InVivoMAb anti-rat CD86 (B7-2)

InVivoMAb anti-rat CD86 (B7-2) (CLONE: OX-48)

Yang G, Kawashima N, Kaneko T, Suzuki N, Okiji T, Suda H (2007). "Kinetic study of immunohistochemical colocalization of antigen-presenting cells and nerve fibers in rat periapical lesions" J Endod 33(2):132-6. PubMed

Immune and nervous systems play key roles in periapical pathosis; however, their spatial associations, which may be a prerequisite for paracrine interactions in the progression of periapical lesions, remain to be examined. In this study we examined the distribution and frequency of spatial associations between major histocompatibility complex class II molecule-expressing antigen-presenting cells (APCs) and protein gene product 9.5-immunoreactive nerve fibers in experimentally induced rat periapical lesions using double-immunofluorescence staining and confocal laser scanning microscopy. When active lesion expansion started, macrophage-like APCs frequently associated with nerve fibers around the apex. When the lesions were starting to stabilize, however, close associations between APCs with dendritic morphology and nerve fibers were found mostly in the periphery of lesions. CD86+ mature dendritic cells were also observed in this area. These findings suggest that functional interactions between APCs and nerve fibers may play some roles in the development of self-defense reactions in periapical lesions.

Wu CJ, Sheu JR, Chen HH, Liao HF, Yang YC, Yang S, Chen YJ (2006). "Modulation of monocyte-derived dendritic cell differentiation is associated with ischemic acute renal failure" J Surg Res 132(1):104-11. PubMed

Background: Dendritic cells (DCs) play a central role in both stimulating and suppressing immune responses and are impacted by surgical injury, exercise, and other physiological stressors. This study aims to determine whether renal ischemia/reperfusion (I/R) injury alters the differentiation, maturation, and activation of DCs from peripheral blood monocytes (PBMo). Materials and methods: Sprague-Dawley (SD) rats were subjected to I/R injury or sham-operated. Creatinine clearance (CCr) was monitored daily during the 14 days of reperfusion that followed the ischemic insult. At 2 and 14 days of reperfusion, the following properties of PBMo derived-DCs were assessed: the amount of generated DCs, surface markers [CD11c, CD80, CD86, and MHC-II (IA)], and functional status including magnitude of mixed lymphocyte reaction (MLR), production of IL-12 p70 by DCs, and production of IFN-gamma and IL-4 by DC-stimulated T cells. Results: CCr was greatly reduced in the injured rats 0 to 4 days after ischemia. Two days after I/R injury to kidney, the numbers of DCs differentiated from PBMo, IL-12 production by DCs, expression of MHC-II (IA), and IFN-gamma production by DC-stimulated T cells were significantly increased in the I/R injured group (compared to the sham-operated group). After 14 days of reperfusion, there was no between-group differences in the numbers of DCs derived from PBMo, MLR, expression of CD80, CD86, and MHC-II (IA), and production of IL-12, IFN-gamma, and IL-4. Conclusions: The increases seen at 2 days of reperfusion may reflect a preparatory step in the renal I/R injury pathway. The relationship between up-regulation of DC differentiation and ischemic acute renal failure (ARF) remains to be elucidated.

Strickland D, Kees UR, Holt PG (1996). "Regulation of T-cell activation in the lung: alveolar macrophages induce reversible T-cell anergy in vitro associated with inhibition of interleukin-2 receptor signal transduction" Immunology 87(2):250-8. PubMed

Alveolar macrophages (AM) are recognized as archetypal 'activated' macrophages with respect to their capacity to suppress T-cell responses to antigen or mitogen, and this function has been ascribed an important role in the maintenance of local immunological homeostasis at the delicate blood:air interface. The present study demonstrates that this suppression involves a unique form of T-cell anergy, in which 'AM-suppressed' T cells proceed normally through virtually all phases of the activation sequence including Ca2+ flux, T-cell receptor (TCR) modulation, cytokine [including interleukin-2 (IL-2)] secretion and IL-2 receptor (IL-2R) expression. However, the 'suppressed' T cells fail to up-regulate CD2, and do not re-express normal levels of TCR-associated molecules after initial down-modulation; moreover, they are unable to transduce IL-2 signals leading to phosphorylation of IL-2R-associated proteins, and remained locked in G0/G1. The induction of this form of anergy is blocked by an NO-synthase inhibitor, and is reversible upon removal of AM from the T cells, which then proliferate in the absence of further stimulation. We hypothesize that this mechanism provides the means to limit the magnitude of local immune responses in this fragile tissue microenvironment, while preserving the capacity for generation of immunological memory against locally encountered antigens via clonal expansion of activated T cells after their subsequent migration to regional lymphoid organs. In an accompanying paper, we demonstrate that a significant proportion of T cells freshly isolated from lung exhibit a comparable surface phenotype.

