Differences in Cyclic AMP Changes after Stimulation by Prostaglandins and Isoproterenol in Lymphocyte Subpopulations

Various lymphocyte populations have been studied for their content in cyclic adenosine 3',5'-monophosphate (cAMP) before and after stimulation by isoproterenol and prostaglandin E(1) (PGE(1)). Basal cAMP levels vary among lymphocytes according to their origin: peripheral blood lymphocytes show high cAMP level while spleen and lymph node cells and thymocytes show lower levels. Thymocytes are extremely sensitive to the stimulating effects of isoproterenol and PGE(1), much more than spleen and lymph node or peripheral blood cells. Corticoresistant thymocytes are less sensitive to isoproterenol stimulation than normal thymocytes, but are significantly more sensitive than peripheral thymus-derived (T)-cells. Studies using bone-marrow-derived (B) or T cell depletion with anti-immunoglobulin-coated columns and antitheta serum (AthetaS) indicate that lymph node B cells synthesize more cAMP in the presence of isoproterenol than T cells. However, this difference between T and B cells has not been found in spleen cells.

Repeated pressure-flow studies in the evaluation of bladder outlet obstruction due to benign prostatic enlargement. Finasteride Urodynamics Study Group

Test-retest reliability of repeated voids in pressure-flow studies and the influence on maximum flow rate (Q(max)pQ), detrusor pressure at maximum flow rate (p(det)Qmax), voided volume, and residual urine were studied. Also the agreement in interpretation of pressure-flow tracings between investigators and a single blinded central reader acting as a quality control center (QCC) were assessed. In addition, correlations between p(det)Qmax and patient age, International Prostate Symptom Score (IPSS), free maximum flow rate (Qmax), and prostate volume were calculated. Using suprapubic pressure recording, 216 men with lower urinary tract symptoms (LUTS) due to benign prostatic enlargement (BPE) were investigated in 11 centers. In each pressure-flow study, three sequential voids were performed, and quality controlled recordings were analyzed for Q(max)pQ and p(det)Qmax by the QCC. Trans rectal ultrasound was used to measure the prostate volume. Mean Q(max)pQ did not change, but p(det)Qmax decreased significantly in the second and third sequential voids. Using the Abrams-Griffiths nomogram definition of obstruction, 125 patients (67%) were classified as obstructed from the first void, but only 111 patients (59%) from the third void. The agreement between the investigator assessment and that of a single blinded reader was good. There was no significant correlation between p(det)Qmax and patient age, IPSS, and Qmax, whereas a modest correlation was found between p(det)Qmax and prostate volume. In summary, there was no significant change in Q(max)pQ, but p(det)Qmax decreased for the three consecutive voids, which can be explained by a decrease in outlet resistance. The agreement between the investigator and QCC interpretations shows the value of a standardized technique, supporting the feasibility of multicenter urodynamic studies. There is a modest, but statistically significant, correlation between detrusor pressure and prostate size, supporting the hypothesis that prostate size is a contributing factor in symptomatic BPH.

Continued improvement in pressure-flow parameters in men receiving finasteride for 2 years. Finasteride Urodynamics Study Group

OBJECTIVES

To assess the long-term effects of finasteride on pressure-flow parameters in men with urodynamically documented bladder outflow obstruction (BOO).

METHODS

One hundred twenty-one men with benign prostatic enlargement (BPE) and lower urinary tract symptoms (LUTS) underwent a pressure-flow study (PFS) at 1 of 11 clinical centers. The PFS technique was standardized, and all tracings were read by a single reader unaware of the treatment group. Patients who were obstructed according to a modified Abrams-Griffiths nomogram were randomized to 5 mg finasteride (n = 81) or placebo (n = 40) for 12 months; all patients continuing into an open extension received finasteride during the second 12 months of therapy. Results of the initial 12-month study demonstrated the benefit of finasteride treatment on PFS parameters. To examine the continuing effects over time, an analysis of the data from 54 patients who completed 24 months of treatment with finasteride is provided.

RESULTS

Detrusor pressure at maximum flow (PdetQmax) continued to decrease during the second 12 months of therapy (decreases of 5.3 and 11.7 cm H2O at months 12 and 24, respectively). The percentage of patients obstructed by Abrams-Griffiths classification decreased from 76.2% at baseline to 66.7% at month 12 and 59.6% at month 24. An intention-to-treat analysis yielded similar results.

CONCLUSIONS

Finasteride improves urodynamic measures of obstruction in men with BPE and LUTS, with continued improvement during the second 12 months of therapy.

Oral administration of the growth hormone secretagogue MK-677 increases markers of bone turnover in healthy and functionally impaired elderly adults. The MK-677 Study Group

Growth hormone (GH) stimulates osteoblasts in vitro and increases bone turnover and stimulates osteoblast activity when given to elderly subjects. Probably a major effect of GH on bone is mediated through stimulation of either circulating or locally produced insulin-like growth factor I (IGF-I). We determined the effect of chronic administration of the GH secretagogue, MK-677, on serum IGF-I and markers of bone turnover in 187 elderly adults (65 years or older) enrolled in three randomized, double-blind, placebo-controlled clinical studies lasting 2-9 weeks. Urine was collected for determination of N-telopeptide cross-links (NTXs), a marker of bone resorption, and blood was collected for determination of serum osteocalcin and bone-specific alkaline phosphatase (BSAP), as bone formation markers, and serum IGF-I levels pre- and post-treatment. Dose response data were initially obtained in healthy elderly subjects who received oral doses of 10 mg or 25 mg of MK-677 or placebo for 2 weeks (n = 10-12/group). Treatment with 10 mg and 25 mg of MK-677 for 2 weeks increased mean urine NTXs 10% and 17%, respectively (p < 0.05 vs. placebo). Additionally, 50 healthy elderly subjects received either placebo (n = 20) for 4 weeks or 25 mg of MK-677 (n = 30) daily for 2 weeks followed by 50 mg daily for 2 weeks. MK-677 increased mean serum osteocalcin by 8% (p < 0.05 vs. placebo). In both studies, MK-677 increased serum IGF-I levels significantly (55-94%). Subsequently, the biological effects of MK-677 were studied in 105 elderly subjects who met objective criteria for functional impairment. Subjects were randomized to receive oral doses of placebo for 9 weeks or either 5, 10, or 25 mg of MK-677 daily for an initial 2 weeks followed by 25 mg of MK-677 daily for the next 7 weeks(n = 63 on MK-677 and n = 28 on placebo completed 9 weeks of therapy). Treatment with MK-677 (all MK-677 groups combined) for 9 weeks increased mean serum osteocalcin by 29.4% and BSAP by 10.4% (p < 0.001 vs. placebo) and mean urinary NTX excretion by 22.6% (p < 0.05 vs. placebo). The change from baseline serum osteocalcin correlated with the change from baseline serum IGF-I in the MK-677 group (r = 0.37; p < 0.01). In conclusion, once daily dosing with MK-677, an orally active GH secretagogue, stimulates bone turnover in elderly subjects based on elevations in biochemical markers of bone resorption and formation.

