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Event: 1715

Key Event Title

The KE title should describe a discrete biological change that can be measured. It should generally define the biological object or process being measured and whether it is increased, decreased, or otherwise definably altered relative to a control state. For example “enzyme activity, decreased”, “hormone concentration, increased”, or “growth rate, decreased”, where the specific enzyme or hormone being measured is defined. More help

Inhibition of JAK3

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. The short name should be less than 80 characters in length. More help
Inhibition of JAK3

Biological Context

Structured terms, selected from a drop-down menu, are used to identify the level of biological organization for each KE. Note, KEs should be defined within a particular level of biological organization. Only KERs should be used to transition from one level of organization to another. Selection of the level of biological organization defines which structured terms will be available to select when defining the Event Components (below). More help
Level of Biological Organization
Molecular

Cell term

Further information on Event Components and Biological Context may be viewed on the attached pdf.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable. More help
Cell term
T cell

Organ term

Further information on Event Components and Biological Context may be viewed on the attached pdf.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable. More help
Organ term
immune system

Key Event Components

Further information on Event Components and Biological Context may be viewed on the attached pdf.Because one of the aims of the AOP-KB is to facilitate de facto construction of AOP networks through the use of shared KE and KER elements, authors are also asked to define their KEs using a set of structured ontology terms (Event Components). In the absence of structured terms, the same KE can readily be defined using a number of synonymous titles (read by a computer as character strings). In order to make these synonymous KEs more machine-readable, KEs should also be defined by one or more “event components” consisting of a biological process, object, and action with each term originating from one of 22 biological ontologies (Ives, et al., 2017; See List). Biological process describes dynamics of the underlying biological system (e.g., receptor signalling). The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signalling by that receptor).Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description. To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons. If a desired term does not exist, a new term request may be made via Term Requests. Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add. More help
Process Object Action
regulation of binding tyrosine-protein kinase JAK3 decreased

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE. Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
Immune dysfunction induced by JAK3 inhibition MolecularInitiatingEvent Yasuhiro Yoshida (send email) Under development: Not open for comment. Do not cite Under Development

Stressors

This is a structured field used to identify specific agents (generally chemicals) that can trigger the KE. Stressors identified in this field will be linked to the KE in a machine-readable manner, such that, for example, a stressor search would identify this as an event the stressor can trigger. NOTE: intermediate or downstream KEs in one AOP may function as MIEs in other AOPs, meaning that stressor information may be added to the KE description, even if it is a downstream KE in the pathway currently under development.Information concerning the stressors that may trigger an MIE can be defined using a combination of structured and unstructured (free-text) fields. For example, structured fields may be used to indicate specific chemicals for which there is evidence of an interaction relevant to this MIE. By linking the KE description to a structured chemical name, it will be increasingly possible to link the MIE to other sources of chemical data and information, enhancing searchability and inter-operability among different data-sources and knowledgebases. The free-text section “Evidence for perturbation of this MIE by stressor” can be used both to identify the supporting evidence for specific stressors triggering the MIE as well as to define broad chemical categories or other properties that classify the stressors able to trigger the MIE for which specific structured terms may not exist. More help

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) can be selected from an ontology. In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help
Term Scientific Term Evidence Link
Homo sapiens Homo sapiens High NCBI
Mus musculus Mus musculus High NCBI
Rattus rattus Rattus rattus High NCBI

Life Stages

The structured ontology terms for life-stage are more comprehensive than those for taxa, but may still require further description/development and explanation in the free text section. More help
Life stage Evidence
All life stages High

Sex Applicability

No help message More help
Term Evidence
Mixed High

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. For example, the biological state being measured could be the activity of an enzyme, the expression of a gene or abundance of an mRNA transcript, the concentration of a hormone or protein, neuronal activity, heart rate, etc. The biological compartment may be a particular cell type, tissue, organ, fluid (e.g., plasma, cerebrospinal fluid), etc. The role in the biology could describe the reaction that an enzyme catalyses and the role of that reaction within a given metabolic pathway; the protein that a gene or mRNA transcript codes for and the function of that protein; the function of a hormone in a given target tissue, physiological function of an organ, etc. Careful attention should be taken to avoid reference to other KEs, KERs or AOPs. Only describe this KE as a single isolated measurable event/state. This will ensure that the KE is modular and can be used by other AOPs, thereby facilitating construction of AOP networks. More help

Janus tyrosine kinase (JAK) 3 is a member of the JAK family, is constitutively associated with the Box-1 region of the cytokine receptor intracellular domain, and becomes activated upon ligand-induced receptor dimerization (40-Stahl-1994).

