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The role of CD40L (gp39)/CD40 in T/B cell interaction and primary immunodeficiency.

The interaction between the CD40 ligand (gp39), expressed by activated T cells, and CD40, constitutively expressed by B cells, is critical for an effective antibody response to T cell dependent antigens. Patients with X-linked hyper IgM (HIM) syndrome fail to express a functional CD40 ligand due to a mutation within the gene for gp39. As a direct consequence, HIM patients, when immunized with T dependent antigens, produce only small amounts of IgM antibody without the development of immunologic memory, amplification and switch from IgM to IgG. Mutations affecting the gene for the HIM syndrome are localized throughout the coding region of gp39 and consist predominantly of point mutations. The resulting amino acid substitutions interfere directly with the receptor binding site or lead to stop codons or deletions secondary to splice site mutations. Expression of gp39 by activated T cells from patients with common variable immunodeficiency (CVI) is low in approximately half of the patients and is associated with depressed expression of IL-2. These findings suggest that inefficient signaling via CD40 may be responsible in part for failure of B cell differentiation in CVI.

Antigens, CD↗

Intracellular growth of Listeria monocytogenes as a prerequisite for in vivo induction of T cell-mediated immunity.

The in vivo induction of T cell-mediated immunity was studied by infecting mice with two genetically closely related mutants from Listeria monocytogenes, differing only with respect to the secretion of an active SH-dependent hemolysin. It is shown that even minute doses of hemolytic bacteria capable of growing in host tissues easily induced the expression of T cell-mediated immunity, as estimated by the level of delayed sensitivity, adoptive protection and long-lasting immunological memory. On the contrary, nonhemolytic bacteria unable to multiply in host tissues totally failed to initiate the expression of T cell-mediated immunity in vivo. This failure was even observed when mice were repeatedly infected by high doses of nonhemolytic bacteria, allowing to maintain a significant amount of viable bacteria for several days in host tissues. These results mean that the presence of viable bacteria at a significant level in the host is not sufficient per se to induce detectable T cell clonal expansion in the in vivo setting, implying that the process of bacterial growth inside macrophages is required to initiate in vivo the expression of T cell-mediated immunity.

Animals↗

Immune response to foot-and-mouth disease virus in a murine experimental model: effective thymus-independent primary and secondary reaction.

The immune response against foot-and-mouth disease virus (FMDV) was studied in a murine model. In untreated control mice, the inoculation of 10,000 suckling mouse 50% lethal doses of Ol Campos FMDV i.p. was followed by a burst of viraemia that disappeared in less than 4 days, i.e. when the neutralizing antibodies (NAb) reached titres above one neutralizing unit. In mice treated with cyclophosphamide, the curves of viraemia and NAb were significantly delayed. Nu/nu mice injected with FMDV had curves of viraemia and NAb identical to those of their nu/t littermates. We then studied the secondary (memory) immune reaction in the same model. In order to investigate which preimmunized cells participate in the elimination of actively replicating FMDV, mice were irradiated, then infected with FMDV, and 24 hr later repopulated with cells obtained from either donor mice that had been previously immunized by infection with live virus, or non-infected controls. The transfer of control (non-immunized) lymphoid cells was unable to eliminate the viraemia in recipient animals at times significantly different from those observed with irradiated recipients receiving no cells, while repopulation of recipients with 10(8) immune lymphoid cells (obtained from pooled thymus, blood, peritoneal exudate, spleen and lymph nodes of preinfected donor mice) led to undetectable titres of viraemia at Day 5 post-infection (p.i.). High doses of thymus cells were totally inactive, while a few as 10(7) donor spleen cells were able to abort viraemia at 6 days p.i. When enriched preparations of B or T spleen cells were adoptively transferred, only B cells were able to abort viraemia in irradiated recipients. It is concluded that, in the murine model of FMDV infection, B cells are mainly responsible for primary response and short-term immunological memory. In both cases the protective immune reaction is T-independent.

Animals↗

Stochastic stage-structured modeling of the adaptive immune system.

