Altered Affinity Maturation in Primary Response to (4-hydroxy-3-nitrophenyl) Acetyl (NP) after Autologous Reconstitution of Irradiated C57BL/6 Mice

Immune responses developing in irradiated environment are profoundly altered. The memory anti-arsonate response of A/J mice is dominated by a major clonotype encoded by a single gene segment combination called CRIA. In irradiated and autoreconstituted A/J mice, the level of anti-ARS antibodies upon secondary immunization is normal but devoid of CRIA antibodies. The affinity maturation process and the somatic mutation frequency are reduced. Isotype switching and development of germinal centers (GC) are delayed

CD4+ CD25+ Regulatory T Cells Control T Helper Cell Type 1 Responses to Foreign Antigens Induced by Mature Dendritic Cells In Vivo

Recent evidence suggests that in addition to their well known stimulatory properties, dendritic cells (DCs) may play a major role in peripheral tolerance. It is still unclear whether a distinct subtype or activation status of DC exists that promotes the differentiation of suppressor rather than effector T cells from naive precursors. In this work, we tested whether the naturally occurring CD4+ CD25+ regulatory T cells (Treg) may control immune responses induced by DCs in vivo. We characterized the immune response induced by adoptive transfer of antigen-pulsed mature DCs into mice depleted or not of CD25+ cells. We found that the development of major histocompatibility complex class I and II–restricted interferon γ–producing cells was consistently enhanced in the absence of Treg. By contrast, T helper cell (Th)2 priming was down-regulated in the same conditions. This regulation was independent of interleukin 10 production by DCs. Of note, splenic DCs incubated in vitro with Toll-like receptor ligands (lipopolysaccharide or CpG) activated immune responses that remained sensitive to Treg function. Our data further show that mature DCs induced higher cytotoxic activity in CD25-depleted recipients as compared with untreated hosts. We conclude that Treg naturally exert a negative feedback mechanism on Th1-type responses induced by mature DCs in vivo

Phenotypic character of phage protein abnormalities induced by bromouracil

The incorporation of bromouracil, a thymine analogue, into the DNA of bacteriophage T2 stimulates the synthesis of significant quantities of abnormal proteins. Their abnormal character is deduced from the study of certain properties of phages produced in the presence of bromouracil: stability of structure, adsorption on a sensitive bacterial strain and immunologic specificity. The modifications studied are not transmitted to the progeny synthesized in the absence of the base analogue. In the presence of bromouracil, the synthesis of phage DNA and protein is much less affected than the synthesis of virus particles. This difference is attributed to the fact that the abnormal proteins cannot be integrated into the phage particles. © 1965.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Effet du bromouracile sur la synthèse et la structure des protéines de phages

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

On the structural alterations of phage proteins synthesized in the presence of pancreatic ribonuclease.

Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

[Abnormal phage proteins synthetized in the presence of ribonuclease].

Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Self non self discrimination within the immune system: A view from the bridge

SCOPUS: cp.jinfo:eu-repo/semantics/publishe

Two types of antibody molecules of identical restricted specificity regularly present in individual rabbits.

Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Importance of short lived lymphocytes in the immune response

SCOPUS: ar.jFLWNOinfo:eu-repo/semantics/publishe