Improvement of pressure flow parameters with finasteride is greater in men with large prostates. Finasteride Urodynamics Study Group

PURPOSE

We assess the effect of finasteride, a 5alpha-reductase inhibitor, on objective voiding parameters in men with lower urinary tract symptoms and benign prostatic enlargement on digital rectal examination (known as clinical benign prostatic enlargement) in a double-blind placebo controlled multicenter study using strict standard pressure flow study techniques.

MATERIALS AND METHODS

A modification of the Abrams-Griffiths nomogram was used by 1 reader to ensure that all patients met objective criteria for bladder outlet obstruction at baseline. After performing a pressure flow study patients with obstruction were randomized 2:1 to receive 5 mg. finasteride (81) or placebo (40) daily. A second pressure flow study was performed at month 12. At baseline and month 12 free urinary flow studies and transrectal ultrasound were performed, and International Prostate Symptom Score questionnaires were completed. Patients were treated between May 1994 and July 1996.

RESULTS

Finasteride caused a significant decrease (-8.1 cm. water) in detrusor pressure at maximum flow (p <0.05 versus placebo p = 0.02), increase (+1.1 ml. per second) in maximum flow rate (p <0.05 versus placebo p = 0.02) and decrease (-22.8%) in prostate volume (p <0.05 versus placebo p <0.001). Men with prostates larger than 40 cc had greater improvement in detrusor pressure at maximum flow (between group difference -14.5 cm. water, 95% confidence interval -26.2 to -2.6, p = 0.02) and maximum flow rate (mean treatment effect +1.6 ml. per second, 95% confidence interval -0.2 to 3.0, p = 0.02) compared to those with prostates 40 cc or less (between group differences not significant).

CONCLUSIONS

Finasteride treatment resulted in improvements in urodynamic parameters, which were greater in men with large prostates.

Are performance-based measures sufficiently reliable for use in multicenter trials? Musculoskeletal Impairment (MSI) Study Group

BACKGROUND

The literature contains few reports of the test-retest reliability of performance-based measures. The purpose of this study was to determine the test-retest reliability of a battery of seven timed, performance-based measures used to assess the functional limitations of frail, older adults.

METHODS

One hundred and five frail, elderly subjects were twice administered a battery of timed tests approximately 2 weeks apart: 8-foot walk, get-up-and-go test, stair climb, single and repetitive standing from a chair, and single and repetitive 10-pound lifts with the upper limbs. Agreement between the mean times recorded for accomplishing each task at the two administrations was assessed.

RESULTS

Intraclass correlation coefficients ranged from .25 for the single chair stand to .79 for the 8-foot walk. Only the time taken for the single 10-pound lift was significantly greater at the first administration as compared with the second.

CONCLUSIONS

Timed performance-based measures have a wide range of test-retest reliability. Performance-based protocols that reflect familiar tasks with discrete starting and ending points may achieve higher reliability than tasks that are unfamiliar to subjects or may have ambiguous elements in them.

Building the French Muscular Dystrophy Association: the role of doctor/patient interactions

The process of creating the French Muscular Dystrophy Association (AFM) is analysed through the interactions between the medico-scientific community on the one hand, and patients and their families on the other, from the 1950s to 1986. Each stage of its development was characterized by a particular mode of co-operation between lay people and doctors. Starting in 1958, the Association built a close relationship with a single partner, Jean Demos, a paediatrician and biochemist who developed a new vasodilation therapy based on his controversial vascular theory of muscular dystrophy. Around 1966, some AFM members, disappointed by Demos' treatment, decided to collaborate with other specialists, primarily neurologists, but channelled most of their resources in social action. Two other organizations were then created around Dr. Demos: the first (Union de Myopathes de France (UMF) acted as a "grass-roots organization" for maintaining "therapeutic orthodoxy" among patients and supporting his research through political lobbying; the other, composed of a handful of wealthy individuals, raised private funds for his laboratory. In the late 1970s, some UMF members questioned Demos' approach. They united with AFM to form a single association and created a Scientific Council representing all French groups interested in neuromuscular diseases. The co-operation established between these two collective partners proved to be most fruitful for both parties.

Growth hormone secretagogues: mechanism of action and use in aging

GH secretagogues present a tool for furthering our understanding of the control of GH secretion, as well as a unique therapeutic opportunity. These compounds activate the receptors of a putative endogenous ligand in the hypothalamus and pituitary. Acting as functional somatostatin antagonists, GH secretagogues potentiate the actions of GHRH on GH secretion, enhancing pulsatile GH secretion. The clinical target of the elderly population presents significant challenges to drug development. Age-related musculoskeletal impairment as a result of muscle wasting (sarcopenia) is not well recognized as a clinical syndrome. In addition, given the inherent day to day variability in function in the "frail" target population as well as the presence of a host of concomitant conditions, the appropriate patient population to be studied remains to be defined, and demonstration of clinically meaningful efficacy may be difficult. It is not clear whether it will be useful to restore to young levels the activity of the GHIGF-I axis in aging. Nevertheless, if beneficial effects on strength, similar to those demonstrated with GH79 can be shown, GH secretagogues could provide a well-tolerated clinical approach for treating or preventing sarcopenia, and perhaps, even forestall the inevitability of age-associated decline in function and independence. Such efficacy would have a great social impact.

Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects

Aging is associated with declining activity of the GH axis, possibly contributing to adverse body composition changes and increased incidence of cardiovascular disease. The stimulatory effects on the GH-insulin-like growth factor I (IGF-I) axis of orally administered MK-677, a GH-releasing peptide mimetic, were investigated. Thirty-two healthy subjects (15 women and 17 men, aged 64-81 yr) were enrolled in a randomized, double blind, placebo-controlled trial. They received placebo or 2, 10, or 25 mg MK-677, orally, once daily for 2 separate study periods of 14 and 28 days. At baseline and on day 14 of each study period, blood was collected every 20 min for 24 h to measure GH, PRL, and cortisol. Attributes of pulsatile GH release were assessed by 3 independent algorithms. MK-677 administration for 2 weeks increased GH concentrations in a dose-dependent manner, with 25 mg/day increasing mean 24-h GH concentration 97 +/- 23% (mean +/- SE; P < 0.05 vs. baseline). This increase was due to an enhancement of preexisting pulsatile GH secretion. GH pulse height and interpulse nadir concentrations increased significantly without significant changes in the number of pulses. With 25 mg/day MK-677 treatment, mean serum IGF-I concentrations increased into the normal range for young adults (141 +/- 21 microgram/L at baseline, 219 +/- 21 micrograms/L at 2 weeks, and 265 +/- 29 micrograms/L at 4 weeks; P < 0.05). MK-677 produced significant increases in fasting glucose (5.4 +/- 0.3 to 6.8 +/- 0.4 mmol/L at 4 weeks; P < 0.01 vs. baseline) and IGF-binding protein-3. Circulating cortisol concentrations did not change, and PRL concentrations increased 23%, but remained within the normal range. Once daily treatment of older people with oral MK-677 for up to 4 weeks enhanced pulsatile GH release, significantly increased serum GH and IGF-I concentrations, and, at a dose of 25 mg/day, restored serum IGF-I concentrations to those of young adults.

