Tumor regression with Q fever rickettsiae and a mycobacterial glycolipid

Summary Regression of established tumors by Coxiella burneti, the rickettsial agent which causes Q fever, was studied using the transplantable line-10 tumor in strain 2 guinea pigs. Suspensions of formalin-killed, purified rickettsiae induced an average of 42% tumor regression after intratumor injection. The activity of C. burneti was enhanced by incorporation of the rickettsiae into oil droplet vaccines containing the mycobacterial glycolipid, P₃. Such vaccines induced 64% tumor regression. The activity of C. burneti that was enhanced by P₃ was found in phenol-water extracts of the rickettsiae. These extracts contained lipopolysaccharides which were less toxic than bacterial endotoxins, and they induced 63% tumor regression when combined with P₃. These lipopolysaccharides may provide agents of high therapeutic activity but relatively low toxicity for cancer immunotherapy.     

Low IgG response of the mouse strain C57BL/10ScSn after immunization with protein antigens

The low IgG response of the strain C57BL/10ScSn is not restricted to the reaction to sheep red blood cells; but it can be demonstrated even after immunization with ARS, DNP or FITC haptens, coupled to various heterologous (BGG, RSA) or autologous (MGG) protein carriers. The level of the IgG response is - using the same immunization schedule - influenced both by the bound hapten and the carrier. In both strains tested (i.e. in the high-responding A/J and the low-responding C57BL/10ScSn), the highest IgG response is elicited by FITC-BGG. The response of the C57BL/10ScSn strain is, similarly as after immunization with SRBC, approximately ten times lower. The IgG response to other antigens tested was lower in both strains and therefore the quantitative differences were less pronounced. The affinity of antibodies against the ARS and TNP determinant, detected by inhibition of plaque-forming cells, is similar in the two strains. Thus the low reactivity of the strain C57BL/10ScSn is not caused by the absence of suitable VH and VL genes, but it rather indicates a defect of some general regulatory mechanism, involved in the synthesis of IgG antibodies. After repeated administration of ARS-BGG, the antigen and the antigen - antibody complexes accumulate in high concentrations primarily in the liver of mouse strain A/J. The amount of antigen accumulated in the liver of strain C57BL/10ScSn is significantly lower.     

Delayed hypersensitivity reaction to transplantation antigens in mice with induced tolerance for allo- and xenografts

The delayed-type hypersensitivity reaction (DTH) in mice tolerant to allo- and xenoantigens has been investigated. To induce tolerance adult mice were thymectomized and given 1 X 10(8) allogeneic or xenogeneic spleen cells and cyclophosphamide (200 mg/kg). Such mice failed to develop DTH to donor antigens, while DTH reaction to foreign allo- and xenoantigens was retained. Spleen cells of mice tolerant to alloantigens significantly suppressed the afferent and efferent DTH phases. The suppression was specific and T-cell-mediated. Spleen cells of mice tolerant to xenoantigens could suppress only the afferent DTH phase. The treatment of cells with anti-T-globulin and complement did not abrogate the suppression. The role of DTH suppressors in the induction and maintenance of transplantation tolerance is discussed.     

以人精子抗原消化道免疫后的体液免疫反应

The inbred Balb/c and C57 mice, and the outbred Swiss Webster mice were intragastrointestinally immunized with human sperm antigens. The lymphocytes from the spleen, mesenteric lymph node (MLN), Peyer's patch (PP) and uterus or epididymis were isolated and cultured. The lymphocyte-secreting antisperm IgG and IgA and the antisperm antibodies in the gut wash and serum were determined with enzyme-linked immunosorbent assay (ELISA). In the Balb/c and Swiss Webster mice, the immune responses to sperm have shown to be stronger than that in C57, stronger in female than in male. The antigenicity of sperm membrane extracts seems to be higher than that of whole sperm. Antisperm antibodies secreted by lymphocytes from the epididymis and uterus have demonstrated to be detectable. For stimulation of the local immune response, the intra-PP and intralumina immunizations are more effective than others.     