We have constructed a computer model of the cytotoxic T lymphocyte (CTL) response to antigen and the maintenance of immunological memory. Because immune responses often begin with small numbers of cells and there is great variation among individual immune systems, we have chosen to implement a stochastic model that captures the life cycle of T cells more faithfully than deterministic models. Past models of the immune response have been differential equation based, which do not capture stochastic effects, or agent-based, which are computationally expensive. We use a stochastic stage-structured approach that has many of the advantages of agent-based modeling but is much more efficient. Our model can provide insights into the effect infections have on the CTL repertoire and the response to subsequent infections.

Adaptation, Physiological↗

A targeted DNA vaccine augments the natural immune response to self TNF-alpha and suppresses ongoing adjuvant arthritis.

Depending on the mode of immunization, a single administration of CFA may result in the development of a local inflammatory process or chronic poly adjuvant-induced arthritis (AA). Administration of naked DNA encoding TNF-alpha results in the generation of immunological memory to its gene product. Upon induction of AA, this memory effectively inhibited the development of disease. Self-specific Abs developed in DNA-vaccinated animals were neutralizing in vitro and could adoptively transfer the beneficial effect of the vaccine. Administration of CFA to induce a local delayed-type hypersensitivity response rather than AA did not lead to an elicited production of Abs to the gene product of the above vaccine. Thus, elicitation of protective immunity is dependent on the development of an autoimmune condition. Most importantly, the administration of the TNF-alpha DNA construct after the onset of disease led to a rapid, long-lasting remission. This suggests a highly effective way by which a DNA vaccine encoding an autologous proinflammatory cytokine can be used to reprogram the immune system to generate protective immunity to its own potentially harmful activities.

Acute Disease↗

Selective enhancement of systemic Th1 immunity in immunologically immature rats with an orally administered bacterial extract.

Infant rats primed during the first week of life with soluble antigen displayed adult-equivalent levels of T-helper 2 (Th2)-dependent immunological memory development as revealed by production of secondary immunoglobulin G1 (IgG1) antibody responses to subsequent challenge, but in contrast to adults failed to prime for Th1-dependent IgG2b responses. We demonstrate that this Th2 bias in immune function can be redressed by oral administration to neonates of a bacterial extract (Broncho-Vaxom OM-85) comprising lyophilized fractions of several common respiratory tract bacterial pathogens. Animals given OM-85 displayed a selective upregulation in primary and secondary IgG2b responses, accompanied by increased gamma interferon and decreased interleukin-4 production (both antigen specific and polyclonal), and increased capacity for development of Th1-dependent delayed hypersensitivity to the challenge antigen. We hypothesize that the bacterial extract functions via enhancement of the process of postnatal maturation of Th1 function, which is normally driven by stimuli from the gastrointestinal commensal microflora.

Adjuvants, Immunologic↗

Mechanisms underlying the suppression of established immune responses by ultraviolet radiation.

The ultraviolet radiation present in sunlight is immune suppressive. Recently we showed that solar-simulated ultraviolet radiation (ultraviolet A + B; 295-400 nm), applied after immunization, suppressed immunologic memory and the elicitation of delayed-type hypersensitivity to the common opportunistic pathogen, Candida albicans. Further, we found that wavelengths in the ultraviolet A region of the solar spectrum (320-400 nm), devoid of ultraviolet B, were equally effective in activating immune suppression as ultraviolet A + B radiation. Here we report on the mechanisms involved. Maximal immune suppression was found when mice were exposed to solar-simulated ultraviolet radiation 7-9 d post immunization. No immune suppression was found in ultraviolet-irradiated mice injected with monoclonal anti-interleukin-10 antibody, or mice exposed to solar-simulated ultraviolet radiation and injected with recombinant interleukin-12. Suppressor lymphocytes were found in the spleens of mice exposed to ultraviolet A + B radiation. In addition, antigen-specific suppressor T cells (CD3+, CD4+, DX5+) were found in the spleens of mice exposed to ultraviolet A radiation. Applying liposomes containing bacteriophage T4N5 to the skin of mice exposed to solar-simulated ultraviolet A + B radiation, or mice exposed to ultraviolet A radiation, blocked immune suppression, demonstrating an essential role for ultraviolet-induced DNA damage in the suppression of established immune reactions. These findings indicate that overlapping immune suppressive mechanisms are activated by ultraviolet A and ultraviolet A + B radiation. Moreover, our findings demonstrate that ultraviolet radiation activates similar immunologic pathways to suppress the induction of, or the elicitation of, the immune response.

