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.

Acute infectious mononucleosis is a widespread viral disease, which most often manifests in childhood. The development of acute infectious mononucleosis is accompanied by the change of the CD4+/CD8+ T-lymphocytes ratio and the increase of the virus-specific CD8+ cytotoxic T-lymphocytes number. One of the T-lymphocytes number regulation mechanisms is the modulation of their progenitor cells apoptosis. The death receptor CD95 takes part in the regulation of T-lymphocytes apoptosis, including naïve T-cells. We studied the effect of CD95 receptor activation on apoptosis of naïve CD4+ and naïve cytotoxic CD8+ T-lymphocytes in healthy children and children with acute infectious mononucleosis. In this study children with acute infectious mononucleosis at the age of 9 to 16 years were included. For comparison healthy children of the same age with no clinical and laboratory signs of the disease were used. Naïve CD4+ and naïve cytotoxic CD8+ T-lymphocytes were isolated by negative magnetic immunoseparation. The analysis of naïve T-cells apoptosis and the CD95 receptor surface expression density was performed by using the flow cytometry analysis. The analysis of T-cells was performed in three variants: freshly isolated naïve CD4+ T-lymphocytes and naïve cytotoxic CD8+ T-lymphocytes, and also cells after 24 hours of the cultivation with anti-CD95 monoclonal antibodies or without them. In healthy children both CD95– and CD95+ naïve CD4+ T-lymphocytes underwent apoptosis. In children with acute infectious mononucleosis CD95– naïve CD4+ T-lymphocytes lost their susceptibility to apoptosis induction. In healthy children and children with acute infectious mononucleosis CD95– naïve cytotoxic CD8+ T-lymphocytes were resistant to apoptosis in contrast to CD95+ naïve CD4+ T-lymphocytes. In healthy children CD95 receptor did not induce apoptosis of isolated naïve CD4+ T-lymphocytes and naïve cytotoxic CD8+ T-lymphocytes. In children with acute infectious mononucleosis CD95 receptor was involved in inhibition of apoptosis of naïve cytotoxic CD8+ T-lymphocytes and did not effect on the level of apoptosis of naïve CD4+ T-lymphocytes. We suggest that CD95-dependent suppression of naïve cytotoxic CD8+ T-lymphocytes apoptosis is a protective mechanism for the maintenance of a sufficient number of cytotoxic T-lymphocytes in the blood for the realization of effective antiviral immune response.

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Alternative splicing (АS) provides a variety of protein and mature mRNA isoforms encoded by a single gene, and is the essential component of cell and tissue differentiation and functioning. dNA-microarrays are highly productive transcriptome research technique both at the level of total gene expression assessment and alternatively spliced mRNA isoforms exploration. The study of AS patterns requires thorough probe design to achieve appropriate accuracy of the analysis.There are two types of splicing-sensitive dNA-microarrays. The first type contain probes targeted to internal exonic sequences (exon bodies); the second type contain probes targeted to exon bodies and exon-exon and exon-intron junctions. So, the first section focused on probe sequence design, general features of splicing-sensitive dNA-microarrays and their main advantages and limitations.The results of AS research obtained using dNA-microarrays have been reviewed in special section. in particular, dNA-microarrays were used to reveal a number pre-mRNA processing and splicing mechanisms, to investigate AS patterns associated with cancer, cell and tissue differentiation. Splicing machinery regulation was demonstrated to be an essential step during carcinogenesis and differentiation. The examples of application of splicing-sensitive dNA-microarrays for diagnostic markers discovering and pathology mechanism elucidation were also reviewed. investigations of AS role in pluripotency, stem cell commitment, immune and infected cells functioning during immune response are the promising future directions. Splicing-sensitive dNA-microarrays are relatively inexpensive but powerful research tool that give reason to suppose their introduction in clinical practice within the next few years.