Biology of Disease

Lectures

Although a compulsory course at Medics, Biology of Disease can be taken by NatScis as well, with 40-50 Bio NatScis taking the course every year. BOD can be rather clinical at times, but it is nevertheless useful for students wishing to eventually enter clinical research or understand the causative agents, molecular mechanisms, and treatment of various diseases. BOD focuses on immunology, as well as diseases caused by common pathogens such as bacteria, viruses, parasites, and fungi, followed by vascular pathologies and cancer. As the course is targeted towards medics, expect a different style of instruction during the lectures and practicals as these are shared. There is a decreased emphasis on experimental techniques and evidence that you might be used to from other courses, and instead more descriptions of mechanisms and pathways. Lectures start at 12pm on Mondays, Wednesdays, and Fridays. Each lecture block generally starts with an introduction to the broad category of the pathogen or disease, followed by a deep dive into specific examples of how the pathogen infects its patient or a disease develops, immune evasion techniques employed by the pathogen, and the host immune response against the pathogen or disease which resolves or worsens the pathological condition. Techniques to prevent and treat the infection are also covered. As the immune system is highly complex with many intersecting pathways, do not be surprised that many immune pathways are shared among different pathogens while having their own exceptions and quirks. There is also a series of Natsci Extension Lectures in Lent and Easter intended for Natscis that focus on the immune system in the context of various pathological conditions and serves as an addendum to the core curriculum. Do also consult the lecture and practical timetable because there are some days without lectures or practicals in Michaelmas and Lent.

The lecture synopses are given below:

Michaelmas:

• Immunology: The very first lecture topic is on immunology, which is a massive topic spread over 5 weeks. These start with a series of lectures covering the immune system, with a general introduction to the innate immune system, inflammation, the complement system, and the adaptive immune system. These are then applied to pathological phenomena such as immune tolerance, autoimmunity and hypersensitivity, and transplantation. Although this block ends early in the academic year, it is central to the course with the diseases covered subsequently referencing immunological processes.
• Viruses: Another big topic which starts off with a general introduction to viral pathogens. Viral transmission, persistence within the host, immune evasion, immune responses against viruses, and prevention and treatment of viral diseases are dealt with in the following lectures. Viruses commonly covered here include Influenza, Hepatitis A, B, and C, HIV, and various Herpesviruses, although knowledge of other viruses which are covered less extensively such as Covid-19 is greatly helpful in the eventual essay exams. Prions are also briefly discussed within this lecture block.
• Fungi: Fungal pathogens are discussed here, with Aspergillus and Candida being some classic examples. The block starts off with a general discussion on fungal characteristics, followed by fungal reproduction and diagnosis of fungal infections. Fungi are then grouped into systemic opportunists versus systemic pathogens, with each group having different pathogenesis and affecting different groups of patients. Lastly, treatment and prevention of fungal diseases are discussed. With only 2 lectures, fungal diseases are not a main focus of the course but can supplement other knowledge.

Lent:

• Parasites: This block delves into the world of parasites, organisms which make their living off a host. Following an introduction to parasitic lifestyles and life cycles, various parasites are discussed. Plasmodium (causative agent of malaria), Leishmania (causative agent of leishmaniasis) and various worms and helminths are among the totally lovely and not-at-all-nasty creatures you will cover. Similar to previous lecture blocks, emphasis is placed on immune evasion techniques and the host immune response to infection. Techniques to prevent and treat parasitic infections are also covered here.
• Bacteria: Yet another major lecture block in BOD, the bacteria block does a deep dive into the structure and function of various pathogenic bacteria. Much like previous lecture blocks, this one covers the initial stages of infection, colonisation, immune evasion, and host immune response to the pathogen. Various Gram-positive and Gram-negative bacteria are discussed, as are measures against bacterial infections such as antibiotics and vaccination. This block concludes with a review lecture of the various immune responses to the pathogens covered so far, such as viruses, parasites, fungi, and bacteria, which is extremely useful in consolidating the various overlapping immune response pathways.
• Vascular Pathologies: This block covers conditions such as atherosclerosis, ischaemia, and various types of anaemia. It starts off with an introduction to both proper and dysregulated responses to vascular injury, setting the foundation for 5 vascular pathologies that are covered in subsequent lectures. One lecture is then dedicated each to atherosclerosis, ischaemia and infarction, and anaemia. Throughout the block, risk factors for the various conditions and the role of different cells or components of the immune system in vascular injury and recovery are discussed.
• Cancer: : The first few lectures act as an introduction to cancer, with discussion on the various mutations of the genes involved in tumorigenesis and the focus of cancer as a multi-stage evolutionary process. Key hallmarks of cancer cells, such as genetic instability and a loss of growth control, are introduced as concepts and the biochemical basis behind these hallmarks discussed in subsequent lectures. Different classes of mutations ranging from point mutations to entire chromosome translocations and the various genes involved in cancer such as tumour suppressors and oncogenes are discussed in detail. Lastly, environmental causes of cancer such as cancer initiators (carcinogens) and cancer promoters as well as hereditary and non-hereditary risk factors of cancer are discussed. As the archetypal genetic disease, a good biochemistry background would be useful in incorporating extracurricular information in the exams.
• NST Extension Lectures 1 – 3: The first of the NST lectures, which all tend to focus on the immune system in different contexts. NST1 comes immediately following the parasitology block and focuses on the immune system’s role in parasitic infections. NST2 follows the bacteriology block and discusses the interplay between the immune system and bacteria in chronic bacterial infections. NST3 comes after the cancer lectures, focusing on chronic infection and wound repair in cancer formation.