Molecular adjuvant IL-33 enhances the potency of a DNA vaccine in a lethal challenge model

Identifying new molecular adjuvants that elicit effective vaccine-induced CD8⁺ T cell immunity may be critical for the elimination of many challenging diseases including Tuberculosis, HIV and cancer. Here, we report that co-administration of molecular adjuvant IL-33 during vaccination enhanced the magnitude and function of antigen (Ag)-specific CD8⁺ T cells against a model Ag, LCMV NP target protein. These enhanced responses were characterized by higher frequencies of Ag-specific, polyfunctional CD8⁺ T cells exhibiting cytotoxic characteristics. Importantly, these cells were capable of robust expansion upon Ag-specific restimulation in vivo and conferred remarkable protection against a high dose lethal LCMV challenge. In addition, we demonstrate the ability of IL-33 to amplifying the frequency of Ag-specific KLRG1⁺ effector CD8⁺ T cells. These data show that IL-33 is a promising immunoadjuvant at improving T cell immunity in a vaccine setting and suggest further development and understanding of this molecular adjuvant for strategies against many obstinate infectious diseases and cancer.     

Influence of iron-deficiency anemia on selected thymus functions in mice: thymulin biological activity, T-cell subsets, and thymocyte proliferation

To define the effects of iron deficiency on thymulin biological activity, T-cell subsets, and thymocyte proliferation, C57BL/6 female mice at weaning were fed an iron-deficient diet (10 mg Fe/kg diet), an iron-sufficient diet (50 mg Fe/kg diet), or restricted amounts of the iron-sufficient diet (the pair-fed group) for 40 d. Iron deficiency did not reduce the concentration of either serum or intracytoplasmic thymulin. Although T-cell subsets in the thymus were not altered, both the cortical and medullar regions were depleted of thymocytes. In the spleen iron deficiency (but not underfeeding) significantly reduced the percentage of L3T4+ cells, of Lyt-2+ cells, and thus of the overall T-cell population. However, it did not affect the ratio of L3T4+ to Lyt-2+ T cells. Thymocyte proliferation was significantly reduced at the concanavalin A (Con A) dose (10 mg/L) that produced maximal stimulation in control and pair-fed mice but not at low (7.5 mg/L) or high (15 mg/L) Con A concentrations. We conclude that the impairment in immune functions associated with iron deficiency is not due to an impairment in thymic endocrine function but rather to decreased immunocompetent lymphocytes.     

NDV-3 protects mice from vulvovaginal candidiasis through T- and B-cell immune response

We have previously reported that vaccination with rAls3p-N protein of Candida albicans, formulated with alum adjuvant (also designated as NDV-3) protects immunocompetent mice from, lethal disseminated candidiasis and mucosal oropharyngeal candidiasis. NDV-3 vaccine was recently, tested in a Phase 1 clinical trial and found to be safe, well-tolerated, and induced robust humoral and, cellular immune responses with increased interferon (IFN)-gamma and interleukin (IL)-17 secretion. In preparation for a Phase 2 clinical trial against vulvovaginal candidiasis (VVC), we evaluated NDV-3, efficacy in a murine VVC model. Here, NDV-3 induced a strong immune response characterized by high, anti-rAls3p-N serum IgG and vaginal IgA titers. Furthermore, moderate doses of the vaccine (a range of 1–30 μg given subcutaneously [SQ] or 0.3–10 μg given intramuscularly [IM]) elicited a 10–1000 fold, decrease in vaginal fungal burden vs. control (mice injected with alum adjuvant alone) in both inbred, and outbred mice infected with different clinical C. albicans isolates. Additionally, NDV-3 required both, T and B lymphocytes for efficacy in reducing C. albicans tissue burden, which is followed by a reduction, in neutrophil influx to the affected site. Finally, anti-rAls3p-N antibodies enhanced the ex vivo killing, of C. albicans by neutrophils primed with IFN-gamma. These data indicate that NDV-3 protects mice, from VVC by a mechanism that involves the concerted priming of both humoral and adaptive immune, responses.     

