Microbiology Exam 3

Neutrophils

granulocyte; 50-70%; activated function: phagocytosis

Eosinophils

granulocyte; 2-4%; activated function: phagocytosis of antibody-coated parasites

Mast Cells

granulocyte: ,1%; activated function: release of chemical mediators of inflammation and allergies

Natural Killer Cells

directly lyse infected cells; also kill tumor/aberrant cells; killing activity enhanced by IFN and IL-2, can mediate ADCC; antibody-dependent cytotoxicity, secrete IFN-gamma

Macrophage

agranulocytes; 2-8%; activated function: phagocytosis (internal killing), external killing, and cytokine secretion

Dendritic cells

activate lymphocytes; cytokine secretion

T-cells

recognize antigen fragments (peptides 8-15 aa’s) in association with MHC 1 & 2; linear or continuous TCR

B-cells

recognize conformational determinants; discontinue epitopes; Ig antigen receptors

Memory Cells

some activated T cells become memory T cells, persist for years in lymphoid tissues, and immediately functional upon subsequent contact with epitope-MHC complex specific to its TCR; memory response is more effective than the primary response

Plasma Cells

differentiated Beta-lymphocyte white blood cells capable of secreting immunoglobulin or antibodies

Defensins

secreted by epithelial cells and phagocytes; antimicrobial activity against bacteria, fungi, and enveloped viruses

Lysozyme

enzyme that catalyzes the destruction of the cell walls of certain bacteria

Complement

part of your immune system that defends your body against injury and foreign invaders like bacteria and viruses that make you sick

Interferons

proteins made and released by host cells in response to the presence of pathogens such as viruses, bacteria, parasites or tumor cells

Toll-Like Receptors

on macrophages and dendritic cells recognize specific molecular patterns of foreign invaders; function in innate recognition and early proteciton, recognize PAMPs and MAMPs, trigger cytokine release, essential for adaptive immunity

Tolerance

state of unresponsiveness regarding a particular antigen; periphery: active tolerance prevents of limits inflammation; central: self-reactive cells are deleted in primary development

Hypersensitivies

exaggerates or inappropriate adaptive immune response, immediate (type1) - IgE and mast cell degranulation, allergy, anaphylactic shock; cytotoxic (type 2) - IgG mediated cellular destruction, incompatible blood transfusion, autoimmune hemolytic anemia

Blocking an allergic response

autoantibodies and autoreactive T-cells, may be organ specific, may be due to immune complex deposition in tissues, genetic factors such as HLA type are important, may be caused by microbial cross-reacting antigens and cytokine dysregulation

Antivirals

targets: binding and entry, genome replication, packaging, budding, egree

limitations: do not remove latent virus, potential for toxic side effects

compound discovery and development: classical approach inhibits CPE in tissue culture assay, rational approach picks target, solves structure and ID active site, designs an inhibitor

Beta-lactam antibiotics

have beta-lactam ring structure: penicillin, cephalosporin, cephamycin

potent inhibitors of bacterial cell wall synthesis: irreversibly bind and inactivate bacterial transpeptidases, prevent cross-linking of peptidoglycan, no similar eukaryotic process

destroyed by beta-lactamases

Shift

diversity arising after recombination or reassortment - relatively rare

Drift

diversity arising from copying errors and immune selection - may occur each time a genome replicates

quasispecies

swarm of viral variants