Cell Injury due to the Biological Agents
Cell Injury due to the Biological AgentsDr A.Aziz Djamal
MSc.DTM&H.SpMK(K)Biological agents that commonly cause cell
injury Bacteria Virus Fungi Parasite OtherBacteriaMechanism of Cell
InjuryExtracellular product : Exotoxins Enzymes.Structural product
: LPS-Endotoxin Immuno-pathologic Mechanism : Autoimmune Immune
complex Hypersensitivity ex. Delayed type
Structure of Plasma membrane as a target of Bacteria or
bacterial productLipid riftSub-domain of Phospholipid part of the
membrane, important on :Trafficking materials.Triggering of
membrane signaling into the cytosol
Lipid rift
As bacterial receptor to attach for several bacteria :Nesseria
gonorrhoeVibrio choleraePseudomonas aeruginosa.Etc Followed by the
release of some extracellular product.Lipid riftUsed as ligand
point of some bacterial extracellular products :ExotoxinEnzyme :
Hyaluronidase Collagenase. Protease. Etc
Following attachment to a ligand :Endocytosis - Endosome
formation Activation of cytosol enzymatic system-Lysis of Endosome
Release of toxinToxin actions :Hijacking the normal cytosol
molecular process : Vibrio cholera toxin / enterotoxin. Ca ion
influx Aktifasi destructive enzymes Toxin Receptor on target
cellSub-domain Lipid at Plasma membrane called as Lipid Rift :
Trafficking material Initiating Membrane signalFollowed
byEndocytosis Endosome Release of toxin target in cytosol
Immunopathologic pathwaysInflammatory processAutoimmunity :
Streptococcus Group A Rheumatic Heart DiseaseImmune Complex :
Streptococcus Group A GNA Complement Activation.VIRUS Adsorption
instead of infection Intracellular Micro-organism For Survival and
Replication. Availability of receptor on the Cell target Ex : Lipid
Rift. Attachment/ Adherent factor on the viral structure. No
receptor no adsorption. SEQUENCE
Atatchment.Penetration.Uncoating.Release of Nucleic acid : Lytic
Lysogenic.Lytic : Transcription mRNA- Translation Development of
viral components - Replication of Viral Nucleic acid- Assembly new
viruses - Cell BurstLysogenic Mostly among DNA Viruses.RNA Virus
Reverse Transcriptase.Inserting the whole Nucleic acid or part of
theGenome into the host cell. Dormant infection Change of cellular
genetic activity ( Oncogenic Virus ) Fungi and ParasiteMostly by
Exporting protein And Complex of a series enzymes.The same pattern
of bacterial toxin.
TERIMA KASIH
