Natural Killer (NK)-T cells are lymphocytes that share the characteristics of both NK cells and T cells.  

Michigan State University

The common lymphoid progenitor matures into four mature categories of lymphocytes:

- B lymphocytes
- natural killer (NK) cells
- NK-T cells
- T lymphocytes

Common Lymphoid Progenitors

Chaplin, D. D. (2010). Overview of the immune response. Journal of Allergy and Clinical Immunology, 125(2), S3-S23.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2923430/
doi: 10.1016/j.jaci.2009.12.980

Overview of the Immune Response

B lymphocytes, which are commonly called B cells, express surface B cell receptors for antigen immunoglobulins.  B cells are further differentiated based on which kinds of antigens they respond to and which type of antibodies they produce. There are two different types of B cells:
1. Plasma B cells
2. Memory B cells

B Lymphocytes

T lymphocytes, which are commonly called T cells, express T cell receptors (TCRs) on their surface.  These are transmembrane proteins that bind to processed antigens that are presented by antigen presenting cells (ATCs).  
There are three types of T cells, differentiated on the basis of their functions:
1. Cytotoxic T- cells
2. Helper T cells 
3. Regulatory T cells

T Lymphocytes

Natural killer (NK) cells are large mononuclear lymphocytes that target abnormal cells, including virus-infected and cancerous cells, and lack either T cell receptors (TCRs) or surface immunoglobulin (Ig). Abnormal cells do not express the normal major histocompatibility complex (MHC). Normal MHC markers prevent NK cell activation, so abnormal MHC expression by abnormal cells recruits NK cells (signals cell distress). Binding of NK cells on target cells (and detect abnormal MHC levels) also leads to activation. After activation, NK cells can employ several mechanisms for target cell destruction.

(Photo credits in References)

Learn Before

Related