Immunity | Immunoglobulins | MHC | Vaccines | Hybridoma Technology | Unit 3 Biotechnology 6th Sem
This is a comprehensive biotechnology lecture covering Unit 3 topics including immunology, immunoglobulins/antibodies, MHC molecules, hypersensitivity reactions, vaccines, and hybridoma technology for monoclonal antibody production.
Summary
This extensive biotechnology lecture covers the complete Unit 3 curriculum for 6th semester students, focusing on immunology and related biotechnological applications. The instructor begins with fundamental immune system concepts, explaining innate and adaptive immunity mechanisms. He details how innate immunity provides the first line of defense through physical barriers, chemical barriers, and cellular components like neutrophils, macrophages, and natural killer cells. The lecture then transitions to adaptive immunity, covering both cellular immunity (T cells) and humoral immunity (B cells). He explains the roles of different T cell types including helper T cells, cytotoxic T cells, memory T cells, and regulatory T cells, as well as how B cells produce antibodies. The discussion includes detailed coverage of immunoglobulins (antibodies), their structure with heavy and light chains, and the five main types (IgG, IgA, IgM, IgE, IgD). MHC molecules are explained in detail, including Class I and Class II molecules and their roles in antigen presentation. The instructor covers hypersensitivity reactions, explaining four types with particular focus on allergic reactions mediated by IgE antibodies. Vaccine preparation methods are discussed for bacterial, viral, and toxoid vaccines, along with storage requirements and cold chain maintenance. The lecture concludes with extensive coverage of hybridoma technology for monoclonal antibody production, including the fusion process, HAT medium selection, and purification methods. Finally, blood products and plasma substitutes are briefly covered.
Key Insights
- The instructor explains that innate immunity serves as the first line of defense and is non-specific, while adaptive immunity is specific and has memory, with innate immunity activating adaptive immunity only when it fails to handle the pathogen
- He demonstrates that MHC Class I molecules are present on all nucleated cells and present intracellular antigens to CD8+ T cells, while MHC Class II molecules are only on antigen-presenting cells and present extracellular antigens to CD4+ T cells
- The instructor explains that Type I hypersensitivity reactions require initial sensitization where the body produces IgE antibodies that bind to mast cells, and symptoms only occur on re-exposure when antigens cross-link with these bound antibodies
- He details that vaccine storage requires strict cold chain maintenance at 2-8°C continuously from manufacturing to administration, with some vaccines like oral polio requiring even colder storage at -15 to -25°C
- The instructor explains that hybridoma technology success depends on using HGPRT-deficient myeloma cells and HAT medium selection, where aminopterin blocks the de novo pathway forcing cells to use salvage pathway, ensuring only hybridoma cells with both B cell and myeloma properties survive
Topics
Full transcript available for MurmurCast members
Sign Up to Access