RT7‐Defined Alloantigens in Rats are Part of the Leucocyte Common Antigen Family

Abstract

Haemopoietic cells carry a variety of cell-surface molecules, some of which are known to have allotypic variation. In rats, the RT7 alloantigenic system has been well documented using alloantisera. We have produced the first mouse hybridoma cell line secreting an antibody, HIS41, which binds to leucocytes of rat strains carrying the RT7.2 but not the RT7.1 determinant. An IgG2b isotype switch variant (HIS41.2b) of the original HIS41 (IgG1 isotype) was also made. HIS41 showed a clear and discrete binding in immunofluorescent and histological experiments and has already been used in several studies on haemopoietic cell turnover and differentiation employing PVG rats congenic for RT7. The present study addresses the question of whether the RT7 gene products are members of the L-CA family, which has been a matter of controversy over the last decade. When using HIS41 for the analysis of tissue distribution and molecular weight of RT7 gene products, a strong similarity was evident with the data reported for the L-CA detected by MRC OX-1 and MRC OX-30. These two MoAb have been reported to bind to all members of the L-CA family. All haemopoietic cells, excluding erythrocytes and the more mature stages of erythropoiesis, stained with HIS41. The molecular weights of HIS41 binding molecules on thymocytes and peripheral T cells were comparable to the L-CA precipitated by MRC OX-1. Capping and sequential immunoprecipitation studies indicated that HIS41 and MRC OX-30-binding molecules were identical. MRC OX-1, however, appeared to bind only a subset of these molecules. Thus, our study confirms the identity of RT7.2 gene products and L-CA. It also revealed a difference between MRC OX-1 and MRC OX-30 not noticed previously.

CD4+ T cells from 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis rodents migrate to the recipient's colon upon transfer; down-regulation by CD8+ T cells

“…The RT7 alloantigenic system, which is part of the leucocyte common antigen (L-CA) family, consists of two known alleles, RT7a (which is the normal PVG or RT1c rat) and RT7b. These alleles encode the RT7.1 and the RT7.2 alloantigens, respectively [23]. An antibody (HIS41) is available against the rat RT7.2 alloantigen.…”

“…ED1 recognizes CD68 [25,26], OX19 is a T cell marker which recognizes CD5 [27], OX33 is a B cell marker which recognizes CD45RA or A/B [28,29], and HIS41 recognizes RT7.2 of the L-CA (or CD45) [23].…”

Long‐Term Donor Chimerism after MHC (RT1) Mismatched Bone Marrow Transplantation in the Rat: the Role of Host Alloreactive NK Cells

“…injected BM cells from a rat strain, PVG.RT7.2, where almost all hemopoietic cells and leukocytes express an alloantigenic variant of the CD45 molecule on their surface. This marker can be specifically detected with the MoAb HIS41 [15], and has the advantage of being nonantigenic, i.e. it does not induce any allograft responses in the PVG and PVG.RT1 congenic recipients used.…”

“…The hybridoma producing HIS41 MoAb (IgG1) against the alloantigenic variant CD45 marker RT7.2 was a kind gift from Dr J. Kampinga, University of Groningen, the Netherlands. RT7.2 is present on all PVG.RT7.2 leukocytes, but absent in PVG and the PVG.RT1 congenic and recombinant rat strains [15]. The MoAb was purified on a protein A column from ascites fluid of BALB/c mice and then FITC conjugated.…”

CD4+ effector T cell distribution in vivo: TGF‐β1/TGF‐β receptor II interaction during activation mediates accumulation in the target tissue by preferential proliferation

“…One day after injection the recipients were exsanguinated and the mLN and pLN were removed. The injected mLN cells were identified by mAb against the LEW RT.7B phenotype via FACS analysis (His41, Serotec, [30]). In addition, the cell suspensions of mLN and pLN were stimulated as described before [8].…”