Healthy monozygous twins do not recognize identical T cell epitopes on the myelin basic protein autoantigen

The T cell response against myelin basic protein (MBP) has been extensively studied in humans because of its putative role in the pathophysiology of multiple sclerosis (MS). Higher concordance rates in monozygous twins as well as an increased risk in relatives suggest the role of genetic factors in MS susceptibility. Very little is known about the shaping of T cell repertoire towards self antigens in humans and their contribution to disease susceptibility in autoimmune disorders. Here we report the comparative T cell epitope recognition patterns towards the MBP auto-antigen in healthy identical twins. We have established MBP-specific T cell lines from eight sets of twins and characterized their fine epitope specificity. Intra-pair comparison showed the co-existence of shared as well as distinct epitopes in six of eight pairs and a complete absence of concordant epitope recognition within two other pairs. These findings indicate that important differences in T cell repertoires against a self antigen may be observed between genetically identical healthy individuals, rendering difficult the interpretation of the differences which may be observed between identical twins discordant for an autoimmune disease.

The effects of subcutaneous insulin-like growth factor-I infusion in insulin-dependent diabetes mellitus

Insulin-dependent diabetes can be associated with low insulin-like growth factor-I (IGF-I) levels despite normal or even high GH secretion. The basis of the diabetic abnormalities in GH-IGF dynamics that contribute to insulin resistance and impaired fuel metabolism are not well understood. To further investigate these matters, this study evaluated baseline IGF system parameters and responses to recombinant human IGF-I in four diabetic adolescents and six pubertal stage-matched controls. Spontaneous overnight and arginine-stimulated GH secretion, insulin, IGF-I, IGF-II, IGF-binding protein-1 (IGFBP-1), and IGFBP-3 levels were measured before, during, and after daily 10-h sc infusions of saline or IGF-I (20 micrograms/kg.h). Baseline overnight GH secretion and IGFBP-1 and -3 levels were not significantly different in the two groups, but IGF-I levels were significantly lower and IGF-II levels were higher in diabetic subjects. IGF-I infusion produced a 3-fold increase in serum IGF-I levels and a reciprocal profound reduction in IGF-II levels in both groups. IGFBP-1 levels increased dramatically in diabetics and modestly in normal subjects in response to IGF-I infusion, but IGFBP-3 levels were not significantly altered. Spontaneous overnight and arginine-stimulated GH secretion were suppressed by about 50% in both groups after IGF-I infusion. Insulin requirements were substantially reduced in diabetics receiving IGF-I, and insulin secretion was suppressed in normal subjects, with no evidence of a change in insulin half-life. Blood glucose remained stable in both groups throughout saline and IGF-I infusions, and no hypoglycemia or other adverse effect occurred during IGF-I infusions. Further studies are necessary to determine whether the addition of IGF-I to insulin replacement therapy may stably reduce the insulin requirement, maintain normal GH levels, and perhaps achieve better metabolic and anabolic balance in the treatment of insulin-dependent diabetes.

Clinical uses of insulin-like growth factor I

Insulin-like growth factor I (IGF-I) has acute insulin-like metabolic effects and long-term anabolic actions. The therapeutic potential of recombinant human IGF-I treatment is being investigated in various growth hormone-resistant and insulin-resistant disorders. Recent studies have shown that IGF-I may substitute for growth hormone in promoting linear growth in children with growth hormone insensitivity. The anabolic, protein-sparing action of IGF-I is being evaluated as a potential therapy for adults with catabolic diseases. Patients with insulin-dependent diabetes mellitus have reduced endogenous IGF-I production, and studies are in progress to determine whether treatment with IGF-I in addition to insulin may improve their metabolic/anabolic status. Insulin-like growth factor I treatment may reduce glucose and triglyceride levels in adults with non-insulin-dependent diabetes mellitus and in some patients with extreme insulin resistance. Further studies are needed to evaluate the efficacy and safety of IGF-I treatment in these and other conditions and to provide a better understanding of this hormone's normal physiologic role(s) and complex relations with growth hormone and insulin.

A gene for familial hemiplegic migraine maps to chromosome 19

Familial hemiplegic migraine is an autosomal dominant disorder of unknown pathogenesis in which the migrainous attacks are marked by the occurrence of a transient hemiplegia during the aura. While investigating CADASIL, mapped previously to chromosome 19, we observed that some patients had recurrent attacks of migraine with aura. Although the clinical and neuroimaging features of familial hemiplegic migraine differ markedly from CADASIL, we hypothesized that the same gene could be involved in the pathogenesis of both conditions. We chose two large pedigrees for linkage analysis of familial hemiplegic migraine. A maximum lod score > 8 was found with two markers that are also strongly linked to CADASIL. Multilocus linkage analysis suggested that the loci responsible for the two diseases reside within an interval of about 30 cM on chromosome 19.

Anti-peripheral nerve antibodies in leprosy patients recognize an epitope shared by the M. leprae 65 kDa heat shock protein

Binding of leprosy sera to peripheral nerve from different species (mouse, guinea pig and rabbit) was evaluated by ELISA. A majority of sera, whatever the clinical form of leprosy, bind to these antigens. Absorption with Mycobacterium bovis BCG demonstrated that these antibodies recognize cross-reactive epitopes between peripheral nerve and mycobacteria. In immunoblot analysis, both leprosy patient sera and a monoclonal antibody directed at the 65 kDa heat shock protein of M. leprae were shown to react with a heat-shock 67-68 kDa sciatic nerve protein. Binding of the monoclonal antibody to this sciatic nerve antigen was prevented by incubation with lepromatous patient sera, showing that some peripheral nerve epitopes recognized by patient antibodies are shared by the 65 kDa heat shock protein of M. leprae.

