Maximus Peto’s Commentary
These results appear to have some possible relevance to the effects of CMV in humans.
Increased IL-15 Production and Accumulation of Highly Differentiated CD8+ Effector/Memory T Cells in the Bone Marrow of Persons with Cytomegalovirus.
Front Immunol. 2017 Jun 19;8:715.
Pangrazzi L, Naismith E, Meryk A, Keller M, Jenewein B, Trieb K, Grubeck-Loebenstein B
PubMed publication date (edat): 7/5/2017
Cytomegalovirus (CMV) has been described as a contributor to immunosenescence, thus exacerbating age-related diseases. In persons with latent CMV infection, the CD8+ T cell compartment is irreversibly changed, leading to the accumulation of highly differentiated virus-specific CD8+ T cells in the peripheral blood. The bone marrow (BM) has been shown to play a major role in the long-term survival of antigen-experienced T cells. Effector CD8+ T cells are preferentially maintained by the cytokine IL-15, the expression of which increases in old age. However, the impact of CMV on the phenotype of effector CD8+ T cells and on the production of T cell survival molecules in the BM is not yet known. We now show, using BM samples obtained from persons who underwent hip replacement surgery because of osteoarthrosis, that senescent CD8+ TEMRA cells with a bright expression of CD45RA and a high responsiveness to IL-15 accumulate in the BM of CMV-infected persons. A negative correlation was found between CMV antibody (Ab) titers in the serum and the expression of CD28 and IL-7Rα in CD8+[Formula: see text] cells. Increased IL-15 mRNA levels were observed in the BM of CMV+ compared to CMV- persons, being particularly high in old seropositive individuals. In summary, our results indicate that a BM environment rich in IL-15 may play an important role in the maintenance of highly differentiated CD8+ T cells generated after CMV infection.
Free Full-Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5474847/