PMI 126 - Lecture 6

PMI 126 - Lecture 6 - PMI 126 Lecture 5(end of midterm I...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
PMI 126 – Lecture 5 (end of midterm I) the building block for specificity of T and B cell are in the germ-line tremendous processes occur at DNA level to creates various receptors that are specific for certain antigen. The genes that are actually exist in T and B cells are not in the germ-line. o They are brought together randomly. o Those genes are not found in one pieces, unlike the gene encoding the pattern-recognition receptors. Antigen vs. Immunogen Antigen : ( refers to anything that T cell receptor or B cell receptor can bind ) - all antigens are not immunogens - receptors (antibodies and T cell receptors (TCR) of the adaptive immune response can specifically bind antigen - Antigenic determinant (epitope): the part of the antigen to which antibody/TCR actually binds o There are lots of epitope on the “single” foreign protein o Only antibody that binds to certain epitope will be neutralizing the ability of the virus get into the cell Immunogen: - all immunogens are antigens - it’s an antigen that can actually induce an adaptive immune response - what make a good immunogen? 1. foreignness (more foreign, the better immunogen) 2. Molecular size (> 100000 Kd ) 3. Chemical composition and complexity (more complex in structure/amino acid stand point, the better immunogen) (proteins probably the best immunogen around) 4. Susceptible to antigen processing and presentation (T cells only recognize “ processed ” antigen with MHC protein) Example: TB skin test - being infected/vaccinated = mount the immune response and generate the memory - when we take PPD (purified protein derivates) = piece of cell wall of the bacteria put on the skin o if you have been infected/vaccinated, you have memory cells specific for that proteins o memory cells migrate to the area where the piece of bacteria located. Memory cells can recognize it and bind to it. But it DOES NOT induce an immune response. PPD is NOT an immunogen. As a part of the bacteria, it can mount the immune response. However, it does NOT induce immune response (not immunogenic) when it’s by itself. Thus, PPD is the antigen that component of the immune system can recognize it without inducing the immune response. Improving Immunogenicity – Adjuvants
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 4

PMI 126 - Lecture 6 - PMI 126 Lecture 5(end of midterm I...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online