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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.

Japanese encephalitis previously known as Japanese B encephalitis is a virus from the family Flaviviridae. it is closely related to the West Nile virus and St. Louis encephalitis virus. Positive sense single stranded RNA genome is packaged in the capsid, formed by the capsid protein. The outer envelope is formed by envelope (E) protein and is the protective antigen. It aids in entry of the virus to the inside of the cell. The genome also encodes several nonstructural proteins also (NS1,NS2a,NS2b,NS3,N4a,NS4b,NS5). NS1 is produced as secretory form also. NS3 is a putative helicase, and NS5 is the viral polymerase. It has been noted that the Japanese encephalitis virus (JEV) infects the lumen of the endoplasmic reticulum (ER) and rapidly accumulates substantial amounts of viral proteins for the JEV. Japanese Encephalitis is diagnosed by detection of antibodies in serum and CSF (cerebrospinal fluid) by IgM capture ELISA.

HCV is a small 50nm, enveloped, single-stranded, positive sense RNAvirus in the family Flaviviridae.
HCV has a high rate of replication with approximately one trillion particles produced each day in an infected individual. Due to lack of proofreading by the HCV RNA polymerase, the HCV has an exceptionally high mutation rate, a factor that may help it elude the host's immune response. Hepatitis C virus is classified into six genotypes(1-6) with several subtypes within each genotype. The preponderance and distribution of HCV genotypes varies globally. Genotype is clinically important in determining potential response to interferon-based therapy and the required duration of such therapy. Genotypes 1 and 4 are less responsive to interferon-based treatment than are the other genotypes (2, 3, 5 and 6).

LAIR1 is a glycoprotein expressed on the surface of the majority of human peripheral blood mononuclear leukocytes including T cells, B cells, NK cells, macrophages and dendritic cells. LAIR-1 functions as an inhibitory receptor in NK cells, T cells and B cells. Inhibitory receptors control the immune response to prevent lysis of cells recognized as self. Lair1 consists of a leader sequence, extracellular domain, transmembrane domain, cytoplasmic region.LAIR1 is a member of both the immunoglobulin superfamily and the leukocyte-associated inhibitory receptor family. LAIR1 maps to a region of 19q13.4 labeled the leukocyte receptor cluster, which contains at least 29 genes encoding leukocyte-expressed receptors of the immunoglobulin superfamily.

Activins are homodimers or heterodimers of the different β subunit isoforms, part of the TGFβ family. Mature Activin A has two 116 amino acids residues βA subunits (βA-βA). Activin displays an extensive variety of biological activities, including mesoderm induction, neural cell differentiation, bone remodelling, haematopoiesis, and reproductive physiology. Activins takes part in the production and regulation of hormones such as FSH, LH, GnRH and ACTH. Cells that are identified to express Activin A include fibroblasts, endothelial cells, hepatocytes, vascular smooth muscle cells, macrophages, keratinocytes, osteoclasts, bone marrow monocytes, prostatic epithelium, neurons, chondrocytes, osteoblasts, Leydig cells, Sertoli cells, and ovarian granulosa cells.

SGTA is a ubiquitously expressed protein that contains three TPR protein-protein interaction duplicates. SGTA takes part as a component of the androgen receptor (AR)-chaperone-cochaperone complex, functions as a cochaperone and participates in androgen signaling. SGTA binds directly to HSC70 and HSP70 and mediates their ATPase activity. SGTA gene encodes a protein that is able to interact with the chief nonstructural protein of parvovirus H-1 and 70-kDa heat shock cognate. In addition, SGTA interacts with Vpu and Gag from HIV-1, SARS-CoV accessory protein 7a, DNAJC5 and DNAJC5B. Since this transcript is expressed universally in several tissues, SGTA serves a housekeeping function. While being involved in apoptosis and androgen signaling, SGTA is a possible molecule for polycystic ovary syndrome, a disorder characterized by androgen excess, obesity and menstrual disturbances.

NCS1 is part of the neuronal calcium sensor gene family, which encode calcium-binding proteins expressed primarily in neurons. NCS1 regulates G protein-coupled receptor phosphorylation in a calcium-dependent manner and can substitute for calmodulin. NCS1 is related with secretory granules and modulates synaptic transmission and synaptic plasticity. NCS1 regulates GRK1 and substitutes for calmodulin. NCS1 stimulates PI4KB kinase activity and participates in long-term synaptic plasticity through its interaction with PICK1. NCS1 takes part in neuron differentiation through inhibition of the activity of N-type voltage-gated calcium channel.

Von Hippel-Lindau disease is a dominant inherited syndrome characterized by the predisposition to develop various kinds of benign and malignant tumors, including clear cell renal carcinomas, pheochromocytomas and hemangioblastomas of the central nervous system and retina. VHL syndrome is caused by germline mutation in the VHL tumor suppressor, and VHL tumors are associated with loss or mutation of the remaining wild-type allele. VHL has two domains: a roughly 100-residue NH2-terminal domain rich in  sheet (-domain) and a smaller -helical domain (-domain), held together by two linkers and a polar interface. VHL protein is also involved in the degradation of hypoxia-inducible factor (HIF).

