Immunorecognition, how the immune system recognises pathogens and infection, has puzzled immunologists for decades. How does the immune system 'know' when to initiate a response and how can it 'see' an antigen? How are these responses regulated and how can interventions be delivered to regulate them to alleviate disease.
The subject of immunology touches upon almost all areas of biomedical sciences, including wellbeing, nutrition, cancer and metastasis, autoimmunity, reproduction and fertility, and senescence. Recent advances in genomics, proteomics, metabolomics, computational chemistry, bioinformatics and structural biology have served as the basis for new approaches for understanding immunological processes.
Next-generation sequencing and high-throughput immune profiling technologies have revolutionized the characterization of human immune responses. We can now determine what defines a healthy immune system and how infection, vaccination or disease disturbs immunity. However, there is much knowledge to be gained with many aspects of immunology still poorly understood. Autoimmunity is still a challenge to understand and treat.
Immunology has not cured cancer or AIDS. AIDS remains, an intractable condition; no effective vaccine is yet available and treatment is mainly achieved by reducing viral replication by taking anti-retroviral drugs. Other viruses that pose a major challenge are Zika and Ebola; no approved vaccines are yet available for these pathogens
Most knowledge gains in immunology have been derived from in vitro assays, in most cases using cell-lines obtained from non-human mammals such as mice, rats and monkeys. There is a need for understanding in vivo immune responses in humans. This is not readily achieved, since refined techniques are required and deontological ethics may slow down progress. Recent techniques, having great potential in immunology, include chimaeric antigen receptors T cells, CAR-T cells, designed for the treatment of cancer and gene editing.
Cell surface receptors such as major histocompatibility complex antigens and T-cell receptors will be discussed in detail. Antibody diversity will be examined from the point of view of genetics and antibody repertoire. Ligand-receptor interaction and cytokines (the hormones of the immune system) will also be studied. Most specific immune responses involve lymphocyte proliferation, induced via Ca+2 release, PKC, IP3 and cell adhesion receptors that work as co-stimulatory molecules. Cell mediated immunity, via macrophage activation, T-helper and T-cytotoxic cells will also be examined. HLA genes and products will be discussed in relation to antigen presentation, organ transplantation (e.g. kidney) and disease associations (e.g. diabetes). Feto-maternal tolerance will be discussed from the point of view of the foetus as a hemi-allograft in the mother carrying 50% of non-self-genes from the father.