Inmuno

Sistema inmunológico

What is immunology?
• It is the science that studies all mechanisms
physiological, specific and nonspecific, which
involved in the defense of an organism.

Concepts
• Immunity
Is defined as resistance to disease, specifically
infectious disease.
• Immune system
. The collection of cells, tissues, and molecules that
mediate resistance to infections
• Immune response
• Thecoordinated reaction of these cells and
molecules to infectious microbes

Function
• The most important physiologic function of the
immune system is t prevent infections and to
eradicate established infections.
• Recognize "self"
• Destroy the "non-self"
• Remember the "enemy“

The immune system arises as a function essential for
life in an environment where coexist pathogens and
hosts. Effectiveness of vaccination for some
common infectious diseases.

INNATE AND ADAPTIVE IMMUNITY
• immunity, which mediates the initial protection
against Host defense mechanisms consist of innate
oefinfections, and adaptive immunity, which
develops mfective defense against infections
• re slowly and provides more specialized and

Innate immunity
• Also called natural immunity or native
immunity, isalways present in healthy
individuals (hence the term innate), prepared to
block the entry of microbes and rapidly
eliminate microbes
that do succeed in entering
Adaptive
immunity
host tissues.
•  Also called specific immunity or acquired
immunity, requires expansion and
differentiation of lymphocytes in response to
microbes before it can provide effective
defense; that is, it adapts to the presenceof
microbial invaders.
.

Antigens
• A variety of molecules produced by microbes as
well as noninfectious substances
It is any substance capable of generating a full immune response.

• What makes a substance is immunogenic?
Other features ...
•   Character strange.
•   Size.
• Chemical complexity

Principal mechanisms of innate and
adaptive immunity.

TYPES OF ADAPTIVE
IMMUNITY
• The twotypes of adaptive immunity, humoral immunity and
immunity cell, are mediated by different cells and molecules
and provide defense against extracellular microbes and
intracellular microbes, respectively.
• Humoral immunity is mediated by proteins called antibodies
• One of the most important functions of antibodies is to stop
microbes that are present at mucosal surfaces and in the blood
from gainingaccess to and colonizing host cells and connective
tissues.
• Immunity Cell. Because it is mediated by cells, which are called T
lymphocytes

• Immunity may be induced in an individual by
infection or vaccination (active immunity) or
conferred on an individual by transfer of
antibodies or lymphocytes from an actively
immunized individual (passive
immunity). In active immunity

,

• Primaryimmune response, is mediated by lymphocytes
called naive lymphocytes that are seeing antigen for the first
time
• Subsequent encounters with the same antigen lead to
responses called secondary immune responses
• Secondary responses are the result of the activation of
memory lymphocytes, which are long-lived cells that were
induced during the primary immune response.

B lymphocytes recognize wholeantigens
T cells recognize antigen fragments
Linfocitos T
• Helper T cells (CD4). Because they help B lymphocytes to produce antibodies and help
phagocytes to destroy ingested microbes.
• Cytotoxic T lymphocytes (CD8). Because they kill cells harboring intracellular microbes.
• Regulatory T lymphocytes. Functions to prevent or limit immune responses.
• Natural killer (NK) cells. Kill infected hostcells, but unlike B and T cells, they do not
express clonally distributed antigen receptors. NK cells are components of innate
immunity, capable of rapidly attacking infected cells.

TEJIDOS
DEL
SISTEMA
INMUNE

• Los tejidos del Sistema immune tienen organos
linfoides en los cuales maduran los linfocitos T
y B y llegan a ser competentes en la eliminación
de antígenos.
• La respuesta immune...