immunology lec 1 NMU

welcome back

الكروت طول السنه مش هتبقي مفصله اوي وفي نفس الوقت مش موجزه اوي واللي رايح يذاكر المنهج ويحفظه صم قبل ما يفتحها غلطان جداااا لانها بتغني تماما عن خطوه الحفظ هي اصلا طريقه حفظ فا كفايه جداااااا تبقي قاري المحاضره وفاهمها

what are the 2 lines of defense of the immune system

1 innate (non-specific) immunity .

2 adaptive (Specific) immunity.

what progenitors does hematopoietic stem cells give (2) ?

1-common lymphoid progenitor

2-common myeloid progenitor

what type of cells does common lymphoid progenitor gives? (3) تفاصيل بسيطه

1- T lymphocytes:

» T helper cell (Th)

» T cytotoxic (Tc).

» T regulatory cells (T reg):

2- B lymphocytes which give plasma cells that secret antibodies.

3- Natural killer (NK) cells.

what type of cells does common myeloid progenitor gives? (3) من غير تفاصيل

1-Leukocytes

2-Erythrocytes

3-Platelets

what are the types of leukocytes ? (6)

• neutrophils,

• eosinophils,

• basophils,

• monocytes,

• mast cells,

• dendritic cells

what is the site of maturation of lymphocytes

primary lymphoid organs

in what state are lymphocytes released from primary lymphoid organs ?

mention 2 primary lymphoid organs

Lymphocytes are released as {naïve (virgin) and mature} to the blood

.

1- bone marrow

2-thymus gland

where does B,T cells maturation occurs respectively

B cells are maturated in the bone marrow

T cells are maturated in the thymus gland

طبعا الاتنين معمولين في الbone marrow

from where are all the blood cells generated and what is the name of the stem cell they are generated from

bone marrow is the site of generation of all blood cells and they all come from a common stem cell (hematopoiesis)

قايلنها فوق لو فاكر عند كلمه progenitor

selection processes of T cells are ? (2)

قول النوعين واشرح كل واحده

1-Positive selection: cells that are able to recognize and bind to self MHC or to peptide + MHC molecules are selected to grow

2- Negative selection: cells that recognize and efficiently bind self peptides are autoreactive cells and undergo apoptotic cell death because they are harmful to the host (autoreactive).

mention 4 secondary lymphoid organs

1-lymph nodes

2-spleen

3-tonsils

4-peyer’s patches (also act as a secondary aggregates)

اللي بين القوسين غالبا قصده علي الاخيره بس

where does the mature naive (virgin) recognize antigen, and initiate the immune response.

Lymphocytes that have not previously encountered antigen (naive), reach the secondary lymphoid organs via blood and lymphatic vessels بتروح هناك يعني

how can lymphocytes be distinguished?

They can be distinguished by surface proteins; called”CD” (cluster of differentiation) and a number; e.g. CD1, CD2, CD3, CD4, CD8, CD16.

كافي تكون فاهمها دول مجرد امثله

steps of B cells formation and maturation

Stem cell → pre-B cell → immature B cell → mature & naïve B cell (which leave the bone marrow to meet antigen in the secondary lymphoid tissues.)

B,T and natural killer cells percentages respectively

نسبه كل واحد فيهم قد اي من ال lymphocytes

B cells: 10-15%

T cells: 75-80%

natural killers: 10%

what are the phenotype markers of B cells? (5)

– surface immunoglobulins

– CD19, CD21

– class II MHC

– Fc receptors

B cells functions? (4)

1- Antibodies production (humoral immunity)

2- Recognize a wide variety of Antigens, including proteins, polysaccharides, lipids. مهمه فشخ

وافتكر الكلام كمان كارتين

3- Recognize Antigen by Antigen specific receptor; called B cell receptor (BCR)

4- Stimulated by antigen → their proliferation and differentiation into plasma cells which secrete antibodies to eliminate Ag and memory B cells formationnnnnnnnnnnnnnnnnnnnn

T cells phenotype markers? (4)

TCR, CD3, CD4, CD8.

انتبه ان في هنا اتنين

helper / cytotoxic (cytolytic) T cells

بيختلفو في CD واحد

helper T cells functions? (3)

CD marker which is only here is ?

help other cells through secretion of helper factors i.e. cytokines.

• Help B lymphocytes to produce antibodies

• Help macrophage activation to destroy ingested microbes

.

CD4 !!!!

cytotoxic T cells functions? (3)

• Kill virus-infected cells.

• Kill tumor cells.

• Rejection of allografts.

helper T cells subtypes ? (2)

T regulatory cells function ?

T helper Subsets: Th1 & Th2 according to cytokine profile.

T regulatory cells function is to suppress the immune system

type of antigens T lymphocytes recognize?

what is their antigen specific receptor celled ?

and what does it consists of ?

T lymphocytes recognize PROTEIN ANTIGENS ONLY

• They recognize antigen by antigen specific receptors ; called TCR

• TCR: consisting of 2 polypeptide chains, called α and β

how does T cells recognize antigens

مش فاهمها كويس فا اعتقد هضطر ابصمجها لحد ما افهمها وانتو كذلك :D

compare between B and T lymphocytes

متوضح بالتفصيل في الكروت اللي فاتت جرب نفسك هنا

7 نقط في الكومبير

natural killers are

هنقول بعض صفاتها هنزل بالصوره عشان سهله

phenotype markers for Natural killers

CD16, Fc receptor for IgG.

name and describe the two NK cell receptors

how is NK cells activated

functions of NK

Activated by IL-12 (interlukin) لو لغات هتفتكرها

functions:

1–Killing tumor cells.

2–Killing virus-infected cells.

3–Produce IFN-γ which activate macrophages.

4– Antibody-dependent cellular cytotoxicity (ADCC)