Jitt # 9 Case Study Lepromatous Leprosy Flashcards Preview

Medical Immunology Bios 443/843 > Jitt # 9 Case Study Lepromatous Leprosy > Flashcards

Flashcards in Jitt # 9 Case Study Lepromatous Leprosy Deck (17):
1

Th1 cells

From the CD4+ lineage; secrete IL-2, IFNg, and lymphotoxin (LT); enables the immune response to activate macrophages and cell-mediated immunity

2

Th2 cells

From the CD4+ lineage; secrete IL-4, IL-5, and IL-10; enables the response to produce antibody production only.

3

Th17 cells

From the CD4+ lineage; secrete IL-17

4

What are the four types of cells that CD4 cells can differentiate into upon recognizing a pathogen?

Th1, Th2 Th17, or Treg.

5

What cytokines are important for Th1 differentiation?

IL-12 and IFNg

6

What cytokine is important for Th2 differentiation?

IL-4

7

What factors influence T-cell phenotype?

cytokine(s) encountered; amount of antigen present; co-stimulation;

8

Positive Feedback Loop in Th1 cells.

Pathogens activate macrophages and NK cells (IFNg) , which produce IL-12; IL-12 causes Th1 differentiation; Th1 secretes IFNg; IFN g favors more Th1 development, but blocks the development of Th2 cells.

9

Positive Feedback loop in Th2 cells.

Pathogens, specifically parasites, cause IL-4 production by mast cells, eosinophils and thymus derived invariant NKT cells (iNKT cells), IL-4 is the cytokine that leads to Th2 differentiation; Th2 cells secrete IL-4 (more development) and IL-10 (blocks Th1 differentiation)

10

Symptoms of leprosy

loss of sensation (caused by bacterial infection of the schwann cells) , hypo-pigmented skin lesions (especially in the hands, ears, and buttocks) , hair-loss, nose bleeds (caused by mycobacterium infection in nasal tissue. leads to congestion and the break down of blood vessels)

11

Treatment for leprosy

dapsone, clofazamine, rifampin

12

Lepromatous Leprosy

Th1 (IL-12, IFNg)) cell mediated response is effective. If the Th2 response predominates, it is not effective; causes tissue damage;

13

Tuberculoid Leprosy

Associated with a vigorous cell-mediated Th1 (IL-1, IFNg, LT)response; activates macrophages to kill mycobacteria. Usually mild; lack suppressor CD8 T cells.

14

What organism causes lepromatous leprosy?

caused by mycobacterium leprae, which colonizes and multiplies within macrophages and other host cells; macrophages protect bacterium from attack by antibodies; can only be eliminated when macrophages are activated and produce microbicidal molecules;

15

What cytokines limit the response of Th1 cells? Where are they secreted from in lepromatous leprosy?

CD8 T cells secrete IL-10 and LT, which limit the immune response.

16

IL-10 suppression of Th1 cells

IL-10 inhibits cytokine release from macrophages and their capacity to kill internalized microorganisms

17

LT suppression of Th1 cells

inhibits killing capacity of macrophages, decreased production of IL-12, fewer T h1 cells and more Th2 cells.

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