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The B19 virus, usually referred to as parvovirus B19 or sometimes as erythrovirus B19, belongs to the family of parvoviruses, genus erythrovirus. B19 virus causes a childhood rash named “fifth disease” or “erythema infectiosum” which is ordinarily known as “slapped cheek syndrome”. Erythroviruses are members of the Parvoviridae family of small DNA viruses. The B19 virus is a non-enveloped, icosahedral virus which contains a single-stranded linear DNA genome. Parvovirus B19 is classified as erythrovirus because of its capability to invade red blood cell precursors in the bone marrow. This virus is mainly spread by infected respiratory droplets; though, blood-borne transmission has also been reported.

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.

Endoglin is a type I membrane glycoprotein located on cell surfaces and is part of the TGF beta receptor complex.
The Endoglin protein consists of a homodimer of 180 kDA with disulfide links. Endoglin has been found on endothelial cells, activated macrophages, fibroblasts, and smooth muscle cells. Furthermore, Endoglin has been found to be part of the TGF-beta1 receptor complex. Endoglin 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. Endoglin expression is regulated during heart development . Experimental mice without the endoglin gene die due to cardiovascular abnormalities.

Leukemia inhibitory factor receptor (LIFR) is the receptor for leukemia inhibitory factor, a pleiotropic cytokine affecting the differentiation, survival, and proliferation of various cells in the adult and the embryo. LIFR plays an imperative role in a number of aspects of early pregnancy such as blastocyst implantation in the uterus.

Protein Kinase IFN Double Stranded RNA Activator, also known as PRKRA, mediates the effects of interferon when a viral infection takes place. PRKRA activates EIF2AK2/PKR in the absence of double-stranded RNA (dsRNA) and leads to phosphorylation of EIF2S1/EFI2-alpha and inhibition of translation and induction of apoptosis. Mutations in PRKRA are associated with dystonia.

Hepatitis A virus cellular receptor 1 (HAVCR1) is a membrane receptor for both human hepatitis A virus (HHAV) and TIMD4. HAVCR1 is a type I trans-membrane structural glycoprotein located in the renal proximal tubule epithelial cells. HAVCR1 protein may be involved in the control of asthma and allergic diseases. The reference genome represents an allele which retains a MTTVP amino acid segment that presents defense against atopy in HHAV seropositive individuals.

Monkeypox virus is transmitted to humans from animalssuch as rodents and primates having similar symptoms similar of smallpox although less severe. Monkeypox is an enveloped double-stranded DNA virus approximately 190 kb which is part of the Orthopoxvirus genus of the Poxviridae family. 2monkeypox genetic clades: central African which is more transmissible& west African clade. Monkeypox virus spreadsfrom animal to human &human to humanvia animal bite or by direct body fluid contact. Incubation period lasts12 days. The MPV common ssymptoms include fever, rash, headache, swelling of lymph nodes and muscle pain,

Human T-lymphotropic virus (HTLV) is a human, single-stranded RNA retrovirus that causes T-cell leukemia and T-cell lymphoma. The virus activates a subset of T-helper cellscalled Th1cells. The result is a proliferation of Th1 cells and overproduction of Th1 related cytokines (mainly IFN-gamma and TNF-alpha). Feedback mechanisms of these cytokines cause a suppression of the Th2 lymphocytes and a reduction of Th2 cytokine production (mainly IL-4, IL-5, IL-10 and IL-13). The end result is a reduction in the ability of the infected host to mount an adequate immune response to invading organisms that require a predominantly Th2 dependant response (these include parasitic infections and production of mucosal and humoral antibodies).

The Epstein-Barr virus (EBV), also called Human herpes virus 4 (HHV-4), is a virusof the herpes family(which includes Herpes simplex virusand Cytomegalovirus. On infecting the B-lymphocyte, the linear virus genome circularizes and the virus subsequently persists within the cell as an episome. The virus can execute several distinct programs of gene expressionwhich can be broadly categorized as being lytic cycle or latent cycle. The lytic cycleor productive infection results in staged expression of a host of viral proteinswith the ultimate objective of producing infectious virions. Formally, this phase of infection does not inevitably lead to lysis of the host cellas EBV virions are produced by budding from the infected cell. The latent cycle(lysogenic) programs are those that do not result in production of virions. A very limited, distinct set of viral proteins are produced during latent cycle infection. These include Epstein-Barr nuclear antigen(EBNA)-1, EBNA-2, EBNA-3A, EBNA-3B, EBNA-3C, EBNA-leader protein (EBNA-LP) and latent membrane proteins(LMP)-1, LMP-2A and LMP-2B and the Epstein-Barr encoded RNAs(EBERs).