To date, PF-06651600 is the only single isoform-selective JAK3 inhibitor to undergo a phase 2 clinical evaluation to treat rheumatoid arthritis. This compound inhibits JAK3 kinase activity with an IC50 of 33.1 nM but without activity (IC50 > 10000 nM) against JAK1, JAK2, or Tyrosine kinase (TYK)2 (7-Telliez-2016,41-Thorarensen-2017). RB1 has been also identified as a novel and highly selective JAK3 inhibitor, which blocks in vitro JAK3 kinase and functional activity in various cell types. When administered to mice orally, RB1 has been proven to mediate the JAK-Signal Transducer and Activator of Transcription (STAT) (JAK-STAT) pathway and reduce the clinical and microscopic manifestations of paw damage in collagen induced arthritis mice.

How It Is Measured or Detected

One of the primary considerations in evaluating AOPs is the relevance and reliability of the methods with which the KEs can be measured. The aim of this section of the KE description is not to provide detailed protocols, but rather to capture, in a sentence or two, per method, the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements. Methods that can be used to detect or measure the biological state represented in the KE should be briefly described and/or cited. These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA).Key considerations regarding scientific confidence in the measurement approach include whether the assay is fit for purpose, whether it provides a direct or indirect measure of the biological state in question, whether it is repeatable and reproducible, and the extent to which it is accepted in the scientific and/or regulatory community. Information can be obtained from the OECD Test Guidelines website and the EURL ECVAM Database Service on Alternative Methods to Animal Experimentation (DB-ALM). ?

The enzymatic activities against JAK1, JAK2, JAK3, and TYK2 are tested by a Caliper Mobility Shift Assay. In the presence of an ATP concentration at Km for ATP for each JAK isoform, RB1 inhibited JAK3 kinase activity with an IC50 value of 40 nM without inhibiting JAK1, JAK2 or TYK2 (IC50 > 5000 nM) (42-Gianti-2015). PF-06651600 is also a potent JAK3-selective inhibitor which can inhibit the JAK3 kinase activity with an IC50 of 33.1 nM but without activity (IC50>10 000 nM) against JAK1, JAK2, and TYK2. PF-06651600 inhibits the phosphorylation of STAT5 elicited by IL-2, IL-4, IL-7, and IL-15 with IC50 values of 244, 340, 407, and 266 nM, respectively (7-Telliez-2016).

Domain of Applicability

This free text section should be used to elaborate on the scientific basis for the indicated domains of applicability and the WoE calls (if provided). While structured terms may be selected to define the taxonomic, life stage and sex applicability (see structured applicability terms, above) of the KE, the structured terms may not adequately reflect or capture the overall biological applicability domain (particularly with regard to taxa). Likewise, the structured terms do not provide an explanation or rationale for the selection. The free-text section on evidence for taxonomic, life stage, and sex applicability can be used to elaborate on why the specific structured terms were selected, and provide supporting references and background information.  More help

JAKs are a family of nonreceptor protein tyrosine kinases that are critical for cytokine-receptor-binding-triggered signal transduction through STAT to the nuclei of cells. The JAK family consists of four members: JAK1, JAK2, JAK3 and TYK. In mammals JAK1, JAK2 and TYK2 are ubiquitously expressed. In contrast, the expression of JAK3 is more restricted: it is predominantly expressed in haematopoietic cells and is highly regulated with cell development and activation (43-Xu-1996,44-Gaffen-1995). JAK3 is solely activated by type I cytokine receptors featuring a common γ-chain (γc) subunit that are activated by IL-2, IL-4, IL-7, IL-9, IL-15, and IL-7 (12-Peschon-1994). Mutations in either the γ-chain or JAK3 have been identified as a cause of severe combined immunodeficiency disease (SCID) in humans, which manifests as a depletion of T, B, and natural killer (NK) cells with no other defects (45-Darnell-1997,46-Decker-1997).

Loss-of-function mutations in the tyrosine kinase JAK3 cause autosomal recessive SCID. Defects in this form of SCID are restricted to the immune system, which led to the development of the immunosuppressive JAK inhibitors.

