Scientific background
Interleukin 23 (IL-23) is a heterodimeric cytokine belonging to the IL-6 / IL-12 family. IL-23 performs a significant role in autoimmune and inflammatory diseases. One of the key functions of IL-23 is its role in the activation of the Th17 pathway.1 This new pathway has been shown to have a critical role in both the development of autoimmune diseases as well as a protective role against infections.
Research on IL-23 has yielded a vast variety of results on the utility of IL-23. IL-23 levels have been monitored and evaluated in some studies of different diseases and some primary conclusions have shown IL-23 to either hinder treatment or aid in immunity.
IL-23 is composed of two subunits, one p40 and one p19. The p40 subunit is identical to the one found in IL-12, and some antibodies made for IL-12 have been found to be targeting the p40 subunit of IL-12 and therefore can also be used against IL-23.
Therapeutic Potential: Autoimmune Diseases
IL-23 has a role in chronic inflammation, which is a common characteristic of many autoimmune diseases. IL-23 promotes the Th17 pathway, which has been shown to be active in the pathogenesis of many chronic inflammatory diseases, including psoriasis, inflammatory bowel disease, arthritis, and multiple sclerosis.
In inflammatory bowel disease, stimulation of colonic leukocytes by IL-23 induced the production of IL-17. Therefore, blocking the IL-23 might be beneficial for the treatment of inflammatory bowel disease.2
Another example of this is with rheumatoid arthritis (RA). IL-23 levels are significantly higher in the peripheral blood of RA patients than in normal controls.3
Autoimmune experimental arthritis has also been shown to be influenced by IL-23. There, IL-23 promoted Th17 differentiation and was required for elevation of IL-22 levels in the arthritis.4 IL-23 is not just essential for the development of experimental autoimmune arthritis, but is also critical in the complete expression of non-autoimmune antigen-induced arthritis (AIA).5/
An additional study has concluded that IL-23 plays an active role in lupus nephritis. The researchers documented the importance of IL-23 receptor and how it allowed for signaling in the development of lupus in the kidneys.6
IL-23 has been found to be elevated in psoriasis patients. An anti-IL-23 monoclonal antibody, ustekinumab (CNTO 1275), has been used to treat patients with psoriasis.7 However, another treatment, pulsed dye laser (PDL) therapy, is used to clear psoriasis plaques. It has been found that the PDL treatment reduced the expression of IL-23.8
The Th17 pathway and IL-23 receptor are also involved in the development of Ankylosing Spondylitis (AS). European and Canadian studies have confirmed the active role IL-23 has in the progression of the disease. However, Korean and Chinese studies on Asian populations show that AS is not associated with IL-23R.9
IL-23 levels have also been found to be elevated in serum and cerebrospinal fluid in amyotrophic lateral sclerosis (ALS) patients as compared to patients with non-inflammatory neurological disorders.10
On the other hand, targeting IL-23 and the Th17 pathway to treat multiple sclerosis (MS) failed and it is now thought that there are multiple pathways, including Th17, that have an active role in the development of MS.11 A different group preformed a trial against Crohn’s disease using an IL-12/IL-23 inhibitor and did not see any efficacy over the placebo group.12
Therapeutic Potential: Inflammation
IL-23 signaling has been shown to regulate allergic asthma inflammation. The over-expression of IL-23 increased the airway inflammation while deficiency in IL-23 displayed reduced airway inflammation.13
Therapeutic Potential: Infections
Since IL-23 has an important role in the development of the Th17 pathway, it becomes important to study what function IL-23 has in different types of infections. One of the more common diseases in the tropics is schistosomiasis, which infects millions of people every year. Some of the common symptoms of schistosomiasis are intestinal inflammation and cachexia. IL-23 is partial responsible for both conditions, and suppression of IL-23 p40 in acute schistosomiasis neutralizes both the inflammation and cachexia.14
Moreover, IL-23 has been shown to be necessary to induce production of IL-12 in bacterial infections such as Mycobacteria and Salmonellae. IL-23 is induced by TLR agonists and the production of IL-23 is necessary for IL-12 production, which is critical in providing immunity.15
IL-23 also has a role in the treatment of streptococcus pneumoniae. IL-23 is important in the clearance of streptococcus pneumoniae infection, and neutralizing the IL-23 and Th17 pathway severely limits the body’s immunity.16
Additionally, IL-23 is required for protection against infection with Listeria monocytogenes. IL-23 is necessary for the regulation of IL-17A and necessary for optimal liver neutrophil recruitment, which is required to eliminate the bacteria and have the host survive.17
Indeed, IL-23 has an important role in autoimmunity. IL-23 is critical for the creation and maintenance of gammadelta and double negative alphabeta T cells. These cells are important components of early, protective immune response and are regulated by IL-23.18