Animals↗

Simultaneous administration of meningococcal C conjugate vaccine and diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae type b conjugate vaccine in children: a randomized double-blind study.

BACKGROUND: Meningococcal C disease can be life-threatening in infants, young children and adolescents. New conjugate vaccines are immunogenic in young infants and induce immunologic memory, so we should consider incorporating them into the routine childhood immunization program. The objective of this study was to measure the safety and immunogenicity of a meningococcal C conjugate vaccine when given with routine childhood vaccines. METHODS: We carried out a randomized, double-blind, controlled clinical trial at children's hospitals in 3 Canadian cities. A convenience sample of 351 healthy 2-month-old infants was enrolled from the community and randomly allocated to receive either meningococcal C conjugate vaccine or the control (hepatitis B) vaccine. All participants received a concurrent injection of the combined diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae type b (DTaP-IPV-Hib) conjugate vaccine in the opposite limb. Participants were immunized at 2, 4, 6 and 15 months of age; adverse events were recorded after each dose. Serum bactericidal and ELISA meningococcal antibody levels in the participants were measured at 6, 7, 15 and 16 months of age; diphtheria, tetanus, H. influenzae type b, poliovirus and pertussis antibodies were measured at 7 months of age. A total of 323 (92%) participants completed all aspects of the study. The proportion of participants who suffered adverse events after each vaccine dose was the primary safety outcome. Geometric mean antibody titres and the proportion of participants with protective antibody levels after immunization were the primary immunologic outcomes. RESULTS: After 2 doses of the meningococcal C conjugate vaccine 99% of participants achieved a protective ( > or = 1:8) bactericidal meningococcal serogroup C antibody level, and after 3 doses this rate increased to 100%. Antibody levels to the concomitant vaccine antigens in the group receiving meningococcal C vaccine were similar to those in the control group except for higher antidiphtheria antibody titres (p < 0.001). Local injection site reactions (redness and induration) after the meningococcal conjugate vaccine were more frequent than after hepatitis B vaccine but less frequent than after the DTaP-IPV-Hib vaccine. CONCLUSIONS: The meningococcal C conjugate vaccine can be safely and effectively administered at the same visit as the other vaccine antigens routinely given to infants in Canada.

Antibody Formation↗

Intradermal ras peptide vaccination with granulocyte-macrophage colony-stimulating factor as adjuvant: Clinical and immunological responses in patients with pancreatic adenocarcinoma.

K-RAS mutations are frequently found in adenocarcinomas of the pancreas, and induction of immunity against mutant ras can therefore be of possible clinical benefit in patients with pancreatic cancer. We present data from a clinical phase I/II trial involving patients with adenocarcinoma of the pancreas vaccinated by i.d. injection of synthetic mutant ras peptides in combination with granulocyte-macrophage colony-stimulating factor. Forty-eight patients (10 surgically resected and 38 with advanced disease) were treated on an outpatient basis. Peptide-specific immunity was induced in 25 of 43 (58%) evaluable patients, indicating that the protocol used is very potent and capable of eliciting immune responses even in patients with end-stage disease. Patients followed-up for longer periods showed evidence of induction of long-lived immunological memory against the ras mutations. CD4(+) T cells reactive with an Arg12 mutation also present in the tumor could be isolated from a tumor biopsy, demonstrating that activated, ras-specific T cells were able to selectively accumulate in the tumor. Vaccination was well tolerated in all patients. Patients with advanced cancer demonstrating an immune response to the peptide vaccine showed prolonged survival from the start of treatment compared to non-responders (median survival 148 days vs. 61 days, respectively; p = 0.0002). Although a limited number of patients were included in our study, the association between prolonged survival and an immune response against the vaccine suggests that a clinical benefit of ras peptide vaccination may be obtained for this group of patients.