Effects of occupational metallic mercury vapour exposure on suppressor-inducer (CD4+CD45RA+) T lymphocytes and CD57+CD16+ natural killer cells

Objectives: To examine the effects of metallic mercury vapour on the cellular and humoral immune system. Methods: We measured T lymphocyte and natural killer (NK) cell subpopulations, B lymphocytes, and serum immunoglobulins (i.e. IgG, IgA and IgM) together with total T (CD3+) lymphocytes and total lymphocytes in blood samples from 20 male, fluorescent-lamp makers (mercury workers) and the same number of gender-, age- and smoking-matched controls. Urinary concentrations of inorganic mercury (UHg) in the 20 workers ranged from 1.8 to 163.5 (mean 44.8) μg/l. They had been exposed to mercury vapour for 4 to 62 (mean 31) months. Results: Numbers of CD4+CD45RA+ (suppressor-inducer) T lymphocytes and total CD4+ T lymphocytes in the mercury workers were significantly smaller than those in the controls (paired-sample t-test, P < 0.01). The number of CD57+CD16+ NK cells was inversely correlated with UHg. Conclusion: It is suggested that numbers of CD4+CD45RA+ T lymphocytes and CD57+CD16+ NK cells are inversely affected by exposure to metallic mercury vapour in workers, with an average urinary inorganic mercury concentration of 45 μg/l being found. Received: 7 September 1999 / Accepted: 6 May 2000     

Brucella abortus Omp19 recombinant protein subcutaneously co-delivered with an antigen enhances antigen-specific T helper 1 memory responses and induces protection against parasite challenge

The discovery of effective adjuvants for many vaccines especially those with limited commercial appeal, such as vaccines to poverty-related diseases, is required. In this work, we demonstrated that subcutaneous co-administration of mice with the outer membrane protein U-Omp19 from Brucella spp. plus OVA as antigen (Ag) increases Ag-specific T cell proliferation and T helper (Th) 1 immune responses in vitro and in vivo. U-Omp19 treated dendritic cells promote IFN-γ production by specific CD4⁺ T cells and increases T cell proliferation. U-Omp19 co-administration induces the production of Ag specific effector memory T cell populations (CD4⁺ CD44^high CD62L^low T cells). Finally, subcutaneous co-administration of U-Omp19 with Trypanosoma cruzi Ags confers protection against virulent parasite challenge, reducing parasitemia and weight loss while increasing mice survival. These results indicate that the bacterial protein U-Omp19 when delivered subcutaneously could be a suitable component of vaccine formulations against infectious diseases requiring Th1 immune responses.     

Synthesis and anticandidal activity of new triazolothiadiazine derivatives

New triazolothiadiazine derivatives were synthesized via the ring closure reaction of 4-amino-5-substituted-2,4-dihydro-3H-1,2,4-triazol-3-thiones with phenacyl bromides. The compounds were tested in vitro against various Candida species and compared with ketoconazole. Among these compounds, the compound bearing cyclohexyl moiety and p-chlorophenyl substituent on triazolothiadiazine ring (2i) was found to be the most potent derivative against Candida albicans (ATCC 90028). It is clear that there is a positive correlation between anticandidal activity and two functional moieties, namely cycloaliphatic group and p-chlorophenyl substituent on triazolothiadiazine ring. The compounds were also investigated for their cytotoxic effects using MTT assay. Compound 2a exhibited the highest cytotoxic activity, whereas compound 2f possessed the lowest cytotoxic activity against NIH/3T3 cells.     

Mutant Escherichia coli enterotoxin as a mucosal adjuvant induces specific Th1 responses of CD4+ and CD8+ T cells to nasal killed-bacillus calmette-guerin in mice

On single nasal immunization of mice with killed-bacillus calmette-guerin (BCG) plus a mutant Escherichia coli enterotoxin, delayed-type hypersensitivity was induced and BCG-infection decreased. Spleen cells, particularly CD4+ T cells among them produced IL-2, IFNgamma and TNFalpha in response to the killed-BCG or purified protein derivatives. CD8+ T cells including cytotoxic T lymphocytes produced IFNgamma and TNFalpha. However, both types of T cells reacted a little to Ag85B. The mutant induces cellular immunity to nasal killed-BCG vaccine and decreases BCG-infection. CD4+ and CD8+ T cells produce cytokines effective for tuberculosis. Although killed-BCG loses some antigens like Ag85B, nasal killed-BCG plus the mutant is useful for tuberculosis.     

