Open AccessPlatelet Immunoregulatory Factors
Author(s) -
Tykocinski Mark L.,
Xiong Na,
Morrow Dwight M.
Publication year - 1996
Publication title -
stem cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.159
H-Index - 229
eISSN - 1549-4918
pISSN - 1066-5099
DOI - 10.1002/stem.5530140731
Subject(s) - biology , haematopoiesis , glycoprotein , microbiology and biotechnology , platelet , immune system , growth factor , cytokine , immunology , stem cell , biochemistry , receptor
A number of soluble and membrane‐associated proteins are known to mediate platelet:leukocyte interactions. Platelet‐derived factors that have attracted the most attention to date include transforming growth factor β, interleukin 1 and platelet factor 4. Recently, we have uncovered another protein within platelets that has leukocyte modulatory activity. It was previously characterized as an endometrial glycoprotein named placental protein 14 (PP14) with suppressive effects upon lymphocyte proliferation, pro‐inflammatory cytokine production and natural killer cell function. The “hematopoietic” PP14 derived from cells of the megakaryocytic lineage shares this immunosuppressive property, as evaluated by two‐way mixed lymphocyte cultures. Interestingly, two alternatively spliced hematopoietic PP14 mRNAs have been cloned which differ in their encoded proteins. Cellfree translation and transfection analyses have verified the translatability of both PP14 mRNA species and allowed for the analysis of their glycosylation properties. PP14, a member of the lipocalin structural superfamily of proteins, now offers an intriguing new link between the coagulation and immune systems.