CD100 is a leukocyte semaphorin

Abstract

CD100 was originally described as an activation molecule on the surface of human T lymphocytes. Its triggering through distinct epitopes leads to different signals of costimulation with phorbol myristate acetate (PMA) or with CD3 and CD2. Interestingly, CD100 was shown to associate with different partner molecules in T cells. First, CD100 can associate with CD45, a key molecule with protein tyrosine phosphatase activity involved in T-cell transduction: this association is physical and has functional consequences for both partners. Second, CD100 interacts in its cytoplasmic domain with a Ser/Thr kinase for which it represents a preferential substrate. Recently, CD100 was identified as a member of the semaphorin gene family. This family comprises approximately 20 structurally related proteins. The first semaphorins were identified in the developing nervous system. Function has been shown for only some of them and involves repulsion during growth cone guidance. Since CD100 was the first semaphorin identified in the immune system, this raises the possibility of the involvement of members of the semaphorin family in other physiological phenomena outside the nervous system.

Regulation of immune cell responses by semaphorins and their receptors

“…In the immune system, Sema4D is expressed in T cells, activated B cells and mature dendritic cells (DCs). 29,44,45 Sema4D promotes the activation of B cells and DCs to induce antibody production and antigen-specific T cells, respectively. 29,46,47 Plexin-B1 and CD72 were identified as the Sema4D receptors in the nervous and immune systems.…”

Biological Activity of Soluble CD100. II. Soluble CD100, Similarly to H-SemaIII, Inhibits Immune Cell Migration

“…C D100 was initially identified using a pair of mAbs produced in our laboratory (1, 2) as a homodimeric human Ag expressed on most hemopoietic cells, except on immature CD34 ϩ cells, erythrocytes, and eosinophiles (3,4). Our previous studies showed that CD100 was an activation molecule on lymphocytes.…”

Papel de CD100 na patogênese da aterosclerose

“…CD100/SEMA4D foi a primeira semaforina caracterizada no sistema imune Hall et al 1996;Delaire et al, 1998), no qual possui um amplo espectro de atividades biológicas já descritas tanto no modelo murino como em humanos (Ishida et al, 2003). Evidências crescentes demonstram um importante papel de CD100 na imunidade humoral e celular Kikutani & Kumanogoh, 2003;Suzuki et al, 2008).…”

“…CD100 is the first human semaphorin described in the immune system Delaire et al, 1998). At the cellular level, human CD100 triggers costimulatory signals to T cells promoting their proliferation and priming (Herold et al, 1996), B cell survival, aggregation, antibody production and also cytokine secretion in response to T-dependent antigens , as well as enhancement of NK cells killing of target cells .…”

“…Essa foi a primeira evidência de que as semaforinas estavam também presentes no sistema imune (Hall et al, 1996;Delaire et al, 1998). CD100 é amplamente expressa por células de origem hematopoiética, com exceção de células-tronco CD34+, eosinófilos e eritrócitos .…”