Alternative titles; symbols
HGNC Approved Gene Symbol: FDCSP
Cytogenetic location: 4q13.3 Genomic coordinates (GRCh38) : 4:70,226,124-70,235,252 (from NCBI)
FDCSP is expressed by follicular dendritic cells (FDCs) and activated leukocytes during ongoing immune responses.
Using PCR-based cDNA subtraction to identify genes specifically expressed in tonsillar FDCs, Marshall et al. (2002) isolated a cDNA encoding a secreted protein that they termed FDCSP. The deduced 85-amino acid protein is 45% identical to the mouse protein and contains an N-terminal signal peptide, followed by a conserved highly charged sequence and a moderately proline-rich central region. Northern blot analysis revealed abundant expression of a 0.5-kb transcript in tonsil, lymph node, and trachea, strong expression in prostate, and lower expression in thyroid, stomach, and colon, with weak or no expression in spleen, peripheral blood leukocytes, and bone marrow. No expression was detected in other tissues or in lymphoid cell lines. In situ hybridization and RT-PCR analysis showed strongest expression in the FDC-rich light zone of tonsillar germinal centers, but no expression in dark zone B cell-rich areas. Expression in FDC lines, but not B-cell lines, could be enhanced by exposure to TNFA (191160). Likewise, intense expression was observed in inflamed tonsillar crypts. Blood leukocyte expression was inducible by lipopolysaccharide but not by TNFA. Western blot analysis showed expression of a probably posttranslationally modified secreted protein of 19 to 22 kD. Flow cytometric analysis suggested that FDCSP binds to B cells that have undergone T cell-dependent IL4 (147780)/CD40L (300386)-mediated activation.
By genomic sequence analysis, Marshall et al. (2002) determined that the FDCSP gene contains 5 exons and spans approximately 10 kb.
By genomic sequence analysis, Marshall et al. (2002) mapped the FDCSP gene to chromosome 4q13, closely linked to genes encoding proline-rich salivary/tear gland proteins and the CXC chemokines (e.g., CXCL2, 139110, and IL8, 146930).
Marshall, A. J., Du, Q., Draves, K. E., Shikishima, Y., HayGlass, K. T., Clark, E. A. FDC-SP, a novel secreted protein expressed by follicular dendritic cells. J. Immun. 169: 2381-2389, 2002. [PubMed: 12193705] [Full Text: https://doi.org/10.4049/jimmunol.169.5.2381]