Modulation of granulomatous hypersensitivity. V. Participation of histamine receptor positive and negative lymphocytes in the granulomatous response of Schistosoma mansoni-infected mice

The possible role of histamine and histamine-receptored inflammatory cells in the granulomatous response of Schistosoma mansoni-infected mice was examined. Special staining revealed the presence of numerous mast cells, many partially degranulated within the liver granulomas. Treatment of infected mice with cimetidine (an H2 receptor antagonist) enhanced, and diphenyhydramine (an H1 receptor antagonist) decreased the granulomatous response. Fluorescein-labeled histamine-rabbit serum albumin conjugate (H-FRSA) and unlabeled conjugate (H-RSA)-coated culture plates were used to identify and isolate cells with histamine receptors. A large proportion of granuloma macrophages, lymphocytes, eosinophils, neutrophils, and splenic lymphocytes had histamine receptors. Elution of adherent cells from H-RSA-coated culture plates with H1 or H2 receptor antagonists suggested that receptors on granuloma cells were predominately H1 with some granuloma lymphocytes bearing H2-type receptors. Splenic lymphocytes from infected mice were functionally divided according to the presence or absence of histamine receptors on their cell surface. Receptor-negative lymphocytes appeared to mediate SEA-stimulated MIF production (TDH cells) and participated in the adoptive transfer of suppression of granulomas (TH cells). Whereas, TS cells appeared to have histamine receptors. Based on these data, it is inferred that lymphocytes that regulate lymphokine production (TS cells) within the granuloma may be triggered via their histamine receptors to exert suppressive activity.     

Antibody production in vitamin A-depleted rats is impaired after immunization with bacterial polysaccharide or protein antigens

Vitamin A nutritional status has been implicated as important in maintaining the integrity of immune functions. We have determined the effect of vitamin A (retinol) depletion on the ability of young animals to produce antibodies after challenge with various bacterial antigens. Male Lewis rats raised on vitamin A-free or adequate diets were immunized either near 40 days of age, before signs of vitamin A deficiency were apparent, or near 47 days of age when symptoms of deficiency were beginning to be manifest. For rats immunized with polysaccharide antigens from Streptococcus pneumoniae or Neisseria meningitidis, antibody production did not exceed 0-19% of the response of control rats. Vitamin A depletion also severely compromised the response to two T cell-dependent antigens, tetanus toxoid and sheep red blood cells. In striking contrast, retinol-depleted rats immunized with lipopolysaccharides from Pseudomonas aeruginosa and Serratia marcesens produced an antibody response indistinguishable from retinol-sufficient animals. These lipopolysaccharides could elicit antibodies in rat pups, whereas the capsular polysaccharide antigens could not. This is consistent with the characteristics of type 1 and type 2 antigens, respectively. These studies indicate that retinol status is an important determinant of the humoral immune response to certain types of antigen and suggest that antibody production to capsular polysaccharides and T cell-dependent antigens is particularly dependent on adequate retinol status.     

Avidity and competitive inhibition of binding native and chaotropically modified immunoglobulins with protein and glycolipid antigens

It is established, that native and chaotropically modified immunoglobulins essentially differ by avidity and character of competitive inhibition of binding with protein (ovalbumin), glycolipid (lipopolysaccharides) antigens and native double-strand DNA. Apparently, it is connected with structural and functional distinctions of their antigen-binding centres.     

Vertical toxoplasmosis in a murine model. Protection after immunization with antigens of Toxoplasma gondii incorporated into liposomes

Distinct Toxoplasma gondii antigens were entrapped within liposomes and evaluated for their ability to protect Balb/c mice against congenital transmission: soluble tachyzoite antigen (L/STAg), soluble tissue cyst antigen (L/SCAg), soluble tachyzoite plus tissue cyst (L/STCAg) or purified 32kDa antigen of tachyzoite (L/pTAg). Soluble tachyzoite antigen alone in PBS (STAg) or emulsified in Freund's Complete Adjuvant (FCA/STAg) was also evaluated. Dams were inoculated subcutaneously with these antigens 6, 4 and 2 weeks prior to a challenge with four tissue cysts of the P strain of T. gondii orally between 10 and 14 days of pregnancy. Significant diminution differences were observed between the frequency of infected pups born of the dams immunized with the antigens incorporated into liposomes and that of pups born of the dams immunized with antigen emulsified in FCA or non immunized group (p<0.05). There was a significant decrease in the number of pups born dead in the groups L/STAg, L/SCAg and L/pTAg when compared with pups from all other groups (p <0.05). All dams immunized with or without adjuvant showed an antibody response and a proliferation of T-cells. However, no correlation was found between immune response and protection against the challenge.     