T-cell receptor identification of an oligodendrocyte-specific autoreactive cytotoxic T-cell clone without self restriction

In addition to myelin basic protein (MBP) and proteolipid protein (PLP), oligodendrocyte (Od) membrane autoantigens, such as the glycoprotein M2/MOG, could participate in the pathogenesis of autoimmune demyelinating diseases of the central nervous system (CNS), such as experimental allergic encephalomyelitis (EAE) or multiple sclerosis (MS). We have described an Od-specific autoreactive and cytotoxic T-cell clone, named C2, which recognized M2/MOG without conventional MHC restriction. In order to analyse the Od/C2 interaction, we determined the alpha/beta T-cell receptor (TCR) variable region usages and structures of C2. Monoclonal antibody stainings of C2 and nucleotide sequences show that the alpha chain is composed of a V alpha 5 and a J alpha identical to J alpha 18BBM142 gene segments, and that the TCR beta chain is composed of V beta 17a, D beta 2.1 and J beta 2.2 gene segments indicating that C2 used a conventional alpha/beta TCR for M2/MOG recognition.

Anatomy of the pituitary insulin-like growth factor system

In situ hybridization was used to map patterns of gene expression for components of the insulin-like growth factor (IGF) system, including IGF-I and -II, IGF-binding proteins 1-5 (IGFBP1-5), the IGF-I receptor, and GH in the rat pituitary. IGF-I mRNA was concentrated in isolated cells scattered throughout the gland with features typical of nonendocrine folliculo-stellate cells. IGF-II mRNA was abundant in neural (NL) and intermediate lobe (IL) capillaries, and low levels were present in endocrine cells of anterior lobe (AL) and IL. IGFBP1 mRNA was not detected in the pituitary. IGFBP2 mRNA was concentrated in epithelial cells lining AL follicles and in astroglial-like cells (pituicytes) of the NL. IGFBP3 mRNA was localized in isolated cells scattered throughout the AL and NL. IGFBP4 mRNA was relatively abundant in NL pituicytes and was diffusely expressed in the AL. IGFBP5 mRNA was equally abundant in NL and AL, and was localized in folliculo-stellate and epithelial cells of the AL and pituicytes and capillaries of the NL. Neither IGF-I nor IGFBP1-5 were detected in the IL. IGF-I receptor mRNA was abundant and homogeneously distributed throughout the AL and IL, compatible with expression by endocrine cells. There was overlap, but no particular correlation, between IGF system gene expression and GH-producing cells, which were clustered in the dorsal-lateral wings of the AL. In summary, IGF system gene expression is bountiful in the rat pituitary, but does not correlate with sites of GH synthesis. IGF-I receptor mRNA, which might have been expected to localize to somatotrophs, appears to be equally abundant in all of the endocrine cells of both AL and IL; the other constituents of the IGF system are localized in connective tissue and support elements that demonstrate no special anatomical relationship to somatotrophs. Finally, there is remarkably abundant gene expression for IGFBP2, -4, and -5 in the NL.

Myalgia and elevated creatine kinase activity associated with subcutaneous injections of diluent

A 16-year-old boy with short stature and mild primary hypothyroidism received subcutaneous injections of either recombinant human growth hormone or placebo in diluent that contained glycerol and m-cresol as a preservative. While he was receiving the study drug, myalgia developed and serum creatine kinase values were elevated. Both resolved when injections were stopped and recurred when injections of diluent alone were given. The myalgia and elevated creatine kinase activity were apparently caused by a component of the diluent.

Structural and functional analysis of the insulin-like growth factor I receptor gene promoter

The insulin-like growth factor I receptor (IGF-I-R) gene is expressed in most body tissues. The levels of IGF-I-R mRNA, however, are regulated by a number of physiological conditions (development, differentiation, and hormonal milieu) as well as in certain pathological states (diabetes and tumors). To understand the molecular mechanisms which control the transcription of the IGF-I-R gene, we have cloned the promoter of the rat receptor gene and have characterized its activity by transient expression assays. Different fragments of the 5'-flanking region (subcloned upstream of a luciferase reporter gene) were transfected into buffalo rat liver 3A cells (a cell line with a low number of IGF-I binding sites) and Chinese hamster ovary cells (a cell line with a higher number of cell-surface receptors). In both cell lines, most of the promoter activity was located in the proximal 416 base pairs of 5'-flanking region. However, further dissection of this proximal fragment revealed a cell type-specific pattern of promoter activity. Thus, in buffalo rat liver 3A cells, subfragments of this region each contributed to total activity, suggesting that contiguous cis-elements can act together to activate transcription. In Chinese hamster ovary cells, on the other hand, subfragments of the proximal promoter region partially substituted for the proximal 416 base pairs of 5'-flanking region. Coexpression studies using an IGF-I-R promoter reporter construct together with an Sp1 expression vector (under the control of an ADH promoter) were performed in SL2 cells, a Drosophila cell line which lacks endogenous Sp1. The results obtained showed that Sp1 can trans-activate the IGF-I-R promoter in vivo. Transient transfection assays were complemented with gel-retardation assays and DNase I footprinting experiments, which showed that transcription factor Sp1 is potentially an important regulator of IGF-I-R gene expression.

M. leprae- and BCG-induced chemiluminescence response of monocytes from leprosy patients and healthy subjects: effects of gamma-interferon and GM-CSF

Mycobacterium leprae, in contrast to BCG, failed to trigger any chemiluminescence (CL) response in mononuclear cells from either leprosy patients or healthy subjects, a deficit not reversed by either interferon-gamma or GM-CSF. Chemiluminescence responses induced without mycobacteria or with BCG were found to be lower in leprosy patients than in controls. M. leprae were also less well phagocytosed than BCG. However, there was a significant difference in phagocytosis between healthy and tuberculoid leprosy subjects. Phagocytosis was not altered by the addition of either lymphokine, and no major differences between healthy subjects and patients were observed. Preincubating mononuclear cells with anti-mycobacteria antibodies (lepromatous patients' sera) did not increase the CL response nor the phagocytosis of M. leprae or BCG.