MCM7 is a highly conserved mini-chromosome maintenance protein (MCM) vital for eukaryotic genome replication initiation. The MCM proteins form a hexameric protein complex which is a key component of the pre-replication complex (pre_RC) which takes part in replication forks formation and in DNA replication related proteins recruitment. The MCM complex is comprised of MCM2, 4, 6 and 7 proteins and possesses DNA helicase activity, such as DNA unwinding.

Ras-related protein Ral-A (RALA) is a member of the small GTPase superfamily, Ras family of proteins. RALA mediates a distinct downstream signaling pathway from Ras which facilitates cellular transformation. Furthermore, RALA is thought to be involved in various signaling cascades, including regulation of the cytoskeleton, vesicle trafficking, and endocytosis.

CBR3 catalyzes the reduction of a large number of biologically and pharmacologically active carbonyl compounds to their corresponding alcohols. CBR3 is one of several monomeric NADPH-dependent oxidoreductases. Furthermore, CBR3 contains 3 exons spanning 11.2 kilobases and is strongly linked to another carbonyl reductase gene, the CBR1. It was suggested that CBR3 mediates 9-cis-retinoic acid-induced cytostatis and is a potential prognostic marker for oral malignancy. CBR3 is identified in the ovary, pancreas, intestine, colon, kidney, brain, thymus, lung, heart, liver, spleen, leukocyte, prostate and the testis. Polymorphisms in CBR3 may give an explanation to interindividual and interethnic variability of doxorubicin pharmacokinetics and pharmacodynamics.

Peptidylprolyl Isomerase C (PPIC) belongs to the peptidyl-prolyl cis-trans isomerase (PPIase) family. PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and hasten the folding of proteins. Like other PPIases, PPIC binds immunosuppressant cyclosporin A.

Human norovirus is classified into two groups, group 1& group 2. Norwalk virus is the species which belongs to group 1 and was discovered in 1968 at Ohio. Norovirus is a familiar virus which causes human gastroenteritis with the following symptoms vomiting, diarrhea and sickness. CDC report revealed that there are 19-21 million Americans infected by Nororvirus annually with 800 deaths, 1 in 15 people with infection. Around the world, this virus affects about 267 million people and causes over 200,000 deaths each year; these losses are mostly in less developed countries and in the very young, elderly and immuno-suppressed population, though, most cases are self-limited with a full recovery within just a few days. Norovirus is extremely contagious and can spread from human to human through infected food, water or contaminated surfaces. The outbreaks usually occur from November-April, while the peak is in January. Norovirus is a positive sense RNA virus with 7.5 kb nucleotides, encoding a major structural protein VP1 with 50-55kDa. The full length of VP1 capsid comprises the internal N-terminal, Hinge, shell (S) and protruding (P) domains. P domain from 225 to 520 forms P1- P2-P1 structure. Moreover, P domain has a receptor binding region which recognizes human histo-blood group antigens (HBGAs). P domain expressed in bacteria can spontaneously form a P dime as well as a P particle aggregated by 12 P dimmers. P particle displays an increased binding activity to HBGAs higher than virus-like particle (VLP) formed by the full-length capsid. For norovirus vaccine development, we consider P domain as a good candidate.

Hepatitis E virus (HEV), the major etiologic agent of enterically transmitted non-A, non-B hepatitis worldwide, is a spherical, non-enveloped, single stranded RNA virus that is approximately 32 to 34 nm in diameter. HEV belongs to a genus of HEV-like viruses (unassigned genus). HEV has a single-stranded polyadenylated RNA genome of approximately 8 kb. Based on its physicochemical properties it is presumed to be a calici-like virus.

Receptors across the cell membrane interact with some viral glycoproteins therefor enabling HSV to enter the host cell. The HSV enter through pores created by the binding of particular receptors across the cell membrane with the virus's coating envelope, following by a fusion of the HSV and the host cell. HSV enters the host cell through the same mechanism and stages as other viruses do. Initially, matching receptors across the virus's envelope and host cell's membrane interacts and bring the two together. During the transitional stage, begins fusion between the host cell and virus (hemifusion state). The closing stage happens when a steady pore was made; through these pores the virus's particles enter the cell.

MV belongs to the Beta herpesvirinae 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.

