How do Maternal Alloantigens promote the development of tolerogenic fetal regulatory T-cells in utero?

Alefacept is a fusion protein that contains the CD2-binding domain of LFA3 fused to human IgG1, and it is used to block CD2 function on human T cells. In addition, following in vivo administration, alefacept was also shown to deplete T cells of the effector or memory subsets that express high levels of CD2. Surprisingly, clinical trials data indicated that patients on alefacept still retained responses to vaccination. For example, one set of data showed that patients on alefacept made similar responses as the control group to a vaccine designed to protect against pneumococcal disease, which is composed entirely of bacterial polysaccharide antigens (pneumococcal polysaccharide vaccine; PPV). This normal response to PPV by patients on alefacept is not surprising because: Alefacept is not very effective at blocking T cell responses. CD2 is not required for all T cell responses to vaccination. Alefacept does not deplete all effector or memory T cells, just a subset. T cells are involved…

If there is a problem with somatic hypermutation in the germinal center, does this affect isotype switching from IgM to IgG for the B cells?

Knockout mice are mice in which certain genes are rendered irreversibly nonfunctional through the technique of homologous recombination. Which knockout mice would you use to study the two pathways of antigen processing and presentation?

Chimeric mice are generated where approximately 50% of the cells in the animal are genetically MHC class I-deficient. The other 50% are deficient for the herpes virus receptor, HVEM, but do express MHC class I molecules. When these mice are infected with herpesvirus by intraperitoneal injection, a robust virus-specific CD8 T cell response is detected at day 7 post-infection in the spleens of the infected mice. Which cells are presenting herpesvirus antigens to prime the CD8 T cell response, and how did they acquire the viral antigens?

Draw a picture of how antihuman globulin (AHG) helps agglutination when IgG antibodies are involved