An introduction to immunology and immunopathology

Conclusion

Innate immunity is the first immunological, non-

specific mechanism for fighting against infections. 

This immune response is rapid, occurring minutes or 

hours after aggression and is mediated by numerous 

cells including phagocytes, mast cells, basophils and 

eosinophils, as well as the complement system. Adaptive 

immunity develops in conjunction with innate immunity 

to eliminate infectious agents; it relies on the tightly 

regulated interplay between T cells, APCs and B cells. A 

critical feature of adaptive immunity is the development 

of immunologic memory or the ability of the system to 

learn or record its experiences with various pathogens, 

leading to effective and rapid immune responses upon 

subsequent exposure to the same or similar pathogens. 

A brief overview of the defining features of innate and 

adaptive immunity are presented in Table 

4

.

There is a great deal of synergy between the adaptive 

immune system and its innate counterpart, and defects in 

either system can lead to immunopathological disorders, 

including autoimmune diseases, immunodeficiencies 

and hypersensitivity reactions. The remainder of this 

supplement will focus on the appropriate diagnosis, 

treatment and management of some of these more 

prominent disorders, particularly those associated with 

hypersensitivity reactions.

Abbreviations

PRRs: pattern recognition receptors; PAMPs: pathogen associated molecular 

patterns; LPS: lipopolysaccharides; RNA: ribonucleic acid; TNF: tumour 

necrosis factor; IL: interleukin; APCs: antigen-presenting cells; NK: natural killer; 

IFN-γ: interferon-gamma; ILCs: innate lymphoid cells; TCR : T cell receptor; 

MHC: major histocompatibility complex; HLA: human leukocyte antigen; Ig: 

immunoglobulin; T reg: regulatory T cell; SLE: systemic lupus erythematosus; 

AIDS: acquired immunodeficiency syndrome; HIV: human immunodeficiency 

virus.