Strain differences in mouse cellular responses to Mycobacterium lepraemurium and BCG subcutaneous infections. II. Production of interleukins 2, 4, and 6 and of interferon-gamma by draining lymph node cells

C57BL/6, BALB/c, and CBA mice were infected either by Mycobacterium bovis BCG or by M. lepraemurium (MLM). Interleukins (IL) 2, 4 and 6 and interferon-gamma (IFN-gamma) were measured in the supernatants of draining lymph node cells (DLN) or control lymph node cells from uninfected mice, restimulated in vitro by the heat-killed infecting Mycobacterium. Uninfected lymph node cells did not develop any IL4, IL2, and IFN-gamma response to BCG and MLM. A significant IL6 response to BCG was observed, with CBA being the best producer and C57BL/6 the weakest. BCG-infected mice, which controlled the BCG infection, displayed variable patterns of lymphokine response to BCG according to the strain. C57BL/6 DLN cells produced more IL6 and IFN-gamma than IL2, whereas BALB/c mice produced more IL2. CBA secreted lymphokines with a similar pattern to that of BALB/c but in lower amounts. IL4 was not detected in any supernatant. MLM-infected mice displayed variable susceptibilities to MLM infection: C57BL/6 was resistant, BALB/c was susceptible after an initial efficient control, and CBA was fully susceptible. In each strain the lymphokine response to MLM was much lower than that triggered by BCG, but the pattern was similar. Thus, C57BL/6 DLN cells still produced significants amounts of IL2, IL6, and IFN-gamma, whereas BALB/c secreted IL2 alone and CBA did not produce any detectable lymphokine. IL4 was again not detected in any supernatant. The failure of BALB/c and CBA strains to develop IFN-gamma and IL6 responses to MLM might contribute to their low resistance to this infection.

T cell response to myelin basic protein epitopes in multiple sclerosis patients and healthy subjects

T cell lines and clones specific for human myelin basic protein (BP) were selected from three multiple sclerosis (MS) patients and two healthy subjects and tested for their proliferative responses to a battery of synthetic peptides, 9 to 21 amino acid residues long. The combined amino acid sequence of the peptides spanned the complete sequence of the human BP. The results suggest the development of T cells sensitized to at least four independent regions of the human BP, indicating some diversity of the human T cell repertoire to BP. However, an immunodominant T cell epitope was located in the C-terminal region, defined by residues 149-162. This epitope was recognized by T cells from three subjects out of five (one MS patient and both healthy controls) in the context of different DR specificities. Another epitope (located in the 57-75 region) which triggered one MS patient's T cell response was also recognized by a mycobacteria-specific T cell clone cross-reacting with BP.

Insulin-like growth factor I mRNA levels are developmentally regulated in specific regions of the rat brain

The expression of mRNAs encoding insulin-like growth factor I (IGF-I) and the IGF-I receptor in the developing rat brain from embryonic day 16 to postnatal day 82 was analyzed using solution hybridization-RNase protection assays. Four distinct developmental patterns in the steady-state levels of IGF-I mRNA were seen. Specifically, the olfactory bulb showed a high perinatal level of IGF-I mRNA which declined dramatically by postnatal day 8. In contrast, cerebral cortex displayed maximal levels of IGF-I mRNA at postnatal day 8 and 13, which subsequently declined to adult levels (P82). A third developmental pattern was seen in the hypothalamus, where IGF-I mRNA increased from E16 up to postnatal day 3 and remained elevated thereafter. Finally, IGF-I mRNA levels in brainstem and cerebellum remained unchanged throughout the time period studied. We conclude that there are specific regional patterns of IGF-I gene expression in the developing rat brain. In contrast, IGF-I receptor gene expression did not exhibit any region-specific developmental changes. The developmental patterns of IGF-I gene expression seen in this study further substantiate the potential role of IGF-I in normal brain development.

Restricted T-cell receptor V beta gene usage by myelin basic protein-specific T-cell clones in multiple sclerosis: predominant genes vary in individuals

Recent studies in experimental autoimmune encephalomyelitis as a model for multiple sclerosis (MS) have demonstrated limited heterogeneity in T-cell antigen receptors (TCR) specific for myelin basic protein (MBP). To investigate restricted beta-chain variable-region (V beta) gene usage in humans, we analyzed TCR gene rearrangements in two lines and 34 MBP-specific T-cell clones that were isolated from five MS patients and two healthy subjects. The T cells were characterized for their specificity to MBP epitopes and HLA-restricting molecules. We demonstrate here that MBP-specific T-cell clones from these different MS patients and healthy individuals, in contrast to T cells from rodents, display a more diverse V beta gene usage as evidenced by their TCR V beta gene rearrangements. However, the different MBP-specific T-cell clones isolated from each individual MS patient showed a common V beta gene usage, suggesting individual-specific TCR restriction. Out of 16 MBP-specific clones derived from a single MS patient, 12 clones (75%) utilized the V beta 15 gene for their TCR gene rearrangement. MBP-specific clones isolated from four other MS patients also showed a consistent tendency for a predominant, but different, TCR V beta gene rearrangement. These results suggest a TCR heterogeneity among MBP-specific T-cell clones from different individuals but a limited TCR V beta gene usage among MBP-specific T-cell clones of the same individual. The predominant V beta gene used by the MBP-specific T-cell clones studied here was not found to correlate with the epitope specificity of T cells or with their restricting HLA molecule. These findings may support the possibility of intervention with monoclonal antibodies to specific V beta gene products as an approach to immune therapy of MS but also imply the necessity for an individual-specific immunotherapeutic approach.

Cloning and characterization of the proximal promoter region of the rat insulin-like growth factor I (IGF-I) receptor gene

We have isolated genomic clones that contain the promoter region of the rat IGF-I receptor gene. A unique transcriptional start site was suggested by the results of primer extension and RNase protection assays, which also defined a 940-base 5'-untranslated region. Despite the single start site, the proximal 415 base pairs of 5'-flanking region were devoid of TATA or CCAAT elements. The region surrounding the start site was, however, similar to a recently described "initiator" sequence that can direct specific transcription initiation in the absence of a TATA element. The 5'-flanking region was GC-rich and contained several possible SP1 sites, but also included potential ETF and AP-2 binding sites. The rat IGF-I receptor gene promoter region appears to have some sequences similar to both "housekeeping" and highly regulated promoters and may be an example of an intermediary class of regulatory region.

Alternative splicing produces messenger RNAs encoding insulin-like growth factor-I prohormones that are differentially glycosylated in vitro

Rat insulin-like growth factor-I (IGF-I) cDNA sequences predict two prohormones that differ in the carboxy-terminal extension peptide (E-peptide) as a result of the inclusion or exclusion of the 52-basepair exon 4 sequence. In the absence of exon 4, the sequence codes for the IGF-Ia prohormone, whose E region contains two potential N-glycosylation sites. With differential splicing and the inclusion of exon 4, the resultant mRNA codes for IGF-Ib, with a longer E-region sequence. In addition, as a consequence of a frame shift, both potential glycosylation sites are lost in the IGF-Ib peptide. We used an in vitro translation system supplemented with canine pancreatic microsomal membranes to analyze cotranslational processing of the IGF-I propeptides. We have demonstrated that IGF-Ia prohormone, which contains two potential N-glycosylation sites in the E region, can be N-glycosylated in vitro, and that both glycosylation sites are probably used. As expected, the IGF-Ib preprohormone is processed by microsomes, but is not glycosylated.

