Splenocyte
From Wikipedia, the free encyclopedia
The spleen is the body’s largest blood filter, performing important functions within the lymphatic system and serving as the most important organ for immune function.[1] Splenocytes are important components of this lymphatic system, consisting of all immune cells that reside within the spleen.[1] The biggest difference between splenocytes and immune cells in other lymphatic organs is the fact that the spleen filters blood, not lymph.[1] They are, therefore, able to protect the body from invaders in ways that the lymphatic system cannot.[1]
Red Pulp Splenocytes
The red pulp is partially responsible for the spleen’s innate immune response. It serves as the primary filter for old erythrocytes (red blood cells), which have stiffening membranes that differentiate them from newer, healthy erythrocytes. The macrophages housed in the red pulp, a kind of splenocyte, are able to dispose of these erythrocytes through phagocytosis.[1] Once the erythrocyte is hydrolyzed, these splenocytes are able to release or store its iron content for future use by the body or to ensure that bacteria are unable to use the iron for their vital functions.[1] The red pulp also serves as a site where plasmablasts lodge, which are known to produce large amounts of antibodies.[1]
Marginal Zone Splenocytes
The marginal zone acts as a transit pathway between the bloodstream and the white pulp area and assists the other regions with their specific immune responses. It also contains a large population of various splenocytes, including two layers of macrophages separated by a layer of B-cells and dendritic cells.[1] The B-cells in the marginal zone are able to translocate themselves to the white pulp, but their structure is specific to their location of origin and they can be easily differentiated under microscopy.[1]
White Pulp Splenocytes
The white pulp is responsible for the spleen’s adaptive immune response and primarily houses numerous T-cells, B-cells, and dendritic cells that are able to identify previously-encountered pathogens and ensure they are removed from the bloodstream quickly.[1] These white pulp splenocytes are contained within established zones, defining their function. When antigen presenting cells (APCs, splenocytes) from the red pulp or marginal zone enter the T-cell zone with a known antigen, the splenocytes are activated and they are able to carry out their immune system functions to eliminate the pathogens.[1]
Splenocyte Role in Antitumor Immune System
Splenocytes play an important role in many immune functions, but a specific example lies within the antitumor immune system. As studied by comparing antitumor immune function in mice with and without spleens, it was discovered that the lack of splenocyte and splenic activity greatly decreases antitumor activity.[2] The livers of the mice were injected with colon cancer cells, with the number of liver metastases measured at 10 days. The splenectomy group had an average of 19.2 liver metastases, compared to 1.5 metastases of the spleen-preserved group.[2] While animal-focused, this study serves as a good indicator of a very strong correlation between splenocyte activity and tumor fighting/prevention activity.[2]
