2B4 is a member of the CD2 subset of the immunoglobulin superfamily molecules expressed on natural killer (NK) cells and other leukocytes. It is the high affinity ligand for CD48. Engagement of 2B4 on NK-cell surfaces with specific antibodies or CD48 can trigger cell-mediated cytotoxicity, interferon-gamma secretion, phosphoinositol turnover and NK-cell invasiveness. The function of 2B4 in CD8+ T cells and myeloid cells remains unknown. The cytoplasmic domain of 2B4 contains unique tyrosine motifs (TxYxxV/I) that associate with src homology 2 domain-containing protein or signaling lymphocyte activation molecule (SLAM)-associated protein, whose mutation is the underlying genetic defect in the X-linked lymphoproliferative disease (XLPD). Impaired signaling via 2B4 and SLAM is implicated in the immunopathogenesis of XLPD. CS1 is a novel member of the CD2 subset that contains two of the unique tyrosine motifs present in 2B4 and SLAM. Signaling through 2B4, CS1 and other members of the CD2 subset may play a major role in the regulation of NK cells and other leukocyte functions.

中文翻译：

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2B4（CD244）和CS1：在自然杀伤细胞和其他白细胞上表达的免疫球蛋白超家族分子CD2子集的新成员。

2B4是在自然杀伤（NK）细胞和其他白细胞上表达的免疫球蛋白超家族分子CD2子集的成员。它是CD48的高亲和力配体。2B4与特定抗体或CD48接触NK细胞表面可触发细胞介导的细胞毒性，干扰素-γ分泌，磷酸肌醇更新和NK细胞侵袭性。2B4在CD8 + T细胞和髓样细胞中的功能仍然未知。2B4的胞质结构域包含独特的酪氨酸基序（TxYxxV / I），与包含src同源性2结构域的蛋白或信号淋巴细胞活化分子（SLAM）相关的蛋白相关，其突变是X连锁淋巴组织增生性疾病的潜在遗传缺陷（XLPD）。通过2B4和SLAM的信号传导受损与XLPD的免疫发病机制有关。CS1是CD2子集中的一个新颖成员，其中包含2B4和SLAM中存在的两个独特的酪氨酸基序。通过2B4，CS1和CD2子集的其他成员发出信号可能在NK细胞和其他白细胞功能的调节中起主要作用。