T cells

Question 1

Antigen presenting cells (APC)

Answer 1

Dendritic cells
B cells (antibody and APC)
Selected Macrophages
Monocytes
Keratinocytes

Question 2

How are MHC (major histocompatibility complex) proteins (antigens) coded

Answer 2

by a number of genes located as a cluster on a part of a chromosome

Question 3

3 types of MHC proteins or antigens

Answer 3

Class I-all nucleated cells (avian RBC)
Class II-present on selected cells
Call III-complement components and sex limited proteins

Question 4

Class I antigens

Answer 4

Cytotoxic T cells recognize abnormal targert calls via class I antigens which becomes associated with foreign antigens

Question 5

If MHC antigen is increased/decreased

Answer 5

Immune response with increase/decrease respectively

Question 6

MHC

Answer 6

complex is inherited as a block
Proteins have a highest rate of mutation
proteins bind to processed antigenic peptides

Question 7

How are antigens presented to T cells

Answer 7

Antigens taken in by antigen presenting cells(APC) are chopped into small pieces and presented on their surface by MHC proteins to T cells

Question 8

Types of Antigens

Answer 8

EXogenous (coming into the body EXternally)
ENdogenous (IN the body)

Question 9

Processing and presentation of Exogenous Antigens

Answer 9

Antigen appears
Antigen chopped to peptide level
Peptide binds to MHC class II
Back to cell membrane to be displaced
Exogenous antigens associate with MHC class II

Question 10

Processing and presentation of Endogenous antigens

Answer 10

processed endogenous antigens associate with MHC class I

Question 11

Lymphocyte structure

Answer 11

Located in the blood, lymph and lymphoid tissue
5-15 micrometers in diameter
most of the cell contains nucleus (thin rim of cytoplasm containing free ribosomes, mitochondria)

Question 12

Specific Immunity involves

Answer 12

T and B lymphocytes

Question 13

T lymphocytes

Answer 13

CD4 and CD8

Question 14

T cell surface markers

Answer 14

T cell receptor (antigen recognition, alphabeta and gammabeta)
CD3 (Signal transduction)
CD4 (Helper) or CD8 (cytotoxic)
CD28 (co-stimulatory molecule)
CD40L (co-stimulatory molecule)
Cytokine receptor (IL-2, INF gamma)

Question 15

T cell selection

Answer 15

majority of developing T cells die within the thymus. Only those cells that are competent leave the thymus. Cells that die include defective cells, cell that react with self-antigens(negative selection). Most emigrated T cells (positive selection)

Question 16

Cortex

Answer 16

most immature immigrants from bone marrow-95% die

Question 17

Medulla

Answer 17

Mature thymocytes ready to exit thymus or T cell

Question 18

Immature cells

Answer 18

lack CD4 or CD8
double positive
CD4+CD8+

Question 19

Mature cells

Answer 19

CD4+CD8- (helper)
CD4-CD8+ (cytotoxic)

Question 20

Types of CD4+ (T helper)(Th)

Answer 20

Th-1
Th-2
Th-17
Treg

Question 21

Th-1

Answer 21

Participates in delayed types hypersensitivity (DTH)
TH-1 cells primarily secrete IFN-gamma and IL-2
immunity against INTRAcellular pathogen
(antibody can not penetrate a cell)

Question 22

Th-2

Answer 22

Help other cells (B or T cells) by secreting interleukin
Th-2 cells primarily secrete IL-4, IL-6, and IL-10
IL-4 attract B cells and make alot of antibodies outside the cell

Question 23

Th-17

Answer 23

regulation of inflammatory response
Th-17 cells primarily secrete IL-17, IL-22 and TNF-alpha
pro inflammatory cytokine

Question 24

Treg

Answer 24

Regulation of immune response by suppressing it
Primarily secrete TGFbeta
ability to interact with all cells
bring back to homeostasis