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Borrelia is a part of the genus of bacteria of the spirochete phylum. Borrelia causes borreliosis, which is a zoonotic, vector-borne disease transmitted mostly by ticks and some by lice, depending on the species. Of the 36 known species of Borrelia, 12 are distinguished to cause Lyme disease or borreliosis and are transmitted by ticks. The Gram-negative bacterium Borreliella spielmanii is one of the pathogens of the Borreliella burgdorferi sensu lato complex causing Lyme disease. DbpA, also known as p17 or Osp17, is a heterogeneous protein among the human pathogenic B. burgdorferi sensu lato species.

Interleukin-21 receptor, also known as IL21R is a member of the type I cytokine receptors family. IL21R forms a heterodimeric receptor complex with the common gamma-chain, a receptor subunit which is also shared by the receptors for interleukin 2, 4, 7, 9, and 15. Furthermore, IL21 receptor transduces the growth promoting signal of IL21, and is significant for the proliferation as well as differentiation of T cells, B cells, and natural killer (NK) cells. The ligand binding of IL21 receptor leads to the activation of numerous downstream signaling molecules, including JAK1, JAK3, STAT1, as well as STAT3.

Procalcitonin is a peptide hormone mainly produced by the C cells of the thyroid and certain endocrine cells of the lung. Under normal expression conditions, procalcitonin is immediately cleaved into three specific fragments, an N terminal residue, calcitonin and katacalcin. Levels of unprocessed procalcitonin rise significantly after bacterial infection, trauma or shock.

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.HIV-1 gp41 Subtype-b reacts to HIV1 antibody from HIV infected patients, over 90% HIV1 samples collected in house were tested strongly positive by rapid test.

Caused by one of four closely related virus serotypes of the genus Flavivirus, family Flaviviridae, each serotype is sufficiently different that there is no cross-protection and epidemics caused by multiple serotypes (hyperendemicity) can occur. In cell culture experiments and mice Morpholino antisense oligos have shown specific activity against Dengue virus.

Interleukin-1b is produced by activated macrophages, IL-1B stimulates thymocyte proliferation by inducing il-2 release, b-cell maturation and proliferation, and fibroblast growth factor activity. IL1B proteins are involved in the inflammatory response, being identified as endogenous pyrogens, and are reported to stimulate the release of prostaglandin and collagenase from synovial cells. IL-1b is an inflammatory cytokine which modulates angiogenesis by interacting directly with vascular endothelial cells & increasing the production of proangiogenic factors through paracrine control. IL-1 beta stimulates endothelial cell migration and proliferation, adhesion-molecule expression, inflammatory mediator production, and leukocyte recruitment. IL1B is essential for tumor growth, metastasis, and angiogenesis in quite a few animal models.

IL-18 is a proinflammatory cytokine. This cytokine can induce the IFN-gamma production of T cells. The combination of this cytokine and IL12 has been shown to inhibit IL4 dependent IgE and IgG1 production, and enhance IgG2a production of B cells. IL-18 binding protein (IL18BP) can specifically interact with this cytokine, and thus negatively regulate its biological activity.

IL17D modulates immune responses indirectly by stimulating the production of myeloid growth factors and chemokines, as well as suppressing the proliferation of myeloid progenitors. IL17D is expressed in the skeletal muscle, heart, adipose tissue, lung, pancreas, and nervous system. Among IL-17 family members, IL17D is most closely related to IL17B, sharing 27% aa sequence identity. The treatment of endothelial cells with IL17D cytokine stimulates the production of other cytokines including IL6, IL8 and CSF2/ GM-CSF. The increased expression of IL8 induced by IL17D cytokine is NF-kappa B-dependent.

Pollen allergen Phl p 6 (PhI p 6) causes an allergic reaction in humans.

Macrophage Inflammatory Proteins (MIP) belong to the family of chemotactic cytokines known as chemokines. In humans, there are two major forms, MIP-1a and MIP-1b that are now officially named CCL3 and CCL4 respectively. Both are major factors produced by macrophages after they are stimulated with bacterial endotoxins. They activate human granulocytes (neutrophils, eosinophilsand basophils) which can lead to acute neutrophilic inflammation. They also induce the synthesis and release of other pro-inflammatory cytokines such as interleukin 1 (IL-1), IL-6 and TNF-a from fibroblasts and macrophages. The genes for CCL3 and CCL4 are both located on human chromosome 17.

