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):

Th1 cells

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


Th2 cells

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


Th17 cells

From the CD4+ lineage; secrete IL-17


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

Th1, Th2 Th17, or Treg.


What cytokines are important for Th1 differentiation?

IL-12 and IFNg


What cytokine is important for Th2 differentiation?



What factors influence T-cell phenotype?

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


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.


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)


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)


Treatment for leprosy

dapsone, clofazamine, rifampin


Lepromatous Leprosy

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


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.


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;


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.


IL-10 suppression of Th1 cells

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


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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