INFLAMMATION INFORMATION -Chronic Low Level Inflammation
ACUTE (short-term) inflammation
- Needed and immediate
Necessary for survival, and is the immune system's IMMEDIATE response to infection or injury
Acute phase Inflammation Response
ACUTE PHASE inflammation is the body's immediate,
necessary and appropriate response to infection or injury -
occuring within minutes to hours
Mechanism of Acute Inflammatory
Phase
- Without inflammation,
infections would go unchecked and wounds would never heal.
E.g. from trauma, surgery, burns;
- Symptoms.
The damage site becomes red, swollen and warm, with possible loss of function,
as healing mechanisms are initiated.
- Repair the damage.
Fibroblasts manufacture the extracellular
matrix (ECM) and collagen to repair damaged connective tissue
- Acute inflammation
response is designed to work best in a well-nourished person with a mild to
moderate injury /infection over a short period of time.
Part of the innate immune system (I.S.)
Innate Immunity - "General Soldiers" - 1st line of
nonspecific immune system's defense against invading organisms.
Immediately or within several hours after an "invasion". Innate immunity
includes mechanical barriers, such as the skin, chemicals in the blood and
immune system cells that attack invading, foreign cells.
Chemicals released to
cause inflammation attract white blood cells called phagocytes (E.g. macrophages
and neutrophils) - which engulf foreign particles (E.g. chemicals,
particulate matter), bacteria,
parasites, dead/dying body cells and debris; being messy "eaters", macrophages
"burp up"fragments of their "meal"that alert other I.S. cells to join the
fight and they also produce chemicals to kill microbes;
• Different methods are
employed to kill microbes. Intracellularly,
phagocyte oxygen consumption increases in a so-called "respiratory burst", which
produces anti-microbial ROS,
namely: Singlet
oxygen,
Hydroxyl radical
and
Hypochlorite ; extracellularly,
nitric oxide is used against bacteria;
some of these oxidants leak into and damage
surrounding tissue, causing more inflammation, especially if the "battle "goes
on for too long;
• Tumor Necrosis
Factor-α (secreted by
activated macrophages) is used to destroy virally infected cells/cancer cells:
• Pus
-
is a combination
of dead tissue, dead bacteria, and live and dead phagocytes.
Macrophages "Dealing with"a parasite
Macrophage "eating" carbon particles in particulate matter
(The black material is inhaled carbon in sputum induced from a healthy
child's lung)
The damaged/infected site becomes red, swollen and warm, with possible
loss of function - as healing mechanisms
are initiated.
Eventually any damage is repaired -
fibroblasts manufacture the extracellular matrix (ECM) and collagen to repair
damaged connective tissue (admittedly sometimes leaving a scar);
Acute inflammation response is designed to work best in a well-nourished
person with a mild to moderate injury /infection over a short period of time - response usually occurs
within minutes to hours, and the problem is often fixed in a few days;
Part of the adaptive immune system (I.S.)
Adaptive immunity - "Specialized Troops"
- 2nd line of
defense and protection against re-infection by same pathogen
HUMORAL immunity
-
involves production of antibodies in
response to an antigen and is mediated by B-lymphocytes
CELL-MEDIATED immunity
- involves production of
cytotoxic T-lymphocytes, activated macrophages, activated NK cells, and
cytokines in response to an antigen and is mediated by T-lymphocytes
Macrophages call in the lymphocytes
(B-cells and T-cells)
- these are mobilized to find the non-self invader (called an
antigen):
• T-cells -
identify and eliminate antigens.
• B-cells -
produce specific antibodies (think of them as flags) to attach to a specific
antigen to identify it as a marked target for destruction by
cytotoxic T-cells (Natural killer T-cells / NKT).
Note, these are distinct from Natural
Killer (NK) cells of innate immunity;
• Helper T-cells -
signal B-cells to multiply to strengthen attack force;
• Suppressor T-cells -
down-regulate other I.S. responses;