Question

Immunology

Question 2

A. Where does MHCII loading of peptides occur (A) and what two regulatory members of the MHC gene family (B) control the loading of peptides in MHCII molecules?

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B. (1 pts) What protein is involved in making sure MHCII is properly folded and also prevents premature loading of peptides in MHCII molecules?                         .

C. (1pt)What cells present antigens to Th2 cells?                                                    .

D. What ER protein facilitates peptide loading , keeps MHCI in the ER until peptides are loaded and forms a bridge between MHCI and TAP during peptide loading?

Answer 1

A. MHC class II molecules (major histocompatibility complex) found only on APC like dendritic cells, mononuclear phagocytes, and B cells. This is responsible for initiating immune responses. phagocytosis is responsible for the Loading of an MHC class II molecule; extracellular antigen are endocytosed and get digested by lysosomes, and the resulting fragments of epitopic peptides are loaded onto MHC class II molecules and through outside by cell surface through exocytosis. In humans, there is a human leukocyte antigen gene complex (HLA) available to encoded the MHC class II protein complex.

B. APC, some chaperons and protein-disulfide isomerase (PDI) family responsible. the invariant chain prevents premature occupation of the peptide-binding pocket by self-peptides. chaperone of MHC class II preventing peptide loading in the ER.

C. Dendritic cells, macrophages, and B cells are the type of antigen-presenting cells in the case of T cells, whereas follicular dendritic cells are the main antigen-presenting cells in the case of B cells. these cells are responsible to present antigens.

D.

Rotein Peptide ო MHC class I Iroteasome Peptides secretory treside Colg? fructeus) ER teneo Plasma retilectant

complex 2 Меје histocompatiblity 19 tuloy mouth INT >92 Regulatory generaf MAC gene family s ☺ genetic becombinatiên lo Linkage disquill boium (6) APC polygenic 1 viral Interference Cunetic cytokine Regulatory signeling Component IFNA, TMF IFNY CITAREX transactivator 2 Decreared hate of bensoribling CD ut T cell recognise pepticle present on APC Transport cepands on type o ronsmembrane! Invarient chain wil which is bined by the help of CLIP Inducible Promoter control expression of I and pousentation CLIP releene due to catalytic action releene of HLA CLIR endasomal phagosomal dystemact vak