Adenocarcinoma↗

Differences in surface phenotype between cytolytic and non-cytolytic CD4+ T cells. MHC class II-specific cytotoxic T lymphocytes lack Leu 8 antigen and express CD2 in high density.

A number of cell surface molecules are differentially expressed on functionally distinct subsets of CD4+ T cells. However, to date CD4+ T cells capable of becoming CTL have not been shown to be phenotypically distinct from other CD4+ T cells, and in the current study we examined the ability of Leu 8+ and Leu 8- CD4+ subpopulations to become cytotoxic effectors after their stimulation with allogeneic lymphoblastoid cell lines. Although CD4+, Leu 8+ cells proliferated more vigorously than CD4+, Leu 8- cells in primary cultures stimulated with allogeneic LCL, the CD4+, Leu 8- population was the major source of cytotoxic effectors, killing targets with specificity for their class II MHC alloantigens. In most subjects, CD4+ precursors of CTL were distinguished not only by their lack of Leu 8 expression but also by their relatively high density of CD2, LFA-1, and LFA-3, molecules known to mediate non-specific cell-to-cell adhesion and postulated to be markers of immunologic memory. The absence of Leu 8 does not appear to be a reliable memory cell marker, however, because Leu 8+ as well as Leu 8-, CD4+ cells from PPD skin test positive subjects responded to the recall Ag, PPD. During 3 mo of continuous culture with allogeneic stimulators, Leu 8- cells retained their cytolytic activity and remained unreactive with anti-Leu 8 mAb, whereas Leu 8+ cells remained non-cytolytic and reactive with anti-Leu 8, suggesting that under the conditions used the Leu 8 phenotype is relatively stable. PHA or anti-CD3 mAb enhanced non-specific killing by alloantigen-stimulated CD4+,Leu 8- lines but failed to unmask any cytolytic potential in CD4+,Leu 8+ lines. We conclude that MHC class II-specific cytolytic CD4+ T cells can be distinguished from non-cytolytic CD4+ cells on the basis of their surface phenotype, and that most CD4+ CTL are contained within the Leu 8- subpopulation.

Animals↗

The immunogenicity of dinitrophenylated polyacrylamide and the adjuvant effect of polyacrylamide.

Dinitrophenyl-substituted polyacrylamide (PAAm-DNP) is weakly immunogenic in guinea pigs and rats. Only 2-mercaptoethanol-sensitive IgM antibodies are elicited, and no immunological memory in guinea pigs is appreciated. A 15000-fold carrier excess, given 6 days before an immunogenic dose of PAAm-DNP, does not impair the anti-DNP response. Different doses of PAAm failed to increase the level of natural anti-DNP or anti-sulfanilic acid antibodies, either in guinea pigs or rats. Nevertheless, when given together with sheep red blood cells. PAAm increases the anti-sheep red blood cell humoral immune response in rats. It is suggested from the above data that the PAAm-DNP immunogenicity is not accounted for by the 'two-signal' model of B-cell activation (via 'associative antibodies'), nor by a model that ascribes B-cell activation to the polyclonal B-cell activating properties of the carrier. However, the possibility that the adjuvant effect showed by PAAm plays a role in allowing the conjugate PAAm-DNP to be immunogenic, remains an open question, and must be further investigated.

Acrylamides↗

Mucosal vaccines based on the use of cholera toxin B subunit as immunogen and antigen carrier.

Stimulation of strong mucosal IgA immune responses as a basis for vaccine-induced protection against various pathogens has proved difficult. Most soluble protein antigens administered either parenterally or oral-mucosally have given disappointing results. A notable exception in this regard are cholera toxin (CT) and, particularly in humans, its non-toxic B subunit pentamer moiety (CTB) both of which stimulate a strong intestinal IgA antibody response and long-lasting immunological memory. Based on this, CTB has become an important component in recently developed oral vaccines against cholera and diarrhea caused by enterotoxigenic E. coli. The strong immunogenicity of CT and CTB can to a large extent be explained by their ability to bind to receptors on the intestinal mucosal surface. This has promoted much recent interest in the use of CTB as an oral delivery carrier for other vaccine-relevant antigens. Oral administration of antigens coupled to CTB either chemically or genetically has in several systems been found to markedly potentiate both intestinal and extra-intestinal IgA immune responses against the CTB-coupled antigens and to elicit substantial circulating antibody responses. In contrast to CTB, CT also has strong adjuvant properties for stimulating mucosal IgA immune responses to unrelated, non-coupled antigens after oral co-immunization. This adjuvant activity appears to be closely linked to the A subunit-catalyzed ADP-ribosylating action of CT leading to enhanced cyclic AMP formation in the affected cells.

