By An indian boi
Okay for question to describe the complement cascade and how it’s activated by a classical okay let’s first take a look at the classical pathway so the classical pathway is basically i created by antibody and antigen-antibody complex where there’s a complement binding site on an antibody where c1 protein can bind to c1 is made of three subunits mainly c1 q c1 r
And c 1 s 2 subunits of c1 r and t 1s and one subunit of c1 q c 1 s is going to be what’s responsible for the cleavage of the following steps so c1 from c4 b to a wire the cleavage of c4 e and c to be c4 b to a is a silicon with in satcon with c 3 b 2 c 3 c 3 2 c 3 b wire the cleavage of c 3 a which c3b combines with the c 4 b to a complex to form a c5 convertase
Sefa 4 b 2 a 3 b c5 then formed c 5b wire a cleavage of c5 a by c5 convertase and c-file be incorporated with c6 c7 and c8 proteins into the cell membrane this complex will then recruits c9 proteins to form the membrane attack complex leading to lysis of a pathogen cell as for the alternative pathway the alternative pathway spontaneous receipt reform c3b and c3a
And c3b from c3 bb wire a combination of vector b and c 3 bb from c to a b bbyo factor d which is a c3 convertase and can catalyze the spontaneous reaction i spoke about earlier c3 bb from c3 b b b gb y a c3 b and this is a c5 convertase the following steps are similar to the classical pathway what are the downstream consequences or complement activation well
As we can see we have c4 e c3 and c5 e which are enough flow toxins responsible for information yourself c3b scattered around all pathogens during the complement cascade leading to opsonization ctb is responsible for opsonization of course you have the membrane entire complex why would an individual we see a deficiency piece observable to nigeria well comp the
Complement pathway is our immune systems mean you need response to lice pathogenic cells like bacteria and viruses why are the membrane attack complex with with a loss of any one of these c6 c7 c8 or c9 proteins you’re not going to be able to form a membrane attack complex hence not able to lyse the cell this is why you will be very susceptible to the sim to similar
Infections of bacteria because you cannot lie stick bacteria by a membrane attack complex ok for for question see what is the age 50 och 50 is the serum needed to lyse 50% of sheep red blood cells to understand the meaning of that we first need to understand how this test is performed say you have a container you will have a fixed amount of sheep red blood cells
And sheep antibodies in the container sheep antibodies will then bind to the sheep red blood cells in the container and keep in mind that this is a fixed amount we will then add the serum patient serum which is a variable amount into the same container the patient serum has a variable amount of complement and as we know complement will bind to an antibody because
Antibodies have complement binding sites once once the complement binds to the antibody this will lead to the lysis of the sheep red blood cell if you have 50% of sheep red blood cells isis this is known as the seen and deficiency but if you have no sheep red blood cell lysis it can be any for compliment efficiency c-file be c6 c7 or c8 as for the last question
Tacrolimus okay keep in mind that track rodimus is also known as fk506 so to understand the mechanism of action of track ulemas we first need to understand the calcineurin pathway so in a t cell when the t cell receives the signal t cells will then lead to an increase in intracellular calcium while calcium channels the calcium channels will then give a positive
Response to calcineurin to d phosphorylate nuclear factor of activated t cells which then leads to interleukin 2 formation interleukin 2 will then lead to proliferation of immune cells so fk506 or tacrolimus will bind to fk binding protein in t cells leading to inhibition of calcineurin inhibition of calcineurin will lead to inhibition of the phosphorylation of
Nuclear factor of elevated t cells hence you won’t have interleukin 2 and hence this produces an immunosuppressive effect
Transcribed from video
Ps 2.complement cascade/c8 deficiency/ch50(COMPLEMENT TEST)/tacrolimus MOA By Daljeet Kaur