IL-23 has also been shown to aid in the survival from fungal infections. Recombinant IL-23 was given to mice infected with cyrptococcosis, which resulted in prolonged survival of the mice.19
However, IL-23 has quite the opposite effect in HIV infections. IL-23 production increases significantly in patients with HIV. Moreover, increased IL-23 production is coupled with a decrease in IL-12 production, which is harmful as IL-12 enhances the body’s protective response against HIV.20
Therapeutic Potential: Cancer
IL-23 research has provided many questions and fewer answers on IL-23’s role in development of different cancers. While the exact mechanism of IL-23 in tumors is uncertain, it is certain that IL-23 has an important role in tumors. Various preliminary experiments have shown IL-23 to promote tumor growth and tumor incidence. One study has IL-23 blocking natural or cytokine induced immunity as well as promoting tumor development.21/ That being said, there is also some research that points towards IL-23 having an anti-tumor immune responses.22
Other than research on the mechanism and roles of IL-23 in cancers, IL-23 is also being examined as a part of a virus’s oncolytic activity against tumor cells. The vesicular stomatitis virus (VSV) has been shown to be effective at attacking tumor cells. The addition of having the virus produce IL-23 has made the virus even more effective. This gives IL-23 large potential for being used in combination with viruses to treat cancers.23
Therapeutic Potential: Regulating IL-23 Production
Due to the involvement of IL-23 in many different diseases and conditions, it becomes imperative to be able to adjust the IL-23 levels to see if IL-23 has an active role in the development of a disease or if it is a side effect or product of a disease. One way to adjust the level of IL-23 is by introducing recombinant IL-23 to increase the amount of IL-23. One can also introduce an antibody to decrease the amount of free IL-23. Another method is to figure out how the body itself regulates IL-23 production, which has been investigated by many research groups.
One group has figured out that dendritic cells (DC) treated with prostaglandin E(2) have a decrease of extracellular signal related kinase (ERK) activation, which is responsible for a decrease in IL-23 production in DC.24
Another chemical that can inhibit IL-23 production is Triptolide, which is a biologically active chemical purified from a Chinese herbal plant. Triptolide inhibits the p40 subunit of IL-23 at the transcriptional level by targeting C/EBPalpha.25 Moreover, celecoxib and TFM-C are also capable of blocking the secretion of IL-23.26
A different group has shown that protein phosphatase 2A (PP2A) inhibits IL-23 production in DC by suppressing the p19 subunit of IL-23. Inhibiting the PP2A enhances IL-23 production.27 Another inhibitor of IL-23 is IFN-gamma.28
Therapeutic Potential: Biomarker
A study from India found out that in patients with latent tuberculosis, tuberculin skin test (TST) with a positive result was associated with a decrease in IL-23 and IL-17.29 Another study has labeled IL-23 as one of many possible biomarkers in lupus nephritis.30
Collaboration Opportunity
SBH Sciences recombinant human IL-23 is a 53.5 kDa authentic heterodimeric protein consisting of two subunits, p19 (170 amino acids) and p40 (306 amino acids) formulated without any carrier protein. The protein is produced from insect cells and is glycosylated. SBH Sciences’ IL-23 is tag-free and authentic, and there is no artificial amino acid bridge between the two subunits.
The in-vitro activity of the recombinant protein is measured according to stimulation of IFN-gamma production by human PBMC.
SBH Sciences is looking for partners to investigate our recombinant IL-23 as a therapeutic agent, as well as a diagnostic tool. We are open for suggestions and would be pleased to hear from you.
References:
1. McGeachy MJ et al. “The interleukin 23 receptor is essential for the terminal differentiation of interleukin 17-producing effector T helper cells in vivo.” Nature Immunology, 10(3): 314-24, Mar 2009.
2. Buonocore S et al. “Innate lymphoid cells drive interleukin-23-dependent innate intestinal pathology.” Nature, 464(7293): 1371-5. Apr 2010.
3. Wang T et al. “Possible mechanisms of peripheral elevated CD8+ IL-17+ T cells in rheumatoid arthritis.” (article in Chinese) Zhonghua Yi Xue Za Zhi, 89(27): 1885-8, Jul 2009.
4. Mus AM et al. “Interleukin-23 promotes Th17 differentiation by inhibiting T-bet and FoxP3 and is required for elevation of interleukin-22, but not interleukin-21, in autoimmune experimental arthritis.” Arthritis and Rheumatism, 62(4): 1043-50, Apr 2010.
5. Cornelissen F et al. “Interleukin-23 is critical for full-blown expression of a non-autoimmune destructive arthritis and regulates interleukin-17A and RORgammat in gammadelta T cells.” Arthritis Research and Therapy, 11(6): R194, 2009.
6. Kyttaris VC et al. “Cutting edge: IL-23 receptor deficiency prevents the development of lupus nephritis in C57BL/6-lpr/lpr mice.” Journal of Immunology, 184(9): 4605-9, May 2010.
7. Zhou H et al. “Population-based exposure-efficacy modeling of ustekinumab in patients with moderate to severe plaque psoriasis.” Journal of Clinical Pharmacology, 50(3): 257-67, Mar 2010.