Rabbit alveolar macrophages after inhalation of soluble cadmium,cobalt, and copper: A comparison with the effects of soluble nickel

Rabbits were exposed to aerosols of chlorides of cadmium, copper, and cobalt (0.4–0.6 mg/m³ as metal) for 1 month (5 days/week and 6 hr/day). The effects on alveolar macrophages were compared with earlier reported effects of nickel chloride (0.3 mg/m³ as Ni). Effects of Cd²⁺ exposure resembled those of Ni²⁺ exposure. The number of macrophages in lavage fluid and the variance of cell diameters were thus increased and many cells contained lamellated inclusions. Contrary to macrophages from Ni²⁺-exposed rabbits, the surface of about 50% of the cells had cytoplasmic blebs. However, such cells were rarely seen by scanning electron microscopy. There were significantly more polymorphonucleated neutrophils and small lymphocytes, suggesting lung parenchymal damage. Cells from Cd²⁺-exposed animals, like cells from Ni²⁺-exposed ones, showed an increased oxidative metabolic activity after stimulation with Esherichia coli bacteria. Bactericidal capacity, on the other hand, tended to be enhanced rather than decreased, as in the nickel experiment. After Co²⁺ exposure, the number of macrophages was slightly increased in the lavage fluid and the cells showed an increased metabolic activity both at rest and upon stimulation with bacteria. Cu²⁺ exposure gave a slight increase in lamellated inclusions in the macrophages.     

Sex-specific association of rs16996148 SNP in the NCAN/CILP2/PBX4 and serum lipid levels in the Mulao and Han populations

Background

This study evaluated the relationship between ulcerative colitis and obesity, which are both chronic diseases characterized by inflammation and increases in immune cells and pro-inflammatory cytokines.

Methods

Mice with chronic ulcerative colitis induced by 2 cycles of dextran sodium sulfate (DSS) in the first and fourth week of the experiment were fed a high-fat diet (HFD) to induce obesity by 8 weeks. The animals were divided into 4 \ groups (control, colitis, HFD and colitis + HFD).

Results

Obesity alone did not raise histopathology scores, but the combination of obesity and colitis worsened the scores in the colon compared to colitis group. Despite the reduction in weight gain, there was increased inflammatory infiltrate in both the colon and visceral adipose tissue of colitis + HFD mice due to increased infiltration of macrophages, neutrophils and lymphocytes. Intravital microscopy of VAT microvasculature showed an increase in leukocyte adhesion and rolling and overexpression of adhesion molecules compared to other groups. Moreover, circulating lymphocytes, monocytes and neutrophils in the spleen and cecal lymph nodes were increased in the colitis + HFD group.

Conclusion

Our results demonstrated the relationship between ulcerative colitis and obesity as aggravating factors for each disease, with increased inflammation in the colon and adipose tissue and systemic alterations observed in the spleen, lymph nodes and bloodstream.     

Vaccination with combination of Fit3L and RANTES in a DNA prime-protein boost regimen elicits strong cell-mediated immunity and antitumor effect

With accumulating evidence indicating the importance of cytotoxic T lymphocytes (CTLs) in the antitumor response, strategies are being pursued to elicit augmented CD8⁺ T-cell responses against tumors with tumor vaccines. Here, we report the protective efficacy of vaccine-elicited antitumor immune responses with an aggressive HBc-expressing B16-HBc melanoma, which expressed HBc as a self and model antigen, tumor model. We demonstrated that the significantly better memory responses or marked inhibition on tumor growth could be achieved after coadministration of cytokine adjuvants RANTES and Flt3L in a DNA prime-protein boost regimen. Furthermore, the augmentation of DNA prime-protein boost regimens by cytokines gene was due to the improvement the immunopotency of DNA vaccine and subsequently the augmented Ag-specific and IFN-γ mediating CD8⁺ T-cell responses after protein boosting. Hence, this study demonstrates for the first time that combinatorial use of chemotactic and potent DC-specific growth factor molecules provides a useful strategy for enhancing antitumor responses.     

