Tumor necrosis factor receptor superfamily, member 4 (TNFRSF4), also known as CD134 and OX40, is a member of the TNFR-superfamily of receptors which is not constitutively expressed on resting naïve T cells, unlike CD28. OX40 is a secondary co-stimulatory immune checkpoint molecule, expressed after 24 to 72 hours following activation; its ligand, OX40L, is also not expressed on resting antigen presenting cells, but is following their activation. Expression of OX40 is dependent on full activation of the T cell; without CD28, expression of OX40 is delayed and of fourfold lower levels.
OX40 has no effect on the proliferative abilities of CD4+ cells for the first three days, however after this time proliferation begins to slow and cells die at a greater rate, due to an inability to maintain a high level of PKB activity and expression of Bcl-2, Bcl-XL and survivin. OX40L binds to OX40 receptors on T-cells, preventing them from dying and subsequently increasing cytokine production. OX40 has a critical role in the maintenance of an immune response beyond the first few days and onwards to a memory response due to its ability to enhance survival. OX40 also plays a crucial role in both Th1 and Th2 mediated reactions in vivo.
[Verse:]
He gave his baby boy a bath
Tub full of bubbles and toys for him to splash
Look at daddy, soapsuds mustache
Funny faces and voices, it makes the baby belly laugh
Dry him off, now you squeaky clean
And watch the water spiral down that drain
Wrap him in a towel so he doesn't get the shivers
Brush his hair, it seems to help it dry it quicker
Laid him on mommy and daddy's bed now that he's dry
And put a diaper on him, gave him his pacifier
Superman pajamas, so tough
Innocent face full of unconditional love
Daddy picked him and rocked him slow
Never takes long for little guy's eyes to close
Dad's technique is different than your mother's
Never learned any lullabies, he sings Stevie Wonder's
There it is, steady breathing, sleep rhythm
Daddy sits and holds him just to listen for a minute
Daddy's hands are the meaning of security
And baby's hands are the evidence of purity
Thinking back to the day baby came
And how it changed the whole game, things ain't the same
Daddy had to stop running it crazy
Keep his ass in the home with the son and his lady
He was there for the birth and the first breath
Not gonna miss the first words or the first steps
Gonna keep the boy healthy and safe
And do his best to try to keep those tears off his face
Gave him a kiss, laid him in his crib
Turned out the lights, goodnight my little prince
That's how good daddy takes care of him