Reports from C. Smith et al highlight recent research in life sciences
2009 AUG 4 - (NewsRx.com) -- "Activation of the nuclear factor-kappa B pathway by Epstein-Barr virus-encoded latent membrane protein-1 (LMP-1) leads to an up-regulation of the major histocompatibility complex class I antigen-processing pathway. Paradoxically, LMP-1 itself induces a subdominant CD8(+) T-cell response and appears to have evolved to avoid immune recognition," scientists writing in the journal Blood report. "Here we show that, although expression of LMP-1 in human cells dramatically enhanced the trans-presentation of CD8(+) T-cell epitopes, cis-presentation of LMP-1-derived epitopes was severely impaired. Testing of a series of LMP-1 mutants revealed that deletion of the first transmembrane domain of LMP-1, which prevented self-aggregation, significantly enhanced cis-presentation of T-cell epitopes from this protein, whereas it lost its ability to up-regulate trans-presentation. Interestingly, we also found that cis-presentation of LMP-1 epitopes was rescued by blocking the proteasome function," wrote C. Smith and colleagues. The researchers concluded: "Taken together, these results delineate a novel mechanism of immune evasion, which renders a virally encoded oncogene inaccessible to the conventional major histocompatibility complex class I pathway limiting its cis-presentation to effector cells. (Blood. 2009; 113:6148-6152)." Smith and colleagues published their study in Blood (Discerning regulation of cis- and trans-presentation of CD8(+) T-cell epitopes by EBV-encoded oncogene LMP-1 through self-aggregation. Blood, 2009;113(24):6148-6152). Additional information can be obtained by contacting R. Khanna, Queensland Institute Med Research, Australian Center Vaccine Development & Tumour Immunology Laboratory, Division Immunology, 300 Herston Rd., Brisbane, Qld 4006, Australia. The publisher of the journal Blood can be contacted at: American Society Hematology, 1900 M Street. NW Suite 200, Washington, DC 20036, USA. Keywords: Australia, Brisbane, Life Sciences, EBV, Virology, Epstein-Barr Virus, Herpes, Herpesvirus, Chronic Fatigue Syndrome, Viral. This article was prepared by Life Science Weekly editors from staff and other reports. Copyright 2009, Life Science Weekly via NewsRx.com.
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