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Mycobacterium antigen ESAT6 has been isolated from low molecular weight fractions of the shot-term-culture filtrate (ST-CF) and it can easily be detected in tuberculosis patients. The export of ESAT-6 which is a potent T-cell antigen, and related proteins requires a dedicated secretory apparatus that is encoded by a group of genes, several of which also code for proteins that are recognized strongly by T cells. The ESAT-6 systems can consequently be considered as immunogenicity islands and there is mounting evidence that the equivalent genes are subject to selective pressure imposed by the immune system of the host. This antigen includes many epitopes detectable in the serum of most patients with tuberculosis (more than 90%). By the attempts to obtain the vaccine on the basis of ESAT-6 it was demonstrated that the optimization of adjuvant is very important when using the combination of dioctadecylammonium bromide and monophosphoryllipide. ESAT-6 is very potential as diagnostic for differentiation between the mycobacterial infection and BCG vaccination. The main topic in ESAT-6 using is in antibody production and in test-systems for tuberculosis elaboration. Early secretory antigen 6 (ESAT6) and cell filtrate protein 10 (CFP10) are 2 antigens secreted as a complex by the replicating Mycobacterium tuberculosis complex (MTC).

Forty-two antigenic domains were identified across the hepatitis A virus (HAV) polyprotein by using a set of 237 overlapping 20-mer synthetic peptides spanning the entire HAV polyprotein. Nineteen antigenic domains were found within the structural proteins, and 22 were found within the nonstructural proteins, with 1 domain spanning the junction of VP1 and P2A proteins. Five of these domains were considered immunodominant, as judged by both the breadth and the strength of their immunoreactivity. One domain is located within the VP2 protein at position 57-90 aa. A second domain, located at position 767-842 aa, contains the C-terminal part of the VP1 protein and the entire P2A protein. A third domain, located at position 1403-1456 a.a, comprises the C-terminal part of the P2C protein and the N-terminal half of the P3A protein. The fourth domain, located at position 1500-1519 a.a, includes almost the entire P3B, and the last domain, located at position 1719-1764 aa, contains the C-terminal region of the P3C protein and the N-terminal region of the P3D protein. Four of the five most immunoreactive domains are derived from small HAV proteins and/or encompass protein cleavage sites separating different HAV proteins.

Forty-two antigenic domains were identified across the hepatitis A virus (HAV) polyprotein by using a set of 237 overlapping 20-mer synthetic peptides spanning the entire HAV polyprotein. Nineteen antigenic domains were found within the structural proteins, and 22 were found within the nonstructural proteins, with 1 domain spanning the junction of VP1 and P2A proteins. Five of these domains were considered immunodominant, as judged by both the breadth and the strength of their immunoreactivity. One domain is located within the VP2 protein at position 57-90 aa. A second domain, located at position 767-842 aa, contains the C-terminal part of the VP1 protein and the entire P2A protein. A third domain, located at position 1403-1456 aa, comprises the C-terminal part of the P2C protein and the N-terminal half of the P3A protein. The fourth domain, located at position 1500-1519 aa, includes almost the entire P3B, and the last domain, located at position 1719-1764 aa, contains the C-terminal region of the P3C protein and the N-terminal region of the P3D protein. Four of the five most immunoreactive domains are derived from small HAV proteins and/or encompass protein cleavage sites separating different HAV proteins.

CMV belongs to the Betaherpesvirinae subfamily of Herpesviridae which includes herpes simplex virustypes 1 and 2, varicella-zoster virus, and Epstein-Barrvirus. The herpesviruses share a characteristic ability to remain latentover long periods. CMV is a double-stranded linear DNA virus with 162 hexagonal protein capsomeres surrounded by a lipid membrane. CMV has the largest genome of the herpes viruses, ranging from 230-240 kilobase pairs. Human CMV is composed of unique and inverted repeats that include the existence of 4 genome isomers caused by inversion of L-S genome components (class E). Replication may be divided into immediate early, delayed early, and late gene expression based on time of synthesis after infection. The DNA is replicated by rolling circles. In vitro, CMV replicates in human fibroblasts.

CMV belongs to the Betaherpesvirinae subfamily of Herpesviridae which includes herpes simplex virustypes 1 and 2, varicella-zoster virus, and Epstein-Barrvirus. The herpesviruses share a characteristic ability to remain latentover long periods. CMV is a double-stranded linear DNA virus with 162 hexagonal protein capsomeres surrounded by a lipid membrane. CMV has the largest genome of the herpes viruses, ranging from 230-240 kilobase pairs. Human CMV is composed of unique and inverted repeats that include the existence of 4 genome isomers caused by inversion of L-S genome components (class E). Replication may be divided into immediate early, delayed early, and late gene expression based on time of synthesis after infection. The DNA is replicated by rolling circles. In vitro, CMV replicates in human fibroblasts.

