Chapter 17 - Specific Immunity Flashcards
The third line of defense is ________
Acquired
Due to dual system of B and T lymphocytes
Third line of defense
Distinction between PAMPs and antigens
Antigen
What are two features that characterize specific immunity?
- Specificity
- Memory
What are the T cells involved in cell mediated immunity called?
Helper and killer T cells
Antibody mediated immunity
B cells
Fight infection
Plasma B cells
Remembers
Memory B cells
What are the major functions of cell receptors?
- To perceive and attach to nonself or foreign molecules
- To promote the recognition of self molecules
- To receive and transmit chemical messages among other cells of the system
- To aid in cellular development
- Receptors found on all cells except RBCs
- Plays role in recognition of self
Major Histocompatibility Complex (MHC)
Genes for MHC clustered in a multigene complex are either:
- Class I
- Class II
- Role in surveillance and recognition
- B-cell receptors
- T-cell receptors
- Clonal Selection Theory
Lymphocyte receptors
Memory cells are stored in the _________ ______
Lymphatic system
- Formed by genetic recombination, with variable and constant regions
- 2 parallel polypeptide chains
- Small, not secreted
T-Cell receptors for antigen
- Bone marrow and stromal cells
- Distinct B cells
- Antigens
- Immunoglobin
B-cell maturation
- Thymus gland
- T-cell receptors
- CD4 and CD8
- Mature T cells migrate to lymphoid organs
T-cell maturation
What does Ag stand for?
Antigen
Foreigness, size, shape, and accessibility
Antigenicity
- Perceived as foreign
- Foreign cells and large complex molecules
- Antigenic determinants
- Epitope
Antigens
Small foreign, molecules that consist only of a determinant group
- Not antigenic unless attached to a larger carrier
Haptens
What are the special categories of antigens?
- Alloantigens
- Superantigens
- Allergen
- Autoantigens
What are the five classes of immunoglobulins (Ig)?
- IgG
- IgA
- IgM
- IgD
- IgE
Produces IgM and IgG
Primary response
Anamnestic response
Secondary response
- Act directly against Ag and foreign cells
- Secrete ctokines
T cells
Sensitized T cells are:
Cell mediated immunity
What are the three types of T cells?
- T helper cells (CD4 or T^H)
- Cytotoxic T cells (CD8 or T^c)
- Natural killer cells
- Reaction has drastic consequences
- Superantigens are a form of a virulence factor
- Provoke overwhelming immune responses by large numbers of T cells
T cells and superantigens
What overwhelming immune responses by large numbers of T cells are provoked by T cells and superantigens?
- Release of cytokines
- Blood vessel damage
- Toxic shock
- Multiorgan damage
Immune serum globulin (ISG), gamma globulin, contains immunoglobulin extracted from pooled blood; immunotherapy
Passive immunity
Deliberately exposing a person to material that is antigenic but not pathogenic
Artificial active immunity (Vaccination)
Stimulate a primary and secondary anamnestic response
Principal of vaccination
Response to a future exposure will be immediate, powerful, and sustained
Vaccination
Most vaccines are prepared from:
- Killed whole cells or inactivated viruses
- Live, attenuated cells or viruses
- Antigenic molecules derived from bacterial cells or viruses
- Genetically engineered microbes or microbial agents
- Cultivate and kill but do not destroy antigenicity
- Often require a larger dose and more boosters to be effective
Killed or inactivated vaccines
Lessens or negates the virulence of viruses or bacteria
Live attenuated cells or viruses
Acellular or subcellular vaccines (subunit-if a virus)
Antigenic molecules
Exact antigenic determinants can be used when known:
- Capsules- pneumococcus, menigococcus
- Surface protein- anthrax, hepatitis B
- Exotoxins- diphtheria, tetanus
_______ can be taken from cultures, produced by genetic engineering, or synthesized
Antigen
Insert genes for pathogen’s antigen into plasmid vector, and clone them in an appropriate host
Genetically engineered vaccines
Experimental vaccines for AIDS, herpes simplex 2, leprosy, tuberclosis
“Trojan horse” vaccine
Experimental vaccines for Lyme disease, hepatitis C, herpes simplex, influenza, tuberculous, malaria
DNA vaccines
Most vaccines are administered by _________; few oral, nasal
Injection
Some vaccines require adjuvant to _______ ____________ and prolong retention of antigen
Enhance immunogenicity
There are _________ requirements for development of vaccines
Stringent
There are more ________ than ____ to vaccines
Benefits than risk
Possible side effects of a vaccine include:
Local reaction at injection site, fever, allergies; rarely back-mutation to a virulent strain, neurological effects
