Ultrastructural findings in the mouse exocrine pancreas during graft-versus host reaction.

12- to 36-hours-old newborn CBA mice were intraperitoneally injected each with 10 X 10(6) allogeneic spleen cells of adult C57Bl mice. Control mice received syngeneic spleen cells of adult CBA mice either in the same way or remained untreated. The animals were killed 1, 3, 7, 14 or 21 days after the spleen cell injection. The pancreas was studied histologically and electron microscopically by common methods. Together with an interstitial lymphohistiocytic infiltration of the pancreas different acinar cell alterations were observed in the mice treated with allogeneic spleen cells: 1. Acute lethal pancreatic cell damages on the day after the intraperitoneal injection of allogeneic spleen cells. 2. Membrane-lined inclusion vacuoles between the 7th and 21st experimental day. 3. Atrophy of pancreatic acinar cells in the terminal stage of a severe graft-versus-host disease. The pathogenesis of the observed pancreatic changes seems to be due to nonimmunological and immunological processes. The membrane-lined inclusion vacuoles of the acinar cells could be the consequence of a cell-mediated immune process in the graft-versus-host reaction.     

Induction of autoimmune disease by graft-versus host reaction across MHC class II difference: modification of the lesions in IL-6 transgenic mice

We examined the effect of IL-6 on the development of autoimmune diseases (primary biliary cirrhosis. Sjögren's syndrome) employing murine grari-versus-host reaction (GVHR) model with MHC class II disparity. For this purpose, we used IL-6 transgenic(B6.6) mice in which a high level of IL-6 was detected. C57B1/6 (B6) spleen T cells were injected into B6.6 mated with B6.C-H-2^(bml2) mutant mice ((bmi2x B6.6)F^I) and GVHR with MHC class II disparity was induced. The iransgenic hybrid mice with GVHR showed a larger spleen index and contained a higher serum level of IL-6 than those without GVHR. Autoimmune-like lesions in transgenic recipients became weakened compared with those in non-transgenic (bml2 x B6)F₁ recipients. In contrast, levels of antimitochondrial antibodies in (bm 12 x B6.6)FI GVHR group were signiiicantly higher than that of (bml2 X B6)F_I GVHR group. These results indicate that lL-6 excessively produced in vivo might regulate the progression of autotmmune diseases.     

CD4+CD25+调节性Treg细胞与急性移植物抗宿主病

CD4+CD25+Treg细胞是调节性T细胞的一个重要亚群,具有免疫无能和免疫抑制的特性,在防止自身免疫病发生、诱导移植耐受及调节肿瘤免疫方面起着重要作用。急性移植物抗宿主病(aGVHD)是异基因造血干细胞移植后最严重的并发症。近年来,有关CD4+CD25+Treg细胞与aGVHD关联性的研究取得了很大的进展,特别是该类细胞可有效地降低aGVHD的发生及作为aGVHD风险预测的一项重要指标。本文就CD4+CD25+Treg细胞的特性、免疫调节作用机制及CD4+CD25+Treg细胞与aGVHD的关联性的一些研究进展作一综述。     

Ability of lymphocytes stimulated by phytohemagglutinin in vitro to participate in the graft versus host reaction

Lymph node cells from CBA mice stimulated for 2 h by phytohemagglutinin were more able, whereas cells cultivated for 44 h with phytohemagglutinin were less able, than intact lymph node cells to participate in the graft versus host reaction when injected into sublethally irradiated (CBA x C57BL/6)F₁ hybrids. Syngeneic lymphocytes and killed allogeneic lymphocytes cultivated in the same way, like phytohemagglutinin itself, had no such action.Department of Immunology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. M. Lopukhin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 5, pp. 579–581, May, 1976.     

不同干细胞骨髓腔内输注对移植物抗宿主病和免疫耐受的影响

观察不同来源的造血干细胞经髓腔内输注能否在减轻移植物抗宿主病(GVHD)的同时诱导稳定的免疫耐受。雌性C57BL/6小鼠接受全身照射(TBI)预处理后,输注雄性BABL/c小鼠来源的骨髓细胞或经rhG-CSF动员后的外周造血干细胞,2 d后腹腔注射环磷酰胺(CTX)。观察各组GVHD发生情况,并通过皮肤移植对受者耐受状态进行检测。结果显示,髓腔内骨髓移植组(IBM-BMT)的受鼠无1例发生GVHD,而髓腔内外周造血干细胞移植组(IBM-PBSCT)的受鼠GVHD发生率较尾静脉组(IV)明显减低(P<0.05);IBM-BMT和IBM-PBSCT组受鼠对供鼠皮肤移植物的存活时间均超过120 d,较IV组明显延长(P<0.01)。实验表明髓腔内输注在降低GVHD发生率的同时,有利于稳定的免疫耐受状态的形成。     