Strain differences in mouse cellular responses to Mycobacterium lepraemurium and BCG subcutaneous infections. I. Analysis of cell surface phenotype in local granulomas

C57BL/6, BALB/c and CBA mice were subcutaneously infected with either Mycobacterium lepraemurium (MLM) or BCG, and studied for bacillary growth, granuloma size of infected footpads and draining lymph nodes (DLN), and DLN cell surface phenotype. Whereas, BCG-infected mice controlled the infection and developed early and large granulomas, MLM-infected mice exhibited major strain variations in their resistance to the infection, as well as in the granuloma size and kinetics. C57BL/6 mice, highly resistant, displayed early and regressive granulomas; BALB/c mice showed lower resistance and early granulomas that grew continuously; CBA mice, highly susceptible, developed late, soft, phagocyte-rich granulomas. Important strain differences in lymph node lymphocyte subset distribution could be observed prior to any infection: C57BL/6 mice displayed higher B cell percentages than both of the other strains and BALB/c mice showed the highest CD4/CD8 ratios, followed by CBA and C57BL/6 mice. BCG and MLM infections both induced similar changes of these parameters in all three strains: that is a decrease of the B cell percentage and a decrease of the CD4/CD8 ratio, and the strain differences observed in uninfected mice persisted. On the other hand, DLN cells stimulated by the infecting bacillus and interleukin 2 also displayed an increase of the CD8 T cell percentage as compared with normal lymph node cells, but this phenomenon was much less pronounced in BALB/c mice, whether infected by MLM or BCG, and in MLM-infected CBA mice, than in BCG- or MLM-infected C57BL/6 (B6) mice. Thus the ability of C57BL/6 mice to generate an early and persistent CD8 T cell response to mycobacteria may contribute to their resistance to MLM.

Specific anti-M leprae PGL-I antibodies and Mitsuda reaction in the management of household contacts in New Caledonia

Household contacts of leprosy patients have been tested for anti-phenolic glycolipid-I IgM antibodies (anti-PGL-I IgM) by an ELISA using the natural disaccharide (NDO) and natural trisaccharide (NTO) synthetic antigens. A group of healthy subjects without known exposure to Mycobacterium leprae served as controls. The percentages of positivity observed in multibacillary patients, paucibacillary patients, and household contacts were significantly higher than those of the negative controls. The absorbance values using NDO and NTO correlated well (range 0.59-0.91) when analysis of each subject group was performed. As reported here, NDO and NTO antigens seem to be equal in detecting leprosy cases; 100% of multibacillary and 21.43% of paucibacillary cases were detected as seropositive. For the screening of household contacts, NDO appears to be more sensitive and NTO more specific. There were more seropositive cases in the young age groups of household contacts, suggesting a higher rate of transmission of M. leprae infection in those age groups. Lepromin and anti-PGL-I IgG tests were also performed in contacts who were followed. The 2 paucibacillary subjects (1 borderline tuberculoid, 1 indeterminate) were Mitsuda negative. At diagnosis, their anti-PGL-I IgM levels were much higher than those of previous results; their anti-PGL-I IgG levels showed an increase in one and a decrease in the other. However, for the entire group anti-PGL-I IgM and anti-PGL-I IgG levels were positively correlated. The data reported here suggest that an increase in specific anti-M. leprae IgM levels in Mitsuda-negative household contacts could reveal the development of overt disease.

Human phagocyte oxidative burst activation by BCG, M. leprae, and atypical mycobacteria: defective activation by M. leprae is not reversed by interferon gamma

The activation of the phagocyte oxidative respiratory burst by various mycobacteria was evaluated in an in vitro assay, by measuring the chemiluminescence, associated to the release of oxidizing species, generated by normal human whole blood phagocytes. All mycobacterium species, except Mycobacterium leprae, induced a significant chemiluminescence response. The strongest stimulus was provided by BCG, followed by M. triviale, M. chelonei, and M. fortuitum. M. kansasii, M. intracellulare, and M. lepraemurium elicited a weak response, although higher than that triggered by M. leprae. Both polymorphonuclear and mononuclear cells contributed to the whole blood cell chemiluminescence stimulated by mycobacteria, mononuclear cells being more efficient on a per cell basis. Phagocyte activation by recombinant interferon gamma did not improve M. leprae ability to trigger a significant chemiluminescence response. The failure of M. leprae and of some atypical mycobacteria to stimulate a strong phagocyte oxidative respiratory burst may have some relevance to their pathogenicity.

Phenolic glycolipid-1 from M. leprae inhibits oxygen free radical production by human mononuclear cells

We studied the effect of PGL1, a phenolic glycolipid unique to Mycobacterium leprae, on the activation of the phagocyte oxidative respiratory burst, by measuring the chemiluminescence (CL) generated by normal mononuclear cells. PGL1 induced a decrease in oxygen free radical production stimulated by mycobacteria (M. leprae, BCG and M. kansasii) or by phorbol myristate acetate, but did not prevent the binding or ingestion of fluorescein-conjugated mycobacteria. In contrast, mycoside A from M. kansasii, a structurally related compound, did not alter the CL response. In addition, treatment of M. leprae with anti-PGL1 antibodies failed to restore the response to this microorganism. PGL1 could act as an oxygen species scavenger and protect M. leprae from killing by toxic oxygen metabolites.

Oligodendrocyte-specific autoreactive T cells using an alpha/beta T-cell receptor kill their target without self restriction

The oligodendrocyte (Od), a glial cell that produces myelin in the central nervous system, may be a target for autoreactive T cells in autoimmune demyelinating processes, although not expressing major histocompatibility complex (MHC) products. To analyze Od-T-cell interactions, we selected from normal SJL/J mouse splenocytes sensitized in vitro by Lewis rat Od a T-cell clone, named C2, exhibiting a surface phenotype of mature T cell (Thy 1+, CD3+, CD8+, CD4-, asialo-GM1-). C2 T cells displayed a specific cytotoxicity to syngeneic Od as well as to rat Od, but not to astrocytes or lymphoblasts, or to YAC-1 cells, a target for natural killer and lymphokine-activated killer activity. The T-cell receptor of clone C2 was found to be a CD3-associated alpha/beta-chain heterodimer similar to that usually expressed by antigen-specific MHC-restricted mature T cells. Attempts to block the C2-mediated cytolysis by a series of monoclonal antibodies showed that both the CD3-T-cell receptor complex and the CD8 accessory molecule were required for OD-T-cell interaction and confirmed the lack of involvement of polymorphic MHC products as epitope-presenting structures. Antibodies directed against a surface Od glycoprotein, previously shown to elicit demyelinating autoantibodies in experimental autoimmune encephalomyelitis, fully blocked the cytotoxicity of T-cell clone C2 to its Od target. These data suggest that an epitope of a surface Od glycoprotein may be directly and specifically recognized and killed by autoreactive T cells expressing an alpha/beta receptor without conventional MHC restriction.