8. Racz E et al. “Cellular and molecular effects of pulsed dye laser and local narrow-band UVB therapy in psoriasis.” Lasers in Surgery and Medicine, 42(3): 201-10, Mar 2010.
9. Thomas GP et al. “Genetics and genomics of ankylosing spondylitis.” Immunological Reviews, 233(1):162-80, Jan 2010.
10. Rentzos M et al. “Interleukin-17 and interleukin-23 are elevated in serum and cerebrospinal fluid of patients with ALS: a reflection of Th17 cells activation?” Acta Neurologica Scandinavica, Mar 2010. (Epub)
11. Codarri L et al. “Cytokine networks in multiple sclerosis: lost in translation.” Current Opinion in Neurology, 23(3): 205-11, Jun 2010.
12. Sands BE et al. “Randomized, double-blind, placebo-controlled trial of the oral interleukin-12/23 inhibitor apilimod mesylate for treatment of active Crohn’s disease.” Inflammatory Bowel Diseases, 16(7): 1209-18, Jul 2010.
13. Peng J et al. “IL-23 signaling enhances Th2 polarization and regulates allergic airway inflammation.” Cell Research, 20(1): 62-71, Jan 2010.
14. Herbert DR et al. “Arginase I suppresses IL-12/Il-23p40-driven intestinal inflammation during acute schistosomiasis.” Journal of Immunology, 184(11): 6438-46, Jun 2010.
15. van de Wetering D et al. “Salmonella induced IL-23 and IL-1beta allow for IL-12 production by monocytes and Mphi1 through induction of IFN-gamma in CD56 NK/NK-like T cells.” PloS One, 4(12): e8396, Dec 2009.
16. Ma J et al. “Morphine disrupts interleukin-23 (IL-23)/IL-17-mediated pulmonary mucosal host defense against Streptococcus pneumoniae infection.” Infection and Immunity, 78(2): 830-7, Feb 2010.
17. Meeks KD et al. “IL-23 is required for protection against systemic infection with Listeria monocytogenes.” Journal of Immunology, 183(12): 8026-34, Dec 2009.
18. Riol-Blanco L et al. “IL-23 receptor regulates unconventional IL-17-producing T cells that control bacterial infections.” Journal of Immunology, 184(4): 1710-20, Feb 2010.
19. Kleinschek MA et al. “Administration of Il-23 engages innate and adaptive immune mechanisms during fungal infection.” International Immunology, 22(2): 81-90, Feb 2010.
20. Louis S et al. “IL-23 and IL-12p70 production by monocytes and dendritic cells in primary HIV-1 infection.” Journal of Leukocyte Biology, 87(4): 645-53, Apr 2010.
21. Teng MW et al. “IL-23 suppresses innate immune response independently of IL-17A during carcinogenesis and metastasis.” Proceedings of the National Academy of Sciences of the United States of America, 107(18): 8328-33, May 2010.
22. Ji Y et al. “Th17 cells: positive or negative role in tumor?” Cancer Immunology, Immunotherapy, 59(7): 979-87, Jul 2010.
23. Miller JM et al. “Vesicular stomatitis virus modified with single chain IL-23 exhibits oncolytic activity against tumor cells in vitro and in vivo.” International Journal of Interferon, Cytokine and Mediator Research, 2010(2): 63-72, May 2010.
24. Hayashi F et al. “Dendritic cell differentiation with prostaglandin E results in selective attenuation of the extracellular signal-related kinase pathway and decreased interleukin-23 production.” Immunology, 131(1): 67-76, Sep 2010.
25. Zhang Y et al. “Triptolide inhibits IL-12/IL-23 expression in APCs via CCAAT/enhancer-binding protein alpha.” Journal of Immunology, 184(7): 3866-77, Apr 2010.
26. McLaughlin M et al. “Inhibition of secretion of interleukin (IL)-12/IL-23 family cytokines by 4-trifluoromethyl-celecoxib is coupled to degradation via the endoplasmic reticulum stress protein HERP.” The Journal of Biological Chemistry, 285(10): 6960-9, Mar 2010.
27. Chang J et al. “Interleukin-23 production in dendritic cells is negatively regulated by protein phosphatase 2A.” Proceedings of the National Academy of Sciences of the United States of America, 107(18): 8340-5, May 2010.
28. Sheikh SZ et al. “Cutting edge: IFN-gamma is a negative regulator of IL-23 in murine macrophages and experimental colitis.” Journal of Immunology, 184(8): 4069-73, Apr 2010.
29. Babu S et al. “Regulatory T cells modulate Th17 responses in patients with positive tuberculin skin test results.” The Journal of Infectious Diseases, 201(1): 20-31, Jan 2010.
30. Manoharan A et al. “Biomarkers in lupus nephritis.” Rheumatic diseases clinics of North America, 36(1): 131-43, Feb 2010.