Untitled - D Ank Unlimited

Nijmegen breakage syndrome (NBS) 533 NOD proteins
reduce NBT. The ability to reduce NBT to the insoluble
formazan crystals depends on the generation of superoxide
in the neutrophil tested.
Nijmegen breakage syndrome (NBS)
A primary immunodeficiency including variable hypogammaglobulinemia
and CID. Ionizing radiation of patient cells
reveals significant levels of chromosomal defects. Induced
by mutations in the gene that encodes nibrin, a protein associated
with the NHEJ pathway of DNA repair.
NK1.1
A natural killer (NK) cell alloantigen identified in selected
inbred mouse strains such as C57BL/6 mice.
NK1.1 CD4 T cells
A minor T cell subset that expresses the NK1.1 marker, a
molecule usually present on natural killer cells. NK1.1 T
lymphocytes also express α:β T cell receptors of limited
diversity and coreceptor molecule CD4 or no coreceptor.
They are present in abundance in the liver and synthesize
cytokines soon after stimulation.
NK1-T cell
A lymphocyte that shares certain characteristics with
T cells such as T cell receptors in addition to those of natural
killer cells.
NK activatory receptors
ITAM-bearing receptors which, when engaged with inhibitory
receptor interaction, lead to natural cytotoxicity and
cytotoxic cytokine secretion by NK cells causing deaths of
target cells bereft of self MHC class I molecules. The group
includes NCR, KAR, NKG2D, -C and –E and Ly-49D, -H,
-P and –W.
NK cell lectin-like receptors
One of the two principal structural classes of NK cell activating
and inhibitory receptors.
NK cells
Refer to natural killer cells.
NK inhibitory receptors
ITIM-bearing receptors that, when engaged by self-MHC
class I molecules on a target, dampen the effects of NK
activatory receptor engagement, thereby inhibiting destruction
of target cells. Includes KIRs; Ly-49A, -B, -C, -E, -F,
-G, Ly-49I: NKG2A and –B; and IL-T2.
NK/T precursor
Common lymphoid progenitor derived predecessor capable
of differentiating into T or NK cells but not B cells.
NKT
Refer to natural killer T cells.
NKT cell
A lymphoid cell that is intermediate between T lymphocytes
and natural killer (NK) cells with respect to morphology
and granule content. Lymphoid cells may be CD4 – 8 – or
CD4 + 8 – weakly expressed α:β T cell receptors (TCRs)
with an invariant α chain and highly restricted β chain
specificity. They have a powerful capacity to synthesize
interleukin-4 (IL4). Many of these TCRs recognize antigens
presented by the nonclassical major histocompatibility
complex (MHC)-like CD1 molecule. Their surface NK1.1
receptors are lectin-like and are believed to recognize
microbial carbohydrates.
NK tolerance
Fostered during NK cell development through selection
of only NK clones bearing NK inhibitory receptors that
are capable of recognizing self-MHC and sending a strong
enough signal to overcome NK activatory receptory signaling
induced by host cells.
N-linked oligosaccharide
An oligosaccharide covalently linked to asparagine
residues in protein molecules. N-linked oligosaccharide
manifests a branched core structure composed of two
N-acetylglucosamine residues and three mannose residues.
The three types differ on the basis of their exterior
branches: (1) high-mannose oligosaccharide reveals two to
six additional mannose residues linked to the polysaccharide
core; (2) complex oligosaccharide composed of two to
five terminal branches that consist of N-acetylglucosamine,
galactose, often N-acetylneuraminic acid, and occasionally
fucose or another sugar; and (3) hybrid molecules
that reveal characteristics of high mannose and complex
oligosaccharides.
N nucleotides
Nontemplated nucleotides that terminal deoxynucleotidyl
transferase (TdT) adds to the 3′ cut ends of V, D, and J
coding segments during rearrangement. They are added
to junctions between V, D, and J gene segments in immunoglobulin
or T cell receptor genes during lymphocyte
development. When as many as 20 of these nucleotides
are added, the diversity of the antibody and T cell receptor
repertoires is expanded.
Nocardia immunity
Infection by microorganisms of this genus usually begins
as a pulmonary infection that may be localized or disseminated.
Nocardia species have complex antigenic structures.
Immunocompromised patients face increased likelihood
of developing nocardial infections. Defects in the mononuclear
phagocyte system increase host susceptibility. The
microorganisms grow in monocytes and macrophages. T
cells of mice immunized against whole cells of Nocardia
species become immunologically reactive against the
microorganism and kill it directly. T cell-deficient athymic
mice show increased susceptibility to nocardial infection,
but B cell-deficient mice do not. Thus, T cells rather than B
cells are critical for host immunity against nocardial infection.
No effective vaccine against Nocardia is currently
available.
NOD (nonobese diabetic) mouse
A mutant mouse strain that spontaneously develops type I
insulin-dependent diabetes mellitus, an autoimmune disease;
the strain exhibits an autosomal-recessive pattern of
inheritance for the NOD mutation. Lymphocytes infiltrate
NOD mouse islets of Langerhans in the pancreas and kill
β cells. Humans with insulin-dependent diabetes mellitus
have defects in the HLA-DQ parts of the major histocompatibility
complex (MHC) class II region. There is also a
defect in the class II IA region of murine MHC class II. A
major DNA segment is missing from the NOD mouse MHC
IE region. When the IE segment is inserted or the IA defect
is corrected in these mice, disease progression is halted.
This strain represents a significant animal model for human
type I diabetes mellitus.
NOD proteins
Nucleotide-binding oligomerization domain proteins.
Cytoplasmic pattern recognition molecules capable of
detecting intracellular pathogen products. Related structurally
to Toll-like receptors. NOD protein engagement leads
to expression of pro-inflammatory cytokines.
N