Class MHC 2 antigen attaches to?

* Class I MHC antigens have loci as HLA-A, HLA-B and HLA-C. CD8+ (i.e. T suppressor) lymphocytes carry receptors for class I MHC: These cells are used to identify class I antigens on them.* Class II MHC antigens have single locus as HLA-D. These antigens have further 3 loci: DR, DQ and DR Class II MHC is identified by 8 cells and CD4+ (i.e. T helper) cells.* Class III MHC antigens are some components of the complement system (C2 and C4) coded on HLA complex but are not associated with HLA expression and are not used in antigen identification.* In view of high polymorphism of class I and Class II genes, they have a number of alleles on loci numbered serially like HLA-A 1, HLA-A 2, HLA-A3 etc.* MHC antigens present on the cell surface help the macrophage in its function of recognition of bacterial antigen, i.e. they help of identify self from foreign and accordingly present the foreign antigen to T cells (CD4+ or CD8+) or to B cells.