PHAGOCYTES: “that eats” – process of endocytosis
(getting something into their own cytoplasm)
PHAGOCYTOSIS
a. Acute
a. 0-12 hours: time limit wherein our body
should ward off pathogens through the
process of phagocytosis
b. Capability of immune system to ward off
infection.
b. Oxidative burst: Capability of digesting the
organism
c. Exocytosis
a. When respiratory burst happens, it
should have been taken out from the
body (exocytosed)
Free radicals: by product of phagocytosis inside the
body
Excessive phagocytosis = increase free radicals =
Harmful to the body
ANTIOXIDANT: Medications that counter the actions
of free radicals
1. Pathogen ingested should be enclosed in a
VACUOLE.
o PHAGOSOME: Antigen enclosed in a
vacuole (enclosed antigen).
2. Must be infused with lysosome(contains
digestive juices/substances to facilitate
respiratory burst: myeloperoxidase,
peroxidase, protease, transaminase,
lactoferrin, etc.)
o PHAGOLYSOSOME: phagocyte and
lysosome infused with one another
3. When oxidative burst happen,
phagolysosome must be EXOCYTOSED.
Phagocytes: neutrophils, monocytes, macrophage,
eosinophil, dendritic cells (most potent), basophils
IMMUNOCYTES
1. Lymphocytes (reactive cells)
a. T cells
a. During infection, there is a
differentiation of either:
i. T helper: CD4 receptors
ii. T cytotoxic: CD8 receptors
b. B cells
a. Produce/ secrete antibodies
(transmitter of which cells will be
killed)
b. Plasma cells: Activated form
c. NK cells/ assassin cells/ null cells
a. Attack viral infected cells, tumor
cells
b. NO NEED RECEPTORS as they are
capable of releasing perforins
(initiate formation of pores within
the cell leading to cell lysis)
c. Also produce granzymes
T REGULATORY: regulates production and
subsequent reaction
T SUPPRESSOR: counteracts and inhibits the
reaction of T cytotoxic
T DELAYED TYPE HYPERSENSITIVITY:
hypersensitivity reaction
HUMORAL IMMUNITY
• Has nothing to do with any type of cells
• Consists of:
o Opsonins, antibodies and acute phase
reactants
INNATE vs ADAPTIVE
Innate
• Present at brith
• Natural, non-specific immunity
• Treat all antigens the same
o Homogenous reaction
• Lacks memory
Adaptive
• Not present at birth
• Acquired, specific immunity
• Diversed reaction
• Has “memory”
o B memory cells will memorize
infection. They will the DNA of the
antigen
CHECKPOINTS/BARRIERS
1. 1st BARRIER
• Skin: LACTIC ACID
• Secretions: LYSOZYMES, TRANSFERRIN,
PROTEASES
• Cilia linings within the gastrointestinal tract:
facilitates locomotion of microorganisms
• Reflexes: sneezing and coughing, prevent
progression to the inner parts of body by
expelling out
• Acidity of genitourinary tract and vagina (pH 5):
Lactobacillus acidophilus
o GIT – pH 1 (HCl) should be maintained
• Normal flora
o Competitive exclusion
2. 2ND BARRIER
• Consists of:
o Phagocytes
o Inflammatory/Fever
o Natural antimicrobial substances
▪ Properdins
▪ Complement system
▪ Betalysin
▪ Interferons
▪ Tumor necrotic factor
