Unit 5 Part 2 Flashcards
the lymphoid system includes (5)
lymphocytes, lymphatic vessels, lymph nodules, primary and secondary lymphoid organs
name 3 lymphocytes
T cells, B cells and NK cells
eg of secondary lymphoid organ
spleen and lymph nodes, MALT, GALT
eg of primary lymphoid organs
bone marrow and thymus
lymph nodules can be found
in Peyer’s patch in small intestine and tonsils
what is hemopoietic stem cells
stem cells in adult bone marrow that give rise to immune system cells (also platelets and erythrocytes)
leukocytes are derived from
lymphoid and myeloid lineages
name 2 types of myeloid cells
monocytes/macrophages and granulocytes (BEN)
fn of hemopoietic GF
promote development of stem cells into a specific type of cell
eg of hemopoietic GF
granulocyte macrophage colony stimulating factor G-CSF
describe fn of primary lymphoid organ
site for lymphopoiesis, differentiation of lymphoid stem cells into mature and fnal lymphocytes–> bone marrow, thymus
describe site of secondary lymphoid organ
site where immune response is generated and disseminated. APC, B and T lymphocytes interact w/each other
what is splenomegaly
enlargement of spleen happens during the course of certain infections
differentiation into mature T cells occur under influence of
thymic peptide hormones like thymulin, thymosin, and thymopoeitin
thymic education is a process by which we
select useful thymocytes for maturation (+ive selection) and eliminates autoreactive or harmful thymocytes (-ive selection)
what are thymocytes
developing T cells
what does it mean by +ive selection
can recognize non-self antigen
fn of thymic nurse cells
specialized cells playing imp role in thymic education of developing T cells
CD denotes
Clusters of Differentiation or Cluster designation molecules
Thymocytes and mature T cells display
cell surface markers and CD3 complex
purpose of monoclonal antibodues
identify cell surface molecules on cells since each cluster is specific for particular molecule
Double negative (DN) is
CD4- and CD8- early immature thymocytes
double postive (DP) is
CD4+ or CD8+ developing immature thymocytes
single positive (SP) is
CD4+ CD8- or CD4- CD8+ mature T cells –>move from thymus to 2nd lymphoid organ
CD molecules are involved in
intracellular interaxn (CAM such integrins) and/or cell activation, differentiation or proliferation (receptors for cytokines)
list an application of cell surface markers
identify B and T lymphocytes in patients with lymphoproliferative disorders
what is leukemia
maturation arrest of stem cells or precursor lymphoid cells
name cell surface markers on T cells
CD2 and CD3
what is CD2 responsible for
phenomenon of rosetting with sheep RBC
where is CD2 found on
all thymocytes and mature T cells
where is CD3 found on
DP and SP T cells
what does CD3 form
a stable association w/T cell receptor or TCR to from fnal TCR complex
list the 4 mature T cells
helper T cells, Tc, regulatory, memory T cells
names feature of Th cells
CD4 +ive. have diff profiles of cytokine production and immunological fns. recognize antigen in context of class II MHC as presented by APCs
features of Th1 (4)
produces IL-2, gamma interferon IFNg. activation of cytotoxic T cells, macrophage, inflammatory and delayed hypersenstivity rxns. proinflammatory and cell mediated immunity
features of Th2 (4)
produces IL-4,6 and 10, activation of B cells and regulation of strong antibody (IgG1 and IgE). promotoes humoral immune response
relation of TH1 and TH2
cytokines by both inhibit the axns of each other
describe Th cells in normal pregnancy
Th1 decreases, Th2 increase. reduce CMI and inflammation (enhance fetus survival). increase production of antibodies for placental transfer
describe Th cells in recurrent spontaneous abortion
increased Th1 and decrease Th2
features of cytotoxic T lymphocytes (killer T cells. Tc)
CD8 +ive. kills abnormal cells; cancer, virally infected. principle cells responsible for cell mediated immune response. recognize antigens in context of class I MHC present by abnormal cells
Features of regulatory T cells
CD4 and CD25 +ive. regulation of inflammation and immune response.. supress pathological immune responses
what are memory T cells
T cells that become stimulated by antigen. long term immunity
fn of CD19
signal transduction. found in most stage of B cell developement
where do B cells mature
bone marrow and independent of antigens
the mature B cells cell surface markers (2)
IgM and IgD. act as receptors for specific antigens
mature B cells in response to antigens differentiate to
short lived plasma cells that secrete antibodies and long lived memory B cells
