Bio 312 Immunology Final F16

al. in 2004 heavily leans on the feedback inhibition model as the major contributor to allelic exclusion in B cells. They studied the effect of phospholipase Cγ1 (PLCγ1), which is expressed throughout B cell development and plays a role in pre-B-cell receptor signaling. When there is reduced expression of PLCγ1 there is impeded early B cell development at the pro-B to pre-B cell transition (Wen et. al., 2004). They also found that Ig heavy chain allelic exclusion was impaired, thus causing defective pre-BCR signaling (Wen et. al., 2004). Rearranged light chains combine with the previously rearranged heavy chain to generate surface IgMs to form the B-cell receptor. This B cell receptor changes the progenitor cell to an immature B

Newly generated lymphocytes, including T-cells and B-cells, will leave their central lymphoid organs where they developed, and will migrate to the peripheral lymphoid tissues, where some further maturation will occur. Mature lymphocytes continually recirculate between the blood and peripheral lymphoid tissues. Thus, high concentrations of lymphocytes can be

This causes the genomic instability. When both arms are exchanged it causes bcl2 to be overexpressed due to the reading frame being under the control of the promoter. The overexpression of bcl-2 occurs in the B-celll lymphoma cells. Cancer cells want an increase in bcl-2 to allow to keep proliferating and evade apoptosis.

An automated analyzer can be used to determine the number of blood cells, and the type of these blood cells, using a method called flow cytometer.

ii. Because these changes are small (usually arise from point mutations) there will still be come cross-reaction with antibodies and T cells produced to the previous variant- provides some level of protection.

patient; these cells are called autologous cells since they come directly from the patient. Cells

The control to quantify the JAK2 expression after transducing CD34+ progenitor cells is the lentiviral vector backbone, which is involved in the lentiviral JAK2 transduction into the human JAK2-GFP in normal CD34+ progenitors. Fluorescence measurement is compared between CD34+ cord blood cells transduced with lentiviral vector backbone and the normal CD34+ cells, in order to examine the transduction efficiency. JAK2 expression of unaffected genes without the transgene is observed, acting as a comparison to the overexpression JAK2 in the transduced CD34+ progenitor cells (1).

In this model, the proteins are characterized into two categories, activators and sensitizers. BIM is an activator that will bind directly to BAX and BAK unless it is sequestered by a pro-survival protein. On the other hand BAD is a sensitizer that displaces the BH3 activators from the pro-survival proteins (17). BH3-only proteins translocate to the mitochondria and bind to other mitochondrial proteins. BAX and BAK are located on the mitochondrial membrane where they undergo conformational changes and oligomerize (24, 30). After this process, BAX and BAK mitochondrial pore formation causes apoptogenic proteins to be released from the mitochondria. BAX-BAK oligomerization can be inhibited by pro-survival proteins like Bcl-2 and Bcl-xL resulting in the inhibition of apoptosis (30, 40, and 44). Pro-survival and pro-apoptotic proteins are competing with each other in order to turn on cell survival or apoptosis, respectively. There are many steps and proteins that are associated with apoptosis. During early apoptosis BIM dissociates from its microtubule complex, translocates to the mitochondria and aids in the release of cytochrome c (33). BIM however, if phosphorylated at serine 69 by ERK, will be targeted for degradation by the proteasome (27). BAD dephosphorylates and inactivates the pro-survival proteins Bcl-2 and Bcl-xL which are bound to BAX on the surface of the

Lymphocytes, one of the main types of cell in the immune system, take part in the function of the immune system. They are made from stem cells in the bone marrow. After the lymphocytes are developed they undergo a second stage. The second stage of development is when they gain their antigen-specific receptors. The many functions of the lymphocyte allows them to respond to invaders in the body, also known as antigens. Lymphocytes destroy antigens in order to avoid infection. Lymphocytes may work with other cells or they might work alone.

So what exactly is causing the cells to not properly divide and die? Well the cells center, the nucleus, is responsible for commanding the cells functions, but it doesn’t always send the right orders. So the question know becomes, why doesn’t the nucleus send the right commands?

Cells are very vast complicated organisms. During their reproduction they undergo a series of steps in order to multiply. This cycle is what allows more cells to be made. The cycle includes G1, S, G2, Mitosis, and Cytokinesis. Multiple things happen in Mitosis that allows cells to split. These specific sub units are known as Prophase, Prometaphase, Metaphase, Anaphase, and Telephase, also known as PMAT. Cells communicate by using chemical signals, which are composed of molecules and proteins. This material is transferred over through gap junctions between cells. There are several different types of signaling such as Paracrine, Synaptic, Endocrine, and signaling by direct contact. Cells use these cycles and signals to perform their proper functions

B-cell tolerance is developed at multiple checkpoints throughout B cell development, both in the bone marrow (BM) and the periphery. In BM, the immature B lymphocytes that recognize self antigens with high affinity, a strong BCR signal, are either passively deleted or their specificity

At the pre-B cell stage, central tolerance mechanism occurs. B cells that bind strongly to self-antigen are removed through apoptosis or B-cell receptor rearrangement. Other cells that bind weakly to self-antigen are became anergy or may go to peritoneal cavity (55, 56). This immature transitional B cells migrate to periphery to complete the maturation process, particularly in the spleen (57, 58).

Adult stem cells are found in various places throughout the body. Adult stem cells will begin to divide once exposed to disease or muscle injury. These cells have been used for many years now, from stem cells that were found in bone marrow. Scientists first found that two kinds of stem cells existed in bone marrow. The first type, called hematopoietic stem cells, are able to differentiate to different types of blood

Introduction : B lymphocytes are the effectors of humoral immunity and provides defense against pathogens by producing antibody. B cells constitute approximately 15% of peripheral blood leukocytes and arise from progenitors and precursors in the bone marrow. B lymphocytes undergo random immunoglobulin variable gene rearrangements at the heavy and light chain loci. These chains pair with the Igα and Igβ polypeptides to form the mature B-cell receptor which is then transported onto the cell surface where it can bind antigen and signal inside the cell. Different populations of B cells result in pre immune pools where each cell in these quiescent populations expresses a B cell antigen receptor with a unique specificity. The BCRs come in contact with their specific antigen and generate several intracellular signals are which leads activation, differentiation, and formation of plasma cells and memory B cells. This process mediates the response to subsequent antigen challenges. B lymphocytes play an essential role by not only producing antibodies but also functioning as antigen-presenting cells and certain B cells can also negatively regulate the immune response by producing regulatory cytokines and directly interacting with pathogenic T cells via cell to cell contact. Newly generated immature B cells are selected to enter the peripheral mature B-cell pool only if they do