TBE is caused by tick-borne encephalitis virus (TBEV), a member of the family Flaviviridae.
A closely related virus in Far Eastern Eurasia, Russian spring-summer encephalitis virus (RSSEV).
The family Flaviviridae includes other tick-borne viruses are closely related to TBEV and RSSEV, such as Omsk hemorrhagic fever virus & Kyasanur Forest virus.
Louping ill virus is also a member of this family.

EBI3 has an induced expression in B lymphocytes in reaction to Epstein-Barr virus infection. EBI3 encodes a secreted glycoprotein belonging to the hematopoietin receptor family, and heterodimerizes with a 28 kDa protein to form iIL-27. EBI3 drives rapid clonal expansion of naive cd4(+) t-cells. EBI3 strongly synergizes with IL-12 to activate IFN-gamma production of naive cd4(+) t-cells. EBI3 mediates its biologic effects through the cytokine receptor wsx-1/tccr.

IL13 is an immunoregulatory cytokine produced primarily by activated Th2 cells. IL-13 is involved in several stages of B-cell maturation and differentiation. It up-regulates CD23 and MHC class II expression, and promotes IgE isotype switching of B cells. This cytokine down-regulates macrophage activity, thereby inhibits the production of pro-inflammatory cytokines and chemokines. This cytokine is found to be critical to the pathogenesis of allergen-induced asthma but operates through mechanisms independent of IgE and eosinophils. This gene, IL3, IL5, IL4, and CSF2 form a cytokine gene cluster on chromosome 5q, with this gene particularly close to IL4.

The SARS Nucleocaspid is a protein that has a crucial structural importance, by making the virions associates with the RNA genome and therefore create a nucleocapsid that has the specific helical form. There has been found 3 different domain structures to the nucleocapsid antigen. This protein contains 3 outer structural proteins, the membrane (M), envelope (E), and spike (S) proteins.

SARS or severe acute respiratory syndrome is a lethal kind of pneumonia generated by coronavirus. Coronaviruses are a family of viruses that causes a mild respiratory tract infection is a large type of creatures such as humans, pigs, cows, mice, cats etc. up to this day, the origin of the coronavirus is still unknown.

VCAM1 is a member of the Ig superfamily. It is a cell surface sialoglycoprotein expressed by cytokine activated endothelium. VCAM-1 contains 6 or 7 immunoglobulin domains, and is expressed on both large and small vessels only after the endothelial cells are stimulated by cytokines. The protein has a number of functions including the regulation of leukocyte migration, leukocyte endothelial cell adhesion and signal transduction and may play a role in a number of inflammatory diseases (artherosclerosis and rheumatoid arthritis).

Interleukin-1 ra is a member of the interleukin 1 cytokine family. This protein inhibits the activities of interleukin 1, alpha (IL1A) and interleukin 1, beta (IL1B), and modulates a variety of interleukin 1 related immune and inflammatory responses. This gene and five other closely related cytokine genes form a gene cluster spanning approximately 400 kb on chromosome 2. A polymorphism of this gene is reported to be associated with increased risk of osteoporotic fractures and gastric cancer. Four alternatively spliced transcript variants encoding distinct isoforms have been reported.

Vascular endothelial growth factor is an important signaling protein involved in both vasculogenesis and angiogenesis. As its name implies, VEGF activity has been mostly studied on cells of the vascular endothelium, although it does have effects on a number of other cell types (e.g. stimulation monocyte/ macrophagemigration, neurons, cancer cells, kidney epithelial cells ).VEGF mediates increased vascular permeability, induces angiogenesis, vasculogenesis and endothelial cell growth, promotes cell migration, and inhibits apoptosis. In vitro, VEGF has been shown to stimulate endothelial cell mitogenesisand cell migration. VEGF is also a vasodilator and increases microvascular permeability and was originally referred to as vascular permeability factor.
Elevated levels of this protein are linked to POEMS syndrome, also known as Crow-Fukase syndrome. Mutations in this gene have been associated with proliferative and nonproliferative diabetic retinopathy.

