Non-Primate Monocytes - CD14, CD16 - Ziegler-Heitbrock


Non-Primate Monocytes
in Health and Disease

After the description of monocyte subsets in flow cytometry in man in the late 1980ies it took more than 10 years until a similar subdivision of monocytes was described for the mouse model. Since then 2 to 3 subsets of blood monocytes have been detected in several species including rat, pig, cow, camel, horse, sheep, dog and chicken.

While cell subsets with features similar to classical and non-classical monocytes have been described in these species, it has to be emphasized that these subsets are not identical to the respective cells in man. To this end the defining cell surface receptors are different in the different species. Also a comparison on man and mouse, while showing many similarities for the subsets, has documented inverse expression patterns for several funtionally relevant cell surface receptors. For example for CD36 a scavenger receptor important in atherosclerosis is high on mouse non-classical monocytes but absent on the respective human cells. Also, TREM-1, a receptor involved in enhanced cytokine production, is high on mouse non-classical monocytes but again absent on the respective human cells.

The mouse is often used as a model for human physiology and disease, but as indicated by the above examples the results cannot be directly transferred to man. Findings in the mouse will have to be confirmed in independent studies man. And this applies to all species.

The non-primate monocyte website compiles publications and procedures for mouse, rat and pig and literature for a couple additional species is compiled under Other Non-Primate Monocytes.

Given that the classical and non-classical monocyte subsets are distinct in phenotype and function, a study looking at monocytes as a bulk population will inadequately describe these cells in health and disease. Therefore the website focusses on studies, which clearly define the monocyte subsets.