Osmosis offers a video with an introduction to the immune system:
How does the immune system work?
When a microorganism manages to get through our physiological barriers and is detected, innate immune cells (See Figure Bellow - blue circle) will immediately start working together to recognize it and to respond accordingly, neutralising or destroying the threat. Innate immune cells activate specialised immune cells (cells from the adaptive response (orange circle), namely B cells and T cells (check explanatory image below):
- B cells produce antibodies (or immunoglobulins – Ig), which are specialised proteins that bind specifically to a microorganism. There are different types of antibodies (IgG, IgM, IgA, IgE and IgD) with distinct immune functions.
- T cells (Figure - orange circle) kill cells that have been infected or somehow changed (e.g. become malignant). T cells do this by releasing specific killing substances and by recruiting other immune cells, like B cells, to act.
A glossary done with you and for you is available at:
The 2 types of immune response have different functions:
All the immune systems offer the body protection against disease, by coordinating their actions and communicating with each other, thus conferring immunity to our bodies.
The figures below give an overview of the immune system’s features in a simplified manner.
But what are the antibodies’ main functions?
The next figure shows how antibodies fight microorganisms. Importantly, after eliminating an infection, antibodies may remain for days or months in the organism, providing protection to fight future infections by the same pathogen. This process is called immunological memory.
An introductory video by KidsHealth explains how the immune system works, you can assist HERE:
To get more information about the immune system, visit our immunology booklet at the link below:
Immunology Patient Friendly.pdf
For additional resources on the immune system and the nomenclature:
To complement your understanding about the immune system watch the video provided by Zero to Finals:
Immunological (Dys)functioning in CDG
In 2019, CDG & Allies conducted a literature review and identified several CDGs with abnormal immunological functioning as a distinguishing clinical feature (check table below). This happens because glycans (sugar athenas) are necessary for the human body to identify enemies, communicate between cells, and make strategic decisions when the body needs to defend itself. Glycans attach to immune cells via the glycosylation mechanism (a process that adds sugars to proteins and lipids), which is defective, abnormal or absent, in people who live with CDG. Furthermore, CDGs are complex diseases with a lot of heterogeneity even within the same type, so it is possible to divide CDGs into two groups based on the degree of immunological involvement:
Still, this subdivision is poorly understood due to a lack of knowledge regarding the clinical features of each CDG type throughout a person's growth (from onset to eventual passing) as well as the underlying mechanisms for these immunological anomalies.
For more information on the immunological involvement of each CDG in the table above, access the full article by clicking HERE.
In the case of PMM2-CDG, infections and/or other immune-related manifestations have been reported in a number of patients, with infections being the most common problem. They are recurrent and mostly predominant during early life and childhood and become less frequent and severe in adolescence and adulthood. Although infections tend to affect in a larger scale the respiratory and gastrointestinal tracts, sometimes they can progress to more generalised and severe manifestations known as sepsis (infection which provokes an exaggerated response of the organism) or septic shock (last and most severe stage of sepsis). This is one of the reasons why infections lead to premature death in young PMM2-CDG children.
Please read the full article titled "New Insights into Immunological Involvement in Congenital Disorders of Glycosylation (CDG) from a People-Centric Approach" for more information on the immune aspect of PMM2-CDG by clicking HERE
Find below a list of the main immune-related manifestations, beside infections, found in PMM2-CDG:
For more information, watch this video brought to you by one of the former CDG & Allies research members, which explains the impact that CDG has on the immune system and its consequences.