Sensibility of the quorum growth thresholds controlling local immune responses

2007/Jul/02 Sensibility of quorum growth thresholds controlling local immune responses – p. 2007/Jul/02 Sensibility of quorum growth thresholds controlling local immune responses – p. 2/36 Motivation 2007/Jul/02 Sensibility of quorum growth thresholds controlling local immune responses – p. 3/36 Immune system Leukocytes (white blood cells) circulate in the blood Leukocytes are produced in the bone marrow. Red and white blood cells Bone marrow 2007/Jul/02 Sensibility of quorum growth thresholds controlling local immune responses – p. 4/36 Lymphocytes Leukocytes are part of the immune system and help defend the body against infectious diseases and foreign materials. Lymphocytes are one kind of leukocytes. Bone marrow 2007/Jul/02 Sensibility of quorum growth thresholds controlling local immune responses – p. 5/36 T cells T cells are one group of lymphocytes that matures in the thymus. In the presence of pathogens, T cells target the invader and secrete cytokines. Thymus 2007/Jul/02 Sensibility of quorum growth thresholds controlling local immune responses – p. 6/36 T cells T cells proliferate with IL-2 cytokines. A quorum population size of T cells (threshold) is needed to develop an immune response. Autoimmunity arises when T cells target self antigens. 2007/Jul/02 Sensibility of quorum growth thresholds controlling local immune responses – p. 7/36 Tregs Regulatory T cells (Tregs) are one subset of T cells. Tregs protect the tissues by limiting immune responses. Misregulation of Tregs can provoke autoimmunity. Proliferation by a secreted cytokine is quorum dependent. Bistability is a common feature of the current Treg models.