Adjuvants, Immunologic↗

Antitumor activity of three mouse mammary cancer cell lines after interferon-gamma gene transfection.

BACKGROUND: The antitumor effects of three mouse mammary tumors transfected to express interferon-gamma were evaluated. METHODS: Three immunologically different tumors were used: DA3, EMT6, and 410. All three cell lines were successfully transfected with highly efficient viral vectors. Wild type or transfected tumor cells were injected subcutaneously into Balb/c mice. Animals were observed for tumor growth and the induction of immunologic memory. RESULTS: A significant decrease occurred in the size of all transfected tumors, EMT6 1.9 cm2, DA3 1.7, and 410 1.8 compared with nontransfected control tumors with a mean size of 4 cm2 on day 30. To further test the development of immunity, animals were injected with either nontransfected or transfected tumors and challenged with nontransfected tumor. Animals immunized with transfected tumor cells had significantly smaller tumors, EMT6 2.5 cm2, DA3 3.1, and 410 2.4 compared with controls with a mean size of 4 cm2. No specific splenocyte cytotoxicity was shown. Expression of major histocompatibility complex class I antigens was enhanced in the 410 and DA3 tumor lines. CONCLUSIONS: Significant antitumor effects were observed after interferon-gamma gene transfection of three mouse mammary cancer cell lines. Up-regulation of major histocompatibility complex class I antigen expression is a partial explanation of these findings. These results provide preliminary studies for gene therapy of human breast cancer.

Animals↗

Insect immunity shows specificity in protection upon secondary pathogen exposure.

Immunological memory in vertebrates, conferring lasting specific protection after an initial pathogen exposure, has implications for a broad spectrum of evolutionary, epidemiological, and medical phenomena . However, the existence of specificity in protection upon secondary pathogen exposure in invertebrates remains controversial . To separate this functional phenomenon from a particular mechanism, we refer to it as specific immune priming. We investigate the presence of specific immune priming in workers of the social insect Bombus terrestris. Using three bacterial pathogens, we test whether a prior homologous pathogen exposure gives a benefit in terms of long-term protection against a later challenge, over and above a heterologous combination. With a reciprocally designed initial and second-exposure protocol (i.e., all combinations of bacteria were tested), we demonstrate, even several weeks after the clearance of a first exposure, increased protection and narrow specificity upon secondary exposure. This demonstrates that the invertebrate immune system is functionally capable of unexpectedly specific and durable induced protection. Ultimately, despite general broad differences between vertebrates and invertebrates, the ability of both immune systems to show specificity in protection suggests that their immune defenses have found comparable solutions to similar selective pressures over evolutionary time.

Animals↗

Immunological T-cell memory in the in vitro-induced experimental autoimmune orchitis: specificity of the reaction and tissue distribution of the autoantigens.

Immunological memory has been induced in vitro against testicular autoantigens by priming normal rat T lymphocytes against autologous testis cells, and by permitting the isolated blast cells to revert back to small secondary lymphocytes (secondary EAO cells) in the absence of the priming antigen. The secondary EAO cells vigorously respond in a secondary response when reconfronted with syngeneic testis or lymphoid cells. Their responsiveness to nonself stimulator cells is, however, reduced. Secondary cells derived from concanavalin A-stimulated blasts, do not show that pattern of specificity. The specificity of the secondary EAO cells is definite, and cannot be affected by further culture on allogeneic fibroblasts, which are antigenic for unprimed T lymphocytes. At least part of the autoantigens are determined by the major histocompatibility gene complex (MHC). Factors provided by the culture system do not appear to determine the specificity of this reaction. Only minor cell populations can restimulate secondary EAO cells. One of these populations is presumably phage-like cells within the lymphoid populations can elicit a secondary EAO response. Thus, the autoantigens relevant in the secondary EAO response are either MHC antigens restricted to these testicular and lymphoid subpopulations, or MHC antigens recognized in conjunction with organ-specific non-MHC determinants.