Cells and secretagogues involved in the human late-phase response

Those scientists interested in allergic inflammatory processes have recently been focusing on the late-phase response, since it appears most similar to the chronic disease states observed in allergic patients. In this review we will focus on the pattern of mediator release and cellular traffic observed in two in vivo human models of the late-phase reaction, one involving the upper airways and the other the skin. We have observed in these models, as had been observed earlier in blood, that the late-phase reaction is associated with a second increase in the level of mediators. We also describe our studies of the secretagogues responsible for this late-phase mediator release and, in so doing, introduce the subjects of histamine-releasing factors and IgE heterogeneity.     

Cells involved in the in vitro stimulation by DNP—carrier complexes of in vivo primed mouse spleen cells

The target cell of in vitro stimulation of primed spleen cells by hapten—carrier complexes was studied. The antigens DNP₂₈—bovine serum albumin (DNP₂₈—BSA), which gives only 2,4-dinitrophenyl (DNP) specific responses and DNP₁₄—mouse immunoglobulin (DNP₁₄—MIg), which probably reveals DNP as well as carrier specificity (new antigenic determinant) were used. Educated T cells could be stimulated with the antigens used for activation. A similar experiment with educated B cells, however, gave no indication that these B cells could be stimulated with antigen in the absence of T cells. Cortisone treatment of primed mice yielded spleen cells which had a higher activity than spleen cells from unprimed, cortisone-treated mice. This also points to stimulation of T cells by antigen. Treatment of primed spleen cells with anti-thymocyte serum (ATS) and complement (C) abolished stimulation by phytohaemagglutinin (PHA) completely, by lipopolysaccharide (LPS) slightly, while the antigen-specific activity was 90 per cent reduced. This indicates a mainly T cell-specific stimulation by the antigen. A corresponding experiment with anti-plasma cell serum (APCS) and C revealed a complete reduction of LPS activity and a small impairment of the PHA and conavalin A (Con A) activity. However, the antigen-specific activity was reduced by one-third to a half for the different antigens. This is an indication for a specific B-cell stimulation by the antigen, although it is on a lower level than the T-cell stimulation. The role of the hapten in the T-cell stimulation is discussed.     

Analysis of interactions among factors involved in the bacteriophage T3 DNA packaging reaction in a defined in vitro system

During head assembly of phage T3, DNA is packaged into the cavity of a preformed protein shell, called the prohead, with the aid of noncapsid, packaging proteins, the products of genes 18 and 19 (gp18 and gp19). gp18 and gp19 separately form complexes with DNA and proheads, respectively. These complexes associate to form a precursor which can be converted to filled heads by the addition of ATP. Interactions among factors involved in DNA packaging were analyzed. In the presence of ATP, gp19 formed functional complexes with proheads. Formation of gp19-prohead complex showed a sigmoidal dependence on ATP concentration with a half maximal concentration of about 7.5 microM. Six molecules of gp19 bound to the prohead at a saturating amount of gp19. gp19 did not bind to proheads lacking the connector of gp8 (8- prohead). In the absence of ATP, proheads were inactivated by gp19. The gp19-prohead complexes formed in the absence of ATP contained 20-30 gp19 molecules per prohead and formed multimeric aggregates. 8- proheads did not bind gp19 and did not form such aggregates even in the absence of ATP. From these results, we conclude that 6 molecules of gp19 bind to the gp8 connector structure in the portal vertex of the prohead. The cleavage patterns of gp19 by several proteases were altered by the addition of ATP, indicating that ATP induces a conformational change in gp19, gp18 bound only to linear, duplex DNA.     

Analysis of the steps involved in Dengue virus entry into host cells

The initial steps of dengue viral entry have been divided into adsorption and penetration using acid glycine treatment to inactivate extracellular virus after attachment to baby hamster kidney (BHK) cells but prior to penetration. First, we showed that virus infection was accomplished within 2 h after adsorption. Second, the assay was used to examine the properties of dengue envelope E protein-specific monoclonal antibodies (MAbs), lectins, and heparin. We found that three MAbs, 17-2, 46-9, and 51-3, may neutralize dengue 2 virus (DEN-2) through inhibition of not only viral attachment but also of penetration. However, one MAb, 56-3.1, interfered specifically with attachment. Therefore, the functional domains of E protein involved in attachment and penetration may be different. Moreover, studies with lectins indicated that carbohydrates, especially alpha-mannose residues, present on the virion glycoproteins may contribute to binding and penetration of the virus into BHK and mosquito C6/36 cells. Finally, virus infectivity was inhibited by heparin through its blocking effects at both virus attachment and penetration. This suggests that cell surface heparan sulfate functions in both viral attachment and penetration of DEN-2 virus. In conclusion, our results further elucidated some aspects of the dengue virus entry process.     

