The Immune System

The immune system is responsible for the prompt detection and elimination of any foreign or harmful substances. It is the main system responsible for the protection of the body from infection. The immune system is particularly effective, considering that there are currently millions of bacteria on your skin alone.

It is essential that the immune system recognizes foreign substances from self tissues and cells. The immune system typically solves this problem by existing in two types, the natural/innate immune system and the adaptive/acquired immune system.

Innate Immune System

The innate immune system is inherited, determined by genetics. This part of the immune system is non-specific. First and foremost, the skin is part of this immune system. The skin is the first barrier that must be overcome by foreign substances.

The presence of certain reactions by the body are also included in the innate immune system; including saliva, tears, perspiration, pH, mucus, urine, macrophages, phagocytes, and respiratory responses such as sneezing and coughing. The hydrochloric acid produced by the stomach is also included in the innate immune system.

Adaptive Immune System

The adaptive immune system is specific and is developed based on individual circumstances and experiences. The production of B cells and T cells is completed by bone marrow stem cells.

B cells are responsible for antibody production and the oversight of humoral (antibody mediated) immunity. B cells are circulated throughout both the lymph and blood systems, marking foreign antigens for destruction by other immune cells such as macrophages or phagocytes.

T cells are sensitized by the thymus, and are responsible for all cell-mediated immunity. T cells will attach and destroy foreign substances, but are also responsible for the organization and regulation of the overall immune response.

Antibodies

Antibodies are located on the outside of all cells, including foreign substances. Antigens are very specific, similar to a lock and key mechanism. It is these antibodies that enable B cells to recognize antigens as foreign in comparison to self. It is also these antigens that are “remembered” by the adaptive immune system, enabling a quicker response if the infection re-occurs. Antigens are currently used in thousands of research projects across the world.

Candidiasis and the Immune System

For a vaginal yeast infection, initial failures of the innate immune system, followed by adaptive immune system failures lead to infection. The innate immune system is not as capable of controlling the Candida bacteria present, as typically the vaginal environment has changes in sugar content and pH. Yeast infections are also more common if the amount of good bacteria (normal flora) is decreased. Normal flora help control levels of foreign bacteria.

Thrush is commonly associated with development in immune systems that are compromised or weakened in some way. Systemic Candidiasis is also more commonly associated with weakened or compromised immune systems. When the immune system is weakened or compromised, it does not elicit normal response mechanisms, making it easier for infections to occur.

Learn more about Candida Albicans and Yeast Infections here.

Sources:
http://uhaweb.hartford.edu/BUGL/immune.htm#intro
http://www.nlm.nih.gov/medlineplus/yeastinfections.html
http://www.niaid.nih.gov/final/immun/immun.htm