stuff 🩷

الكلوب المكسورة هاي ملاحظات الي انتم عايفيها

Tumour cells make B7 attaches to CTLA-4 so the body recognises the tumour cell as ‘self’

CD8 requires activation by T-helper 1 (activating cytokines) In AIDS AIDS attacks CD4+ cells =function of CD8 is defective due to lack of activation by Th1

⭐️ Signal 2 (Co-stimulation) مهم B7 molecule on APC binds to CD28 on T cell. Prevents self-activation and autoimmune disease.

CD4 binds with class II on APC CD8 binds with class I on all nucleated cells EXCEPT sperms

Double positive cells have CD4&CD8 in thymus Travel to secondary lymphoid organs >

naive T cells

Then it learns, matures & transforms to either CD4+(T-helper cell) OR CD8+(Cytotoxic T-cell)

B Lymphocyte acquires IgM in bone marrow then IgM undergoes class switching to turn to IgD Immature B (IgM) Mature B (IgM,IgD)

الملاحظات مهمة

👑 A patient receives his first exposure to an antigen with molecular weight 150,000 Da. Five days later, laboratory analysis shows an antibody with low affinity, strong complement-fixing ability, and very high molecular weight. Which of the following combinations is MOST accurate? 🔹A) IgG — monomer — crosses placenta — secondary response 🔹B) IgA — dimer — mucosal immunity — high affinity 🔹C) IgM — pentamer — primary response — 900,000 Da 🔹D) IgE — monomer — binds mast cells — 0.002% serum Ig 🔹E) IgD — monomer — B-cell receptor — secondary response

⭐️ النسب بما انو دكاترتنا طلعوا يحبون الارقام 🤨 B lymphocytes = 15–35% of total lymphocytes IgG = 75% of serum IgM = 10% of serum IgE = 0.002% of serum IgG subclasses: -IgG1 = 65% -IgG2 = 32% -IgG3 = 8% -IgG4 = 4% -IgG = 150,000 Da (low molecular weight) -IgM = 900,000 Da (heavy molecular weight)

Immunogen >100,000 Da = potent immunogen Immunogen <10,000 Da = weak immunogen

👑 A 16-year-old boy with severe atopic dermatitis and recurrent allergic rhinitis has markedly elevated serum levels of an immunoglobulin that binds with high affinity to Fc receptors on mast cells and basophils. Which of the following cytokine patterns is MOST directly responsible for increased production of this immunoglobulin? 🔹A) IFN-γ and IL-2 🔹B) IL-12 and TNF-α 🔹C) IL-4 and IL-5 🔹D) TGF-β and IL-1

🔹IgM has TWO forms: 1-Monomeric IgM •Present on B lymphocyte surface as antigen receptor with IgD 2-Pentameric IgM •Composed of 5 monomers •Connected by J chain that is produced by plasma cells

⭐️ IgA Note 🔹Serum IgA: ➡️ Monomeric 🔹Mucosal/secretory IgA: ➡️ Dimeric 🔹Two IgA molecules join by: ➡️ J chain 🔹Dimeric IgA binds: ➡️ Poly-Ig receptor on epithelial cells 🔹After transport through epithelium: ➡️ Gains secretory component “Blood IgA = single Secretions IgA = double.”

هذا ملاحظة من الدكتورة محاضرة 2

👑 A 19-year-old patient with selective deficiency of an IgG subclass presents with recurrent pyogenic infections. Laboratory evaluation shows that the deficient subclass normally constitutes only a very small percentage of total IgG and is unique because it does not activate the classical complement pathway. Which of the following subclasses is deficient? 🔹A) IgG1 🔹B) IgG2 🔹C) IgG3 🔹D) IgG4

يله خلص العيد تونستوا اخذتوا عيديات هسه حدز بعد 😎