Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology

A mitogen is a chemical substance that encourages a cell to commence cell division, triggering mitosis. A mitogen is usually a protein.

The most commonly used mitogens in laboratory medicine are:

NameActs upon T cells?Acts upon B cells?
phytohaemagglutinin (PHA)yesno
concanavalin A (conA)yesno
lipopolysaccharide (LPS)noyes
pokeweed mitogen (PWM)yesyes
Lipopolysaccharide toxin (LPS) from gram-negative bacteria is thymus independent. LPS may directly activate B cells. Staphylococcus aureus Cowan strain stimulates only B cells.


Bacterial products - LPS, Staphylococcus aureus Cowan (SAC)
B cell stimulation

Pokeweed stimulates both T cells and B cells (mnemonic: "weed is everywhere").

Pokeweed mitogen (PWM) stimulates B and T lymphocytes, phytohemagglutinin (PHA) and concanavalin A stimulates T cells, and LPS and SAC stimulate B lymphocytes.

Lectins are sugar-binding proteins which are highly specific for their sugar moieties (Latin legere, "to select")

Crystallographic structure of a tetramer of concanavalin A. Image source: Wikipedia, public domain.

Concanavalin A is a lectin protein, binds specifically to glycoproteins - widely used in labs to characterize glycoproteins.

Concanavalin A is a lymphocyte mitogen along with phytohaemagglutinin (PHA) and pokeweed (PWM)

Pokeweed (PWM). Image source: Wikipedia, GNU Free Documentation License.

Pokeweed mitogen (PWM) is derived from Phytolacca americana, considered a major pest by farmers


Mitogen. Wikipedia.
Pokeweed mitogen and Staphylococcus aureus Cowan I induced immunoglobulin A synthesis by lymphocytes of IgA deficient blood donors. K Oen, M L Schroeder, and D Krzekotowska. Clin Exp Immunol. 1985 November; 62(2): 387–396.


Published: 05/05/2010
Updated: 08/28/2010

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