DR3 regulation of apoptosis of naive T-lymphocytes in children with acute infectious mononucleosis

Acute infectious mononucleosis (AIM) is a widespread viral disease that mostly affects children. Development of AIM is accompanied by a change in the ratio of immune cells. This is provided by means of different biological processes including the regulation of apoptosis of naive T-cells. One of the potential regulators of apoptosis of T-lymphocytes is a death receptor 3 (DR3). We have studied the role of DR3 in the regulation of apoptosis of naive CD4+ (nTh) and CD8+ (nCTL) T-cells in healthy children and children with AIM. In healthy children as well as in children with AIM, the activation of DR3 is accompanied by inhibition of apoptosis of nTh. In healthy children, the stimulation of DR3 resulted in the increase in apoptosis of nCTL. On the contrary, in children with AIM, the level of apoptosis of nCTL decreased after DR3 activation, which is a positive contribution to the antiviral immune response. In children with AIM, nCTL are characterized by reduced level of apoptosis as compared with healthy children. These results indicate that DR3 can be involved in the reduction of sensitivity of nCTL to apoptosis in children with AIM

Changes in mRNA expression of members of TGFB1-associated pathways in human leukocytes during EBV infection

Transforming growth factor β 1 (TGFB1) likely contributes to the pathogenesis of Epstein-Barr virus (EBV)-mediated cancer. A microarray containing 59 probes for detecting mRNA of members of TGFB1-associated pathways was developed. mRNA expression of TGFB1 receptors and members of connected pathways were examined in peripheral blood leukocytes of patients during acute EBV infection and after recovery. TGFB1 and TGFBR2 mRNA expression was increased in patients with EBV infection. Similarly, mRNA expression of protein kinase C (PRKCB), MAP3K7, PDLIM7, and other members of TGFB1 and NF-κB signaling pathways increased. A shift of mRNA transcript variant expression of some key members (TGFBR2, PRKCB, and NFKBIB) of involved signaling pathways was detected. After the patients’ recovery, most of the altered mRNA expression has been normalized. We speculate that in patients with EBV infection, members of TGFB1-associated pathways contribute to the suppression of proapoptotic and induction of pro-survival factors in leukocytes. The modulation of TGFB1-associated pathways may be considered as a potential risk factor in the development of EBV-associated tumors in patients with acute EBV infection

Methodological approaches to differential detection of EBV1/EBV2 and HHV6A/HHV6B in saliva

Epstein-Barr virus (EBV) and human herpesviruses 6A and 6B (HHV6A and HHV6B) are ubiquitous, infecting all social groups. In Russia, information on the genetic heterogeneity of EBV, even at the level of the main types (EBV1 and EBV2), as well as HHV6A and HHV6B, their prevalence and clinical significance are limited to isolated publications. Plasma and blood leukocytes were mainly investigated. Saliva is the main factor in the transmission and spread of EBV and HHV6A/B infections, an affordable, inexpensive, non-invasive material for detecting viral DNA. The aim of this work is to improve the methodological base for differential detection of HHV6A/HHV6B and the main types of EBV in saliva. The material of the study was the unstimulated mixed saliva of children aged 1-17 years with acute infectious mononucleosis (n=22) and no clinical symptoms of this disease (n=26), as well as conditionally healthy adults (n=9). Samples were collected once and dynamically (daily for 14 days). The quantitative detection of EBV and HHV6A/В DNA was carried out by the method of polymerase chain reaction (PCR) in real time. For differential detection of EBV1/EBV2 and HHV6A/HHV6В, an optimized one-round PCR variant with electrophoretic detection of amplification products in agarose gel was used. As a result, the detection rate of EBV, HHV6A/В and EBV+HHV6A/В DNA in acute infectious mononucleosis was 95%, 91% and 86%, among conventionally healthy children - 69%, 85% and 61.5%, respectively. It was found that among children of the Nizhny Novgorod region, only EBV1 and HHV6B predominate in saliva. According to the results of 14-day dynamic monitoring of saliva virus secretion in healthy virus carriers (adults and children), it was shown that a single EBV DNA study does not allow to reliably assess the infection of individuals or the intensity of EBV secretion. In this case, HHV6A/B is characterized by a more constant and uniform release. The methodological approach optimized in this work makes it possible to separately detect EBV1/EBV2 and HHV6A/HHV6B using a single laboratory protocol, and in combination with an additional stage of saliva sample preparation increases the diagnostic sensitivity of PCR analysis, minimizes the proportion of discordant and false negative results. Such an integrated approach can be applied for diagnostic, epidemiological and research purposes