Acute Rejection of Transplanted Organs

Unit 4 Video 30 Chapter 15
This video covers acute rejection of transplanted organs by the direct pathway of allorecognition, as well as the mixed lymphocyte reaction used to screen for this possibility before organ transplant.

[@CameronGhassemi]

this was great, thank you

[@hannahbailey2]

Thank you so much !!! this makes so much more sense

[@LAMl17]

🥲🥰😍

[@theresetran8215]

I have a question! You said that there are not antibodies involved, but can't recipient CD4 cell stimulate antibody production as well in this case by release of cytokines that promote B cell proliferation and differentiation into plasma cells? Just verifying! Love the vid!

[@t.c.s.7724]

Nice presentation. Unfortunately, the volume is extremely low especially in comparison to obnoxious, loud advertisements.

[@JoeDeMasiScience]

Sorry about that

[@sean-lucshanahan9140]

You speak about alloreactive T-cells as being capable of binding non-self MHC molecules with an even greater affinity than self-MHC molecules + foreign antigen. Is it understand how alloreactive T-cells are trained to recognize non-self MHC molecules with such strong binding? Clearly it must be driven more by the differences in the MHC molecule itself than any allogenic peptide it may be presenting...

[@noa3788]

Why HLA typing is required in renal and cardiac transplant while it is not necessary for other solid organ transplant ?

[@lululewiss2063]

thank you so much

[@JoeDeMasiScience]

You are welcome!

[@agrawalgeorgia6370]

very good video. answered a lot of my questions

[@JoeDeMasiScience]

Good to hear!

[@MarwaAhmed-sv1sl]

I can't understand why do t-cell binds to mhc molecules of donor without infection ... How it recognize 3 dimensional shape of it ?!

[@je6874]

Essentially, donor APCs (e.g. DCs) are still active immune cells that constantly sample their environment and phagocytise debris. They will then enter a draining lymph node as they follow chemokine signals like in any other human (e.g. CXCL13) once the blood vessels are joined. They present peptide:MHC to recipient T-cells but you have to remember that the T-cells will recognise an overall conformation of peptide:MHC --> for recipient MHC, their peptide sequences are different (assuming you don't have a 100% match) and so have a different overall conformation. This difference is recognised by the recipient T-cell, which becomes activated in the usual fashion (e.g. co-stimulation by B7, CD40, cytokines etc.).

[@hananhasan2692]

Thank you

[@bigdaddyblackful]

3:59 shouldn't it be donor dendritic cells and recipient T cells? Not the other way around

[@sean-lucshanahan9140]

yeah should be flipped.

[@liliumauratum9593]

since when T cells have MHC -1 on them?

[@nikitakhazov2403]

all nucleated cells do