Forty-two antigenic domains were identified across the hepatitis A virus (HAV) polyprotein by using a set of 237 overlapping 20-mer synthetic peptides spanning the entire HAV polyprotein. Nineteen antigenic domains were found within the structural proteins, and 22 were found within the nonstructural proteins, with 1 domain spanning the junction of VP1 and P2A proteins. Five of these domains were considered immunodominant, as judged by both the breadth and the strength of their immunoreactivity. One domain is located within the VP2 protein at position 57-90 aa. A second domain, located at position 767-842 aa, contains the C-terminal part of the VP1 protein and the entire P2A protein. A third domain, located at position 1403-1456 aa, comprises the C-terminal part of the P2C protein and the N-terminal half of the P3A protein. The fourth domain, located at position 1500-1519 aa, includes almost the entire P3B, and the last domain, located at position 1719-1764 aa, contains the C-terminal region of the P3C protein and the N-terminal region of the P3D protein. Four of the five most immunoreactive domains are derived from small HAV proteins and/or encompass protein cleavage sites separating different HAV proteins.

SARS Coronavirus is an enveloped virus containing three outer structural proteins, namely the membrane (M), envelope (E), and spike (S) proteins. Spike (S)-glycoprotein of the virus interacts with a cellular receptor and mediates membrane fusion to allow viral entry into susceptible target cells. Accordingly, S-protein plays an important role in virus infection cycle and is the primary target of neutralizing antibodies.It has recently been shown that SARS is caused by a human coronavirus. Human coronaviruses are the major cause of upper respiratory tract illness in humans, such as the common cold. Coronaviruses are positive-stranded RNA viruses, featuring the largest viral RNA genomes known to date (27-31 kb). The first step in coronavirus infection is binding of the viral spike protein, a 139-kDa protein, to certain receptors on host cells. The spike protein is the main surface antigen of the coronavirus. The most prominent protein in the culture supernatants infected with SARS virus is a 46 kDa nucleocapsid protein. This suggests that the nucleocapsid protein is a major immunogen that may be useful for early diagnostics.

Human immunodeficiency virus (HIV) is a retrovirusthat can lead to a condition in which the immune systembegins to fail, leading to opportunistic infections. HIV primarily infects vital cells in the humanimmune systemsuch as helper T cells(specifically CD4+ T cells), macrophagesand dendritic cells. HIV infection leads to low levels of CD4+ T cells through three main mechanisms: firstly, direct viral killing of infected cells; secondly, increased rates of apoptosisin infected cells; and thirdly, killing of infected CD4+ T cells by CD8 cytotoxic lymphocytesthat recognize infected cells. When CD4+ T cell numbers decline below a critical level, cell-mediated immunityis lost, and the body becomes progressively more susceptible to opportunistic infections. HIV was classified as a member of the genus Lentivirus, part of the family of Retroviridae. Lentiviruses have many common morphologies and biological properties. Many species are infected by lentiviruses, which are characteristically responsible for long-duration illnesses with a long incubation period. Lentiviruses are transmitted as single-stranded, positive-sense, enveloped RNA viruses. Upon entry of the target cell, the viral RNA genomeis converted to double-stranded DNAby a virally encoded reverse transcriptasethat is present in the virus particle. This viral DNA is then integrated into the cellular DNA by a virally encoded integraseso that the genome can be transcribed. Once the virus has infected the cell, two pathways are possible: either the virus becomes latentand the infected cell continues to function, or the virus becomes active and replicates, and a large number of virus particles are liberated that can then infect other cells.

Platelet endothelial cell adhesion molecule (PECAM1) induces susceptibility to atherosclerosis. PECAM1 averts phagocyte ingestion of closely apposed viable cells by transmitting detachment signals, and transforms function upon apoptosis, thus promoting tethering of dying cells to phagocytes. The encounter of a viable cell with a phagocyte via the homophilic interaction of PECAM1 on both cell surfaces as a result causing the viable cell's active repulsion from the phagocyte.