Evidence for Perturbation by Stressor

Overview for Molecular Initiating Event

When a specific MIE can be defined (i.e., the molecular target and nature of interaction is known), in addition to describing the biological state associated with the MIE, how it can be measured, and its taxonomic, life stage, and sex applicability, it is useful to list stressors known to trigger the MIE and provide evidence supporting that initiation. This will often be a list of prototypical compounds demonstrated to interact with the target molecule in the manner detailed in the MIE description to initiate a given pathway (e.g., 2,3,7,8-TCDD as a prototypical AhR agonist; 17α-ethynyl estradiol as a prototypical ER agonist). Depending on the information available, this could also refer to chemical categories (i.e., groups of chemicals with defined structural features known to trigger the MIE). Known stressors should be included in the MIE description, but it is not expected to include a comprehensive list. Rather initially, stressors identified will be exemplary and the stressor list will be expanded over time. For more information on MIE, please see pages 32-33 in the User Handbook.

non

References

List of the literature that was cited for this KE description. Ideally, the list of references, should conform, to the extent possible, with the OECD Style Guide (https://www.oecd.org/about/publishing/OECD-Style-Guide-Third-Edition.pdf) (OECD, 2015). More help

7.        Telliez, J. B., Dowty, M. E., Wang, L., Jussif, J., Lin, T., Li, L., Moy, E., Balbo, P., Li, W., Zhao, Y., Crouse, K., Dickinson, C., Symanowicz, P., Hegen, M., Banker, M. E., Vincent, F., Unwalla, R., Liang, S., Gilbert, A. M., Brown, M. F., Hayward, M., Montgomery, J., Yang, X., Bauman, J., Trujillo, J. I., Casimiro-Garcia, A., Vajdos, F. F., Leung, L., Geoghegan, K. F., Quazi, A., Xuan, D., Jones, L., Hett, E., Wright, K., Clark, J. D., and Thorarensen, A. (2016) Discovery of a JAK3-Selective Inhibitor: Functional Differentiation of JAK3-Selective Inhibition over pan-JAK or JAK1-Selective Inhibition. ACS Chem Biol 11, 3442-3451

12.      Peschon, J. J., Morrissey, P. J., Grabstein, K. H., Ramsdell, F. J., Maraskovsky, E., Gliniak, B. C., Park, L. S., Ziegler, S. F., Williams, D. E., Ware, C. B., Meyer, J. D., and Davison, B. L. (1994) Early lymphocyte expansion is severely impaired in interleukin 7 receptor-deficient mice. J Exp Med 180, 1955-1960

40.      Stahl, N., Boulton, T. G., Farruggella, T., Ip, N. Y., Davis, S., Witthuhn, B. A., Quelle, F. W., Silvennoinen, O., Barbieri, G., Pellegrini, S., and et al. (1994) Association and activation of Jak-Tyk kinases by CNTF-LIF-OSM-IL-6 beta receptor components. Science 263, 92-95

41.      Thorarensen, A., Dowty, M. E., Banker, M. E., Juba, B., Jussif, J., Lin, T., Vincent, F., Czerwinski, R. M., Casimiro-Garcia, A., Unwalla, R., Trujillo, J. I., Liang, S., Balbo, P., Che, Y., Gilbert, A. M., Brown, M. F., Hayward, M., Montgomery, J., Leung, L., Yang, X., Soucy, S., Hegen, M., Coe, J., Langille, J., Vajdos, F., Chrencik, J., and Telliez, J. B. (2017) Design of a Janus Kinase 3 (JAK3) Specific Inhibitor 1-((2S,5R)-5-((7H-Pyrrolo[2,3-d]pyrimidin-4-yl)amino)-2-methylpiperidin-1-yl)prop -2-en-1-one (PF-06651600) Allowing for the Interrogation of JAK3 Signaling in Humans. J Med Chem 60, 1971-1993

42.      Gianti, E., and Zauhar, R. J. (2015) An SH2 domain model of STAT5 in complex with phospho-peptides define "STAT5 Binding Signatures". J Comput Aided Mol Des 29, 451-470

43.      Xu, B. C., Wang, X., Darus, C. J., and Kopchick, J. J. (1996) Growth hormone promotes the association of transcription factor STAT5 with the growth hormone receptor. J Biol Chem 271, 19768-19773

44.      Gaffen, S. L., Lai, S. Y., Xu, W., Gouilleux, F., Groner, B., Goldsmith, M. A., and Greene, W. C. (1995) Signaling through the interleukin 2 receptor beta chain activates a STAT-5-like DNA-binding activity. Proc Natl Acad Sci U S A 92, 7192-7196

45.      Darnell, J. E., Jr. (1997) STATs and gene regulation. Science 277, 1630-1635

46.      Decker, T., Kovarik, P., and Meinke, A. (1997) GAS elements: a few nucleotides with a major impact on cytokine-induced gene expression. J Interferon Cytokine Res 17, 121-134