Connective Tissue Growth Factor belongs to the CCN family of proteins. The CCN family presently consists of six members in human also known as: Cyr61 (Cystein rich 61), CTGF (Connective Tissue Growth Factor), Nov (Nephroblastoma Overexpressed gene), WISP-1, 2 and 3 (Wnt-1 Induced Secreted Proteins). The CCN genes encode secreted proteins associated with the Extracellular Matrix (ECM) and cell membrane.
CCN proteins are matricellular proteins which are involved in the regulation of various cellular functions including: proliferation, differentiation, survival, adhesion and migration. They are expressed in derivatives of the three embryonic sheets and are implicated in the development of kidney, nervous system, muscle, bone marrow, cartilage and bone. During adulthood, they are implicated in wound healing, bone fracture repair, and pathologies such as: fibrosis, vascular ailments and tumorigenesis.
Full length secreted CCN proteins can show an antiproliferative activity, whereas truncated isoforms are likely to stimulate proliferation and behave as oncogenes.
The full length protein consists of four modulesModule I shares partial identity with the N-terminal part of the Insulin-like Growth Factor Binding Proteins (IGFBPs).
Module II includes a stretch of 70amino acid residues – which shares sequence identity with the Von Willebrand Factor Type C repeat (VWC).
Module III contains sequences sharing identity with the Thrombospondin type 1 repeat (TSP1) (WSXCSXXCG), which is thought to be implicated in the binding of sulfated glycoconjugates and to be important for cell adhesion.
Module IV, also designated CT, is encoded by exon5. It is the leasts conserved one of the four domains at the level of nucleotide sequence, but it appears to be critical for several of the biological functions attributed to the CCN proteins. Module IV resembles the CT domain of several extracellular protein including, Von Willebrand's factor and mucins. Sequence similarities to heparin-binding motifs are also found within this domain.
Proteolysis of the secreted full-length CCN proteins that has been reported in the case of CCN2 and CCN3 might result in the production of CCN-derived peptides with high affinity for ligands that full-length CNN proteins bind only poorly. Amino-truncated CCN2 isoforms were biologically active whereas no specific biological activity has been attributed to the truncated CCN3. Although the molecular processes underlying the production of these secreted isoforms is presently unknown, it is important to note that proteolysis occur at the same amino acid residues in both CCN2 and CCN3. An elevated expression of CCN2 has also been detected by Northern blotting in human invasive mammary ductal carcinomas, dermatofibromas, pyogenic granuloma, endothelial cells of angiolipomas and angioleiomyomas, and in pancreatic tumors. A study performed with chondrosarcomas representative of various histological grades established that CCN2 expression was closely correlated with increasing levels of malignancy.
In agreement with CCN2 playing a role in brain tumor angiogenesis, immunocytochemistry studies indicated that both glioblastoma tumor cells and proliferating endothelial cells stained positive for CCN2. In astrocytomas, CCN2 expression was particularly elevated in high grade tumors, with a marked effect of CCN2 on cell proliferation. Downregulation of CCN2 expression in these cells was associated with a growth arrest at the G1/S transition while over-expression of CCN2 induced a two-fold increase of the number of cells in the G1 phase. Gene profiling analysis allowed to identify a set of about 50 genes whose expression might account for the proliferative activity of CCN2 in these cells.
CCN2 was seen in a higher proportion of mononuclear cells of patients with acute lymphoblastic leukemia.

Cathepsin S (CTSS) belongs to the peptidase C1 family. CTSS is a lysosomal cysteine proteinase that participates in the degradation of antigenic proteins to peptides for presentation on MHC class II molecules. CTSS functions as an elastase over a broad pH range in alveolar macrophages.

Akt1, also known as Akt or else protein kinase B (PKB) is an important molecule in mammaliancellular signaling. In humans, there are three genes in the "Akt family": Akt1, Akt2, and Akt3. Moreover, these enzymes are members of the serine/threonine-specific protein kinase family (EC2.7.11.1). Akt1 is involved in cellular survival pathways, by inhibiting apoptoticprocesses. Akt1 is also able to induce protein synthesis pathways, and is therefore a key signaling protein in the cellular pathways which lead to skeletal muscle hypertrophy, and general tissue growth. Since it can block apoptosis, and thereby promote cell survival, Akt1 has been implicated as a most important factor in numerous types of cancer. Akt (now also called Akt1) was at first identified as the oncogenein the transforming retrovirus, AKT8.

Human HSP40 (heat shock protein with molecular size of 40kDa) is one of the mammalian homologues of bacterial DnaJ heat shock protein and regulates cellular processes by aiding in the folding, transport and assembly. HSP40 protein contains the J-domain which controls interaction with the ATPase domain of DnaK.

ARG2 participates in the regulation of extra-urea cycle arginine metabolism and also in down-regulation of nitric oxide synthesis. Extrahepatic arginase functions to regulate L-arginine bioavailability to NO synthase. Since NO synthase is found in the penile corpus cavernosum smooth muscle, the clitoral corpus cavernosum and the vagina, ARG2 takes part in both male and female sexual arousal and therefore a potential target for the treatment of male and female sexual arousal disorders.

Iduronate 2-Sulfatase also known as IDS, belongs to the highly-conserved sulfatase family of enzymes which catalyze the hydrolysis of O-sulfate and N-salfate esters from a variety of substrates. IDS is essential for the lysosomal degradation of the glycosaminoglycans (GAG) heparan sulfate as well as dermatan sulfate. Furthermore, IDS hydrolyzes the 2-sulfate group of the IDS units of the GAG.