Vaccination response to protein and carbohydrate antigens in patients with rheumatoid arthritis after rituximab treatment

Introduction  

Rheumatoid arthritis (RA) is frequently complicated with infections. The aim of our study was to evaluate vaccination response in patients with RA after B-cell depletion by using rituximab.     

Conformational changes associated with complex formation between a mycobacterial polymethylpolysaccharide and palmitic acid.

The anomeric proton magnetic resonances of Mycobacterium smegmatis 3-O-methylmannose polysaccharide have chemical shifts intermediate betwen those of nonaglucoamylose and alpha-cyclodextrin, and on addition of palmitic acid most of these resonances are shifted upfield toward that of the cyclodextrin. This suggests that the methylated polysaccharide could have a conformation with some secondary structure intermediate between those of the two reference compounds, and that it forms a tightened coil upon addition of the lipid which yields an inclusion complex with the polysaccharide. The change in chemical shift is linear with lipid concentration, which indicates that the complex undergoes rapid exchange with free polysaccharide. The changes in proton chemical shifts of the polysaccharide and of the palmitic acid are consistent with the fatty acid being inserted in the coiled polysaccharide with its carboxyl group near the methyl aglycon.     

Airway hyperresponsiveness, late allergic response, and eosinophilia are reversed with mycobacterial antigens in ovalbumin-presensitized mice

Pretreatment with mycobacterial Ags has been shown to be effective in preventing allergic airway inflammation from occurring in a mouse model. Because most asthmatics are treated after the development of asthma, it is crucial to determine whether mycobacterial Ags can reverse established allergic airway inflammation in the presensitized state. Our hypothesis, based upon our previous findings, is that mycobacteria treatment in presensitized mice will suppress the allergic airway inflammation with associated clinical correlates of established asthma, with the noted exception of factors associated with the early allergic response (EAR). BALB/c mice sensitized and challenged with OVA were evaluated for pulmonary functions during both the EAR and late allergic response, and airway hyperresponsiveness to methacholine. Following this, sensitized mice were randomized and treated with placebo or a single dose (1 x 10(5) CFUs) of bacillus Calmette-Guérin (BCG) or Mycobacterium vaccae via nasal or peritoneal injection. One week later, the mice were rechallenged with OVA and methacholine, followed by bronchoalveolar lavage (BAL) and tissue collection. Mice treated with intranasal BCG were most significantly protected from the late allergic response (p < 0.02), airway hypersensitivity (p < 0.001) and hyperreactivity (p < 0.05) to methacholine, BAL (p < 0.05) and peribronchial (p < 0.01) eosinophilia, and BAL fluid IL-5 levels (p < 0.01) as compared with vehicle-treated, sensitized controls. Intranasal M. vaccae treatment was less effective, suppressing airway hypersensitivity (p < 0.01) and BAL eosinophilia (p < 0.05). No changes were observed in the EAR, BAL fluid IL-4 levels, or serum total and Ag-specific IgE. These data suggest that mycobacterial Ags (BCG>M. vaccae) are effective in attenuating allergic airway inflammation and associated changes in pulmonary functions in an allergen-presensitized state.     

Delayed hypersensitivity in mice infected with reovirus. I. Identification of host and viral gene products responsible for the immune response

Delayed-type hypersensitivity (DTH) can be demonstrated in mice infected with reovirus by challenging primed animals in the footpad with virus. Maximal responses occur 7 days after immunization with as little as 10(5) viral particles. DTH to reovirus is transferable by lymph node cells and is mediated by T cells as the transfer of reactivity can be abrogated by treatment of cells with anti-Thy 1.2 plus complement. DTH to reovirus is serotype specific, animals infected with reovirus type 1 or 3 only develop DTH responses when challenged with the same serotype with which they were infected. Using recombinant viral clones containing genes from both parental serotypes, we have demonstrated that the S1 gene, the gene encoding the viral hemagglutinin, determines serotype specificity. Furthermore, in adoptive transfer experiments between mice of varying histocompatibility backgrounds, it was found that D or K, IA-IB region identity was required for the transfer of reactivity. These studies demonstrate that specific host and viral genes determine the in vivo cellular immune response to reovirus and should allow a more precise definition of the host cellular immune response to viral antigens.     

