AIDS CURED WITH NO MEDICAL INTERVENTION

People with AIDS are getting cured with no medical intervention

People with AIDS are getting cured with no medical intervention

Outline

What kind of virus causes HIV

Name at least 2 characteristics of this virus

What is the mechanism used by this virus to cause the disease?

Experiment

Concluding remarks

What kind of virus causes HIV?

AIDS is characterized by a gradual depletion of CD4+ T cells from the blood, which correlates with declining immunocompetency. The mechanism of CD4+ cell loss, however, is still not clear. Some proposed mechanisms focus on the CD4+ cells that replicate HIV, and include: (1) direct virus-mediated cell lysis; (2) cellular or humoral virus-specific immune killing of productively infected cells ; (3) viral induction of apoptosis upon replication in cells ; or (4) induction of apoptosis in productively infected cells following signaling by certain receptors (for example, TCR and CD4) . These mechanisms do not reconcile a major enigma in the current understanding of HIV pathogenesis: the clear data showing that, in vivo, very few cells (approximately 1 in 100 000) produce virus at any given time. It is unlikely that removal of productively infected cells would report for any significant loss of CD4+ T cells.

Name at least 2 characteristics of this virus

Other theories to explain how HIV depletes CD4+ T cells focus on the killing of uninfected cells, and include: (1) 'kiss of death' (membrane fusion) of uninfected 'bystander' cells upon contacting productively infected cells; (2) autoimmune killing of uninfected cells ; (3) HIV superantigen-mediated deletion of certain T-cell subpopulations , and (4) induction of apoptosis in bystander cells by HIV proteins ( Tat, gp120) released from productively infected cells. These theories try to interpret the outcome that bystander cells not making virus are the predominant cells shown to be staining in the lymph nodes of patients, and they are undergoing apoptosis. Many of these ideas have not been sustained by in vivo data. Fusion of uninfected with infected cells does not occur in untransformed primary lymphocytes, and lymphoid syncitia are rarely observed in HIV-infected individuals B.F. Burns et al., The diverse histopathology of lymphadenopathy in the homosexual male.

Experiment

This section shows h HIV -1 viral load control

ow to develop a control law for the system linearized by feedback. This is done both under the hypothesis of flawless (in the first stage) and partial information of the scheme parameters.

Control with known parameters

Assume that the concentration of infected cells x2 is to be driven to a reference value r and kept there. At the equilibrium defined by x2=r one has by equating the derivatives to zero in andIn terms of the linearized system (that operates with transformed variables) this results in the equilibrium point z=S(x), i.e.:It is then possible to design a LQ controller, using the linearized dynamics, that keeps the system at the desired reference value r.

The transformation T(r) allows to compute the equilibrium point in terms of the variables (z1,z2). The controller is designed by minimizing the quadratic cost:where Qz and ? adjust ...