The tuberculin skin test increases the responses measured by T cell interferon-gamma release assays.

RUTI is a vaccine consisting of Mycobacterium tuberculosis bacilli grown in stress conditions that is fragmented, detoxified and liposomed. RUTI was designed to shorten the treatment of latent tuberculosis infection (LTBI) with isoniazid from 9 months to just 1 month, by additional treatment with two inoculations of RUTI 4 weeks apart. During the validation process for monitoring the immunogenicity of administration of RUTI in a Phase I clinical trial, the question arose whether to introduce the tuberculin skin test (TST) in the screening of non-LTBI volunteers. This study was designed to evaluate the effect of TST on subsequent different T-cell interferon-gamma release assay (TIGRA) responses, using a spectrum of M. tuberculosis-related antigens (ESAT-6, CFP-10, 16 kDa, 19 kDa, MPT64, Ag 85B, 38 kDa, hsp65, PPD and BCG). The results showed an increase in post-TST response even in non-LTBI subjects for most antigens tested, as measured both by whole blood assay (WBA) and ELISPOT. Increased ELISPOT response decreased toward pre-TST levels within 1 month whereas the WBA response did not. Taking into account that there is no definitive correlation between TST and TIGRA tests to diagnose LTBI and the feasibility that TST might alter the immune monitoring included in clinical trials, these data suggest that TST determination should be carefully planned to avoid any interference with TIGRA.

[In-vitro comparison of morphology of current microkeratomes for LASIK]. / Morphologische In-vitro-Vergleichsanalyse aktueller Mikrokeratome zur LASIK.

BACKGROUND: We have performed an in-vitro examination of the morphology of flap thickness and stromal bed after LASIK in porcine eyes. MATERIALS AND METHODS: Freshly enucleated porcine eyes and synthetic eye models were used for cutting flaps with the microkeratomes Hansatome-Excellus (Bausch&Lomb), M2 single use (Moria), Amadeus (AMO), MK-2000 (Nidek) and Carriazo-Pendular (Schwind). The flap thickness of porcine eyes was determined using a non-contact, confocal optical distance measuring device (CHR 150N, Jurca), in the eye models a mechanical thickness measuring device (Käfler) was used. The morphology of the stromal bed was examined by photography, histology, scanning electron microscopy and confocal optical distance measurements. RESULTS: The optical/mechanical flap thickness measurements showed an average difference compared to the adjusted thickness of - 3/+ 90 microm (Hansatome-Excellus), + 7/+ 100 microm (M2 single use), - 35/+ 40 microm (Amadeus), - 4/+ 80 microm (MK-2000) and + 11/+ 0 microm (Carriazo-Pendular). Histology showed no mechanical damage and smooth, slightly undulating surfaces with all microkeratomes. In the scanning electron microscopic examination, the stromal surface was found to be homogeneous and smooth for all of the microkeratomes. Average roughness of the ablation surface was 0.27 microm (Hansatome-Excellus), 0.23 microm (M2 single use), 0.21 microm (Amadeus), 0.23 microm (MK-2000) and 0.29 microm (Carriazo-Pendular). CONCLUSION: The stromal bed showed in all cases only a slightly roughness, which seems to be acceptable for the clinical outcome. However, the more critical point is the large variations in flap thickness compared to the intended thickness.

The role of gammadelta T cells in generating antiviral factors and beta-chemokines in protection against mucosal simian immunodeficiency virus infection.

In view of the role of gammadelta(+) T cells in mucosal protection against infection, the proportion of gamma delta T cells was examined in cells eluted from lymphoid and mucosal tissues of macaques immunized with simian immunodeficiency virus (SIV) gp120 and p27 in alum and challenged with live SIV by the rectal mucosal route. This revealed a significant increase in gammadelta T cells eluted from the rectal mucosa (p < 0.01) and the related iliac lymph nodes (p < 0.0001) in protected as compared with infected macaques. Preferential homing of PKH-26-labeled gammadelta(+) T cells from the primed iliac lymph nodes to the rectal and cervico-vaginal mucosa was demonstrated after targeted iliac lymph node as compared with i. m. immunization. Investigations of the mechanism of protection revealed that gammadelta(+) T cells can generate antiviral factors, RANTES, macrophage inflammatory protein (MIP)-1alpha and MIP-1beta which can prevent SIV infection by binding to the CCR5 coreceptors. Up-regulation of gammadelta(+) T cells was demonstrated by immunization of macaques with heat shock protein (HSP)70 linked to peptides and with granulocyte-macrophage colony-stimulating factor (GM-CSF). This was confirmed by in vitro studies showing that GM-CSF can up-regulate gammadelta(+) T cells from macaques immunized with HSP-linked peptides but not those from naive animals. We suggest that a novel strategy of immunization with HSP70 linked to antigen may generate both cognate immunity to the antigen and innate immunity by virtue of up-regulation of gammadelta(+) T cells. These cells generate antiviral factors and the three beta-chemokines that prevent binding and transmission of SIV or M-tropic HIV by the CCR5 coreceptor.

Change of Th0 to Th1 cell-cytokine profile following tuberculosis chemotherapy.

