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The introduction of pathogens and foreign proteins into the human body can stimulate immune recognition, leading to inflammatory and allergic responses. Aspects of these responses are subject to pharmacological modulation. Before describing the actions of pharmacological agents affecting allergy and immunity, this chapter describes the cellular and molecular basis of immune and allergic responses and the points of pharmacological intervention. Subsequent chapters in this section cover in detail the classes of agents that can alter allergic and immune responses, as well as the biology and pharmacology of inflammation.
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Abbreviations
APC: antigen-presenting cell
BCR: B-cell receptor
C#: complement component # (e.g., C3, C5)
CAR: chimeric antigen receptor
CLL: chronic lymphocytic leukemia
CR1: complement receptor 1
CTLA-4: cytotoxic T-lymphocyte–associated protein 4
DC: dendritic cell
DN: double negative
DP: double positive
ER: endoplasmic reticulum
GI: gastrointestinal
HLA: human leukocyte antigen
HSC: hematopoietic stem cell
ICI: immune checkpoint inhibitor
IFN: interferon
Ig: immunoglobulin
IL: interleukin
iNOS: inducible nitric oxide synthase: NOS2
IRF: interferon regulatory factor
ISG: interferon-stimulated gene
ISRE: interferon-stimulated response element
LT: long term
MADCAM-1: mucosal vascular addressin cell adhesion molecule 1
MALT: mucosa-associated lymphoid tissue
MHC: major histocompatibility complex
NF-κB: nuclear factor-κB
NK cell: natural killer cell
NO: nitric oxide
PAMP: pathogen-associated molecular pattern
PD-1: programmed cell death protein 1
PRR: pattern recognition receptor
Rh: rhesus
ROS: reactive oxygen species
SARS-CoV-2: severe acute respiratory syndrome coronavirus 2
scFv: single-chain variable fragment
ST: short term
TC: cytotoxic T cell
TCR: T-cell receptor
TH: helper T cell
TLR: toll-like receptor
TNFα: tumor necrosis factor α
TReg: T-regulatory cells
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CELLS AND ORGANS OF THE IMMUNE SYSTEM
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All blood cells, including immune cells, originate from pluripotent hematopoietic stem cells (HSCs) of the bone marrow. HSCs are a population of undifferentiated progenitor cells that are capable of self-renewal. On exposure to cytokines and contact with the surrounding stromal cells, HSCs can differentiate into megakaryocytes (the source of platelets), erythrocytes (red blood cells), and leukocytes (white blood cells). This process is known as hematopoiesis (Figure 38–1).
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The HSC pool can be divided in two populations: long-term (LT) and short-term (ST) HSCs. LT-HSCs are capable of lifelong self-renewal, allowing for continuous hematopoiesis throughout life. ST-HSCs have limited self-renewing capability and differentiate into multipotent progenitors—the common myeloid progenitor and the common lymphoid progenitor. The common myeloid progenitor gives rise to the myeloid lineage of cells that includes megakaryocytes, erythrocytes; granulocytes (neutrophils, eosinophils, basophils, mast cells), monocytes, macrophages, and dendritic cells (DCs). In contrast, the common lymphoid progenitor gives rise to the lymphoid lineage of cells ...