Local graft versus host reaction in the xenogeneic system.

The injection of viable rat spleen cells beneath the renal capsule of cyclophosphamide (CY)-treated adult mice produced a localized graft versus host reaction (GvHR), manifested by the kidney enlargement index (KI). The optimal xenogeneic GvHR was obtained after injection of 30-50 million rat spleen cells into mouse recipients treated 24 hr before with CY, 200 mg/kg intraperitoneally (i.p.), and killed 7 days later. Splenomegaly in recipient mice suggested systemic dissemination of the local GvHR.     

Mechanisms involved in the evasion of the host defence by Pseudomonas aeruginosa.

Pseudomonas aeruginosa, an extracellular opportunistic pathogen, utilizes two major mechanisms to evade the host defence system. One of these mechanisms is the production of a large number of extracellular products, such as proteases, toxins, and lipases. The two proteases, alkaline protease and elastase, inhibit the function of the cells of the immune system (phagocytes, NK cells, T cells), inactivate several cytokines (IL-1, IL-2, IFN-r, TNF), cleave immunoglobulins and inactivate complement. Inhibition of the local immune response by bacterial proteases provides an environment for the colonization and establishment of chronic infection. The other mechanism by which P. aeruginosa evades the host defence system is the biofilm mode of growth of the bacteria in chronic infections. The biofilm-grown bacteria induce a low phagocyte response, and provide a barrier for the bacteria against antibodies, complement, and the cells of the immune system. Protection from the host defence system combined with increased antibiotic resistance of the bacteria in the biofilm are the major reasons for the persistence of P. aeruginosa in chronic infections.     

Sperm surface components involved in the control of the acrosome reaction

Several lines of evidence suggest that decapacitation of sperm occurs normally in the male reproductive tract, and as a result the acrosome is stabilized and the acrosome reaction is controlled. Since the defining experiments in 1951, where decapacitation was reversed in the female reproductive tract by capacitation, investigations have pursued the molecular events of this process. This review attempts to examine critically the older literature and compare that perspective with the current theories. The theories for decapacitation of sperm include the possible role of a peptide decapacitation factor, a glycoprotein-mediated steroid transfer to the sperm, masking of a galactosyl transferase by some macromolecule-containing carbohydrate, preclusion of calcium influx by a binding protein, and sperm interaction with the acrosome stabilizing factor. Although these theories are diverse, there are some unifying aspects. However, there remain some major unanswered questions. For example, although we point to some circumstantial evidence that infers a single decapacitation factor, this needs to be further substantiated. It is concluded that with the purification of a macromolecule involved in capacitation, specific proposals on the mechanism of capacitation, and new tools to evaluate the capacitation process, it is likely that another decade will not pass without emergence of a unifying molecular theory of sperm capacitation.     

Interaction between the graft versus host reaction and pregnancy

A graft versus host reaction (GVHR) was induced in F₁(CBA×C57BL/6) female hybrids by intravenous injection of a suspension of lymphocytes from the spleen and lymph glands from C57BL/6 females. Pregnancy, which developed as a result of crossing the experimental females with syngeneic males 1–10, 10–20, 30–40, and over 40 days after injection of the lymphocytes, aggravated the transplantation sickness due to the GVHR. On the other hand, the GVHR under these conditions reduced the percentage of animals that became pregnant and disturbed the reproductive function of the experimental mice (stillbirth, death of the pregnant females, abortion). An exacerbation of the GVHR was observed in some of the experimental animals after giving birth. The rate of survival of the progeny was lowered.Department of Microbiology, Smolensk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 9, pp. 68–71, September, 1975.     

Participation of phytohemagglutinin-transformed mouse lymphocytes in the graft versus host reaction

Transformed lymphocytes obtained by stimulating lymph node cells of CBA mice with phytohemagglutinin (PHA) do not give the graft versus host reaction (GVHR) if injected into sublethally irradiated (CBA×C57BL/6) F₁ hybrids. In a population of PHA-stimulated cells the GVHR was induced by small lymphocytes having the same concentration of antigens, detectable by antilymphocytic serum, as intact lymphocytes.Department of Immunology, Medico-Biological Faculty, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. M. Lopukhin.) Translated from Byulletin' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 9, pp. 1096–1098, September, 1976.