T Cell Development

Question 1

T cell The development

Answer 1

Pluripotential stem cell
lymphoid committed stem cell (CALLA)
Pre T cell (CD 2,3)
Pre cortical T cell CD 1 2 3
Cortical T cell CD 2348
Medullary T cell CD 2,3 4/8
Circulating virgin T cell
Small non cleaved T cell
Large non cleaved T cell
T immunoblast

Question 2

T-cells are derived from ______ cells often simply called pre-T-cells

Answer 2

pre-thymic cells

Question 3

The pre cortical T-cell is often identified by its expression of CD1 antigen. All T-cells form Pre T cell express CD2 and CD3

The cortical T-cells lose the expression of ____ antigen. So, they become ____negative.

Answer 3

CD1

Question 4

As they lose this expression and retain that of CD2 and CD3, they gain the expression of other CD antigens such as_____.

Thus, the cortical T-cells are?

Answer 4

CD4 and CD8

CD1-, CD4+, CD8+, and CD2+ and CD3+

Question 5

In addition to expressing these cluster of differentiation antigens, the cortical cells also express.

Answer 5

T-cell receptors

Question 6

CD1 antigen is _______ T-cell specific.

Answer 6

Pre cortical T cell

Question 7

The medullary T-cells are of two major types: CD4+/CD8- and CD4-/CD8+.

Those that are CD8+/CD4- are

The CD4+/CD8- cells are referred to as

Answer 7

Cytotoxic T cell 94/95% of T Cells

Helper T cells

Question 8

There are three other subtypes of T-cells that could form in small proportion in circulation:

Answer 8

• T-delay-hypersensitivity cells
• T-suppressor cells
• T-natural killer cells

Question 9

The difference between the surface membrane immunoglobulin and T-cell receptor is that whereas the surface membrane immunoglobulin can identify antigens expressed on microbial agent or any foreign antigen, the T-cell receptor can identify antigens that are complexed with MHC antigens. (HLA antigens are capable of complexing other antigens.)
Only antigens complexed with HLA antigens are recognized by T-cells receptors. We say that T-cell receptors is MHC antigen restricted.

Question 10

The T cell mediates

Answer 10

Cellular immunity
By this we mean a T cell identifies a pathological cell and delivers cytolytic kill and the T cell exacted the kill

Question 11

How does T cell escape the kill

Answer 11

Presence of CALCIRETICULIN
able to neutralize it’s cytolytic proteins

Question 12

T cells cytolytic proteins are

Answer 12

Perforins
Caspaces

Question 13

How does the T cell identify neo antigen on pathological cell

Answer 13

T cell receptor TCR

Question 14

T cell receptor is the equivalence of

Answer 14

Surface membrane immunoglobulin

Question 15

After antigenic stimulation what does the virgin T cell do

Answer 15

Travels to PARACORTEX of follicle of lymph node

To become
Small non cleaved
Large non cleaved
T immunoblast

Question 16

The T immunoblast doesn’t mature what does it do instead?

Answer 16

The T immunoblast it accumulates effector molecules with which it is able to implement cytolytic function

Question 17

Memory T cell

Answer 17

Virgin T cell that had previously undergo maturation to T immunoblast

T immunoblast can also undergo reversal of maturation to look like original virgin T cell from which it was derived.

Question 18

Function of T delayed hypersensitivity cell

Answer 18

Gives helper signals to macrophages to support or enhance micro phage functions against chronic bacteria & fungal illnesses

Question 19

T suppressor cells

Answer 19

Exist to limit immune hypersensitivity.

Question 20

Individuals deficient in T suppressor tend to have

With example

Answer 20

Excessive immune reactions or auto immune diseases eg SLE

Systemic Lupus Erythromatosis

Question 21

T Natural killer cells

Answer 21

Immunity against development of cancers

Callable if identifying neo antigens in cells undergoing mitotic changes and deliver cytolytic kill

Question 22

CD 8+ cells

Answer 22

Aka cytotoxic T cell

cells given by nature as a major defence against viral infections
Cells in the human bodythat are infected by the viruses are identified and cytolytic kill

Question 23

CD4 + cell aka
Function

Answer 23

They help other immune cells to function properly.

Offer helper functions to B cell, macrophages, CTL, T suppressor cell, TDHS, T NK cell

In it’s absence or deficiency no other immune cell functions properly

Question 24

CD4+ cell are

Answer 24

The pivotal cell of immunity

Question 25

Types of t helper cell and their functions

Answer 25

TH1: effector cell able to cytolyze other cells

TH2 : T regulatory cells (pivotal)

TH17
(Produces cytokine: interleukine 17)

Question 26

Connection between HIV & T helper cell

Answer 26

T-helper cells all express :CD4 molecule: This molecule is the receptor which:HIV uses to infect human cell.

Any human.cell expressing CD 4 molecule uses its membrane Glycoprotein 120 to interact with the CD4 molecule such that the virus becomes anchored to the molecule membrane.

The virus is also able to fuse its own membrane with that of the CD4+ cell such that it becomes internalized into the cytoplasm of CD 4 positive cell by well understood mechanisms

Question 27

Hiv eliminates T helper cells removing the pivotal cell of immunity such that the individual is now at a risk it

Answer 27

Chronic bacterial infection
Chronic fungal
Acute bacterial
Development of cancer

Question 28

List and explain 4 goals of Antiretroval therapy

Answer 28

1. Virologist goal
2. Immunological goal
3. Clinical goal
4. Epidemiological goal

Question 29

Virologic goal

Answer 29

Virus becomes undetectable in blood

Question 30

Immune reconstruction

Answer 30

Cytopathic effects of virus on CD4+ T cell is lifted.
Bone marrow can form new ones

Question 31

Clinical goal

Answer 31

Cessation of development of opportunistic illnesses

After immunity is reconstituted, increased disposition to bacteria fungal and cancer is lifted.

Question 32

Epidemiological goal

Answer 32

The individual with HIV becomes in infectious to sex partners
For every 1 individual that is on effective antiretroviral therapy, 5-10 new infections have been prevented in general populace