For Tc you can use CD8. While some NK cells express CD8, I've found that one can separate Tc and NK cells based on their relative staining intensity for CD8. For Th cells, I would expect at minimum you would want to look at CD4 and CD25 (Treg populations would be CD25 high, Th would be CD25 low). CD56 (human) or CD49 (mouse) are good NK markers.

For differentiating the lineages, you need to first do CD3 gating which will comprise of all T cell population. After that, you gate CD8 cells for cytotoxic T cells and CD4 for T helper cells. You can follow @Govind Sharma protocol for Th cells.

Since you are already gating out your T cell population with CD3 you can either use CD8+CD3-ve cells as NKT cells or use CD56 (human) or CD49 (mouse) along with CD11b are good NK markers.

I think you will need a combination of surface markers: CD3, CD4, CD8, NK1.1/CD49b

cytotoxic T: CD3+CD8+

helper T: CD3+CD4+

NK cells: CD3-NK1.1+ or CD3-CD49b+

NK1.1 is a more specific NK cell marker compared to CD49b (DX-5) as basophils also express CD49b. However, NK1.1 expression is dependent on the background of the mice. For example NK cells of C57Bl/6 mice express NK1.1, but NK cells of BALB/c do not express NK1.1. If you are using mouse strain that does not express NK1.1, I will use CD49b, but include a lineage marker such as c-kit (CD117) to exclude basophils. Mature NK cells are c-kit+, but basophils are c-kit negative.

Thanks @ Govinda, @ Kasturi and @ Pin Shie Quah. Your suggestions and comments are helpful and much appreciated. Cheers!

previous suggestions of CD3+ CD4+ (Th) and CD3+ Cd8+ (Tc) are sensible.  for your NKs it depends on what strain of mice you are using.  If they are C57BL6 mice then use NK1.1 as a marker.  Most other strains don't express this marker so you need to use DX5 instead 

Just wanted to add that NKp46 (CD335) is another good choice for NK  cells. It's not strain specific, so you don't have to worry about your mouse background, and to my knowledge it's only expressed on NK and some small subsets of ILC cells, making it more specific than CD49b.

Good luck 

Thanks everyone for their valuable suggestions. I now have the requisite leads to start up my research. Cheers!

You need to have CD3 otherwise you don't know that any CD4+ or CD8+ cells are actually T cells. Being part of the T cell receptor it is highly specific for T cells and not found on other cell types

https://www.researchgate.net/profile/PF_Zabrodskii/research

T- lymphocytes having ( CD-3) surface antigens , so u can use antibodies aginst these cell surface antigen

I agree with Pin Shie Quah