Immunomodulatory activity of Asparagus racemosus on systemic Th1/Th2 immunity: Implications for immunoadjuvant potential

Ethnopharmacological relevance

Roots of Asparagus racemosus Willd (Shatavari in vernacular) are widely used in Ayurveda as Rasayana for immunostimulation, galactogogue as also in treatment of conditions like ulcers and cancer. Various studies have indicated immunomodulatory properties of Shatavari root extracts and formulations.

Aim of the study

To study the effect of standardized Asparagus racemosus root aqueous extract (ARE) on systemic Th1/Th2 immunity of SRBC sensitized animals.

Materials and methods

We used HPTLC to quantify steroidal saponins (Shatavarin IV, Immunoside^®) and flow cytometry to study effects of ARE on Th1/Th2 immunity. SRBC specific antibody titres and DTH responses were also monitored as markers of Th2 and Th1 responses, respectively. We also studied lymphocyte proliferation. Cyclosporin, cyclophosphamide and levamisole were used as controls.

Results

Treatment with ARE (100 mg/(kg b.w. p.o.)) resulted in significant increase of CD3⁺ and CD4/CD8⁺ percentages suggesting its effect on T cell activation. ARE treated animals showed significant up-regulation of Th1 (IL-2, IFN-g) and Th2 (IL-4) cytokines suggesting its mixed Th1/Th2 adjuvant activity. Consistent to this, ARE also showed higher antibody titres and DTH responses. ARE, in combination with LPS, Con A or SRBC, produced a significant proliferation suggesting effect on activated lymphocytes.

Conclusion

The study suggests mixed Th1/Th2 activity of ARE supports its immunoadjuvant potential.     

驱虫斑鸠菊注射液对小鼠免疫功能的影响

目的:探讨驱虫斑鸠菊对小鼠免疫功能的影响。方法:采用[3H]-TdR掺入法和脾细胞介导羊红细胞定量溶血分光光度法以及迟发型超敏反应试验等观察了驱虫斑鸠菊对小鼠兔疫功能的作用。结果:驱虫斑鸠菊在体内外均可以明显抑制ConA刺激的小鼠T淋巴细胞的增殖反应和LPS刺激的小鼠B淋巴细胞的增殖反应（P<0.01）;对小鼠胸腺指数和脾脏指数、绵羊红细胞（SRBC）诱导的正常小鼠脾抗体细胞生成反应以及小鼠皮肤迟发型超敏反应都显示出明显的抑制作用,而且上述抑制作用与药物浓度有一定的剂量效应关系。结论:驱虫斑鸠菊对机体体液免疫、细胞免疫都有明显的抑制作用。     

Development of acute autoimmune encephalomyelitis in mice: Factors regulating the effector phase of the disease

The development of acute experimental autoimmune encephalomyelitis (EAE) in mice is potentiated by the use of Bordetella pertussis vaccine as an adjuvant. Histamine sensitizing factor (HSF) extracted from B. pertussis is the active adjuvant agent and causes a mild increase in cerebrovascular permeability. During the development of EAE, there is an additional increase in vascular permeability of the brain and spinal cord. The adjuvant action of B. pertussis HSF does not appear to mimic a generalized beta-adrenergic blockade, since the course of EAE is not potentiated by adrenalectomy. The cerebrovascular permeability changes observed in EAE are probably mediated by vasoactive amines, since the expression of EAE can be blocked by vasoactive amine antagonists.     

The Follow-Up Study of Skin Reactivity to Recall Antigens and E- and EAC-RFC Profiles in Blood in Asbestos Workers

We have determined cutaneous DTH reactions to SK-SD and PPD and peripheral blood lymphocyte profiles in a group of asbestos workers in two consecutive surveys. It was found that asbestosis and, to a lesser extent, the presence of ANA are significantly correlated with the lack of response to the above antigens. 83% of asbestos workers when tested at a 4 year interval fell into the same two categories of responsiveness (lack of response or response at least to one antigen).The asbestosis cases had lower total lymphocyte count as well as proportions and absolute number of E-RFC as compared to asbestos workers without asbestosis and/or ANA. Furthermore, the latter group showed the lower percentages and absolute number of E-RFC than the matched controls. The presence of ANA is also correlated with lower proportions of E-RFC. However, this is related at least in part to asbestosis.     

Loss of tolerance to a maternal kidney transplant is selective for HLA class II: evidence from trans-vivo DTH and alloantibody analysis