Animals↗

Regulation of guinea-pig immune functions by interleukin 2: critical role of natural killer activity in acute HSV-2 genital infection.

We have previously demonstrated that recombinant interleukin 2 (rIL 2) has a protective effect against acute HSV-2 infection in guinea pigs with a biphasic dose response which peaked between 4 and 20 X 10(4) U/kg, whereas 8 X 10(5) U/kg showed no effect on disease. Animals that escaped infection appeared lack immunologic memory to HSV-2, suggesting a nonspecific immune mechanism. In this study we have found that NK activity of fresh splenocytes measured against HSV-2 infected human foreskin fibroblast (HFF) is stimulated in vitro and in vivo by rIL 2 in a biphasic dose range similar to that determined for protection against disease. In contrast, lymphokine-activated killer (LAK)-mediated lysis of P815 showed a linear response to increasing concentrations of rIL 2 both in vitro and in vivo. Transfer of LAK cells did not alter the rate of infection after HSV-2 challenge. Anti-asialo GM-1 eliminated rIL 2 protection against HSV-2 infection. It also blocked HSV-2/HFF lysis and partially decreased P815 lysis in vitro; however, in vivo it inhibited both natural killer (NK) activity and LAK generation, failing to distinguish which of the lytic cells was responsible for the effect against infection. Early IgG production (7 days post-infection) was enhanced by rIL 2 administration before viral inoculation, but it did not influence the rate of infection as compared with controls. Polyclonal IgM secretion was not found to play a role in acute protection. Circulating serum interferon levels were enhanced with increasing concentrations of rIL 2 but did not correlate with the biphasic dose curve for protection. Therefore of these mechanisms the one that is most closely related to the protective effect of rIL 2 against primary HSV-2 infection appears to be NK-mediated lysis, although the other mechanisms may add to this effect.

Animals↗

Antitumor vaccination: where we stand.

BACKGROUND AND OBJECTIVES: Vaccination is an effective medical procedure of preventive medicine based on the induction of a long-lasting immunologic memory characterized by mechanisms endowed with high destructive potential and specificity. In the last few years, identification of tumor-associated antigens (TAA) has prompted the development of different strategies for antitumor vaccination, aimed at inducing specific recognition of TAA in order to elicit a persistent immune memory that may eliminate residual tumor cells and protect recipients from relapses. In this review characterization of TAA, different potential means of vaccination in experimental models and preliminary data from clinical trials in humans have been examined by the Working Group on Hematopoietic Cells. EVIDENCE AND INFORMATION SOURCES: The method employed for preparing this review was that of informal consensus development. Members of the Working Group met four times and discussed the single points, previously assigned by the chairman, in order to achieve an agreement on different opinions and approve the final manuscript. Some of the authors of the present review have been working in the field of antitumor immunotherapy and have contributed original papers to peer-reviewed journals. In addition, the material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline. STATE OF THE ART: The cellular basis of antitumor immune memory consists in the generation and extended persistence of expanded populations of T- and B-lymphocytes that specifically recognize and react against TAA. The efficacy of the memory can be modulated by compounds, called "adjuvants", such as certain bacterial products and mineral oils, cytokines, chemokines, by monoclonal antibodies triggering co-stimulatory receptors. Strategies that have been shown in preclinical models to be efficient in protecting from tumor engraftment, or in preventing a tumor rechallenge, include vaccination by means of soluble proteins or peptides, recombinant viruses or bacteria as TAA genes vectors, DNA injection, tumor cells genetically modified to express co-stimulatory molecules and/or cytokines. The use of professional antigen-presenting cells, namely dendritic cells, either pulsed with TAA or transduced with tumor-specific genes, provides a useful alternative for inducing antitumor cytotoxic activity. Some of these approaches have been tested in phase I/II clinical trials in hematologic malignancies, such as lymphoproliferative diseases or chronic myeloid leukemia, and in solid tumors, such as melanoma, colon cancer, prostate cancer and renal cell carcinoma. Different types of vaccines, use of adjuvants, timing of vaccination as well as selection of patients eligible for this procedure are discussed in this review. PERSPECTIVES: Experimental models demonstrate the possibility of curing cancer through the active induction of a specific immune response to TAA. However, while pre-clinical research has identified several possible targets and strategies for tumor vaccination the clinical scenario is far more complex for a number of possible reasons. Since experimental data suggest that vaccination is more likely to be effective on small tumor burden, such as a minimal residual disease after conventional treatments, or tumors at an early stage of disease, better selection of patients will allow more reliable clinical results to be obtained. Moreover, a poor correlation is frequently observed between the ability of TAA to induce a T-cell response in vitro and clinical responses. Controversial findings may also be due to the techniques used for monitoring the immune status. Therefore, the development of reliable assays for efficient monitoring of the state of immunization of cancer patients against TAA is an important goal that will markedly improve the progress of antitumor vaccines. (ABSTRACT TRUNCATED)