CCL-20 is a chemotactic factor that draws lymphocytes & neutrophils, rathar than monocytes. MIP-3 alpha inhibits proliferation of myeloid progenitors in colony formation assays. MIP3A plays a role in the formation and function of the mucosal lymphoid tissues by attracting lymphocytes and dendritic cells towards epithelial cells. C-terminal processed forms have been shown to be equally chemotactically active for leukocytes. CCL-20 holdes antibacterial activity e.coli atcc 25922 and s.aureus atcc 29213. CCL-20 gene transcription is activated by H. pylori, which activates NF-kappaB through intracellular signal pathway which involves IkappaB kinase and NF-kappaB-inducing kinase. MIP-3 alpha is invloved in chemokine-mediated lymphocyte trafficking during gastric inflammation in Helicobacter infection. CCL-20 expression is involved in the recruitment of CD45R0-positive T cell subsets into the intestinal lamina propria.
MIP-3A is in charge of the advancement of pulpal inflammation through the recruitment of C-C motif Receptor 6-expressing lymphocytes Vaginal epithelial cells respond to factors present in semen by secreting MIP-3 alpha, which increases langerhans cells recruitment during HIV transmission.

IFN-gamma produced by lymphocytes activated by specific antigens or mitogens.
IFN-gamma, in addition to having antiviral activity, has important immunoregulatory functions, it is a potent activator of macrophages, and has antiproliferative effects on transformed cells and it can potentiate the antiviral and antitumor effects of the type I interferons.

Interleukin 13 Receptor, Alpha 2 (IL13RA2) is a member of the type I cytokine receptor family, Type 5 subfamily. IL13RA2 is related to l13RA1, a subunit of the interleukin 13 receptor complex. IL13RA2 binds IL13 with high affinity, though lacking the cytoplasmic domain, and does not appear to function as a signal mediator. IL13RA2 plays a role in the internalization of IL13.

GALE is an enzyme that participates as the third enzyme in the Leloir pathway of galactose metabolism. GALE is a homodimeric epimerase localized in bacterial, plant, and mammalian cells. GALE inhances the reverse chemical reaction, the conversion of UDP-glucose to UDP-galactose. UDP-galactose builds galactose-containing proteins and fats, which have a crucial part in chemical signaling, building cellular structures, transporting molecules, and producing energy.

Entry of HSV into the host cell involves interactions of several viral glycoproteins with cell surface receptors. The virus particle is covered by an envelope which, when bound to specific receptors on the cell surface, will fuse with the cell membrane and create an opening, or pore, through which the virus enters the host cell. The sequential stages of HSV entry are analagous to those of other viruses. At first, complementary receptors on the virus and cell surface bring the two membranes into proximity. In an intermediate state, the two membranes begin to merge, forming a hemifusion state. Finally, a stable entry pore is formed through which the viral envelope contents are introduced to the host cell.

Lassa virus, which is a member of the Arenaviridae virus family, causes acute viral hemorrhagic fever. It was first reported in 1969 in the town of Lassa, in Borno State, Nigeria. Natal multimammate mouse is the primary reservoir of Lassa virus, found in sub-Saharan Africa. The virus is transmitted by contact with the feces or urine of animals, contributing to its high rate of incidence. Lassa fever occurs generally in West Africa. Lassa fever results in 300,000 to 500,000 cases annually and causes about 5,000 deaths each year. Outbreaks of this disease have been observed in Nigeria, Liberia, Sierra Leone, Guinea, and the Central African Republic. Protein structure: Lassa virus genome is comprised of two single-stranded RNA molecules defined as small (S) and large (L). Two genes on the S segment encode the nucleoprotein (NP) and two envelope glycoproteins (GP1 and GP2); while, the L segment encodes the viral polymerase (L protein) and RING finger Z matrix protein. GP1 subunit serves a putative role in receptor binding, while the structure of GP2 subunit is consistent with viral transmembrane fusion proteins. NP is a virion protein which binds and protects the viral RNA.

