Early in life, thymic export establishes the size and the diversity of the human naive T-cell pool. Yet, on puberty thymic activity drastically decreases. Because the overall size of the naive T-cell pool decreases only marginally during ageing, peripheral postthymic expansion of naive T cells has been postulated to account partly for the maintenance of T-cell immunity in adults. So far, the an...

Cellular activation is critical for the propagation of human immunodeficiency virus type 1 (HIV-1) infection. It has been suggested that truly naive CD4(+) T cells are resistant to productive HIV-1 infection because of their constitutive resting state. Memory and naive CD4(+) T-cell subsets from 11 HIV-1-infected individuals were isolated ex vivo by a combination of magnetic bead depletion and ...

The extent to which the progeny of one primary memory CD8 T cell differs from the progeny of one naive CD8 T cell of the same specificity remains an unresolved question. To explore cell-autonomous functional differences between naive and memory CD8 T cells that are not influenced by differences in the priming environment, an experimental model has been developed in which physiological numbers o...

Measurements on the average telomere lengths of normal human naive and memory T cells suggested that 1) naive and memory human T cells have similar division rates, and 2) that the difference between naive and memory cells reflects the degree of clonal expansion during normal immune reactions. Here we develop mathematic models describing how the population average of telomere length depends on t...

OBJECTIVE Using SCID-Hu mice models and in vitro culture systems, it has been shown that syncytium inducing/CXCR4 using (X4) HIV-1 variants affect thymic function through infection and killing of CXCR4 thymocytes. The effect of X4-emergence on naive, memory and effector T-cell subset kinetics in vivo is, however, not known. DESIGN Prospective cohort study. METHODS Analysis of changes in nai...

background tenofovir disoproxil fumarate (tdf) is a new effective treatment option for patients with chronic hepatitis b (chb). objectives to evaluate tdf efficacy in nucleos(t)ide analogues (nas)-naive iranian patients with chb. patients and methods the na-naive patients received tdf for at least six months. the primary endpoint was the proportion of patients achieving a complete virological r...

Class binarizations are effective methods for improving weak learners by decomposing multi-class problems into several two-class problems. This paper analyzes how these methods can be applied to a Naive Bayes learner. The key result is that the pairwise variant of Naive Bayes is equivalent to a regular Naive Bayes. This result holds for several aggregation techniques for combining the predictio...

It is well known that the naive Bayesian classiier is linear in binary domains. However, little work is done on the learnability of the naive Bayesian classiier in nominal domains, a general case of binary domains. This paper explores the geometric properties of the naive Bayesian classiier in nominal domains. First we propose a three-layer measure for the linearity of functions in nominal doma...

During ageing thymic function declines and is unable to meet the demand for peripheral T helper (Th) cell replenishment. Therefore, population maintenance of naive Th cells must be at least partly peripherally based. Such peripheral postthymic expansion of recent thymic emigrants (RTEs) during ageing consequently should lead to loss or dilution of T cell receptor excision circles (TRECs) from a...

Naive T cells are usually excluded from nonlymphoid tissues. Only when such tertiary tissues are subjected to chronic inflammation, such as in some (but not all) autoimmune diseases, are naive T cells recruited to these sites. We show that the CCR7 ligand CC chemokine ligand (CCL)21 is sufficient for attracting naive T cells into tertiary organs. We performed intravital microscopy of cremaster ...