Kinases17 Aug 2022 10:44
https://www.differencebetween.com/difference-between-jak1-jak2-and-jak3/
light introduction to the Jak 1,2 &3
Worth a light read and it does now indicate as to why we showed good efficacy with Covid.
Deurcravaticinib has no inhibition of Jaks 1,2 and 3. Patients in trials with Deucravacitinib experienced no difference to people that had not had Deucravacitinib.
Deuravacitinib not of any use with regards to Covid.
Baricitinib (Jak 2 and Jak1 but no Tyk2) indicated efficacy in treatment.
I remember Tim discussing in presentation requirements for covid cytokine storm
gp 130
gm-csf
type 1 interferon alpha beta
type 2 interferon gamma.
First two are Jak2 inhibited and last two are Jak1 inhibited.
So although we are predominently a Tyk 2 inhibitor there are as we can see advantages in not being completely 100% selective over the other Jaks 1 2 and 3.
Jak3 type 1 receptors using common gamma chain and Interleukins 2,4, 7, 9,15and 21
As we can see from below Il-2 from Jak3 gives regulation of white blood cells. ( too much Il-2 inhibition ofJak3 and we risk severe infection)
Interleukin-2 (IL-2) is an interleukin, a type of cytokine signaling molecule in the immune system. It is a 15.5–16 kDa protein[5] that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes. The major sources of IL-2 are activated CD4+ T cells and activated CD8+ T cells.[6
Jak1 and Jak2 for inhibition of Il-10 consists of 4 sub units 2 of which Jak1 and 2 of which Tyk2
IL-10 is capable of inhibiting synthesis of pro-inflammatory cytokines such as IFN-?, IL-2, IL-3, TNFa and GM-CSF made by cells such as macrophages and Th1 T cells.
(Th1 cells are involved in the pathogenesis of organ-specific autoimmune disorders, Crohn's disease, Helicobacter pylori-induced peptic ulcer, acute kidney allograft rejection, and unexplained recurrent abortions. In contrast, allergen-specific Th2 responses are responsible for atopic disorders in genetically susceptible individuals.)
It does get very complex indeed. The balance of auto immune regulation is more an art that a science at times I think.
This will do this and this will do that along with the pros and cons. All about getting the balance right.
Regards to all