CHAPTER 1 IMMUNO teil 1

They kill ingested microbes.

40 through 45%.

They are self-limited and decline, allowing the system to return to homeostasis.

206,939 cases in 1921.

It is always present and rapidly eliminates microbes that enter host tissues.

To prevent and eradicate infections.

They engulf and show microbes within 6 to 12 hours after infection.

They proliferate and differentiate into effector cells and memory cells.

Antibody production (humoral immunity).

They kill infected cells and eliminate reservoirs of infection.

Increased risk for serious, often life-threatening infections.

Protection against infectious pathogens and reactions to some noninfectious substances.

Antibodies produced by B lymphocytes.

It enhances responses upon repeat exposures to the same microbe.

To eliminate antigens.

Humoral immunity and cell-mediated immunity.

Antibodies that eliminate extracellular microbes.

To lymph nodes.

Very low.

They prevent infections and eliminate extracellular microbes.

Antigens.

In the generative lymphoid organs (bone marrow and thymus).

T lymphocytes.

They differ in function and lifespan, with memory cells being long-lived.

Lymphocytes recognize peptides displayed by infected or tumor cells and kill these cells.

By exposure to microbial antigens through infection or vaccination.

B lymphocytes, helper T lymphocytes, cytotoxic T lymphocytes, and regulatory T lymphocytes.

Intracellular microbes that survive inside host cells.

Secondary responses are larger, more rapid, and better at eliminating the antigen compared to primary responses.

Only for as long as the transferred antibodies are present in the body.

It allows the immune system to distinguish millions of different antigens and respond specifically to the infecting microbe.

They die by apoptosis after several months to a few years and are replaced by new cells.

Anti-X antibody and anti-Y antibody.

They prevent microbe entry shortly after infection.

Cell-mediated immunity.

By recruiting phagocytes to sites of infection.

They secrete cytokines to activate phagocytes and kill infected cells.

Regulatory T cells limit the activation of other lymphocytes, particularly T cells, and prevent autoimmunity.

IgM and IgD.

The inciting antigens cannot be eliminated.

They can protect against infections and tumors but can also lead to pathologic inflammation and diseases.

Vaccines confer long-lasting protection against infections through the activation of memory cells.

They are specialized to defend against different kinds of microbes and at different sites of infections.

Innate immunity and adaptive immunity.

It adapts to the presence of microbial invaders through the proliferation and differentiation of lymphocytes.

Progenitors in the bone marrow.

They display peptide fragments of protein antigens to T lymphocytes.

Components of the innate immune system, such as phagocytes and the complement system, defend against them.

They eliminate microbes that have breached the body’s barriers.

It ensures that immune responses are precisely targeted to microbial pathogens.

It enables the immune system to respond to a large variety of antigens.

Microbes bind to B lymphocytes through their Y-shaped receptors.

Mediators of humoral immunity and specific recognition of antigens.

Killing of infected cells.

They are indicated by the troughs formed after the peaks.

Natural immunity or native immunity.

Circulation, extracellular tissue fluids, and lumens of mucosal organs.

Clones of lymphocytes specific for different antigens develop before encountering those antigens.

A collection of cells, tissues, and molecules that mediate reactions to pathogens and other substances.

When a large fraction of the population develops immunity through vaccination or natural infection.

Because populations had not been previously exposed and were hence not immune.

Any molecule specifically recognized by lymphocytes or antibodies.

Immune responses recognizing and responding to tissue grafts and newly introduced proteins.

Antibodies.

The marked proliferative expansion of the clone of lymphocytes specific for any antigen upon exposure to that antigen.

Long-lived plasma cells in the bone marrow.

It leads to autoimmune diseases.

All cells of one clone express identical antigen receptors, which are different from the receptors of other clones.

Antigen recognition.

CD4+ T cells help B lymphocytes and phagocytes; CD8+ T cells kill cells harboring microbes.

Myeloid cells and lymphoid cells (lymphocytes).

Epithelial barriers, antimicrobial substances, and certain immune cells.

1,192 cases.

152,209 cases in 1968.

