1.Would you expect the viral l
1.Would you expect the viral load in the blood of HIV-infectedindividuals in the early years of the asymptomatic phase of HIV-1infection to vary significantly (assuming no drug treatment)? Whatabout CD4+ T-cell counts? Why? Explain.
2. Beginning with sensitisation, describe the immune events thatyou expect to take place following the transplantation of a kidneybetween nonidentical siblings who share half their MHC molecules.You can assume that they are matched for ABO blood group antigensand have successfully passed the cross-match (i.e., they areantibody negative in a cross-match test). Explain.
3. What is the biologic basis for attempting to use solubleCTLA-4Ig or anti-CD40L to block allograft rejection? Explain
1.Eventhough the infection into a chronic stage starts onlyafter the antibodies are formed in the body,during the initialperiod of infection following the entry of virus and thereby theviral antigens can be detected in the plasma within weeks.This isbecause the virus has already started to take over the cellsmachinery and hence there is integration of viral particles withinthe body resulting in the presence of viral antigens.
For CD4+ cells the levels tend to decline during this periodbecause during the course of the T cells to fight the antigen thevirus inturn kills these cells resulting in the reduction of theirnumber
2.The first step is sensitization where the Cd4+ and CD8+ cellsproliferate that recognizes the non self antigen followed by theeffector phase where antibodies are developed against theantigen.When half the MHC molecules are same the chances of graftrejection are reduced by half because those antigens are notidentified as non self
3.Soluble CTLA-4-Ig when used causes the selective inhibitionwhere the Tcells are proliferated in allograft rejection.Thisinturn reduces the chances of rejection.