Killer cell immunoglobulin-like receptor 2DL4, also known as KIR2DL4 is part of the killer cell Ig-like receptor (KIR) family. KIR proteins with the long cytoplasmic domain transduce inhibitory signals through an immune tyrosine-based inhibitory motif (ITIM), whereas KIR proteins which contain the short cytoplasmic domain, lack the ITIM motif and as a substitute associate with the TYRO protein tyrosine kinase binding protein to transduce activating signals. KIR2DL4 stimulates NK cells to produce IFN-gamma and stimulation with IL-2 upregulates cell surface expression on CD56dimcells and leads to the inhibition of the cytolytic NK cell function.

Insulin Receptor (INSR) is a receptor tyrosine kinase which mediates the pleiotropic actions of insulin. Binding of insulin to the insulin receptor (INSR) stimulates glucose uptake. Once the precursor signal peptide is removed, the insulin receptor precursor is post-translationally cleaved into 2 chains (alpha and beta) which are covalently linked. Insulin binding initiates phosphorylation of several intracellular substrates, including, insulin receptor substrates (IRS1, 2, 3, 4), SHC, GAB1, CBL and other signaling intermediates. Each of these phosphorylated proteins function as docking proteins for other signaling proteins which contain Src-homology-2 domains (SH2 domain) that specifically recognize different phosphotyrosines residues, including the p85 regulatory subunit of PI3K and SHP2.

Endoglin is a type I membrane glycoprotein located on cell surfaces and is part of the TGF beta receptor complex.
The protein consists of a homodimer of 180 kDA with disulfide links. It has been found on endothelial cells, activated macrophages, fibroblasts, and smooth muscle cells. Endoglin has been found to be part of the TGF-beta1 receptor complex. It thus may be involved in the binding of TGF-beta1, TGF-beta3, activin-A, BMP-2, and BMP-7. Beside TGF-beta signaling endoglin may have other functions. It has been postulated that endoglin is involved in the cytoskeletal organization affecting cell morphology and migration. Endoglin has a role in the development of the cardiovascular system and in vascular remodeling. Its expression is regulated during heart development . Experimental mice without the endoglin gene die due to cardiovascular abnormalities.

Inhibitor of Growth Family, Member 2 (ING2) belongs to the inhibitor of growth (ING) family. ING family members associate with and modulate the activity of histone acetyltransferase (HAT) and histone deacetylase (HDAC) complexes and serve in DNA repair and apoptosis. ING2 appears to be involved in p53/TP53 activation and p53/TP53-dependent apoptotic pathways, most likely by enhancing acetylation of p53/TP53. ING2 is a component of an mSin3A-like corepressor complex, which is probably involved in deacetylation of nucleosomal histones. ING2 activity is modulated by binding to phosphoinositides (PtdInsPs).

HBsAg is the surface antigen of the Hepatitis-B-Virus (HBV). The capsid of a virus has different surface proteins from the rest of the virus. The antigen is a protein that binds specifically on one of these surface proteins. It is commonly referred to as the Australian Antigen.

Forty-two antigenic domains were identified across the hepatitis A virus (HAV) polyprotein by using a set of 237 overlapping 20-mer synthetic peptides spanning the entire HAV polyprotein. Nineteen antigenic domains were found within the structural proteins, and 22 were found within the nonstructural proteins, with 1 domain spanning the junction of VP1 and P2A proteins. Five of these domains were considered immunodominant, as judged by both the breadth and the strength of their immunoreactivity. One domain is located within the VP2 protein at position 57-90 aa. A second domain, located at position 767-842 aa, contains the C-terminal part of the VP1 protein and the entire P2A protein. A third domain, located at position 1403-1456 aa, comprises the C-terminal part of the P2C protein and the N-terminal half of the P3A protein. The fourth domain, located at position 1500-1519 aa, includes almost the entire P3B, and the last domain, located at position 1719-1764 aa, contains the C-terminal region of the P3C protein and the N-terminal region of the P3D protein. Four of the five most immunoreactive domains are derived from small HAV proteins and/or encompass protein cleavage sites separating different HAV proteins.

Treponema pallidum is a gram-negative spirochaete bacterium and is considered to be metabolically crippled. There are at least four known subspecies: T. pallidum pallidum, T. pallidum pertenue, T. pallidum carateum and T. pallidum endemicum. The helical structure of T. pallidum pallidum allows it to move in a corkscrew motion through viscous mediums such as mucus. Treponema pallidum sub sp. pallidum has one of the smallest bacterial genomes at 1.14 million base pairs (Mb) and has limited metabolic capabilities, reflecting its adaptation through genome reduction to the rich environment of mammalian tissue.