18,617 cases in 2019, compared to a maximum of 265,269 in 1934.

0 cases.

57,686 cases in 1969.

The immune system does not normally respond to self molecules.

They produce cytokines that activate B cells, macrophages, and other cell types.

It generates more memory cells and activates previously generated memory cells.

The immune system's unresponsiveness to self antigens, allowing coexistence with potentially antigenic self molecules.

The total collection of lymphocyte specificities, which is extremely diverse and allows the immune system to react to many pathogens.

Membrane-bound antibodies that recognize antigens.

It responds immediately, within hours after infection.

Immature B lymphocytes in the bone marrow and naive T lymphocytes in the thymus.

Microbes attaching to B lymphocytes or T lymphocytes.

Smallpox.

Naïve cells, activated or eTector lymphocytes, and memory lymphocytes.

They represent primary and secondary antibody responses to antigens X and Y over weeks.

There is no herd immunity or effective vaccine.

Primary anti-X response.

Secondary anti-X response.

Neutralization of microbes, phagocytosis, and complement activation.

An immune individual has been exposed to the microbe's antigens, while a naive individual has not.

They recognize peptides displayed by MHC molecules and secrete cytokines to stimulate various immune mechanisms.

CD3 positive, CD4 negative, CD8 positive.

Responding to antigens.

Innate immunity and adaptive immunity.

In the bone marrow.

Innate immunity.

Antibody-secreting plasma cells.

Signals in addition to antigens (specific signals not shown).

Specificity, diversity, memory, and nonreactivity to self.

Peptide fragments of protein antigens presented on cell surfaces.

Immunity conferred by the transfer of antibodies from an actively immunized individual.

Cytokine secretion and cytotoxic activity.

It controls tissue regeneration and scarring.

Memory cells can survive for long periods in the absence of antigen, while effector T lymphocytes are short-lived.

Relatively high.

The process where a specific antigen selects a preexisting clone of lymphocytes with identical receptors to proliferate and differentiate.

By preventing them from infecting tissue cells and neutralizing toxins.

Stimulating immune responses through vaccination.

They help to initiate immune responses.

They produce clonally distributed receptors specific for diverse antigens.

By the expression of surface molecules recognized by monoclonal antibodies.

Primary anti-Y response.

The risks for developing a severe case of COVID-19.

They decline with time.

It boosts immune defenses and protects against infections.

It optimizes the immune system's ability to combat persistent and recurrent infections.

A naive individual receives antibodies from another immune individual or from laboratory-produced protective antibodies.

Newborns receiving antibodies from their mothers through the placenta and breast milk.

About 0.5 to 1 × 10^12 B and T lymphocytes.

To prevent or limit immune responses.

The bone marrow and thymus where mature lymphocytes are produced.

It delineates surface proteins that define a particular cell type or stage of cell differentiation.

Memory and specificity.

The ability of the adaptive immune system to mount faster and more effective responses to repeated exposures to the same antigen.

Naive lymphocytes encountering the antigen for the first time.

Microbial antigens presented by antigen presenting cells and cytokines.

Therapeutic blockade of cytokines.

In blood, it's 35-60% and in lymph nodes, it's 50-60%.

They arise in generative lymphoid organs to recognize a wide variety of antigens.

The study of the immune system and its functions.

It can prevent tumor growth and stimulate immune responses against tumor cells, foundational for cancer immunotherapy.

They can cause inflammatory diseases, allergies, autoimmune diseases, and damage transplanted tissues.

It is the primary defense against infections, and deficient immunity increases susceptibility to infections.

Cancer immunotherapy.

They produce anti-X antibodies that bind to anti-Y B cells.

Inflammatory responses to the virus.

As few as 1 in 100,000 or 1 in 1,000,000 lymphocytes.

Neutrophils, macrophages, dendritic cells, and mast cells.

Activation of memory lymphocytes, which are long-lived cells induced during the primary immune response.

Antigen presentation to T cells and initiation of T cell responses.

Suppression of other lymphocytes.

It can treat immunodeficiency diseases and provide emergency treatment for some viral infections and snakebites.