Lymphocyte proliferative response to glial cells in SJL/J mice immunized with rat whole spinal cord and rat myelin basic protein

Lymph node cells (LNC) from SJL/J mice immunized with either rat whole spinal cord (WSC) homogenate or rat myelin basic protein (MBP) in the presence of complete Freund's adjuvant were assayed for their in vitro proliferative response to MBP and whole or sonicated purified oligodendrocytes (OD), and astrocytes. WSC-immunized mice displayed a strong and persistent response to both syngeneic and rat OD, that disappeared after sonication (suggesting a preferential recognition of surface OD antigen(s], and a much weaker response to rat MBP. LNC from MBP-immunized mice showed a small response to MBP, but no response to OD, indicating that OD are not able to present their endogenous MBP to lymphocytes. Conversely, rat astrocytes (whole or sonicated), isolated from cultures initially comprising OD, could trigger the proliferative response of MBP-sensitized LNC, suggesting that astrocytes may act as antigen-presenting cells for OD products.

Influence of thymic hormone on cell-mediated and humoral immune responses in Marek's disease

A reduction in the secretion of thymic hormones, and in particular thymulin, can be demonstrated in chickens following the thymic atrophy induced by Marek's disease virus (MDV) infection. In very sensitive histocompatible (B13/B13) chickens inoculated with the HPRS-16 strain of MDV at 10 days of age, treatment with synthetic thymulin by daily subcutaneous injection failed to modify the time course of Marek's disease (MD) and did not prevent the development of macroscopic tumors. No effect was noted on the levels of neutralizing anti-viral antibodies. Nevertheless, thymulin treatment resulted in significant suppression of the cellular immune response 4-6 weeks post-inoculation, monitored by splenic cytotoxicity against MD-specific and natural killer-sensitive lymphoblastoid cell lines.

Use of anti-M. leprae phenolic glycolipid-I antibody detection for early diagnosis and prognosis of leprosy

Untreated patients suffering from tuberculoid, lepromatous and indeterminate leprosy, their domiciliary contacts, and healthy controls, all living in Guadeloupe, West Indies, were tested by an ELISA for detecting IgM antibodies to the terminal disaccharide of the phenolic glycolipid-I antigen of Mycobacterium leprae. On most subjects, a Mitsuda test was also performed. A large majority of the tuberculoid patients and healthy subjects were Mitsuda positive. The seropositivity rate reached 44% among tuberculoid patients, and 6% among healthy subjects, with low antibody levels. Lepromatous patients were all Mitsuda negative and seropositive, with antibody production varying from low levels, as seen in tuberculoid patients, to much higher levels. Indeterminate leprosy patients included 62% Mitsuda-positive subjects and 54% seropositive subjects with a large dispersion of antibody levels. Comparing the results of the Mitsuda test to those of the ELISA by factorial analysis allowed us to define several subgroups among this population: some (25%) showed a "lepromatous-like" immune status (Mitsuda negative, seropositive); others (54%) exhibited "tuberculoid-like" profiles (Mitsuda positive without antibodies or with low antibody levels). "Lepromatous-like" cases were significantly older than "tuberculoid-like" patients. A group of subjects (17%) was Mitsuda negative and seronegative, thus displaying a true "indeterminate" immune profile, which had not been seen in other forms of the disease and had been observed in only 2 out of 51 healthy controls. A large majority of contacts was Mitsuda positive, with 33% of them being seropositive, indicating that the prevalence of M. leprae infection greatly exceeds that of overt leprosy in this population.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-MHC-restricted, tissue-specific T cells recognizing autologous oligodendrocytes in the normal SJL/J mouse

The oligodendrocyte (OD), a glial cell that produces myelin in the central nervous system (CNS), represents a possible target for autoreactive T cells in autoimmune demyelinating processes. To analyze OD/T lymphocyte interactions, we sensitized in vitro SJL/J mouse spleen cells (SC) over Lewis rat OD cultures and maintained them as long-term T-cell lines in interleukin-2 (IL-2)-containing medium. The proliferative response of these lines could be elicited by syngeneic OD as well as by Lewis rat OD, but appeared to be tissue-specific since SC failed to trigger their proliferation. A T-cell clone of the CD3+, CD8+, CD4- phenotype was obtained from these lines. This clone could mount an IL-2-dependent, tissue-specific, non-major histocompatibility complex (MHC)-restricted proliferative response to OD from rat, guinea pig and various strains of mice (including syngeneic OD), but not to SC, whether resting or activated, nor to astrocytes, kidney cells or Langerhans islets. Thus, we showed that SC from normal unimmunized SJL/J mice include a so far undescribed anti-OD autoreactive T-cell population which can be grown in vitro and develop tissue-specific, non-MHC-restricted proliferative responses.

Mechanisms of Mycobacterium leprae-specific T-cell deficiency in lepromatous leprosy

Patients suffering from lepromatous leprosy fail to develop an efficient cell-mediated immunity towards Mycobacterium leprae, the causative agent. The mechanism of such a specific T-cell tolerance to the bacillus remains a key question in the pathophysiology of leprosy. Macrophages do not show any intrinsic defect in phagocytizing and killing M. leprae or in presenting antigen to helper T-cells. On the other hand, M. leprae-reactive helper T-cells do persist in lepromatous patients, but their activation appears to prevented by active suppressor mechanisms, involving both suppressor T-cells and macrophages. The target of this specific suppression could be the interleukin 2-producing T-cell subset. A better molecular definition of M. leprae antigens, both by monoclonal antibodies and T-cell clones, should open new perspectives for further analysis of the regulation of immune responses to M. leprae.

Comparison of synthetic antigens for detecting antibodies to phenolic glycolipid I in patients with leprosy and their household contacts

Three synthetic antigens related to the natural antigen phenolic glycolipid I (PGL-I) were compared for their efficacy in detecting leprosy when used as antigens in an enzyme-linked immunosorbent assay (ELISA) for IgM antibody to PGL-I. Absorbance values for ELISAs using the three antigens correlated well (.79 less than r less than .99) and had a high rate of agreement (89.5% less than a less than 98.4%). Of three subjects (household contacts of patients with leprosy) who later developed the disease, one with lepromatous and one with indeterminate leprosy were seropositive by ELISAs using the three antigens before the clinical onset of disease; one who developed borderline tuberculoid leprosy was seronegative. The predictive value of a positive result for the test was very low (less than 2.4%) and the predictive value for a negative result was high (greater than 99.9%) because of the low prevalence of leprosy in French Polynesia (1.78 per 1000). The high sensitivity, specificity, and efficiency of the tests using the three antigens confirmed their great value for serodiagnosis of leprosy, especially the multibacillary form; the ELISA using NTP seems to be more specific and sensitive for detecting the paucibacillary form.

