Pathology - L1 - Immunologic Diseases Flashcards Preview

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Flashcards in Pathology - L1 - Immunologic Diseases Deck (48)
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1

antigen

any substance able to induce a specific immune response

2

B-lymphocyte functions?

neutralizes microbes, phagocytosis, complement activation

3

where are B-cells found?

in lymphoid follicles of lymph nodes, bone marrow, and extranodal lymphatic tissue (i.e. tonsils, appendix, Peyer's patch)

4

types of T lymphocytes?

helper, cytotoxic, regulatory

5

helper T-cells functions?

activation of mac's, in inflamm, activation (proliferation & differentiation) of T & B lymphocytes

6

Cytotoxic T lymphocyte function?

killing of infected cell or cells harboring microbes

7

regulatory T lymphocyte function?

suppression of immune response

8

where are 60-70% of circulating lymphocytes found?

in thymus and paracortical areas of lymph nodes.

9

60% of lymphocytes have what ?

CD4+ marker; so they are T-helper cells

10

T-helper cells regulate T and B cell rxns by secretion of _____.

cytokines

11

30% of circulating lymphocytes have ____. What cells are these?

CD8+ marker; = cytotoxic T-cells (kill cells harboring microbes).

12

To respond, T cells must have what?

the antigen presented by antigen-presenting cells (APC).

13

APCs express what molecules?

major histocompatibility molecules (MHC)

14

T-helper lymphocytes recognized antigens expressed on ____ molecules, whereas cytotoxic lymphocytes recognized antigens expressed on ____ molecules.

class II MHC; class I MHC

15

antibody-dependent cell-mediated cytotoxicity (ADCC)

- mechanism of cell-mediated immune defense whereby an effector cell of the immune system actively lyses a target cell, whose membrane-surface antigens have been bound by specific antibodies.
- one of the mechanisms through which antibodies, as part of the humoral immune response, can act to limit and contain infection.
- Classical ADCC is mediated by natural killer (NK) cells; macrophages, neutrophils and eosinophils can also mediate ADCC.
- ADCC is part of the adaptive immune response due to its dependence on a prior antibody response.

16

natural killer cells make what % of blood lymphocytes?

10-15%

17

Natural killer cells ?

- have no T-cell markers or Ab production
- lyse tumor cells or infected cells w/o previous sensitization
- 1st line of defense against some tumors & viruses
-also can lead to AB-dependent cell-mediated cytotoxicity (ADCC)

18

function of macrophages?

1) required to process and "present" antigens to lymphocytes;
2) effectors of cell-mediated immunity; produce cytokines influencing growth and function of lymphocytes, inflammation, fibroblast proliferation, and collagen deposition;
3) Phagocytic in response to T-cell activation or opsonization.

19

members of the macrophage family, although weakly phagocytic?

dendritic cells (in lymphoid tissue); Langerhans cell (in epidermis, oral mucosa)

- important for presenting antigens
-also produce anti-viral cytokines

20

Ag-Ab activates what...?

9 sequential components aka complement

21

Complement activates ?

- anaphylaxis (i.e. c3a, c5a)
- chemotaxis (c5a)
- opsoninization (c3b)
- lysis of cells (MAC)

22

what are cytokines of innate immunity?

intercellular mediators produced in response to microbes and other stimuli and mediate inflammation and anti-viral defense (TNF, IL-1, type 1 IFNs)

23

functions of cytokines of adaptive immunity?

promote lymphocyte proliferation and differentiation and to activate effector cells (IL-2, IFN-y)

24

____ stimulates hematopoiesis (colony stimulating factors).

cytokines

25

innate immunity?

defense mechanisms that are present before infection (i.e. epidermis, phagocytic cells, dendritic cells, NK cells)

26

adaptive immunity?

- lymphocytes and their products
- humoral vs cell-mediated

27

humoral immunity?

- associated w/ AB production\
- B lymphocytes and ABs play predominant role
- AB (IgA, IgE, IgG, IgM) act on Ags, resulting in neutralization, lysis, phagocytosis.

28

cell-mediated immunity?

- cellular neutralization of Ags
- predominant role is played by T-lymphocytes
- Ags are destroyed by lymphocytes, macrophages, etc directly or via cytokines

29

X-Linked Agammaglobulinemia?

aka Bruton Disease
- failure of pre-B cells to differentiate into B cells
- Ig molecules are not assembled due to failure of light chain production

30

Clinical features of X-liked Agammaglobulinemia?

- absent or decreased #'s of B cells
- depressed serum levels of all Ig classes
- normal T cell-mediated
- germinal centers (composed mostly of B cells) reduced in size
-recurrent bacterial (pharyngitis, sinusitis, pneumonia) and certain viral infections (enteroviruses)