An HIVgp41 vaccine protects CD4 central memory T cells in SHIV-infected macaques

Background

The immunodeficiency defining AIDS results from a progressive decline in the number of CD4⁺ T cells. Although no single viral protein is likely to be the sole effector of immune impairment, the gp41 envelope protein is believed to contribute significantly to AIDS pathogenesis. We have shown that 3S, a unique motif of gp41, is highly conserved in HIV-1 strains and specifically induces NKp44L, a ligand of the natural cytotoxicity receptor NKp44, on CD4⁺ T cells, rendering them sensitive to NK lysis. We therefore hypothesized that a 3S/gp41 vaccine strategy designed to modulate the NK cell compartment might improve CD4⁺ T cell resistance, independently of any effect on viral load.

Methods

Nine macaques were chronically infected with the SHIV163P3; four were then immunized with the 3S/gp41 peptide and five with the carrier alone. Frequency of CD4⁺ T cell subsets, proliferation, cell activation and apoptosis were analyzed in the periphery and the lymph nodes, spleen and rectum by flow cytometry.

Results

The anti-3S antibodies prevented NKp44L expression on CD4⁺ T cells in vivo and subsequently preserved the CD4⁺ central memory T cells in 3S/gp41-vaccinated animals. They also limited the NK cytotoxic activity against autologous CD4⁺ T cells, the cell activation, the proliferation, and the apoptosis in peripheral blood and secondary lymphoid tissues remained intact.

Conclusion

These data suggest a new paradigm for AIDS vaccine development, aimed at generating specific responses to protect a specific subset of CD4⁺ T cells from attack by activated NK cells.     

The immunopathology of actinomycetoma lesions caused by Streptomyces somaliensis

The immune responses in actinomycetoma lesions caused by Streptomyces somaliensis in Sudan were characterized by immunohistochemistry during 1997-1998. In sections stained with haematoxylin and eosin, the inflammatory reaction around the grain was of 2 types. In type I there were 3 zones: a neutrophil zone immediately around the grain, an intermediate zone containing mainly macrophages, and a peripheral zone consisting of lymphocytes and plasma cells. Zone 1 stained positively for CD15 (neutrophils), zone 2 for CD68 (macrophages) and CD3 (T lymphocytes), and zone 3 for CD20 (B lymphocytes). In the type II reaction, there was no neutrophil zone, the grains being surrounded only by macrophages and giant cells. This was confirmed by immunohistochemistry, which demonstrated the presence of CD3 positive cells. Immunoglobulins G and M and complement were demonstrated on the surface of the grain and on filaments inside the grain. Neutrophils and macrophages were recruited into the lesion by complement and were involved in the fragmentation of the grain. The cytokine profile in the lesion and regional lymph nodes was of a dominant Th2 pattern (interleukins-10 and 4).     

Recombinant Mycobacterium bovis bacillus Calmette–Guérin expressing Ag85B-IL-7 fusion protein enhances IL-17A-producing innate γδ T cells

Interleukin 7 (IL-7) has an important function in the development and maintenance of IL-17A+ γδ T cells. We here constructed a recombinant Mycobacterium bovis bacillus Calmette–Guérin expressing antigen 85B (Ag85B)-IL-7 fusion protein (rBCG-Ag85B-IL-7). The Ag85B-IL-7 fusion protein and IL-7 were detected in the bacterial lysate of rBCG-Ag85B-IL-7. rBCG-Ag85B-IL-7 was the same in number as control rBCG expressing Ag85B (rBCG-Ag85B) in the lung at the early stage after intravenous inoculation, whereas the numbers of IL-17A+ γδ T cells and Ag-specific Th1 cells were significantly higher in the lungs of mice inoculated with rBCG-Ag85B-IL-7 than those inoculated with rBCG-Ag85B. The Ag-specific Th1 cell response was impaired in mice lacking IL-17A+ γδ T cells after inoculation with rBCG-Ag85B-IL-7. Thus, rBCG-Ag85B-IL-7 increases the pool size of IL-17A+ γδ T cells, which subsequently augment the Th1 response to mycobacterial infection.     

