SARS Associated Coronavirus Envelope
Recombinant SARS Associated Coronavirus Matrix
Recombinant SARS Associated Coronavirus Nucleocaspid (1-49)
Recombinant SARS Associated Coronavirus Nucleocaspid (1-49,192-220)
Recombinant SARS Associated Coronavirus Nucleocaspid (340-390)
Recombinant SARS Coronavirus Nucleocapsid (1-422)
Recombinant SIV p55
Recombinant Tick-Borne Encephalitis Virus CE/gE
Recombinant Tick-Borne Encephalitis Virus Core
Recombinant Tick-Borne Encephalitis Virus gE
Recombinant Tick-Borne Encephalitis Virus gE C-end (296-414)
Recombinant Tick-Borne Encephalitis Virus gE middle (50-250)
Recombinant Tick-Borne Encephalitis Virus NE/gE
Recombinant Tick-Borne Encephalitis Virus NE/GE/CE/gE
Recombinant Tick-Borne Encephalitis Virus NS3
Recombinant Tick-Borne Encephalitis Virus preM
Recombinant Toxoplasma Gondii MIC3
Recombinant Toxoplasma Gondii P24 (GRA 1)
Recombinant Toxoplasma Gondii P29 (GRA 7)
Recombinant Toxoplasma Gondii P30 (SAG 1)
Recombinant Toxoplasma Gondii ROP4 RH2
Recombinant Treponema pallidum p15
Recombinant Treponema pallidum p15 (partial)
Recombinant Treponema pallidum p15 (Partial), His Tag
Recombinant Treponema pallidum p17
Recombinant Treponema pallidum p17 (Partial)
Recombinant Treponema pallidum p41
Recombinant Treponema pallidum p41 Mosaic
Recombinant Treponema pallidum p47
Recombinant Treponema pallidum p47 (Partial)
Recombinant Treponema pallidum TmpA
Recombinant Treponema pallidum TmpA (Partial)
Recombinant Varicella Zoster Virus gE
Recombinant Varicella Zoster Virus ORF26
Recombinant Varicella Zoster Virus ORF9
Recombinant West Nile Envelope Virus
Recombinant West Nile Pre-M Virus | 
