Immunity and Infection with Biomaterials

Question 1

innate vs acquired

Answer 1

innate- at birth, phagocytes, complement system, immune cells
acquired - exposure, antibodies, B and T cells, complement system

Question 2

humoral vs. cell-mediated

Answer 2

humoral - B cells>plasma cells>antibody

cell-mediated - Tcells + macrophages + B cells + cytokines/lymphokines

Question 3

antigens

Answer 3

generate antibodies, often greater than 10,000 MW, normally not part of the host, attract an immune response

Question 4

MHC

Answer 4

determines outcome of organ transplant, forms the basis of antigen recognition for T cell responses, individual MHC called Human Leukocyte Antigen(HLA)
found on APCs, presents antigen to T-cell receptors

Question 5

antibodies

Answer 5

B cells > Plasma cells > secrete antibody
in Plasma: >GAMDE>
in secretions: >AGM>

Question 6

antibody development in newborns

Answer 6

first maternal IgG (drops off after birth), then newborn IgG, then IgM and IgA

Question 7

Antibody Response

Answer 7

first exposure, IgG and IgM low; second exposure, IgG higher, IgM same

Question 8

adjuvant

Answer 8

enhances vaccine efficacy, causes mild inflammation to alert antigen presenting cells

Question 9

cell-mediated immunity

Answer 9

Helper T cells - 75% of T cells, major regulator of immune response, produce lymphokines
Cytotoxic T Cells - direct attack of cells, secrete perforins
Regulatory T cells - regulate control

Question 10

cytokines

Answer 10

IL-1, IL-6, TNFalpha

Question 11

types of transplant rejection

Answer 11

hyperacute(rare) - minutes to hours
acute - days to months, cellular destruction/organ failure, humoral and cell-mediated
chronic - present in most transplanted tissue, slow deterioration, cell-mediated

Question 12

xenotransplant difficulties

Answer 12

alpha1,3-galactosyltransferase is present on endothelium of lower animals, not on humans = immune response

Question 13

hypersensitivity to materials

Answer 13

complement mediated, antibodies, probably IgE

for cell-mediated, Tcells, cytokines/lymphokines, PMN response

Question 14

complement system

Answer 14

most made in liver

1. initiation
2. amplification or regulation
3. cell activation & recognition via receptors

Question 15

gram positive/negative

Answer 15

positive is stained purple, negative stained red, gram negative has lipopolysaccharide layer , gram negative has thicker peptidoglycal layer

Question 16

biofilm

Answer 16

hydrated anionic acidic polysaccharides & glycoproteins

cells in biofilm protected form phagocytes, antibiotics