Class Notes (786,168)
Canada (482,024)
Biology (512)
BLG 307 (38)
Clare Chua (38)
Lecture

genetically hardwired germline
genetically hardwired germline

6 Pages
105 Views
Unlock Document

School
Ryerson University
Department
Biology
Course
BLG 307
Professor
Clare Chua
Semester
Fall

Description
ANTIBODY STRUCTURE AND FUNCTION INNATE ADAPTIVE IMMUNITY genetically hardwired plastic – involves shuffling DNA germline evolution somatic stereotypic response varied primary defense delayed BUT efficient Innate immunity cannot protect against bacterial evasion mechanisms (capsulation) innate only recognizes features common (LPS) to certain pathogens Innate response is essential for adaptive response MAJOR PLAYERS B Cells – differentiate and cab secrete antibodies secreted antigen receptor = antibody membrane bound are involved in B cell differentiation to PLASMA cells (T cells also help mediate differentiation) secreted antibodies - neutralization (toxins/viruses) - OPSONIZATION (promotes phagocytosis upon pathogen binding) - COMPLEMENT assistance (leads to pore formation in pathogen) T cells – recognize antigens presented of SURFACE of infected cells CLONAL SELECTION THEORY 1. B cells generate antibody diversity AT RANDOM 2. an antigen encounter leads to PROLIFERATION AND DIFFERENTIATION 3. progeny have IDENTICAL antigen recognition 4. self-responsive antibodies are deleted (TOLERANCE) LAG period between encounter and primary response proliferation takes time memory cells are produced which mediate secondary response more cells that recognize antigen to start with  heightened response STRUCTURE – (IgG) PAPAIN cleavage – 3 fragments 2 identical Fab’s 1 Fc PEPSIN cleavage – 1 fragment (Fab ) 2 Heterogeneous response to infection – “polyclonal” MYELOMA’s – huge homogeneous production of antibodies; “monoclonal” Hybridomas – fuse antibody producing B cells (from spleen) to myelomas can screen for desired antibodies led to antibody AA sequencing SECONDARY STRUCTURE “beads on a string” every chain divided into 100 AA domains (V = variable; C = constant) V – binds antigen C – invariant among antibody class effector role light chain – 2 domains (1V, 1C) heavy chain – 4 domains (1V, 3C) “superdomain” = overlap of heavy and light variable chains heavy and light chains stitched together by sulfhidryl linkages flexible hinge/elbow proven by DNP/EM studies hinge – 180 degrees flexion/ 180 rotation (between C1 and C2) elbow – 50 flesion/ 0 rotation (between V and C1) **increases antigen recognition variablity** ANTIBODY CLASSES (5) all have same basic building plan as IgG but are distinguishable ONLY by heavy chains IgG = gamma IgA = alpha IgM = mu IgD = delta (most abundant on cell surface, but FUNCTION UNKNOWN) IgE = epsilon (involved in allergic response) each can ass
More Less

Related notes for BLG 307

Log In


OR

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


OR

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.

Submit