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.

IL-7 is a cytokine important for B and T cell development. This cytokine and the hepatocyte growth factor (HGF) form a heterodimer that functions as a pre-pro-B cell growth-stimulating factor. This cytokine is found to be a cofactor for V(D)J rearrangement of the T cell receptor beta (TCRB) during early T cell development. This cytokine can be produced locally by intestinal epithelial and epithelial goblet cells, and may serve as a regulatory factor for intestinal mucosal lymphocytes. Knockout studies in mice suggested that this cytokine plays an essential role in lymphoid cell survival.

Listeriolysin O (aka LLO) is a hemolysin produced by Listeria monocytogenes bacteria, the pathogen responsible for causing listeriosis. The toxin may be regarded as a virulence factor, since it is crucial for the virulence of L. monocytogenes. LLO is a single polypeptide protein encoded by the hlyA gene and composed of 529 residues. LLO is a thiol-activated cholesterol-dependent pore forming toxin protein; therefore, it is activated by reducing agents and inhibited by oxidizing agents. Still, LLO differs from other thiol-activated toxins, as its cytolytic activity is maximized at a pH of 5.5. Inside the acidic phagosomes (average pH ~ 5.9) of cells that have phagocytosed L. monocytogenes, LLO is selectively activated by maximizing activity at a pH of 5.5. Following the phagosome lysis by LLO, the bacterium breaks out into the cytosol, where it is able to grow intracellularly, and the toxin has reduced activity in the more basic cytosol. Thus, LLO permits L. monocytogenes to break out from the phagosomes into the cytosol without harming the plasma membrane of the infected cell, which allows the bacteria to live intracellularly, where they are sheltered from extracellular immune system factors such as the complement system and antibodies. LLO also brings about dephosphorylation of histone H3 and deacetylation of histone H4 in the early phases of infection, before entry of L. monocytogenes into the host cell. The pore-forming activity is not implicated in causing the histone modifications. The modifications of the histones affect the down regulation of genes encoding proteins involved in the inflammatory response. Therefore, LLO may be significant in subverting the host immune response to L. monocytogenes. At its NH2-terminus it possesses a 25 residues long typical signal sequence excited during the secretion process. Moreover, in its NH2-terminus there is also a 19 amino acids PEST- like sequence that may target this toxin for degradation. The PEST-like sequence found in LLO and is considered crucial for virulence, given that mutants lacking the sequence lysed the host cell. Nevertheless, contrary to PEST's supposed role in protein degradation, evidence implies that the PEST-like sequence may control LLO production in the cytosol rather than increase degradation of LLO.

Factor IX is a glycoprotein, which is synthesized in the liver. The domain structure of factor IX is similar to that of the other vitamin K dependent coagulation factors. The NH2-terminal region contains 12 g-carboxyglutamic acid (gla) residues, which facilitate the calcium dependent binding of factor IX to negatively charged phospholipid surfaces. Two domains which are homologous to epidermal growth factor (EGF) span the region between the NH2-terminal gla domain and the activation peptide (Ala-146 to Arg-180). Factor IX is activated by either factor XIa or the factor VIIa/tissue factor/phospholipid complex. Cleavage at site A yields the intermediate IXa, which is subsequently converted to the fully active form IXab by cleavage at site B. The NH2-terminal light chain (GLA and EGF domains) remains covalently attached to the COOH-terminal heavy chain by a disulfide bond. The serine protease catalytic triad (Ser-365, His 221, Asp-269) is located in the heavy chain. Factor IXab is the catalytic component of the “intrinsic factor Xase complex” (factor VIIIa/IXa/Ca2+/phospholipid) which proteolytically activates factor X to factor Xa.

Anaplasma p44 which belongs to the outer membrane antigen superfamily (OMP1/Msp2/p44), is a serodiagnostic antigen for HGA. Anaplasma p44 allows the bacterium to adhere to the host cell and prevents host immune surveillance.