Biomedical subjects

L Schaffar

Publications and source records attributed to L Schaffar.

21 records · Page 2Linked to original sources

PubMed1987

IL2-like material is present in human placenta and amnion.

Human term placenta was shown to react with different polyclonal and monoclonal anti-interleukin 2 (IL2) antibodies by using indirect immunofluorescence on frozen sections. Labelling was localized on syncytiotrophoblast membrane, amniotic epithelium and cytotrophoblast of the reactivity [corrected]. The reproducibility of the observations with different basal plate. These features were observed with two different rabbit anti-IL2 polyclonal antibodies, a sheep IL2 antiserum and 15.2, an anti-IL2 monoclonal antibody. However, DMS-1, a second anti-IL2 monoclonal antibody, did not react. Pre-incubation of anti-IL2 sera with IL2 resulted in the disappearance of syncytiotrophoblast reactivity. The reproducibility of the observations with different reagents strongly suggests that the recognized molecule shares several epitopes with IL2. However, it has not been possible to demonstrate the presence of a conventional IL2 receptor by using two monoclonal antibodies directed to the 55 kDa chain of IL2 receptor.

Amnion↗

PubMed1984

[Frequency of anti-HBV, CMV, and HTLV antibodies in donors at risk].

From July 1983 to January 1984 (7 months) information on AIDS and high-risk groups was given to each blood donor. A total of 139 subjects out of 136 384 (1.02%) declared to belong to such groups. Their blood donations were reserved to research purpose. Anti-HBc antibody was present in 43 subjects (31 %) in a frequency 6 times superior to what observed in an unselected population. Anti-CMV antibody was detected in 73% of these subjects. Both anti-HBc and anti-CMV antibodies were detected in 28% and were not in 24%. Antibody anti-p24 HTLV was never observed. beta 2 microglobuline was in a normal level in 70 of the 71 tested samples (mean 1.3 mg/l).

Antibodies, Viral↗

PubMedDate not supplied

CD3-stimulated Jurkat T cells mediate IL-1 beta production in monocytic THP-1 cells. Role of LFA-1 molecule and participation of CD69 T cell antigen.

In this study we investigated the T cell signals required for monocyte activation. We used an in vitro co-culture system involving two human cell lines: Jurkat T cells and THP-1 monocytes. Monocyte activation was monitored by measuring IL-1 beta production, whereas IL-2 secretion reflected Jurkat activation. We showed that CD-3 -stimulated Jurkat cells delivered an IL-1-inductive signal to THP-1 cells through a cellular contact which was independent of THP-1 Fc receptors cross-linking. Stimulation of IL-1 beta production did not appear to require lymphokine secretion by T cell since a lymphokine defective mutant of Jurkat cell was able to deliver the stimulatory signal. The LFA-1 molecule was clearly shown to participate in the cooperation process, but its role was likely to be restricted to mediating initial adhesive interaction rather than to transducing the IL-1 -inductive signal. Interestingly, the co-culture stimulated by (Fab')2 fragments of CD3 mAb displayed an enhanced IL-1 beta production without any increase of IL-2 secretion. This result indicated that Jurkat cells could stimulate THP-1 cells even when they were only partially activated. The kinetics and conditions of IL-1 beta production called our attention to the early T cell activation antigen CD69. We then showed that CD69 mAb interfered with transmission of the IL-1 inductive signal (40-50% inhibition of IL-1 production). Our results are suggestive of a new role for CD69 molecule intervening in the T lymphocyte-dependent monocyte activation process.

Antibodies, Monoclonal↗