Immunology Notes

3 Pages
Unlock Document

Western University
Microbiology and Immunology
Microbiology and Immunology 3300B
Rodney Dekoter

Immunology NotesOct 1312 The Fab region of B cell receptorantibody is similar to T cell receptor The TCR is a disulphide linked heterodimer with a variable and constant region The variable region like B cells recognizes antigen but there is only one type of receptor on T cells It is made ofandchains connected by a disulphide bond Both chains have carbohydrate side chains attached to each domain Coreceptors must be used to signal TCRs to the cell TCR antigen recognition T cells via T cell receptors only recognize foreign antigens displayed on the surface of the bodys own cells Antigen is displayed as peptide fragments bound to MHC molecules Peptides can stimulate T cells only when bound by MHC and this phenomenon is called MHC restriction the way T cells recognize antigen is limited Different MHC molecules encoded by different genes as well as by different alleles of genes have specific differences in what subset of peptides they are able to present to T cells MHC restriction TCR can only recognize a certain peptide if its presented on a certain MHC molecule If the same peptide is presented on a different MHC TCR wont recognize it If the MHC molecule is bound to a different peptide TCR wont recognize it The structures of class I and II MHC molecules are similar but different MHC molecules have a peptidebinding cleft Class I is a heterodimer with threedomains and one 2microglobulin domain The 3 domain spans the membrane The peptidebinding cleft is made of twohelices that are joined together Class II contains two chains The 2 and 2 domains span the membrane The 1 and 1 domains form the peptidebinding cleft but these two domains are not joined by a covalent bond The cleft is bigger than class I and it is open at both ends The endogenous pathway of peptide processing and presentation Class I and class II MHC proteins differ in their expression patternNearly all cells in the body express class I proteins facilitates self vs nonsel
More Less

Related notes for Microbiology and Immunology 3300B

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.