Parenteral Feeding Depletes Pulmonary Lymphocyte Populations

Background: The effect of parenteral nutrition (PN) on lymphocyte mass in the lung is unknown, but reduced mucosal lymphocytes are hypothesized to play a role in the reduced immunoglobulin A–mediated immunity in both gut and lung. The ability to transfer and track cells between mice may allow study of diet‐induced mucosal immune function. The objectives of this study are to characterize lung T‐cell populations following parenteral feeding and to study distribution patterns of transferred donor lung T cells in recipient mice. Methods: In experiment 1, cannulated male Balb/c mice are randomized to receive chow or PN for 5 days. Lung lymphocytes are obtained via collagenase digestion, and flow cytometric analysis is used to identify total T (CD3+) and B (CD45/B220+) cells. In experiment 2, isolated lung T cells from chow‐fed male Balb/c mice are pooled and labeled in vitro with a fluorescent dye (carboxyfluorescein diacetate succinimidyl ester [CFSE]), and 1.1 × 10⁸ CFSE+ cells (3.1 × 10⁶ T cells) are transferred to chow‐fed Balb/c recipients. Cells recovered from recipient lungs and intestinal lamina propria (LP) are analyzed by flow cytometry to determine CFSE/CD3+ T cells at 1, 2, and 7 days. In experiment 3, cells are transferred to PN‐fed recipients. Results: In experiment 1, PN significantly decreases lung T‐ and B‐cell populations compared with chow feeding. In experiment 2, CFSE+ T‐cell retention is highest on day 1 in lung and LP, and decreases on day 2. Cells are gone by day 7; 98.1% of retained donor lung T cells migrate to recipient lungs and 1.9% to the intestine on day 1. Similar results are seen in experiment 3 after transfer of cells to PN‐fed recipients. Conclusions: PN reduces pulmonary lymphocyte populations consistent with impaired respiratory immunity. Transferred lung T cells preferentially localize to recipient lungs rather than intestine with maximal accumulation at 24 hours. Limited cross‐talk of transferred lung T cells to the intestine indicates that mucosal lymphocyte traffic might be programmed to localize to specific effector sites.     

Reduction in T lymphocyte subpopulations following acute exposure to 4 ppm nitrogen dioxide

The effect of acute exposure to nitrogen dioxide (NO2) on splenic T lymphocyte subpopulations was studied in C57BL/6cum mice. The mice were exposed to 4 ppm NO2 for 8 hr. Monoclonal antibodies to T lymphocyte differentiation antigens and fluorescence-activated cell sorter (FACS) analysis were used to detect changes in T lymphocyte subpopulations. Percentages of total T lymphocytes (Thy-1.2-positive), T-helper/inducer lymphocytes (L3T4-positive), and T-cytotoxic/suppressor lymphocytes (Lyt-2-positive) were significantly lower in NO2-exposed animals than in filtered-air-breathing controls. Large T-cytotoxic/suppressor cells were found to be the most susceptible subpopulation. Spleen and body weights of the mice were also determined. There were no differences between body weights of control and exposed animals; however, exposed mice had significantly lower spleen weights. This is the first report providing evidence linking alterations in T lymphocyte subpopulations to acute NO2 exposure at occupational levels. T lymphocytes play a central role in regulatory and effector immunological functions such as mediating delayed hypersensitivity, regulating immunoglobulin production, and lysing virus-infected and neoplastic cells. The biological significance of these findings remains to be established, but it is very likely that functional impairment occurs since an optimal immune response depends upon a proper balance of the T lymphocyte subpopulations. Detection of alterations in T lymphocyte subpopulations using monoclonal antibodies and FACS analysis may provide an extremely sensitive means of demonstrating NO2-induced changes in the immune system.     

