Suppressor T cell growth and differentiation: production of suppressor T cell differentiation factor by the murine thymoma BW5147

Previous studies have identified a lymphokine, termed Ts differentiation factor (TsDF), in primary MLR supernatants that induces effector function of alloantigen-primed MLR-Ts. The present report describes constitutive production of TsDF by the murine thymoma BW5147, and its use to analyze alloantigen and TsDF requirements for MLR-Ts activation to TsF production. Serum-free supernatants of BW5147 restored the capacity of MLR-TsF production to alloantigen-primed MLR-Ts cultured with glutaraldehyde-fixed allogeneic stimulator cells, and were not themselves directly suppressive in the MLR assay. BW5147 supernatant induced MLR-TsF production from primed L3T4-Ly2+ MLR-Ts in the absence of concomitant proliferation, suggesting that the function of BW5147 supernatant, like that of MLR-derived TsDF, is a differentiative rather than a proliferative one, and is required for the synthesis or release of TsF. The differentiative activity of BW5147 supernatant was associated with a molecular species of approximately 14,500 m.w. by HPLC fractionation and was expressed independently of detectable IL 2, IL 3, IFN-gamma, and IL 1. The functional activity of BW5147 supernatant has therefore been provisionally designated BW5147-derived Ts differentiative factor, or BW-TsDF. By using BW-TsDF, it was demonstrated that MLR-Ts fail to respond to TsDF in the absence of, or preceding, reexposure to priming alloantigen. Instead, alloantigen binding by primed MLR-Ts appears to create a transient state of TsDF responsiveness. Primed MLR-Ts were fully sensitive to delayed addition of TsDF for approximately 12 hr after reexposure to alloantigen, but became TsDF-unresponsive within 24 to 36 hr. MLR-Ts cultured alone for 36 hr were fully responsive to the combined addition of TsDF and alloantigen. Thus, MLR-Ts activation to TsF release requires the sequential events of specific alloantigen binding, which induces a TsDF-responsive state, followed by interaction with TsDF. The transience of induced TsDF responsiveness suggests a precise mechanism for control of antigen-initiated Ts activation to effector function.     

Hypogammaglobulinemia: therapeutic rationale.

Hypogammaglobulinemia is a feature of several B-cell disorders and is manifested clinically by recurrent infection, most commonly chronic upper and lower respiratory tract disease. Immunoglobulin replacement therapy is available, with at least four different routes of administration. There are as yet no convincing data that allow comparison of the cost-effectiveness of these methods. However, by individualizing therapy for each patient, it is possible to prevent life-threatening acute infections, reduce the severity of chronic upper and lower respiratory tract disease, improve pulmonary function and achieve normal levels of IgG. These are the currently acceptable goals of therapy in patients with hypogammaglobulinemia.     

The expression of tissue and urokinase-type plasminogen activators in neural development suggests different modes of proteolytic involvement in neuronal growth.

Tissue and urokinase-type plasminogen activators are serine proteases with highly restricted specificity, their best characterised role being to release the broad specificity protease plasmin from inactive plasminogen. It has frequently been suggested that these, and similar proteases, are involved in axonal growth and tissue remodelling associated with neural development. To help define what this role might be, we have studied the expression of the plasminogen activators in developing rat nervous tissue. Urokinase-type plasminogen activator mRNA is strongly expressed by many classes of neurons in peripheral and central nervous system. We have analysed its appearance in spinal cord and sensory ganglia, and found the mRNA is detectable by in situ hybridisation very early in neuronal development (by embryonic day 12.5), at a stage compatible with it playing a role in axonal or dendritic growth. Tissue plasminogen activator mRNA, on the other hand, is expressed only by cells of the floor plate in the developing nervous system, from embryonic day 10.5 and thereafter. Immunohistochemical and enzymatic analysis showed that active tissue plasminogen activator is produced by, and retained within, the floor plate. A mechanism is suggested by which high levels of tissue plasminogen activator produced by the stationary cells of the floor plate could influence the direction of growth of commissural axons as they pass through this midline structure.     

The constitutively expressed octamer binding protein OTF-1 and a novel octamer binding protein expressed specifically in cervical cells bind to an octamer-related sequence in the human papillomavirus 16 enhancer.

A novel octamer binding protein expressed specifically in cervical cells but not in other cell types has been identified. This protein differs in size and sequence specificity from the constitutively expressed octamer binding protein OTF-1. In particular it binds with higher affinity to a sequence in the human papillomavirus 16 (HPV) upstream regulatory region which has a seven out of eight base pair match compared to the consensus octamer motif. This is the first example of a tissue specific protein which has been observed to bind to the papillomavirus enhancer. The possible role of this protein in producing the observed tissue specific activity of the enhancer and in cervical carcinogenesis induced by HPV is discussed.     

The methylene blue colorimetric microassay for determining cell line response to growth factors

The validity of the methylene blue colorimetric microassay for determining the response of monolayers of human ovarian tumour cell lines to different growth factors was investigated. Linearity of the relationship between cell density and optical density was confirmed for each cell line (r=0.989–0.999,p<0.001), and when initial cell density was optimised to give exponential growth over the assay period, differences in response to medium supplements were obvious. The response of target cells to growth factors, obtained using the methylene blue assay, were compared with, and found to parallel, previously documented responses obtained non-colorimetrically. Thus Mink lung epithelial cells (MLEC) were inhibited by TG (Holleyet al., 1983), EGF had an inhibitory effect on A431 cells (Gill & Lazar, 1981; Barnes, 1982), and the mesothelial cell line showed a proliferative response to EGF and hydrocortisone (Connell and Rheinwald, 1983).The methylene blue colorimetric microssay was found to be a simple, reliable, sensitive method with low variability, for determining the response of cultured cells to growth factors.     

球体蛛在我国首次发现及一新种记述（蜘蛛目：球体蛛科）

球体蛛在我国首次被发现,本文记述了产于我国海南的纳尔蛛属一新种,定名为华纳尔蛛Wendilgarda sinensis sp. nov.,模式标本保存在河北教育学院生物系。     

中国皿蛛科——新纪录属及天山前延首蛛的重描述（蜘蛛目：皿蛛科）

本文记述我国皿蛛科一新纪录属:前延首蛛届Archaraeoncus Tanasevitch 1987,并对天山前延首蛛A.tianshanicus(Hu et Wu,1989)n.comb.重新作了描述,本种的雌蛛系首次发现。本文还对Araeoncus tianschanica Hu et Wu 1989原学名命名的原始拚缀作了改正。文中测量数据均以mm为单位。     

中国皿蛛科蜘蛛一新属和一新种记述(蛛形纲:蜘蛛目)

本文记述采自新疆的皿蛛科蜘蛛一新届——颚齿蛛属Maxillodens gen.nov.及其一新种——鞭状颚齿蛛M.flageuatus sp.nov。