VEGF-C152S is a point mutant generated by the replacement of the second conserved Cys residue of the recombinant processed VEGF-C by a Ser residue. VEGF-C 152S is analog to the human VEGF-C 156S mutant and only active toward VEGFR-3/FLT-4 but, unlike wild type VEGF-C, is unable to bind to and to activate signaling through VEGFR-2/KDR. VEGF-C152S was inactive in the vascular permeability assay and did not increase migration of the capillary endothelial cells, indicating that these VEGF-like effects of VEGF-C require VEGFR-2 binding. VEGF-C, also known as Vascular Endothelial Growth Factor Related Protein (VRP), is a recently discovered VEGF growth factor family member that is most closely related to VEGF-D. The rat VEGF-C cDNA encodes a pre-pro-protein of 416 amino acids residues. It is almost identical to the mouse VEGF-C protein. Similar to VEGF-D, VEGF-C has a VEGF homology domain spanning the middle third of the precursor molecule and long N- and C-terminal extensions. In adults, VEGF-C is highly expressed in heart, placenta, ovary and small intestine. Recombinant rat VEGF-C, lacking the N- and C-terminal extensions and containing only the middle VEGF homology domain, forms primarily non-covalently linked dimers. This protein is a ligand for both VEGFR-2/KDR and VEGFR-3/FLT -4. Since VEGFR-3 is strongly expressed in lymphatic endothelial cells, it has been postulated that VEGF-C is involved in the regulation of the growth and/or differentiation of lymphatic endothelium. Although recombinant rat VEGF-C is also a mitogen for vascular endothelial cells, it is much less potent than VEGF-A.

The bone morphogenetic protein (BMP) receptors are a family of transmembrane serine/threonine kinases that include the type I receptors BMPR1A and BMPR1B and the type II receptor BMPR2. These receptors are also closely related to the receptors, ACVR1 and ACVR2. The ligands of these receptors are members of the TGF-beta superfamily. TGF-betas transduce their signals through the formation of heteromeric complexes with 2 different types of serine (threonine) kinase receptors: type I receptors of about 50-55 kD and type II receptors of about 70-80 kD. Type II receptors bind ligands in the absence of type I receptors, but they require their respective type I receptors for signaling, whereas type I receptors require their respective type II receptors for ligand binding.

RAC1 is a GTPase which belongs to the RAS superfamily of small GTP-binding proteins. Members of this superfamily appear to regulate a diverse array of cellular events, including the control of cell growth, cytoskeletal reorganization, and the activation of protein kinases. RAC-1 regulates the actin cytoskeleton but also other cellular processes. RAC1 have been shown to be involved in the regulation of cell-cell adhesion.

Bronchoalveolar lavage fluid from mice with experimentally induced allergic pulmonary inflammation contains a novel 9.4 kDa cysteine-rich secreted protein, RELM-alpha (FIZZ1, found in inflammatory zone). RELM-alpha is a secreted protein that has a restricted tissue distribution with highest levels in adipose tissue stroma. Murine RELM-alpha (FIZZ1) is the founding member of a new gene family including two other murine genes expressed, respectively, in intestinal crypt epithelium (RELM-beta) and white adipose tissue (Resistin), and two related human genes.
RELMalpha inhibits the differentiation of 3T3-L1 preadipocytes into adipocytes but has no effect on proliferation of 3T3-L1 preadipocytes. RELMalpha is able to form heterooligomers with resistin but not RELMbeta. Since RELMalpha is expressed by adipose tissue and it is a secreted factor, our findings suggest that RELMalpha may be involved in the control of the adipogenesis as well as in the process of muscle differentiation.
In the lung, RELM-alpha is induced by hypoxia and was renamed as hypoxia-induced mitogenic factor (HIMF). HIMF strongly activated Akt phosphorylation. The phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 (10 micromol/L) inhibited HIMF-activated Akt phosphorylation. It also inhibited HIMF stimulated RPSM proliferation. Thus, the PI3K/Akt pathway, at least in part, mediates the proliferative effect of HIMF. Further studies showed that HIMF had angiogenic and vasoconstrictive properties. HIMF increased pulmonary arterial pressure and vascular resistance. Further studies suggest that HIMF regulates apoptosis and may participate in lung alveolarization and maturation.

RANKL binds to tnfrsf11b/opg and to tnfrsf11a/rank. Osteoclast differentiation and activation factor. Augments the ability of dendritic cells to stimulate naive t-cell proliferation. May be an important regulator of interactions between t-cells and dendritic cells and may play a role in the regulation of the t-cell-dependent immune response. sRANKL may also play an important role in enhanced bone-resorption in humoral hypercalcemia of malignancy.

SARS-Associated Coronavirus Nuclecapsid is an enveloped viral componentthat contains three external structural antigens, the mains are membrane (M), envelope (E), and spike (S) proteins. Spike (S)-glycoprotein of the virus interacts with a membrenal receptor and mediates membrane fusion to grant viral entry into the target cells. therefore, S-protein has a crucial part in virus infection cycle and is the main target of neutralizing antibodies.

Trichomonas vaginalis, an anaerobic, flagellated protozoan parasite, is most dominant protozoan causing sexual transmitted disease. T. vaginalis induced vaginal tract infection occurs as multiple steps involving interactions between host macromolecules and protozoan virulent factor. Adhension protein P65 of T. vaginalis has a vital part in assisting the penetration into vaginal tract surface.