There are some articles on TH17/ RORgt. You may see these to have the answer of your query.

1.

Annu Rev Immunol. 2009;27:485-517. doi: 10.1146/annurev.immunol.021908.132710.

IL-17 and Th17 Cells.

Korn T, Bettelli E, Oukka M, Kuchroo VK.

Source

Technical University Munich, Department of Neurology, 81675 Munich, Germany. [email protected]

Abstract

CD4+ T cells, upon activation and expansion, develop into different T helper cell subsets with different cytokine profiles and distinct effector functions. Until recently, T cells were divided into Th1 or Th2 cells, depending on the cytokines they produce. A third subset of IL-17-producing effector T helper cells, called Th17 cells, has now been discovered and characterized. Here, we summarize the current information on the differentiation and effector functions of the Th17 lineage. Th17 cells produce IL-17, IL-17F, and IL-22, thereby inducing a massive tissue reaction owing to the broad distribution of the IL-17 and IL-22 receptors. Th17 cells also secrete IL-21 to communicate with the cells of the immune system. The differentiation factors (TGF-beta plus IL-6 or IL-21), the growth and stabilization factor (IL-23), and the transcription factors (STAT3, RORgammat, and RORalpha) involved in the development of Th17 cells have just been identified. The participation of TGF-beta in the differentiation of Th17 cells places the Th17 lineage in close relationship with CD4+CD25+Foxp3+ regulatory T cells (Tregs), as TGF-beta also induces differentiation of naive T cells into Foxp3+ Tregs in the peripheral immune compartment. The investigation of the differentiation, effector function, and regulation of Th17 cells has opened up a new framework for understanding T cell differentiation. Furthermore, we now appreciate the importance of Th17 cells in clearing pathogens during host defense reactions and in inducing tissue inflammation in autoimmune disease.

PMID:

19132915

[PubMed - indexed for MEDLINE]

2.

Mucosal Immunol. 2013 Oct 16. doi: 10.1038/mi.2013.79. [Epub ahead of print]

TNFα-dependent development of lymphoid tissue in the absence of RORγt+ lymphoid tissue inducer cells.

Furtado GC, Pacer ME, Bongers G, Bénézech C, He Z, Chen L, Berin MC, Kollias G, Caamaño JH, Lira SA.

J Exp Med. 2011 Oct 24;208(11):2321-33. doi: 10.1084/jem.20110462. Epub 2011 Oct 17.

3.

The Th17 immune response is controlled by the Rel-RORγ-RORγ T transcriptional axis.

Ruan Q, Kameswaran V, Zhang Y, Zheng S, Sun J, Wang J, DeVirgiliis J, Liou HC, Beg AA, Chen YH.

Source

Department of Pathology and Laboratory of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.

4.

J Immunol. 2010 Dec 15;185(12):7161-4. doi: 10.4049/jimmunol.1002750. Epub 2010 Nov 12.

Cutting edge: The transcription factor Kruppel-like factor 4 regulates the differentiation of Th17 cells independently of RORγt.

Lebson L, Gocke A, Rosenzweig J, Alder J, Civin C, Calabresi PA, Whartenby KA.

Source

Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.

Best wishes

Basically IL6 (a pleotropic cytokine) ,TGF b milieu create a different population of T helper cells having orphan receptor RORg/ RORgt . Still now it is not very much sure that RORgt is responsible for IL17 but the inflammatory condtion favours stable TH17 and IL17 production.

The basis of inflammation is mixed reaction initially between tolerance and inflammatory responses. So switch between FOXP3+ / IL10 cells to RORgt+/ IL17 cells is highly possible and relevant. But this should not influence much on your RORgt/ IL17 flow cytometry data which determines functional TH17 cells.

Later, depending on endogenous or exogenous signals, balance shifts towards inflammatory TH1 or TH17 responses which establishes inflammatory condition over tolerance. So chances of getting IL17hi- RORgt int. is possible.

