The plasma cell enriched transcriptome

Plasma cells result from the terminal differentiation step of mature B lymphocytes. This cell type is a key component of humoral immunity, with the potential to secrete several thousand molecules of antibody. These antibodies bind to their target antigen and initiate its neutralization or destruction. Antibody production continues for several days or even months, gradually decreasing as the stimulus is removed (such as the clearance of infection).

In this section we detail the predicted core plasma cell transcriptome, highlighting genes classified as having predicted specificity in plasma cells in multiple tissue types. Such genes could be useful general markers for plasma cells across tissue beds, and are likely critical for plasma cell specific functions. These genes are sub-divided into 3 categories, based on the number of tissues in which they were independently classified as plasma cell enriched.

Plasma cells were profiled in 14 of the tissues featured in the Tissue Cell section.

• 94 genes predicted as enriched in plasma cells in 75-100 % tissues
• 48 genes predicted as enriched in plasma cells in 50-75 % tissues
• 39 genes predicted as enriched in plasma cells in 25-50 % tissues

Protein expression of genes enriched in plasma cells across tissue types

An example of a protein with enriched expression in plasma cells across several cell types is the CD79a molecule (CD79A), which is a forms a dimer with CD79B and associates with the immunoglobulin heavy chain to form the B-cell receptor complex.

CD79A - Skin
CD79A
CD79A - Stomach
CD79A
CD79A - Thyroid
CD79A

The Joining chain of multimeric IgA and IgM (JCHAIN) protein serves to link monomer units of IgM or IgA into their pentameric (IgM) or dimeric (IgA) forms, and facilitates binding of the antibody complexes to secretary components to transport the immunoglobulins across mucous membranes such as in the GI tract.

JCHAIN - Liver
JCHAIN
JCHAIN - Lung
JCHAIN
JCHAIN - Colon
JCHAIN
JCHAIN - Breast
JCHAIN

Genes with predicted specificity in plasma cells in individual tissues

A summary table of all genes with predicted high enrichment in plasma cells in profiled tissues is provided below. Identified genes are subdivided into 3 categories in each tissue, based on the difference between the enrichment score in plasma cells, compared to the other cell types profiled (see Methods Summary page for details):

• Predicted specificity: ´Very high´ - Differential score vs. other profiled cell types within the tissue >0.35
• Predicted specificity: ´High´ - Differential score vs. other profiled cell types within the tissue >0.25
• Predicted specificity: ´Moderate´ - Differential score vs. other profiled cell types within the tissue >0.15

Table 1: Genes predicted to be enriched in plasma cells by tissue type