T cells mediate protection against tuberculosis, but little is known about their role during chemotherapy of patients with active disease. Here we examined the cytokine profile of CD4 T cells before and after four months of chemotherapy in six initial skin test anergic cases. Purified protein derivative (PPD) and 16-kDa antigen-reactive CD4 T-cell clones prior to therapy resided mostly in disease-associated body fluids and were of the Th0 (interferon (IFN)-gamma + interleukin (IL)-4) secreting profile. In contrast, the majority of postchemotherapy CD4 T-cell clones originated from blood and were of the IFN-gamma secreting Th1 type. However, the recognition of several peptides derived from the 16-kDa antigen was not significantly different between the Th1 and Th0 clones. We conclude that chemotherapy shifts CD4 T cells from the affected body fluids to the blood circulation, accompanied by a change from Th0 to Th1 cytokine profile.

Heat shock proteins generate beta-chemokines which function as innate adjuvants enhancing adaptive immunity.

Heat shock proteins (HSP) are widely distributed and highly immunogenic molecules. A novel property reported here is that stimulation with HSP70 of CD8-enriched T cells derived from naive non-human primates caused a dose-dependent increase in concentrations of the beta-chemokines RANTES, macrophage inflammatory protein (MIP)-1alpha or MIP-1beta. However, the concentrations of these beta-chemokines were greatly increased when the CD8 T cells derived from HSP70-immunized non-human primates were stimulated with HSP70. HSP linked to peptides or proteins combined generation of beta-chemokines with an adjuvant function by enhancing specific T cell proliferative responses and IgG and IgA antibodies. The beta-chemokine and adjuvant functions were also elicited by topical mucosal administration of HSP linked to an antigen. We postulate that microbial HSP can stimulate beta-chemokine production which may be responsible for innate adjuvanticity, as was found in cells eluted from normal rectal mucosal tissue, and constitutes a significant component of the mucosal-associated lymphoid system. Furthermore, stimulation of innate immunity may drive adaptive immunity and account for the protective effects of HSP against tumors and viruses.

Activation of T cells recognizing an epitope of heat-shock protein 70 can protect against rat adjuvant arthritis.

We have previously reported that CD4+ T cells recognizing a peptide comprising residues 234-252 of the heat shock protein (HSP)70 of Mycobacterium tuberculosis (M.tb) in the context of RT1.B MHC class II molecule emerged in the peritoneal cavity during the course of Listeria monocytogenes infection in rats and suppressed the inflammatory responses against listerial infection via IL-10 production. We report in this work that pretreatment with peptide 234-252 of HSP70 derived from M.tb suppressed the development of adjuvant arthritis (AA) in Lewis rats induced using heat-killed M.tb. T cells from rats pretreated with peptide 234-252 produced a significant amount of IL-10 in response to the epitope. T cells from rats pretreated with the peptide and immunized with M.tb produced the larger amount of IL-10 in response to the peptide, but only a marginal level of IFN-gamma in response to purified protein derivative of M.tb. Administration of anti-IL-10 Ab partly inhibited the suppressive effect of pretreatment with peptide 234-252 on the development of AA. Furthermore, transfer of a T cell line specific for the epitope at the time of AA induction markedly suppressed AA. These findings suggested that T cells recognizing peptide 234-252 may play a regulatory role in inflammation during AA via the production of suppressive cytokines including IL-10.

Broad clonal heterogeneity of antigen-specific CD4+ T-cells localizing at the site of disease during tuberculosis.

The repertoire of CD4+ T-lymphocytes was investigated in six patients affected by tuberculosis, who had a negative PPD skin test at diagnosis. Polyclonal CD4+ T-cell lines from the peripheral blood failed to proliferate to PPD and to the 16- or 38-kDa proteins of Mycobacterium tuberculosis, while CD4+ T-cell lines from the site of disease responded to PPD, and to the 16- and 38-kDa proteins, and derived epitopes in vitro. The repertoire of CD4+ T-cells accumulating at the site of disease was found to be widely heterogeneous as demonstrated by the finding that at least seven different peptides from the 16- and 38-kDa proteins were recognized by every patient. These results indicate that CD4+ T-cells localized at the site of disease in tuberculosis recognize a vast array of M. tuberculosis epitopes.

Sequestration of T lymphocytes to body fluids in tuberculosis: reversal of anergy following chemotherapy.

The specificity of CD4 T lymphocytes was investigated in 6 patients affected by tuberculosis who had negative tuberculin purified protein derivative (PPD) skin tests at diagnosis. Polyclonal CD4 T cell lines from the peripheral blood failed to proliferate to PPD and to the 16- or 38-kDa proteins of Mycobacterium tuberculosis, while CD4 cell lines from the disease site responded to PPD and to the 16- and 38-kDa proteins and derived epitopes in vitro. Four months after chemotherapy, the patients became responsive to PPD. The proliferative response to PPD and to the 16- or 38-kDa proteins and their derived peptides decreased in CD4 T cell lines from the disease site and increased in lines from the peripheral blood. These results indicate that CD4 T cells recognizing a vast array of M. tuberculosis epitopes are compartmentalized at the site of disease in anergic patients but appear in peripheral blood after chemotherapy.