Strickland D, Kees UR, Holt PG (1996). "Regulation of T-cell activation in the lung: isolated lung T cells exhibit surface phenotypic characteristics of recent activation including down-modulated T-cell receptors, but are locked into the G0/G1 phase of the cell cycle" Immunology 87(2):242-9. PubMed

Peripheral lung tissue contains large numbers of T cells, strategically located for immune surveillance at the blood-air interface. Given the intensity of antigenic exposure at this site, it is clear that local T-cell activation events require strict control, in order to maintain tissue homeostasis. How this control is achieved in this unique tissue microenvironment is unknown, and the present study sought to elucidate the process via detailed analysis of the surface phenotypic characteristics of freshly isolated lung T cells. We report below that these cells display typical characteristic of 'postactivation', notably elevated basal Ca2+ concentrations, down-modulated T-cell receptors, expression of Ia and 'late' activation antigens and concomitant CD4/CD8. However, levels of interleukin-2 receptor and CD2 expression were below those expected of 'activated' T-cell populations, and virtually all of the cells were found to be in the G0/G1 phases of the cell cycle. These properties bear a remarkable similarity to those of T cells activated in the presence of endogenous tissue (alveolar) macrophages from the lung (see accompanying paper). We hypothesize that they reflect the in vivo operation of an endogenous macrophage-mediated T-cell anergy-induction process, the function of which is to limit the local clonal expansion of T cells in peripheral lung tissue after in situ activation.

Bañuls MP, Alvarez A, Ferrero I, Zapata A, Ardavin C (1993). "Cell-surface marker analysis of rat thymic dendritic cells" Immunology 79(2):298-304. PubMed

Rat thymic dendritic cells have been isolated by collagenase digestion, separation of the low-density cell fraction by centrifugation on metrizamide, and differential adherence. The resulting dendritic cell preparation had a purity of > 90%, and has been analysed by flow cytometry (FCM) using a large panel of monoclonal antibodies (mAb). Dendritic cells expressed major histocompatibility (MHC) class I and class II molecules, the leucocyte common antigen CD45, the rat leucocyte antigen OX44, the rat macrophage marker ED1, and the adhesion molecules Mac-1, LFA-1 and ICAM-1. They were negative for the T- and B-cell-specific forms of CD45, CD45R and B220, and the B-cell marker OX12. Concerning T-cell marker expression, they were negative for T-cell receptor (TcR) and OX40, but they expressed CD2, CD4 and CD8, and interestingly, 50% of DC were CD5+, 50% expressed the alpha-chain of interleukin-2 receptor (IL-2R), and 80% were positive for the T-cell activation antigen recognized by the mAb OX48. Moreover, 60% of DC expressed high levels of Thy-1, whereas 40% displayed intermediate levels of this T-cell marker.

Ferrero I, Bañnuls M, Alvarez A, Ardavín C (1993). "Rat thymic dendritic cells: cell surface marker variations in culture" Immunol Lett 37(2-3):241-7. PubMed

Rat thymic dendritic cells (DC) have been analyzed by flow cytometry in order to study the variations on the cell surface marker expression upon culture at 37 degrees C. Our results demonstrate that whereas expression of major histocompatibility complex (MHC) molecules, CD45, Mac-1, LFA-1, B-cell markers, macrophage markers and some T-cell markers (as CD2, CD4 and CD8) did not undergo changes in culture, the level of expression of the adhesion molecules VLA-4 and ICAM-1, and the T-cell markers CD5, CD25 and Thy-1 increased after 14 h incubation at 37 degrees C. VLA-4, ICAM-1 and Thy-1 expression was up-regulated from intermediate to high levels, the percentage of CD5+ cells increased from 20% to 50%, and the interleukin-2 (IL-2) receptor alpha chain (CD25) was induced in 50% of DC after the culture period. These results are discussed with regard to the functional significance of DC phenotypic variations, and their implications concerning the development of in vitro systems designed for T-cell differentiation studies involving purified DC.

