HLA antigens?

Question

hey, im somewhat puzzled about this thing.....

i) how do we justify the existence of 6 variants of HLA 1 n 12 of HLA 2?
ii) and does an individual has all the 3 alleles of HLA 1 (A,B n C)? if so, d individual-individual variation is only due to the type of allele which predominates and the mutations in them?
iii) also, how does the HLA profile decides the susceptibility or the reistance to a particular microbial disease or pathogen ( say, HIV)?

Answer 1

I am not sure what you mean by 'justify'. With all the variation we see with humans, I don't find it hard to believe that there are plenty of variants of HLA molecules.

Since the proteins encoded by HLAs are the proteins on the outer part of body cells that are (effectively) unique to that person (wikipedia), some people with certain HLA variants are immune to some microbial diseases since many microbes use these receptors for recognition, docking and then entry into immune cells.