BIOL 318 Immunology Lecture 1 (2024)

BIOL 318 Immunology Lecture 1 Lecture by Andrea Verdugo Meza, PhD Candidate in BIMB, MSc, BioEng Email: [email protected] September 4, 2024 Today’s Lecture Syllabus ov...

BIOL 318 Immunology Lecture 1 Lecture by Andrea Verdugo Meza, PhD Candidate in BIMB, MSc, BioEng Email: [email protected] September 4, 2024 Today’s Lecture Syllabus overview Students’ and Instructor’s expectations Learning tools o Canvas o Achieve Introduction to Immunology Syllabus Syllabus Learning goals Syllabus Syllabus Kuby Immunology, 8th, Achieve Syllabus Syllabus For detailed instructions, please check @Canvas BIOL_O 318 > Modules > Achieve Instructions > UBC Achieve_Canvas Integration.pdf Activity time → In groups, please share Name, major and career goal What are you most excited to learn about in this class?  Immunology What is the first thing that comes to your mind? What is this image? Key Words Antigen: any substance (usually foreign) that binds specifically to an antibody or a T-cell receptors; often used as a synonym for immunogen Immunogen: a substance capable of eliciting an immune response. All immunogens are antigens but some antigens are not immunogens Antibody: Y-shaped proteins used by the adaptive immune branch to identify and neutralize foreign objects invaders or cells by recognizing specific antigens. Inflammation: to set on fire Infiltration of leukocytes (white blood cells) from blood to injury Cardinal signs: pain, heat, redness, swelling and loss of function Acute: initial response to harmful stimuli if unchecked: Chronic: prolonged & absence of healing destruction of the tissue  A historical perspective of immunology What is immunity? – protective attempt to remove the stimuli foreign pathogens or substances (antigens) Latin term immunis, meaning “exempt,” is the source of the English word immunity – Observations of immunity go back over 2000 years Thucydides, an ancient historian, wrote in 430 BC of a plague in Athens where those who had recovered could safely nurse the currently ill  Overview of the immune system Purpose: Protection from pathogens Intracellular (viruses, some bacteria and parasites) Extracellular (most bacteria, fungi, and parasites) Eliminate modified or altered “self” Cancer or transformed cells Immune responses are quickly tailored to the type of organism (virus, fungi, parasite or bacteria) involved. Can we generate immunity without inducing disease? Small pox caused by Variola major has a 30% mortality rate but the survivors were ‘immune’. A portion of immunity involves both humoral and cellular components Pasteur showed that vaccination worked but he did not understand how? cells? a soluble agent? A portion of immunity involves both humoral and cellular components Humoral Immunity: combats pathogens via antibodies (Ab) – made by B cells – is named because it involves substances found in the humours (body fluids) – can be transferred between individuals to provide passive immunity Cell-mediated Immunity: mediated by T lymphocytes and innate cells – can eradicate pathogens, clear infected self-cells, or aid other cells in inducing immunity – involves the activation of immune cells that can release of various cytokines in response to an antigen – sentinel innate immune cells of tissues (ie act like guards) Immune responses are tailored to the type of organism involved Pathogens fall into four major categories Viruses Bacteria Fungi Parasites Immune responses depend on the structure of the pathogen and its location, i.e., intra- or extra-cellular Important concepts for understanding the mammalian immune response Immune responses rely on recognition molecules Germ-line encoded (pattern recognition receptors, PRRs) These bind to pathogen-associated molecular patterns (PAMPs)―generic molecules found on many different types of pathogens (e.g., peptidoglycan) Randomly generated (B and T cell receptors) These bind to very specific antigens, rather than generic molecules found on many pathogens Clonal selection and generation of diversity Tolerance ensures that the immune system avoids destroying host tissue Many of the random Tolerance helps to keep rearrangements used to these anti-self recognition create B- and T-cell molecules/cells from receptors could be anti- circulating in the self bloodstream Vertebrate immune systems use two interconnected systems to respond to pathogens Memory is the hallmark of adaptive immunity Collaboration between Innate and Adaptive Immunity in Resolving an Infection The good, bad, and ugly of the immune system Dysfunctions of immunity―two broad categories Overly active or misdirected immune responses Allergies/asthma Autoimmune disease (e.g., multiple sclerosis, Crohn’s disease) Immunodeficiency Primary (genetic) loss of immune function Secondary (acquired) loss of immune function Opportunistic infections (e.g., oral thrush) can occur in people with impaired immune responses Question Do you feel over-whelmed by the complex subject of immunology? YES NO Do you feel overwhelmed by the complex subject of immunology?  Over-Whelmed? Immunity is a complex subject, broken down into many different layers and areas – This is just a quick summary of the basics of the field―there’s MUCH more to come! Understanding how immunity works allows us to: – Exploit it to prevent infections (vaccination) – Exploit it to treat illness (shutting down autoimmune disease or ramping up anti-cancer responses) – Provide safer organ and tissue transplants