T-cell memory: You must remember this ..

While antigen-inexperienced (naive) T cells appear to require constant tickling of their receptor by self-antigens for homeostasis, antigen-experienced (memory) T cells have no such requirement. An implication is that long-term T-cell memory does not depend on persisting antigen.     

Regulation of the generation and maintenance of T-cell memory: a direct,default pathway from effectors to memory cells

Memory T cells are derived directly from effector cells without need for additional antigen, TcR triggering or induced cytokines. A large fraction of effectors can become memory cells without division, supporting a default pathway with little further differentiation. This suggests that the same signals during infection/vaccination determine the extent and nature of both effector and memory cell development.     

Latent virus influences the generation and maintenance of CD8+ T cell memory

The influence of latent virus on CD8+ T cell memory is poorly understood. HSV type 1 specifically establishes latency in trigeminal ganglia (TG) after corneal infection of mice. In latently infected TG, IL-15 deprivation reduced the following: 1) accumulation of HSV-specific CD8+ effector T cells (HSV-CD8(eff)), 2) accumulation of CD127(+) putative HSV-CD8 memory precursors, and 3) the size and functionality of the memory (HSV-CD8(mem)) population. Although compromised in IL-15(-/-) mice, the HSV-CD8(mem) pool persisted in latently infected tissue, but not in noninfected tissue of the same mice. Anti-IL-2 treatment also dramatically reduced the size of the HSV-CD8(eff) population in the TG, but did not influence the concomitant generation of the CD127+ putative HSV-CD8(mem) precursor population or the size or functionality of the HSV-CD8(mem) pool. Thus, the size of the memory pool appears to be determined by the size of the CD127+ CD8(mem) precursor population and not by the size of the overall CD8(eff) pool. HSV-CD8(mem) showed a higher basal rate of proliferation in latently infected than noninfected tissue, which was associated with a reduced population of CD4+FoxP3+ regulatory T cells. Thus, the generation, maintenance, and function of memory CD8+ T cells is markedly influenced by latent virus.     

Dendritic cell-T cell interactions in the generation and maintenance of CD8 T cell memory

Dendritic cells (DCs) are the critical antigen-presenting cells involved in initiating CD8 T cell responses to microbial and viral pathogens. Hence the generation of memory T cells from naïve T cells is intricately intertwined with DCs at every level. This review broadly addresses DC-CD8 T cell interactions that result in the generation and maintenance of CD8 memory T cells.     

Learning and memory: neurophysiological mechanisms

The analytical review of study of neurophysiological basis in different kinds of learning and memory in animal and human is given. The main attention is paid to the consideration of systemic and neuronal levels of habituation and conditioned reflexes. A conception on the brain functional state as the main mechanisms of learning and distributed multicomponent engram corresponding to the integrative process peculiarities is developed.     

Soil clean-up: lessons to remember

In the past, various attempts have been made to alter the microbial composition of the soil. Moreover, considerable effort has been devoted to develop mechanisms to control the soil (micro)biological processes. Currently, a number of novel and powerful strategies are proposed to optimise the microbiota in order to achieve soil clean-up. Nevertheless, in practice the most relevant approach is the so-called intrinsic remediation, which often corresponds with minimal intervention. It is important for the scientist, the regulator and the practitioner to carefully weigh the social consequences of treatment such as `Isolating–controlling–monitoring' versus an approach based on `Binding and immobilization of the pollutants'.     

T-cell memory: the importance of chemokine-mediated cell attraction

A recent study demonstrates the involvement of certain chemokines in immune response initiation and CD8+ T-cell memory formation. These seminal findings broaden our understanding of the role of chemokines in adaptive immune processes.