Immunity | Immunoglobulins | MHC | Vaccines | Hybridoma Technology | Unit 3 Biotechnology 6th Sem

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.