CD8 T cells in a culture are analyzed for their ability to produce the cytokine IFN-g, and the numbers of IFN-g-producing CD8 T cells are quantified. As a control, T cells are also stimulated with an irrelevant non-viral peptide (ova) plus dendritic cells. The results are shown in the figure below. Why is the T cell response different between the two lymph node populations?

picture 1 shows the directed migration of two immune cell types, neutrophils (red) and macrophages (green) to a laser-induced injury in the ear of a mouse. As you can observe from the video, there are three stages to this process: 1) an initial phase characterized by fast recruitment of neutrophils (red) to the site of injury followed by 2) the slower recruitment of macrophages after which 3) the interaction between both cell types is stabilized. Recruitment to the injury site is mediated by leukotriene B4 (LTB4), a potent immune signaling molecule (Figure 1A). LTB4 binds to BLT1, a G-protein coupled receptor (GPCR), activating various signaling pathways and resulting in immune cell migration to the site of injury (Figure 1B). With this background information and your knowledge of cell and molecular biology, describe in detail in your own words, as many molecular processes as you can identify that must take place for the cell migration process depicted in the video to be achieved. For…

If the thymus of an adult experimental animal is removed, the following observations can be made: (a) No immediate effect occurs, and (b) after 1 year, decreases occur in the number of lymphocytes in the blood, the ability to reject grafts, and the ability to produce antibodies. Explain these observations.

What is the function of tapasin? Select one: a. Tapasin is an antagonist of HLA-DM and causes more significant increases in MHC class I than MHC class II on the cell surface. b. Tapasin is a lectin that binds to sugar residues on MHC class I molecules, T-cell receptors, and immunoglobulins and retains them in the ER until their subunits have adopted the correct conformation. c. Tapasin is a thiol-reductase that protects the disulfide bonds of MHC class I molecules. d. Tapasin participates in peptide editing by trimming the amino terminus of peptides to ensure that the fit between peptide and MHC class II molecules is appropriate. e. Tapasin is a bridging protein that binds to both TAP and MHC class I molecules and facilitates the selection of peptides that bind tightly to MHC class I molecules.

These red blood cells (black arrows) indicated which of the following components of B cell activation Choose one from the following:   (A) neutralization (B) opsonization (C) agglutination (D) cell lysis

B cell receptor diversity is behind our ability to fight new infections. However, epitope-specific B Cell memory is critical for the secondary immune response protecting against new infections. You are ready to integrate concepts. In this question, you will combine B Cell receptor diversity and cloning! Please answer each question in less than 150 characters (including spaces). 1.Can a mature B Cell produce an epitope-specific antibody first and then switch to make an antibody against a different epitope? Explain.   2.Please describe what is transferred into an egg during cloning by somatic nuclear cell transfer.   3.How many B Cell receptors/antibodies could be generated in a mouse cloned by somatic nuclear cell transfer from a mature B Cell (after recombination)?

About Antigen presenting cells, it is CORRECT to affirm that: a). Macrophages, B lymphocytes and dendritic cells are APCs. meaning they express MHC-ll. b). Only APCs present MHC-11. c). Macrophages,B lymphocytes and dendritic cells are phagocytes, but not APCs.d). All the non-APC cells of our body present MHC-1.

In a mixed lymphocyte reaction, T cells from individual A make a robust response to antigen-presenting-cells from individual B, as long as the two individuals express different alleles of MHC molecules. Estimates indicate that up to 10% of the T cells from individual A may contribute to this response. If one performed this assay using responder T cells from a child and antigen-presenting cells from one parent, the result would be:          A massive proliferative response made by the antigen-presenting cells of the parent A very weak response by the child’s T cells, involving only 0.1% of their T cells The complete absence of any proliferative response by the child’s T cells A robust cytolytic response that kills all of the parent’s antigen-presenting cells A robust response by the child’s T cells

In the secondary response, the IgG levels rise much faster than they did during the first antibody response. Why is this?Choose one: A.  The plasma cells that were produced for the first response have a very long half-life, so they are able to produce antibodies for the second response without activation of other B cells. B.  Memory B cells are capable of producing antibodies directly, so there is no need to spend time differentiating them into plasma cells. C.  By the secondary response, there are B cells and T cells that have differentiated into plasma cells, giving more total plasma cells to work with. D.  Memory B cells are present for the secondary response. Those cells are much easier to activate than the naive B cells; therefore, the response occurs much more quickly and on a larger scale.

True or False Can cytotoxic T cells have the ability to identify class 1 MHCs or do they recognize the antigen? B cells are what cause cellular immunity?