.. quite large (green line) or experience exponential growth (black dotted line). If the population of cells becomes more other factors change the rate of growth, such as feedback from inflammation and tolerance mechanisms schematically in red. DOI: 10. 1371/journal. Thu. 0,009,648. g005
likely scenario will be the first autoreaktivnyh cells escape negative selection, do not feel it yourself and the environment as antigens of immature cells. This cell maturation is naive in the population where it can be stimulated by self antigen or allergen. Antigenic stimulation causes the cells multiply in a little autoreaktivnyh memory cells. These autoreaktivnyh memory cell may still require survival factors survival or rapid reproduction. If so, increased competition for survival factors can suppress this cell clone, and thus prevent the disease. Suppression autoreaktivnyh cells thus accompanied by passive depletion of the memory population. Large values of attrition, and leads to more rapid loss of immunological memory. On the other hand, long-term stable population of memory should be low value of attrition, and so people with greater ranger of values
will grow. Inequality in the formula. 6 defines the boundary between the suppression and the spread, which is a function of rate of infection. shows the pedagogical example. The value
, usually property environment. To clone autoreaktivnyh cells limit determines the minimum flow of infection need to suppress that clone lasix 12.5mg. For clones with large values
large enough to suppress them. Similarly it is possible that all >> << value below a certain threshold can be suppressed homeostatic sources of attrition, although this is not a common feature of all niches. Conversely, if we consider the external environment, which is well characterized by a specific value, the border in the figure defines the lower limit autoreactivities we are likely to find in this environment. Low cost >> << related BЂњfilthyBЂ Wednesday ". The following subsections we approach curve data for human and mouse CD
T-cell memory to make quantitative predictions for these borders. We can find the asymptotics of passive depletion autoreaktivnyh suppression in the limit of rare infections, i. e low. Balance the total number of memory cells for a given rate of infection is given. This is simply the value
, for which the right side of the equation. 1 is equal to zero, the homeostatic balance. If we consider the case when the level of contamination is small enough that the amendment K. In this limit equation. 7 is reduced to the form obtained by Anti et al. etc.
As seen from this equation, clones with
). is zero and there is no lower limit on the ability autoreaktivnyh cells to proliferate in sterile conditions. Asymptotics of the border that divides the field stop and be present around the curve. This asymptotic behavior can be seen an inch, and that it is a common feature of homeostatic regulation. For large values >> << it may not be possible to satisfy the equation. 6. This is demonstrated and discussed in the following subsections, where we model cell homeostasis in IL-15 regulated niche (CD
T-cell memory) cells and IL-7 niche (CD
and naive T cells), respectively. There we also give quantitative predictions for the speed range of antigenic stimulation. pool of memory T cells. These cells differ from effector memory, the presence of a high level of CD122 on the cell surface. CD122 protein is part of the receptor for IL-15. In the absence of IL-15 CD
memory T cells can not survive. Other cell types usually has no effect on IL-15 knockout mouse
shows that the niche is not universal and that competition between cells that niche for IL-15 should have little impact on other cell types. We also know that sterile environment memory population in this niche is stable yield. In the homeostatic equilibrium total number of cells remains constant. Since there is no homeostatic influx of new cells in this pool (
) as homeostatic division rate
ago level. With CSFE staining and other methods was noted in mice that homeostatic division rate of about once every 2BЂ "3 weeks, meaning. To distinguish whether IL-15 inhibits apoptosis and stimulates the division, consider two possible cases separately. Suppression of apoptosis is described:
is a population, the first term on the right side represents the population growth by division, and the second is reduced by apoptosis. Number. Judge et al. Memory T cells in IL-15, a saturated solution. In saturated environments might be expected, if the equation. 11 were correct description we see the proliferation rate of the population level. Instead of the population was observed twice in less than three days, excluding the equation. 11, is really a model. From this we conclude that IL-15 not only inhibit apoptosis. Next we consider the stimulation of division by IL-15, described by the equation, and increasing growth. Another experiment Judge et al. Memory T cells in IL-15 in mice. In the absence of IL-15 and stimulating antigen, Equation 12 predicts the collapse of the number of cells with speed. Observed decline was approximately 2 weeks
according to the model. This means that in first approximation, IL-15 stimulates the division. We can compare the homeostasis is expressed in the formula. 12 of our general model to obtain the asymptotic limit of the suppression that separates from the suppression of proliferation described by the equation. 6. Our previous requirement that requires that
also generally reduced. Physically, this corresponds to concentrations >> << be less than a few cells are competing for it. This gives us (in formula 6). Conditions for the suppression. Physically, this corresponds to cells that can support the number of antigenic stimulation alone (characterized by large
) and do not require homeostatic signals for survival. The condition for suppression autoreaktivnyh cells, and requires that. This asymptote is drawn explicitly >> << and occurs in areas. .
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