Adjuvants, Immunologic↗

The effect of neonatal BCG vaccination on atopy and asthma at age 7 to 14 years: an historical cohort study in a community with a very low prevalence of tuberculosis infection and a high prevalence of atopic disease.

BACKGROUND: There are conflicting reports on the effect of BCG vaccination on the subsequent development of atopy and asthma. There are no data on the effects of neonatal BCG vaccination on cytokine responses of lymphocytes that are exposed in vitro to allergens. OBJECTIVES: We sought to test the hypothesis that neonatal BCG vaccination or, alternatively, evidence of an immunologic memory of this vaccination is associated with a reduced prevalence of allergic sensitization, asthma, eczema, and hay fever during childhood. METHODS: An historical cohort study was conducted among 7- to 14-year-old children who were born in 2 districts in Sydney, Australia, and whose mothers were born in southeast Asia. One district had routinely administered BCG vaccination to infants born to overseas-born mothers and the other had not. Eligible subjects were identified from birth registers. Consenting subjects completed questionnaires, performed spirometric and airway hyperresponsiveness testing, and had allergen skin prick testing and tuberculin skin testing. Blood was collected to measure total serum IgE levels and for in vitro lymphocyte culture in the presence of an extract of house dust mite, the dominant allergen in this region, and purified protein derivative of Mycobacterium tuberculosis (tuberculin). IL-4, IL-5, IL-10, and IFN-gamma were measured in the culture supernatant. RESULTS: The cohort included 309 BCG-vaccinated subjects and 442 non-BCG-vaccinated subjects. BCG-vaccinated subjects did not have a lower rate of allergic sensitization than nonvaccinated subjects. However, among the subgroup of subjects with a family history of rhinitis or eczema, BCG vaccination was associated with a lower prevalence of current asthma (defined as recent wheezing plus airway hyperresponsiveness; relative risk, 0.46; 95% CI, 0.22-0.95). BCG vaccination was also associated with lower levels of allergen-stimulated IL-10 production in vitro. Among the BCG-vaccinated subjects, the 44 (14.3%) who had tuberculin skin test reaction sizes of 5 mm or greater and the 31 (18.3%) who demonstrated an in vitro IFN-gamma response to purified protein derivative of M tuberculosis did not have lower rates of allergic sensitization and, overall, did not have a lower prevalence of allergic disease than tuberculin skin test or IFN-gamma nonreactors. CONCLUSION: We conclude that neonatal BCG vaccination has an effect on T-cell allergen responsiveness 7 to 14 years after vaccination and that among a subgroup of subjects with an inherited predisposition to allergic disease, this is associated with clinically relevant beneficial effects. The findings of this study encourage the view that external influences on the immune system in the neonatal period have consequences that extend into later childhood and influence the expression of asthma. Genetic factors are likely to modify the effect of those external factors.

Adjuvants, Immunologic↗