McKnight AJ, Classon BJ (1992). "Biochemical and immunological properties of rat recombinant interleukin-2 and interleukin-4" Immunology 75(2):286-92. PubMed

We have previously described the isolation and sequencing of cDNA clones encoding rat interleukin-2 (IL-2) and interleukin-4 (IL-4). In the present study, we report the generation of stably transfected Chinese hamster ovary (CHO) cell lines which constitutively synthesize and secrete high levels of rat recombinant IL-2 (rIL-2) and IL-4 (rIL-4). The expression of the cytokine cDNA sequences is driven by the human cytomegalovirus promoter/enhancer within the respective pEE6. HCMV-GS vector constructs, following the successful transfection and isolation of methionine sulphoximine (MSX)-resistant CHO cell lines. Analyses of metabolically labelled CHO.rIL-2 and CHO.rIL-4 have been performed, in addition to studies which demonstrate certain biological properties of these recombinant cytokines including T-cell growth factor activity (rIL-2) and the ability to enhance expression of class II major histocompatibility complex (MHC) molecules on spleen cells (rIL-4). The availability of large quantities of these rat recombinant cytokines, conveniently produced by a mammalian cell line, will prove invaluable in future studies into the induction and regulation of immune responses in this species.

Somoza C, Fernández-Ruiz E, Rebollo A, Sanz E, Ramírez F, Silva A (1990). "OX48, a monoclonal antibody against a 70,000 MW rat activation antigen expressed by T cells bearing the high-affinity interleukin-2 receptor" Immunology 70(2):210-5. PubMed

The monoclonal antibody (mAb) OX48 recognizes a 70,000 MW cell-surface protein present in a small percentage of activated rat T cells and in CD8+ rat x BW5147 interleukin-2 (IL-2)-dependent T-cell hybridomas, but not in resting spleen cells or in IL-2-independent T-cell hybrids. OX48 antibody added simultaneously with concanavalin A (Con A) to resting spleen cells inhibits the cell proliferation and reduces the IL-2 production. However, addition of IL-2 does not restore the mitogenic response. Growth of rat blast T cells or IL-2-dependent hybrids is not affected by the OX48 antibody. There is a close correlation between the expression of high-affinity IL-2 receptors (IL-2R) and the OX48 antigen in T-cell hybridomas. In spite of this striking correlation, OX48 mAb does not inhibit the binding of 125I-IL-2 to the IL-2-dependent hybrids, and is unable to immunoprecipitate any of the proteins chemically cross-linked to 125I-IL-2. Therefore, the OX48 molecule represents a new rat activation antigen, undefined in other species, and probably involved in the early steps of T-cell activation.

Paterson DJ, Jefferies WA, Green JR, Brandon MR, Corthesy P, Puklavec M, Williams AF (1987). "Antigens of activated rat T lymphocytes including a molecule of 50,000 Mr detected only on CD4 positive T blasts" Mol Immunol 24(12):1281-90. PubMed

Mouse monoclonal antibodies (MAbs) have been prepared against rat T cell blasts. One MAb called MRC OX-40 recognized an antigen that differed from any previously described in that its expression was detected only on T blasts that also expressed the CD4 antigen. The OX-40 MAb did not detect an activation determinant of CD2 or CD4 molecules but recognized a distinct chain of mol. wt 50,000. The OX-40 MAb augmented T cell proliferation at late stages on in vitro responses. Other MAbs without obvious counterparts in other species were MRC OX-48 and MRC OX-49,50 which recognized cell surface molecules of mol. wts of about 95,000 and 90,000, respectively. The OX-48 antigen was not expressed on resting lymphocytes but was found on a subset of T and B blasts and also on other leucocytes. The OX-49,50 antigen was found on most haemopoietic cells but was expressed at greatly increased levels after lymphocyte activation and this was also the case for MRC OX-47 antigen which is of unknown Mr. The MRC OX-39 MAb was found to bind the rat IL-2 receptor; expression of this antigen was detected on thymic dendritic cells as well as on T blasts. The phenotype of rat T blasts compared to resting cells was also examined and changes in expression of L-CA, Thy-1, OX-2 and CD8 antigens were seen in addition to the changes found with the above MAbs.