The secretion of aspartyl proteinase,a virulence enzyme,by isolates of Candida albicans from the oral cavity of HIV-infected subjects

Prevalence, serotype and in vitro secretion of aspartyl proteinase, a virulence enzyme, were studied in Candida isolates from the oral cavity of 337 HIV-infected subjects. Controls were 95 age-sex-matched HIV- (seronegative) subjects, belonging to either HIV-risk categories (47) or to the normal, general population (48). Fungi were isolated from 155 HIV+ subjects. C. albicans was the most prevalent species (85.8% of all isolates). 94.6% of C. albicans isolates were serotype A and all were agglutinated by a monoclonal antibody (AF1) directed against a major mannoprotein immunogen of the candidal cell wall, confirming previous results with C. albicans isolates from non-immunodeficient subjects. With regard to the stage of HIV infection, there were no statistically significant differences in the incidence of oral Candida carriage between asymptomatic (stage II) HIV+ and HIV- subjects, and between stage II and lymphadenopathic (stage III) individuals. Also, the low (3.8%) incidence of oral candidiasis in the subjects of the latter stage was insignificant with respect to stage II subjects. However, the incidence of C. albicans in stage IV (AIDS) subjects (46.8%) was significantly higher than in all other subjects, and in almost all cases, fungal isolation was accompanied by oral thrush and lower CD4+ lymphocyte counts (< 400 × 10°/L).All isolates of C. albicans were proteolytic in vitro, as assessed by scoring the proteinase activity on BSA agar and monitoring the secreted proteinase antigen by a highly sensitive (1 ng) and specific immunoenzymatic assay. However, by both methods, the isolates from subjects at stages III and IV of infection produced more secretory proteinase than the isolates from either HIV+ asymptomatic subjects or HIV- controls. The differences could not be attributed to particular culture media or source of Candida isolation (carriage versus active infection). Thus, the isolates of C. albicans from advanced HIV infection are serologically similar but more proteolytic than the isolates from earlier stages of HIV infection or those from HIV-uninfected subjects. The apparently higher virulence of C. albicans from AIDS subjects may represent a co-factor in determining and/or aggravating oral candidiasis in these patients.     

病毒学抑制的HIV - 1感染者免疫衰老相关CD4+T淋巴细胞亚群的分析

目的 了解病毒学抑制的HIV - 1感染者CD4+ T淋巴细胞免疫衰老状态,探索主成分分析法能否用于评价HIV - 1患者的免疫衰老。方法 选择抗逆转录疗法治疗半年以上成年病毒学抑制HIV - 1感染者,根据CD4+T淋巴细胞计数结果分为CD4无缺陷组（≥500个/μl）和缺陷组（＜500个/μl）,每组65人,另选择22名未暴露且HIV - 1抗体检测阴性者作为对照组,采用流式细胞仪检测其CD4+T淋巴细胞（CD45RA+CD27+）、活化CD4+T淋巴细胞（HLA - DR+CD38+）和复制性衰老CD4+T淋巴细胞（CD57+CD28-）水平,运用主成分分析对三种细胞进行综合分析。结果 缺陷组（27.64%）和无缺陷组（32.04%）的初始CD4+T淋巴细胞较对照组（51.27%）有明显下降（F = 24.35,P＜0.001）,活化CD4+T淋巴细胞（14.26%,13.03%）较对照组（2.35%）有明显上升（F = 19.75,P＜0.001）;缺陷组（12.64%）的复制性衰老CD4+T淋巴细胞较无缺陷组（7.36%）和对照组（3.58%）有明显升高（F = 6.68,P = 0.002）,而无缺陷组和对照组之间无统计学差异;主成分分析能区分出三组对象CD4+T淋巴细胞免疫衰老的差异程度:缺陷组＞无缺陷组＞对照组（F = 20.787,P＜0.001）。结论 病毒学抑制良好的HIV - 1感染者即使CD4+T细胞数量正常也表现为免疫衰老,CD4+T细胞数量异常的人免疫衰老状态更严重,可运用主成分分析对病毒学抑制的HIV - 1感染者免疫衰老相关细胞进行综合分析。     