Naturally occurring antibodies to liposomes. I. Rabbit antibodies to sphingomyelin-containing liposomes before and after immunization with unrelated antigens

Liposomes were prepared from a mixture of sphingomyelin, cholesterol, and dicetylphosphate or L-alpha-dimyristoyl phosphatidylcholine, cholesterol, and dicetylphosphate, in the presence of glucose. The amount of trapped glucose released from these liposomes was monitored after incubation with a variety of normal and immune sera in the presence of guinea pig complement. All normal rabbit sera tested were found to release, in the presence of complement, detectable amounts of trapped glucose from sphingomyelin-containing liposomes. After immunization with a variety of unrelated antigens, the anti-sphingomyelin liposome activity increased signficantly and in direct proportion to the number of injections, despite the fact that the liposomes used in the assay did not contain the relevant antigen used for immunization. Liposomes prepared from dimyristoyl phosphatidylcholine showed only marginal release of their trapped marker when assayed with the same rabbit sera and complement. These liposomes, however, were fully reactive when the appropriate antigen was inserted in their bilayer structure. The antiliposome activity was associated mainly with the IgM antibody class. These results raise the interesting possibility that antigenic stimulation may trigger the activation of lymphocyte clones directed against autologous cell-membrane components that cross-react with artificial model membranes containing sphingomyelin.     

Protection against canine distemper virus in dogs after immunization with isolated fusion protein.

Canine distemper virus attachment (hemagglutinin [H] equivalent) and fusion (F) antigens were purified by affinity chromatography with monoclonal antibodies. The purified antigens were used to immunize groups of three dogs. Radioimmune precipitation assays with sera from these animals showed that the F antigen preparation was pure and induced only an F polypeptide-specific antibody response but that the H antigen preparation had a slight contamination by the F antigen. Immunized animals were challenged with virulent canine distemper virus. Two animals in each group developed pronounced humoral and cellular immune responses after challenge. Among these infected animals, only the dogs immunized with H antigen developed symptoms, albeit mild. In contrast, three nonimmunized control animals developed severe disease, with a fatal outcome in two cases. The complete resistance against challenge in two dogs was interpreted to reflect in one case anti-F immunity and in the other case most likely a high level of anti-H immunity. It is suggested that the F antigen may be of particular interest for the development of morbillivirus and possibly other paramyxovirus subunit or synthetic vaccines, because it can induce immunity capable of blocking virus infection and in situations of virus replication prevent the emergence of symptoms.     

Relationships between cell-mediated immunity and the IgE antibody response: II. Delayed hypersensitivity and antibody production to DNP-Ascaris conjugates

Rats of the W/F strain were immunized with DNP-Ascaris conjugates using complete Freund's adjuvant (CFA), Al(OH)₃ gel (alum), or B. pertussis vaccine as adjuvants. Cell-mediated immunity was assessed by lymphotoxin in vitro and by delayed hypersensitivity in vivo. IgE and IgG antibody determinations were made on serum pools obtained at various times during the primary and secondary responses. Although delayed hypersensitivity appeared earlier than lymphotoxin, these two parameters correlated during the primary but not during the secondary response. The discrepancies suggested that different cells may be responsible for these two phenomena. Antibody production was influenced by the adjuvant used. CFA led to IgG antibody responses to both hapten and carrier but not to IgE antibody production. The use of B. pertussis resulted in both IgE and IgG antibody production. In the case of alum, anti-hapten antibodies appeared during the primary response while anti-carrier antibodies of both IgE and IgG classes were detected after booster. The results indicated that cell-mediated immunity, IgE, and IgG antibodies appeared independently in an ordered, temporal sequence, and that these responses were not mutually exclusive but were under strong modulatory influences of the various adjuvants used.