4: Immunology Flashcards
Which immunoglobulin is the initial antibody made after exposure to an antigen?
IgM
Which cell type regulates CD4 and CD8 cells?
Suppressor T cells
Which immunoglobulin is the most abundant in the body?
IgG
Which type of hypersensitivity reaction results from immune complex deposition?
Type III hypersensitivity reaction
[Serum sickness, SLE]
Which type of hypersensitivity reaction results from IgG or IgM reacting with cell-bound antigen?
Type II hypersensitivity reaction
[ABO blood incompatibility, Graves disease, myasthenia Gravis]
Which immunoglobulin is involved in allergic reactions and parasite infections?
IgE
Bee stings, peanuts, hay fever are all examples of which type of hypersensitivity reaction?
Type I hypersensitivity reaction
Serum sickness and SLE are all examples of which type of hypersensitivity reaction?
Type III hypersensitivity reaction
What do natural killer cells detect?
Cells that lack self-MHC
[Part of the body’s natural immunosurveillance for cancer]
MHC class I proteins present antigens to T cell receptors with which co-receptor?
CD8
[CD8 is a transmembrane glycoprotein that serves as a co-receptor for the T cell receptor]
Which immunoglobulin is the largest, having 5 domains (10 binding sites)?
IgM
What are the 2 secondary lymphoid organs?
- Spleen
- Lymph nodes
MHC class II proteins present antigens to T cell receptors with which co-receptor?
CD4
Which type of hypersensitivity reaction is delayed and occurs when an antigen stimulates previously sensitized T cells?
Type IV hypersensitivity reaction
[TB skin test (PPD), contact dermatitis]
Which immunoglobulin is responsible for secondary immune response?
IgG
Which immune cell type is not restricted by MHC, does not require previous exposure, and does not require antigen presentation?
Natural killer cells
[Not considered T or B cells]
Infections by intracellular pathogens such as TB and viruses occur more readily in patients with defects in which component of immunity?
Cell-mediated immunity
What is considered a tetanus-prone wound?
- Wounds greater than 6 hours old
- Wounds with obvious contamination and devitalized tissue (Crush, burn, frostbite, or missile injuries)
Which immunoglobulin is membrane-bound on B cells and serves as an antigen receptor?
IgD
Which MHC class protein activates helper T cells?
MHC class II
Which cell type is involved in delayed-type hypersensitivity by secreting chemokines that recruit inflammatory cells?
Helper T cells
Which 2 immunoglobulins fix complement?
IgM and IgG
Which immunoglobulin is responsible for preventing microbial adherence and invasion in the gut?
IgA
Which MHC class of proteins is present on all nucleated cells?
MHC Class I
ABO blood incompatibility, Graves disease, and myasthenia Gravis are all examples of which type of hypersensitivity reaction?
Type II hypersensitivity reaction
Which cytokine released by helper T cells mainly causes maturation of B cells into plasma cells?
IL-4
Which cell type recognizes and attacks non-self-antigens attached to MHC class I receptors (eg viral gene products)?
Cytotoxic T cells
When should a wounded patient be given tetanus immunoglobulin?
Only when a patient who has not been immunized (or immunization status in not known) has a tetanus-prone wound
Which MHC class of proteins stimulate antibody formation after interaction with B cell surface IgM?
MHC class II
Which cytokine released by helper T cells mainly causes maturation of cytotoxic T cells?
IL-2
Which 2 immunoglobulins are opsonins (molecule that enhances phagocytosis)?
IgM and IgG
Which immunoglobulin can cross the placenta and provide protection in the newborn period?
IgG
Which MHC class protein is the target for cytotoxic T cells?
MHC class I
Which MHC class of proteins is present only on antigen-presenting cells?
MHC class II
Which type of hypersensitivity reaction happens immediately and is caused by eosinophils with IgE receptors for the antigen releasing major basic protein?
Type I hypersensitivity reaction
[Bee stings, peanuts, hay fever]
How should a patient with a tetanus-prone wound be treated with regards to tetanus prophylaxis?
Always give the tetanus toxoid vaccine unless the patient has had greater than 3 doses and it has been less than 5 years since the patient’s last booster
TB skin test (PPD) and contact dermatitis are examples of which type of hypersensitivity reaction?
Type IV hypersensitivity reaction
[Delayed-type hypersensitivity]
Which signal molecule converts lymphocytes into tumor-infiltrating lymphocytes (TILs)?
IL-2
[Wikipedia: Tumor-infiltrating lymphocytes, are white blood cells that have left the bloodstream and migrated into a tumor. They are mononuclear immune cells, a mix of different types of cells (i.e., T cells, B cells, NK cells, macrophages) in variable proportions, T cells being the most abundant cells. They can often be found in the stroma and within the tumour itself. TILs are implicated in killing tumor cells. The presence of lymphocytes in tumors is often associated with better clinical outcomes.
The use of TILs as an adoptive cell transfer therapy to treat cancer was pioneered by Dr. Steven Rosenberg at the National Cancer Institute. Autologous lymphocytes are isolated from patients’ tumors and cultured to large numbers of cells in vitro. Prior to TIL treatment, patients are given nonmyeloablative chemotherapy to deplete native lymphocytes that can inhibit the response. Once lymphodepletion is completed, patients are infused with TILs in combination with interleukin 2 (IL-2). Lion Biotechnologies is developing adoptive cell transfer with TILs as a cancer therapy.]
Which signal molecule converts lymphocytes to lymphokine-activated killer (LAK) cells by enhancing their immune response to tumor?
IL-2
[Wikipedia: In cell biology, a lymphokine-activated killer cell (also known as a LAK cell) is a white blood cell that has been stimulated to kill tumor cells. If lymphocytes are cultured in the presence of Interleukin 2, it results in the development of effector cells which are cytotoxic to tumor cells.
It has been shown that lymphocytes, when exposed to Interleukin 2, are capable of lysing fresh, non-cultured cancer cells, both primary and metastatic. LAK cells respond to these lymphokines, particularly IL-2, by lysing tumor cells that were already known to be resistant to NK cell activity.
The mechanism of LAK cells is distinctive from that of natural killer cells because they can lyse cells that NK cells cannot. LAK cells are also capable of acting against cells that do not display the major histocompatibility complex, as has been shown by the ability to cause lysis in non-immunogenic, allogeneic and syngeneic tumors. LAK cells are specific to tumor cells and do not display activity against normal cells.
LAK cells, along with the administration of IL-2 have been experimentally used to treat cancer in mice and humans, but there is very high toxicity with this treatment.]
What do the variable and constant regions of an immunoglobulin recognize or get recognized by?
- Variable region: Antigen recognition
- Constant region: PMNs and macrophage recognition
Which cell type is the major source of histamine in the tissue?
Mast cell
What are the 3 primary lymphoid organs?
- Liver
- Bone
- Thymus
The intradermal TB skin test is used to test which component of immunity?
Cell-mediated immunity
How should a patient with a non-tetanus-prone wound be treated with regards to tetanus prophylaxis?
The tetanus toxoid vaccine should be administered only if the patient has received fewer than 3 doses or if the patient’s tetanus status is unknown
Which cell type is the major source of histamine in the blood?
Basophil
What happens when eosinophils with IgE receptors for an antigen release major basic protein?
Mast cells and basophils get activated, resulting in the release of histamine, serotonin and bradykinin
[Type I hypersensitivity reaction]
