Among healthy adults who were administered a cold virus, those with shorter telomere length (a structure at the end of a chromosome) in certain cells were more likely to develop experimentally-induced upper respiratory infection than participants with longer telomeres, according to results of preliminary research published in the February 20 issue of JAMA.
Telomeres shorten with each cell division and function as protective caps to prevent erosion of genomic DNA during cell division. Telomere shortening in leukocytes (white blood cells) has implications for immunocompetence and is associated with poorer antibody response to vaccines. "Shorter leukocyte telomere length also is associated with aging-related illness and death from conditions with immune system involvement, including infectious diseases, cancer, and cardiovascular disease," the authors write. It is not known whether leukocyte telomere length is related to acute disease in younger, healthy populations.
Sheldon Cohen, Ph.D., of Carnegie Mellon University, Pittsburgh, and colleagues conducted a study to determine whether shorter telomeres in leukocytes, especially CD8CD28- T cells, are associated with decreased resistance to upper respiratory infection and clinical illness in young to middle-aged adults. Between 2008 and 2011, telomere length was assessed in peripheral blood mononuclear cells (PBMCs) and T-cell subsets (CD4, CD8CD28+ , CD8CD28-) from 152 healthy 18- to 55-year-old residents of Pittsburgh. Participants were subsequently quarantined (single rooms), administered nasal drops containing a common cold virus (rhinovirus 39), and monitored for 5 days for development of infection and clinical illness.