Immune responses to Epstein–Barr virus lytic proteins in patients with nasopharyngeal carcinoma

Abstract

Immune responses to three Epstein-Barr virus (EBV) lytic proteins, DNase, thymidine kinase (TK), and BMRF-1 gene products (50/52 kDa diffused early antigen, EA-D complex) were determined in EBV-infected control individuals and patients with nasopharyngeal carcinoma (NPC). Immunofluorescence assays (IFA) were used to detect their humoral immune responses using recombinant EBV lytic proteins expressed in a baculovirus system as antigens. Cell proliferation assays were performed to evaluate their cellular immune responses by monitoring 3H-thymidine incorporation. Seventy patients with NPC and 32 non-cancer controls were analyzed. The results of IFA showed antibody titers to all three EBV lytic proteins to be higher in the patients with NPC especially for the IgA class. Positivity rates of the three IgA antibodies also were higher in the patients with NPC population. Furthermore, the profiles of the IgA antibodies correlated with those to total early antigens (EA) expressed in the early phase and viral capsid antigen (VCA) expressed in the late phase, of EBV replication. The most interesting finding was that antibody titers to the three EBV lytic proteins were associated significantly with metastases of cervical lymph nodes in patients with NPC. As for cellular immunity to the EA-D complex and DNase, weak responses were observed in the cell proliferation assays. Peripheral blood cells from most individuals could not be stimulated to proliferate, except for a few patients with NPC whose antibody titers against the EA-D complex and DNase also were very high.

The prognostic value of IgA/[EBNA1+VCA-p18] on survival of nasopharyngeal cancer patients

“…This led to conclusion that the role of EA serology was less important than viral EBV DNA load (Liu et al, 2004;Twu et al, 2007). Similar findings was reported by Adham et al (2013) among NPC patients in Indonesia.…”

Evaluation of commercial EBV RecombLine assay for diagnosis of nasopharyngeal carcinoma

“…Analysis of the spectrum of IgG and IgA responses to different EBV proteins was shown to be relevant for NPC diagnosis (Fachiroh et al, 2004;Karray et al, 2005). Multiple studies have focused on the use of individual recombinant EBV proteins, but no single protein test was sufficient to reliably diagnose NPC and a combination of test is required (Liu et al, 2004). The complementary use of EBNA1 with EAd was reported achieve the sensitivity more than 98% (Chow et al, 1997;Hsu et al, 2001).…”

IgA antibodies against the Epstein‐Barr nuclear antigen1 as a valuable biomarker for the diagnosis of nasopharyngeal carcinoma in Tunisian patients

“…In previous studies, however, IgG antibody responses against ZEBRA, Tk or DNAse have been described as specific serological markers for the diagnosis of nasopharyngeal carcinoma when using the only healthy EBV carriers as control group [Dardari et al, 2000[Dardari et al, , 2008Liu et al, 2004].…”