Vaccine-Mediated Immunity: General Physiology
Pathogen-derived antigen Adjuvants boost the immune response Preservatives inhibit microbial growth
Stabilizers prevent vaccine degradation
Vaccine components are formulated and administered to patient
Antigen Presenting Cells (APCs) phagocytose and process antigen
Adjuvants in vaccines activate local immune response
↑ Production of pro-inflammatory signals (chemokines & cytokines)
Chemokines & cytokines act as signaling molecules that attract APCs to draining lymph nodes
APCs present antigen on MHC I molecules to CD8+ T cells
APCs present antigen on major histocompatibility complex II (MHC-II) molecules to naïve CD4+ T helper cells
Recognition of antigenic material activates naïve CD4+ T helper cells
A subset of naïve B cells differentiate into short-lived plasma cells
Plasma cells produce antibodies
Antibodies cover the pathogen’s surface (neutralization)
Antibody-coated pathogens are phagocytosed by macrophages/neutrophils (opsonization)
↑ Pathogen-specific antibody titers
CD8+ T cells multiply to form an antigen- specific cytotoxic T cell population (clonal expansion)
↑ Lymphocyte counts
Authors: Tanis Orsetti Reviewers: Allesha Eman Michelle J. Chen Dr. Russell Sterrett* Prevention of specific pathogen from causing severe disease upon subsequent exposure * MD at time of publication
Some activated CD4+ T helper cells stimulate naïve B cells
A subset of activated CD4+ T helper cells differentiate into memory CD4+ T cells
A subset of CD8+ T cells differentiate into memory CD8+ T cells
A subset of naïve B cells differentiate into memory B cells
Memory B cells circulate the body and monitor for secondary exposure to the pathogen
Memory T cells circulate the body and monitor for secondary exposure
Memory T cells are activated upon secondary exposure to the pathogen
Activated memory T cells differentiate into effector T cells
Memory B cells differentiate into plasma cells when there is a secondary exposure to the pathogen
Effector CD4+ T helper cells stimulate B lymphocytes
CD8+ cytotoxic T cells induce apoptosis of infected cells
Vaccine-Mediated Immunity
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published Nov 23, 2024 on www.thecalgaryguide.com