Seroatlas · Human Serome Atlas

CD28

T-cell-specific surface glycoprotein CD28

Also known as: CD28_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P10747
Gene
CD28
Ensembl
ENSG00000178562
Chromosome
2
Canonical length
220 aa
Protein class
CD markers, Predicted membrane proteins
Subcellular location
Plasma membrane
Quaternary structure
Homodimer

OverviewNCBI Gene

The protein encoded by this gene is essential for T-cell proliferation and survival, cytokine production, and T-helper type-2 development. Several alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Jul 2011]

Canonical amino-acid sequenceUniProt

220 residues, UniProt reviewed canonical sequence.

>P10747|CD28
     1  MLRLLLALNL FPSIQVTGNK ILVKQSPMLV AYDNAVNLSC KYSYNLFSRE FRASLHKGLD
    61  SAVEVCVVYG NYSQQLQVYS KTGFNCDGKL GNESVTFYLQ NLYVNQTDIY FCKIEVMYPP
   121  PYLDNEKSNG TIIHVKGKHL CPSPLFPGPS KPFWVLVVVG GVLACYSLLV TVAFIIFWVR
   181  SKRSRLLHSD YMNMTPRRPG PTRKHYQPYA PPRDFAAYRS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CD28 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)
0.44
Highest tissue expression
29 nTPM

Expression across tissuesHPA

Tissue

  • thymus: 29 nTPM
  • lymph node: 26 nTPM
  • tonsil: 17 nTPM
  • appendix: 14 nTPM
  • placenta: 14 nTPM
  • spleen: 6.8 nTPM

Single-cell type

  • t-cells: 147 nCPM
  • hofbauer cells: 113 nCPM
  • thymocytes: 51 nCPM
  • macrophages: 16 nCPM
  • innate lymphoid cells: 12 nCPM
  • platelets: 8.4 nCPM

Immune cell

  • T-reg: 102 nTPM
  • memory CD4 T-cell: 55 nTPM
  • MAIT T-cell: 51 nTPM
  • naive CD4 T-cell: 48 nTPM
  • memory CD8 T-cell: 26 nTPM
  • naive CD8 T-cell: 19 nTPM

Brain region

  • choroid plexus: 2.3 nTPM
  • thalamus: 0.8 nTPM
  • cerebral cortex: 0.6 nTPM
  • medulla oblongata: 0.6 nTPM
  • white matter: 0.6 nTPM
  • amygdala: 0.5 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about CD28.

Disease | AllUniProt

Conditions CD28 is implicated in, by any mechanism.

  • Immunodeficiency 123 with HPV-related verrucosis (IMD123) MIM:620901

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 21 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Immunodeficiency 123 with HPV-related verrucosis

Disease | AutoantibodyPubMed

Conditions in which antibodies against CD28 are reported. Each links to that disease's full target list.

ReferencesPubMed · IEDB

Publications for CD28 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Reference: AutoantibodyPubMed

19 publications

Show 14 more

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

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)
0.71
gnomAD pLI
0.36
gnomAD missense Z
0.8
DepMap mean gene effect
0
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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 CD28 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 CD28 as an antibody target. Whether an autoantibody or antibody against CD28 could matter depends on whether native CD28 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CD28 is annotated at the cell surface, where native CD28 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 CD28 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CD28. 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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