Insulin decreases blood glucose concentration. It increases cell permeability to monosaccharides, amino acids and fatty acids. It accelerates glycolysis, the pentose phosphate cycle, and glycogen synthesis in liver.

SARS Coronavirus is an enveloped virus containing three outer structural proteins, namely the membrane (M), envelope (E), and spike (S) proteins. Spike (S)-glycoprotein of the virus interacts with a cellular receptor and mediates membrane fusion to allow viral entry into susceptible target cells. Accordingly, S-protein plays an important role in virus infection cycle and is the primary target of neutralizing antibodies.It has recently been shown that SARS is caused by a human coronavirus. Human coronaviruses are the major cause of upper respiratory tract illness in humans, such as the common cold. Coronaviruses are positive-stranded RNA viruses, featuring the largest viral RNA genomes known to date (27-31 kb). The first step in coronavirus infection is binding of the viral spike protein, a 139-kDa protein, to certain receptors on host cells. The spike protein is the main surface antigen of the coronavirus. The most prominent protein in the culture supernatants infected with SARS virus is a 46 kDa nucleocapsid protein. This suggests that the nucleocapsid protein is a major immunogen that may be useful for early diagnostics.

Platelet endothelial cell adhesion molecule (PECAM1) induces susceptibility to atherosclerosis. PECAM1 averts phagocyte ingestion of closely apposed viable cells by transmitting detachment signals, and transforms function upon apoptosis, thus promoting tethering of dying cells to phagocytes. The encounter of a viable cell with a phagocyte via the homophilic interaction of PECAM1 on both cell surfaces as a result causing the viable cell's active repulsion from the phagocyte.

The Defensin family are highly similar in their protein sequence and are microbicidal & cytotoxic peptides made by neutrophils. Beta Defensin-1 is an antimicrobial peptide having the resistance of epithelial surfaces to microbial colonization. Beta Defensin-1 has close proximity to Defensin Alpha-1 and has been implicated in the pathogenesis of cystic fibrosis.
Skin of patients having atopic dermatitis patients and mycosis fungoides (non-lesional and lesional) show lower human Beta Defensin-1 mRNA expression and higher human Beta Defensin-2 and human Beta Defensin-3 mRNA expression.
BBeta Defensin is highly expressed by epithelial cells.
Beta-defensin 1 may play a role in the pathogenesis of severe sepsis.
Variation in human Beta Defensin-1 contributes to asthma diagnosis, with apparent gender-specific effects. Human Beta Defensin-3 is a dimer, while Human BD-1 and Human BD-2 are monomeric. The expression of Human BD1 is correlated with induction profiles in gingival keratinocytes.
The level of expression of human DEFB1 mRNA is lower than that of human BD3 and human BD-2 in reconstructed epidermis.
Human BD1 is down-regulated in human prostatic and renal carcinomas.

Immunoglobulin J chain (IGJ) helps to link 2 monomer units of either IgM or IgA and also also helps to bind these immunoglobulins to secretory component. When it comes to IgM, the J chain-joined dimer is a nucleating unit for the IgM pentamer and in the case of IgA it induces larger polymers.

Defensins are cationic peptides with a large spectrum of antimicrobial activity that comprise an important arm of the innate immune system. The Alpha defensins are differentiated from the Beta-defensins by the pairing of their 3 disulfide bonds.
4 human Beta-defensins have been identified to date; BD-1, BD-2, BD-3 and BD-4.
Beta-defensins are expressed on some leukocytes and at epithelial surfaces.
In addition to their direct antimicrobial activities, they are chemoattractant towards immature dendritic cells and memory T cells. The beta-defensin proteins are expressed as the C-terminal portion of precursors and are released by proteolytic cleavage of a signal sequence and, in the case of BD-1 (36 a.a.), a propeptide region. Beta-defensins contain a six-cysteine motif that forms three intra-molecular disulfide bonds. Beta-Defensins are 3-5 kDa peptides ranging in size from 33-47 amino acid residues.

Tumor necrosis factor is a cytokine involved in systemic inflammation and is a member of a group of cytokines that all stimulate the acute phase reaction. TNF is mainly secreted by macrophages.
TNF causes apoptotic cell death, cellular proliferation, differentiation, inflammation, tumorigenesis and viral replication, TNF is also involved in lipid metabolism, and coagulation. TNF's primary role is in the regulation of immune cells.
Dysregulation and, in particular, overproduction of TNF have been implicated in a variety of human diseases- autoimmune diseases, insulin resistance, and cancer.