We studied late graft rejection in a patient who had received a kidney transplant 9–10 years earlier from his mother and who had been off all immunosuppressive drugs for 7 years at the time of graft rejection onset. The mother differed for one HLA-A (A3) and one HLA-B (B62) antigen but had only a subtype mismatch at the HLA-DRβ1 locus (donor: DRβ1*1104; recipient: DRβ1*1102). A gradual rise in serum creatinine from 1.8 to 2.0 mg/dl at year 9 prompted a biopsy, which was negative for rejection (focal infiltrates but no tubulitis). Ten months later the patient’s creatinine had risen to > 3.4 mg/dl, and a second biopsy revealed extensive tubulitis, cellular rejection, and glomerular sclerosis. Sonicates of donor leukocytes triggered no delayed-type hypersensitivity (DTH) response above background (PBMC only) in the patient’s peripheral blood leukocytes obtained prior to year 9. A gradual recovery of antidonor DTH response between year 9 and 10 closely paralleled the change from tolerant to rejection status. Antidonor antibody was also undetectable in serum prior to year 9, but a donor-reactive antibody did develop at year 10.2 shortly after the peak of DTH response. The serum level of soluble donor HLA class I B62 antigen rose > 10-fold over prerejection level at the time of the biopsy-proven rejection, suggesting a possible trigger for both the cellular and humoral immune response. Nonetheless, we found no evidence for the de-velopment of humoral or cellular immunity to maternal HLA class I. Instead, DTH analysis of memory T cells of the patient obtained after rejection showed that a single maternal HLA DRβ1*1104 allopeptide, differing by two amino acids in sequence from the peptide of the recipient (DRβ1*1102), stimulated a strong memory DTH response. Similarly, we found an anti-HLA class II donor-specific antibody in serum that appeared to be crossreactive with DRβ1*1104 and DRβ1*1101 but not with the recipient DRβ1*1102 antigen. The data support the idea of a profound unresponsive state at both the cellular (DTH) and humoral level toward maternal HLA class I antigens that was not reversed even during late cellular rejection, despite the release of high levels of soluble HLA class I. Furthermore, the data suggest that DTH recovery was a close correlate of the onset of rejection and this “indirect” alloresponse, like the anti-donor alloantibody response that followed, was directed not to noninherited maternal HLA-A,B antigens but to the maternal HLA DRβ1*1104 subtype.     

盐单胞菌Halomonas-GY1的分离鉴定与活性产物的研究

目的:从连云港赣榆附近海泥样品中分离嗜盐菌株并鉴定,对产物的活性做初步研究。方法:以Gibbons培养基富集培养并分离纯化菌株,以《伯杰氏系统细菌手册》第1卷(1984)等为主要依据,对分离得到的菌株进行鉴定,琼脂扩散法测定体外抗菌活性,小鼠迟发型变态反应测定免疫活性。结果:分离得到一株盐单胞菌Halomonas-GY1,Halomonas-GY1符合盐单胞菌属特征,但其生理生化特征与几个典型的盐单胞菌属菌种存在差异。体外抗菌试验表明,Halomonas-GY1培养产物对革兰阳性菌以及部分革兰阴性菌有明显的抗菌作用,其多糖提取物对正常小鼠的迟发型变态反应有增强作用,对环磷酰胺所致免疫低下小鼠迟发型变态反应有恢复作用。结论:Halomonas-GY1为盐单胞菌菌株,其培养产物对革兰阳性菌及部分革兰阴性菌有明显的抗菌作用,多糖提取物具有明显的免疫保护作用。     

Phenotypic and functional properties of Th lines and clones recognizing larval antigens of Schistosoma mansoni

Five T cell clones and two lines were derived from the lymph nodes (LN) of C57BL/6 mice immunized with radiation-attenuated lung-stage larvae of Schistosoma mansoni. All seven clones/lines were CD4⁺, CD^8- and expressed high levels of CD44 and CD45RB surface markers. After prolonged maintenance in-vitro, with soluble antigen from 18 h schistosomula (SSP), five retained the ability to proliferate readily and release IFNg in response to conca-navalin A (Con-A) and to SSP and/or soluble adult worm antigen (SWAP). These Th clones/lines induced significant footpad DTH reactions when injected with SWAP, but were unable to confer protective immunity after transfer to naïve recipient mice. This result could be explained by the antigen specificity of the clones/lines, since they were not able to release IFNg when cultured in-vitro with living lung-stage larvae. A second possibility is that the high level of CD45RB expression, which is not seen on the surface of pulmonary CD⁴⁺ memory/effector cells isolated directly from protectively-vaccinated mice, alters the ability of the clones/lines to release IFNg and to induce a DTH response in the lungs when they encounter antigen released from migrating schistosomula.     

TLR2- and 4-independent immunomodulatory effect of high molecular weight components from Ascaris suum

Components of high molecular-weight (PI) obtained from Ascaris suum extract down-regulate the Th1/Th2-related immune responses induced by ovalbumin (OVA)-immunization in mice. Furthermore, the PI down-modulates the ability of dendritic cells (DCs) to activate T lymphocytes by an IL-10-mediated mechanism. Here, we evaluated the role of toll like receptors 2 and 4 (TLR2 and 4) in the modulatory effect of PI on OVA-specific immune response and the PI interference on DC full activation. An inhibition of OVA-specific cellular and humoral responses were observed in wild type (WT) or in deficient in TLR2 (TLR2^−/−) or 4 (TLR4^−/−) mice immunized with OVA plus PI when compared with OVA-immunized mice. Low expression of class II MHC, CD40, CD80 and CD86 molecules was observed in lymph node (LN) cells from WT, TLR2^−/− or TLR4^−/− mice immunized with OVA plus PI compared with OVA-primed cells. We also verified that PI was able to modulate the activation of DCs derived from bone marrow of WT, TLR2^−/− or TLR4^−/− mice induced in vitro by agonists of TLRs, as observed by a decreased expression of class II MHC and costimulatory molecules and by low secretion of pro-inflammatory cytokines. Its effect was accompanied by IL-10 synthesis. In this sense, the modulatory effect of PI on specific-immune response and DC activation is independent of TLR2 or TLR4.