Mouse anti Human HLA Class I Heavy Chain (Restricted expression)

The HLA class I gene family is composed of a group of genes whose products encode cell surface glycoproteins of MW 40–45 kDa, associated non-covalently with the beta-2-microglobulin light chain. They include the three polymorphic molecules HLA-A, -B, and -C, which are ubiquitously expressed and which are able to present intracellular peptides to cytotoxic T cells. Three additional class I genes are known, commonly referred to as non-classical or class Ib genes, all highly homologous to the other class I genes and all of which associate with beta-2-microglobulin light chain. In humans, each of the class Ib genes appears to exhibit a distinct pattern of expression in developing and adult tissues. HLA-E transcripts are distributed widely in adult tissues and have also been found in the placenta and fetal liver. In the adult, the presence of HLA-F has been shown in skin, resting T cells, and B cells, whereas its expression during development has been reported in fetal liver and at low levels in placenta and extra-placental tissues. HLA-G was originally thought to be expressed only in certain populations of placental trophoblasts, but low levels have also been found in a variety of human tissues. Recently it was shown that HLA class I expression in breast cancer cells can have a predictive value for chemotherapy response.