Check RORgt vs FOXP3 in flow which will tell you the differences in relative intensities between the two regulator positive cells. What is your IL17 mRNA expression and protein level in ELISA?

I am pleased on your literature search. The articles will help you to sketch on TH17/ IL17/ IL 23. You can also add Dr. L. Steinman's reference here on TH1/TH17 cytokine levels.

I feel you've got your answer. Best wishes.

Dear Dr. Subhajit, Thank you for sharing information. I have put the same query on Linkedin also. Find below the conversation from there FYI:

1) Johan Van Weyenbergh

Senior Scientist at FIOCRUZ - Visiting scientist at KU Leuven

Try CD161 staining in parallel, as demonstrated by the group of Romagnani, human Th17 cells frequently loose IL-17 expression, but CD161 is a reliable marker, not only in the Th compartment, but also for CD8+, NK and NKT cells with a "capacity" of IL-17 production (past or present!). Hope this helps, Johan

2) Vasileios Bekiaris; Postdoctoral Research Fellow at Lund University

What patients? Could these cells be Th22? From what I remember in humans there is a RORgt+ population that primarily expresses IL-22 and little IL-17. It was a paper by Spits in NI. gd T and some NKT tend to be brighter for RORgt than TCRab cells but they also tend to be bright for IL-17, at least in mouse. I'd try a gd T, Va24 and IL-22 staining. To be sure for RORgt levels it will also be helpful if you sort these populations and do qPCR for RORgt since the eBio Ab is not that specific.

3) My reply: Divya B., Ph.D fellow at AIIMS

Dear Johan and Vasileios, Thank you for your responses. @John: Thank you for providing ref. of Romagnani; as it is mentioned in that article that the CD161 not only expressed by (A) IL-17 producing CD4+TCRab+ but by (B) CD8+TCRab+, (C ) CD4-CD8-TCRab+, and (D) CD4- CD8- TCRgd+ cells. As the (P2) population RORgt+IL-17- which I have been getting are gated from (P1) CD3+CD8- cells, so my P2 cells can not be A as are all IL-17-. My P2 cells can also not be B as I have gated the cells from P1, which are CD8- (although I put tight gate on CD3+CD8- but chances of CD8low may be there). The possibilities that my P2 population is positive for either C or D are there, as my P2 is CD8-TCRab+ (I don't know the expression of CD4 on my P1 cells as I presumed CD3+CD8- as Th cells). It is also possible likewise that my P2 might be D (Tgama delta) as gamma delta cells are CD3+ but CD4-CD8- and my P2 popultaion is also CD8- and CD3+.

@ Vasileios : These are steroid dependent nephrotic syndrome's patients, its a kidney disease involved Th/Th2 and Treg/Th17 imbalance. Decrease in Tregs and increase in Th17 as well as Th2 polarization during relapse state. Yes the chance that my P2 cells can be Th22 is there, which I can confirm after having done CD161 staining as suggested by John, as Th22 are CD161-, if my P2 shows CD161+ signal then theses might be either C or D as explained above.

Again thank you both. I hope I get more references and knowledge on this..Kind regards,Divya

Two papers in European J of Imm. in 2010, one by Romagnani (as mentioned by John) and other by by Carlo Chizzolini. In Romagnani's paper it is mentioned that CD161+ cells have higher frequency of IL-22 producing cells. While in second article they assessed that CD161 is virtually absent from IL-22 producing Th22 cells. I have not read much about Th22. But these are the two findings that are contradictory. But still if I conclude from two replies that CD161 staining would be helpful in discriminating my RORgt+IL-17- cells into Tgammadelta (CD161+) or Th22 (CD161-) cells.

Divya, this is Dr. Anil from Prof. Moin Saleem's Lab, Bristol. We are here to find accomoation for you and pls let me know duration of your stay.

my email: [email protected]

Regards to Dr. Bagga