Seroatlas · Human Serome Atlas

ICOSLG

ICOS ligand

Also known as: B7-H2, B7h, B7H2, B7RP-1, B7RP1, CD275, GL50, ICOS-L, ICOSL, ICOSL_HUMAN, KIAA0653

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
O75144
Gene
ICOSLG
Ensembl
ENSG00000160223
Chromosome
21
Canonical length
302 aa
Protein class
CD markers, Plasma proteins, Predicted intracellular proteins, Predicted membrane proteins
Subcellular location
Vesicles,Plasma membrane

OverviewNCBI Gene

Enables identical protein binding activity and receptor ligand activity. Involved in T follicular helper cell differentiation. Located in intracellular membrane-bounded organelle. Is active in plasma membrane. [provided by Alliance of Genome Resources, Apr 2025]

Canonical amino-acid sequenceUniProt

302 residues, UniProt reviewed canonical sequence.

>O75144|ICOSLG
     1  MRLGSPGLLF LLFSSLRADT QEKEVRAMVG SDVELSCACP EGSRFDLNDV YVYWQTSESK
    61  TVVTYHIPQN SSLENVDSRY RNRALMSPAG MLRGDFSLRL FNVTPQDEQK FHCLVLSQSL
   121  GFQEVLSVEV TLHVAANFSV PVVSAPHSPS QDELTFTCTS INGYPRPNVY WINKTDNSLL
   181  DQALQNDTVF LNMRGLYDVV SVLRIARTPS VNIGCCIENV LLQQNLTVGS QTGNDIGERD
   241  KITENPVSTG EKNAATWSIL AVLCLLVVVA VAIGWVCRDR CLQHSYAGAW AVSPETELTG
   301  HV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against ICOSLG can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.39
Highest tissue expression
16 nTPM

Expression across tissuesHPA

Tissue

  • bone marrow: 16 nTPM
  • cerebral cortex: 12 nTPM
  • lymph node: 11 nTPM
  • hippocampal formation: 11 nTPM
  • spinal cord: 10 nTPM
  • tonsil: 9.8 nTPM

Single-cell type

  • pdcs: 3.2 nCPM
  • podocytes: 3.1 nCPM
  • foveolar cells: 2.7 nCPM
  • b-cells: 2.6 nCPM
  • esophageal apical cells: 2.5 nCPM
  • cdc: 2.1 nCPM

Immune cell

  • naive B-cell: 4.3 nTPM
  • memory B-cell: 2.6 nTPM
  • neutrophil: 1.6 nTPM
  • plasmacytoid DC: 1.2 nTPM
  • basophil: 1.1 nTPM
  • intermediate monocyte: 1 nTPM

Brain region

  • white matter: 95 nTPM
  • basal ganglia: 70 nTPM
  • cerebral cortex: 69 nTPM
  • thalamus: 62 nTPM
  • medulla oblongata: 61 nTPM
  • midbrain: 61 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about ICOSLG.

Disease | AllUniProt

Conditions ICOSLG is implicated in, by any mechanism.

Disease | GeneticClinVar

2 pathogenic / likely-pathogenic of 321 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.92
gnomAD pLI
0
gnomAD missense Z
1.13
DepMap mean gene effect
0.05
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of ICOSLG in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads ICOSLG as an antibody target. Whether an autoantibody or antibody against ICOSLG could matter depends on whether native ICOSLG is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

ICOSLG is annotated at the cell surface, where native ICOSLG is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label ICOSLG as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/ICOSLG. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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