Immediate immune system

Immune system immediate response.

First line of defense (0-4 hours), lack of specificity

1.-Physical barriers

2.-Complement System

Tags bacterium for destruction by phagocytosis

located outside of our body

Mechanical

Skin, Gut, Lungs

chemical

Microbiological

Flow air or fluid, movement mocus, tears

Fatty acids, Antimicrobial peptides, enzymes

Microbiota

bacteria persist?

30 plasma proteins make the C.System

Complement (C3) the most important

Activation: C3 fragmented in

C3a (small fragament)

C3b (large fragment)

thioester bond

permit the cleavage to patogen´s surface

chemotrattractant

recruits phagocytes

Activation pathways

3 different pathways

First to be activated

second to be activated

third to be activated

Pathogen surface activate C3b

yes

Mannose binding lectine binds to the patogen

macrophage activation

use of c5 proteins or antibodies

NOT PART OF IMMEDIATE RESPONSE

Part of the immediate response

2.1 .- Alternative pathway

Alternative MAIN IN IMMEDIATE response

Alternative

Lectin

Classical

Initiation

C3 present in plasma

Detect bacteria, and the enviroment of it

lead to hydrolize c3 to IC3

Binds b and d factors

D factor break B in Ba and Bb

C3 is fragmented

complex C3bBb formed

C3bBb catalizes formation of new C3bBb

C3b binds the bacteria

C3b coat the bacteria

regulated by

Factor P (properdin) and factor H

Macrophages recognize the calling

Complement receptor 1 (CR1) binds to C3b

Macrophage endocytoses bacteria

create a phagosome +lysosome =phagolysosome

Bacteria is engulfed

Terminal complement

activated by C5 convertase

Reclute C6,C5b,C7,C8 to make an structure for C9

C9 makes a hole in the bacterial membrane

or

2 C3b+Bb

create

Bacteria is destroyed

Antimicrobial peptides

Defensins

Kill patogen disrupting microbial membranes

Pentraxins

2 classes

Alpha and beta

Bind microorganism and deliiver to phagocytes

Author:Manuel Enrique Alvarez del Rio

Parham, P. (2021). The Immune System: Fifth International Student Edition with Registration Card. WW Norton & Company.