Mucosal vaccination increases local chemokine production attracting immune cells to the stomach mucosa of Helicobacter pylori infected mice

Background

Vaccination is an attractive approach for the prevention of Helicobacter pylori infection and disease. In a mouse model, infection induces an accumulation of dendritic cells, macrophages, granulocytes, and B- and T cells to the stomach mucosa, which is further heightened when the infection is preceded by a mucosal immunization. We have studied the chemokines and chemokine receptors guiding infection- and vaccination-induced immune cells to the stomach and their relation to protection against H. pylori infection in mice.

Materials and methods

C57BL/6 mice were immunized sublingually with H. pylori lysate antigens and cholera toxin adjuvant or left unimmunized, and then challenged with live H. pylori bacteria. Stomach tissue was taken at 3, 7, 14 and 21 days after challenge and bacterial colonization, chemokine and chemokine receptor gene expression, and influx of cells into the stomach mucosa were evaluated.

Results

RT-PCR array screening revealed differential expression of a broad range of chemokine and chemokine receptor genes between immunized and unimmunized mice. A significant upregulation of chemokines known to attract, among other cells, eosinophils (CCL8), T cells (CXCL10, CXCL11) and neutrophils (CXCL2, CXCL5) and of their cognate receptors CCR3, CXCR3 and CXCR2, preceded or coincided with vaccine-induced protection, which was first evident 7 days after infection and was then sustained at the later time-points. Consistent with the increase in chemokines and chemokine receptors flow cytometric analysis indicated a sequential accumulation of CD4⁺ T cells, eosinophils, neutrophils and CD103⁺ dendritic cells in the gastric lamina propria of immunized mice.

Conclusions

This study provides insights into vaccination-induced chemokines that guide the influx of protective immune cells into the stomach of H. pylori infected mice.     

Bombesin Improves Adaptive Immunity of the Salivary Gland During Parenteral Nutrition

Background: The parotid and submandibular salivary glands are gut‐associated lymphoid tissues (GALTs) that secrete immune compounds into the oral cavity. Parenteral nutrition (PN) without enteral stimulation decreases GALT function, including intestinal lymphocyte counts and secretory immunoglobulin A (sIgA) levels. Since the neuropeptide bombesin (BBS), a gastrin‐releasing peptide analogue, stimulates intestinal function and restores GALT parameters, we hypothesized that PN + BBS would stimulate parotid and salivary gland IgA levels, T lymphocytes, and IgA plasma cell counts compared with PN alone. Methods: Male (Institute of Cancer Research) ICR mice received intravenous catheters and were randomized to chow with saline, PN, or PN + BBS (15 µg/tid/mouse) for 5 days (8/group), 2 days after cannulation. Salivary glands were weighed and either frozen for IgA and amylase analysis or fixed for histological analysis of acinar cells, IgA+ plasma cells, and T lymphocytes. Small intestinal wash fluid was collected for IgA regression analysis with salivary glands. Results: PN reduced organ weight, acinar cell size, and amylase activity compared with chow; BBS had no significant effects on these parameters. Compared with chow, PN significantly reduced salivary gland IgA levels, IgA+ plasma cells, and T lymphocytes. PN + BBS significantly elevated IgA and restored cellularity compared with PN. Salivary gland tissue homogenate IgA levels significantly correlated with intestinal fluid IgA levels. Conclusions: Compared with chow, PN results in atrophy of the salivary glands characterized by reduced amylase, IgA, and immune cellularity. BBS has no effect on acinar cells or amylase activity compared with PN but maintains tissue IgA and plasma cells and T‐lymphocyte numbers compared with chow.