[Study on the cloning, in vitro expression and bioactivity of Ailuropoda melanoleuca Qinling subspecies interleukin-2].

AIM: To identify if any difference exisit between the population of Sichuan and Qinling giant panda. express IL-2 protein in BL21(DE3)with biological activity. METHODS: IL-2 was amplified by RT-PCR from adult Qinling giant panda peripheral blood lymphocyte which was induced by ConA, and cloned into prokaryotic expression vector of pET32a-IL-2. The fusion protein was expressed in BL21(DE3)/pET system and identified by SDS-PAGE and Western blot; inoculate rabbit with purified expression products to prepare polyclonal antibody; use lymphocytes proliferation in vitro to detect biological activity. RESULTS: The protein of IL-2 was obtained by recombination expression, molecule weight is 34 000 .The specificity of polyclonal antibody was obtained, in vitro activity test indicated that the recombinant protein IL-2 having an activity of promoting the proliferation of lymphocytes. The effect can be stopped by polyclonal antibody which was prepared before. CONCLUSION: The IL-2 gene of Qinling giant panda was cloned and expressed in E.coli successfully, and the homology of IL-2 gene in these two population is 99.4% and the recombination protein can promote the proliferation of lymphocytes in vitro from giant panda.

The interleukin (IL)-2 family cytokines: survival and proliferation signaling pathways in T lymphocytes.

Lymphocyte populations in the immune system are maintained by a well-organized balance between cellular proliferation, cellular survival and programmed cell death (apoptosis). One of the primary functions of many cytokines is to coordinate these processes. In particular, the interleukin (IL)-2 family of cytokines, which consists of six cytokines (IL-2, IL-4, IL-7, IL-9, IL-15 and IL-21) that all share a common receptor subunit (gammac), plays a major role in promoting and maintaining T lymphocyte populations. The details of the molecular signaling pathways mediated by these cytokines have not been fully elucidated. However, the three major pathways clearly involved include the JAK/STAT, MAPK and phosphatidylinositol 3-kinase (P13K) pathways. The details of these pathways as they apply to the IL-2 family of cytokines is discussed, with a focus on their roles in proliferation and survival signaling.

Mouse multivalent IgG(2a, b) antibody--ricin A-chain immunotoxins combined with homologous or heterologous interleukin 2 in the treatment of a murine malignant lymphoproliferation (EL4).

Two immunotoxins containing ricin A-chain, staphylococcal protein A and mouse anti-Thy 1.2 antibodies of IgG(2a,b) subclass, were prepared. The two multivalent immunotoxins of 750 and 370 kDa and molar ratio A-chain: IgG of 1:2, were used for the treatment of mice bearing ascitic EL4 lymphoma. The immunotoxin-treatment, performed intraperitoneally, was combined or not with homologous or heterologous interleukin 2. The antitumor effects expressed by increase of mice survival time (p < 0.001 as compared with nontreated animals) corresponded to a proportion of 88-90% lymphoma cell-kill by immunotoxin and 93-95% by combination treatment (immunotoxin + interleukin 2), as calculated from the relationship between the survival time of nontreated mice and the number of tumor cells inoculated.

Molecular cloning of IL-2R alpha, IL-2R beta, and IL-2R gamma cDNAs from a human oligodendroglioma cell line: presence of IL-2R mRNAs in the human central nervous system.

In the present study, we analyzed human adult brain, fetal spinal cord, and an interleukin-2 (IL-2)-responsive human oligodendroglioma subclone, TC620.6A2, for the presence of mRNAs for the alpha, beta, and gamma chains of the interleukin-2 receptor (IL-2R alpha, IL-2R beta, and IL-2R gamma). IL-2R beta mRNA, but not IL-2R alpha or IL-2R gamma was detectable by Northern blot analysis in adult human brain tissues. Northern blot analysis of TC620.6A2 and human fetal tissues revealed mRNAs of 1.5 kb and 1.3 kb that hybridized to the IL-2R alpha cDNA at low to medium stringency. Reverse transcriptase-polymerase chain reaction (RT-PCR) experiments were done on the TC620.6A2 cell line utilizing primers to IL-2R alpha, IL-2R beta, and IL-2R gamma. Southern blot analysis of the TC620.6A2 RT-PCR reactions detected products identical in size to the peripheral blood lymphocyte (PBL) positive controls at high stringency. Several of the TC620.6A2 IL-2R alpha, IL-2R beta, and IL-2R gamma cDNAs were cloned and sequenced. The sequences were found to be identical to the known IL-2R sequences. To our knowledge, these experiments are the first to demonstrate the presence of authentic IL-2R mRNAs in a human oligodendrocyte-like cell line. Demonstration of mRNA for IL-2R beta in human adult brain, IL-2R alpha in fetal brain, and IL-2R alpha, IL-2R beta, and IL-2R gamma in a malignant neural cell line suggests the possibility of a role for IL-2/IL-2R interactions in development and disease.

Eosinophil differentiation factor also has B-cell growth factor activity: proposed name interleukin 4.

A mouse lymphokine that stimulates the production of functional eosinophils in liquid bone marrow cultures has recently been described [Sanderson, C.J., Warren, D.J. & Strath, M. (1985) J. Exp. Med. 162, 60-74]. This factor appears to be specific for the eosinophil lineage in hemopoietic differentiation and is analogous to colony-stimulating factors described for other hemopoietic lineages. In this paper we report that this factor appears to be identical to the B-cell growth factor II described by Swain and Dutton [Swain, S.L. & Dutton, R.W. (1982) J. Exp. Med. 156, 1821-1834]. This conclusion is based on the coordinate expression of the two activities by a panel of alloreactive T-cell clones and lines and on copurification through a series of protein separation techniques. The reason for a single lymphokine's having these widely differing biological activities is unclear, and its duality presents problems in using terminology based on either assay system. For this reason we propose the name "interleukin 4" for this molecule, and we suggest the defining property should be its eosinophil-differentiating activity.