Human T-cell response to myelin basic protein in multiple sclerosis patients and healthy subjects

In order to explore the T-cell repertoire to myelin basic protein (BP) of both multiple sclerosis (MS) patients and healthy subjects (HS), we raised BP reactive T-cell lines from blood mononuclear cells of eight MS patients and five HS. These lines were triggered in vitro by human BP. When analyzing their patterns of recognition of human BP versus heterologous BP, we could observe differences between healthy subjects and MS patients. Whereas T-cell lines from healthy subjects developed a response to heterologous BP, which was in most cases equal or higher than that elicited by human BP, T-cell lines from most MS patients displayed a low response, or no response at all, to one or several of the heterologous BP tested. A low response to bovine BP was only observed in active cases, whereas decreased responses to rat and/or monkey BP were observed both during remission and during active disease. This may indicate that T-cell repertoire to BP in MS patients differs from that of healthy subjects. BP-reactive T-cell clones were obtained by limiting dilution from two healthy subject lines. Their pattern of response to heterologous BP as compared to human BP suggest that T-cells from the same individual can recognize different BP epitopes.

Mycobacterium leprae-reactive T-cell clones isolated from polar lepromatous and tuberculoid leprosy patients

T-cell clones capable of mounting a proliferative response to Mycobacterium leprae were obtained in three leprosy patients (two polar lepromatous and one polar tuberculoid) either from M. leprae-activated or from protein-purified derivative-activated polyclonal T lymphoblasts. All these clones expressed the CD4 surface marker. Some of them proliferated to the antigen only in the presence of interleukin-2. A majority expressed cross-reactive responses to other mycobacteria. Clones obtained from the lepromatous patients did not differ in any of these features from those obtained from the tuberculoid patient. M. leprae-reactive clones obtained from one lepromatous patient displayed strong antigen-specific cytotoxicity toward autologous antigen-coated target cells. This phenomenon was not observed for any clone of the other lepromatous patient and was seen only for one clone in the tuberculoid patient.

Phenotypic composition and in vitro functional capacities of unmodified fresh cells infiltrating acutely rejected human kidney allografts

Cell surface markers of isolated graft-infiltrating cells (GIC) were studied, and functional in vitro assays performed in 8 cases of acute irreversible rejection of human renal allografts. The GIC were mostly activated T cells (OKT11+, OKT3+, Ia+), with predominance of the cytotoxic/suppressor T cell phenotype (OKT8+). A small proportion of B cells and monocytes/macrophages were also present among these GIC. The GIC were able to proliferate with lectin of allogeneic stimulation and were strongly cytotoxic toward specific donor target cells. Within the T cell subset, OKT8+ cells displayed most of the specific cytotoxicity. Despite allograft morphology typical of cellular rejection, anti-HLA complement-dependent antibodies and antibody-dependent cell cytotoxicity were found in the eluted material from rejecting kidneys. The results of our phenotypic and functional testing of unmodified GIC (no enzyme treatment, no additional culture with or without interleukin 2), show that T cells, especially OKT8+ cells, are of paramount importance in the mechanism of this type of acute irreversible rejection of human renal allografts (i.e., to the point of allograft rupture), but other potential effector mechanisms are also present in situ.

Strain-dependent protective effect of adult thymectomy on murine infection by Mycobacterium lepraemurium

C57BL/6, DBA/2, BALB/c and CBA mice were thymectomized as adults, or sham-thymectomized, and infected subcutaneously with 10(6) MLM. The number of MLM in the spleen and in the inoculated footpad was measured after 1 year of infection as well as the DTH reactions and the IgM and IgG antibody levels to MLM. Non-thymectomized mice exhibited a broad spectrum of resistance to MLM infection and of T cell mediated immunity grading from the highly resistant C57BL/6 strain to the highly susceptible CBA strain. In between, DBA/2 was found more resistant than BALB/c mice. Adult thymectomy reduced by 100 times the MLM number in the spleen of infected DBA/2 mice, without affecting that measured in the inoculated footpad, and significantly decreased DTH reaction in the same strain. No effect of adult thymectomy was observed in any other strain, except for an increase of anti MLM antibodies in BALB/c mice. These results may suggest that the medium-resistant DBA/2 strain develops after MLM infection suppressor T cells which favour MLM dissemination and are sensitive to adult.

Influence of route of inoculation on anti-Mycobacterium lepraemurium antibody isotypes in murine leprosy

Mice of the C57BL/6 strain were injected either subcutaneously (s.c.) in the foot pad or intravenously (i.v.) with 10(5) or 10(8) Mycobacterium lepraemurium (MLM). Anti-MLM sonicate total immunoglobulin (Ig), IgM, and IgG antibody production was followed during the course of the infection. The kinetics of appearance and the magnitude of anti-MLM antibodies were found to be related to the size and route of inoculation. The i.v. route induced earlier and higher amounts of anti-MLM antibodies than did the s.c. route. In i.v.-infected mice, a relatively predominant IgM response to MLM was observed, while a relatively higher IgG response was seen in s.c.-infected mice. IgM antibody level was found to increase sharply with the bacterial load as assessed in the spleens of mice with i.v.-disseminated infection; whereas a slow progression of both IgM and IgG levels was noted with time in s.c.-infected mice.

IL-2 receptor and HLA class II antigens on cerebrospinal fluid cells of patients with multiple sclerosis and other neurological diseases

The presence of IL-2 receptor and HLA class II antigens as detected by monoclonal antibodies on mononuclear cells from both cerebro-spinal fluid (CSF) and peripheral blood was examined by cytofluorographic analysis in patients with multiple sclerosis (MS) and other neurological diseases. CSF as compared to blood was enriched in cells expressing IL-2 receptor and HLA class II molecules both in MS patients and in other inflammatory diseases of the central nervous system suggesting that activated T-cells concentrate within the central nervous system.

[Expression of interleukin 2 receptor and class II histocompatibility antigens on lymphocytes of the cerebrospinal fluid in patients with multiple sclerosis and other neurological diseases]

The presence of IL2 receptor and HLA class II antigens on mononuclear cells from both cerebrospinal fluid (CSF) and peripheral blood was examined in patients with multiple sclerosis (MS) and other neurological diseases. Cytofluorographic analysis of mononuclear cells was performed by means of indirect immunofluorescence on a flow cytometer using a linear scale. CSF as compared to blood was enriched in cells expressing IL2 receptor and HLA class II molecules both in MS patients and in other inflammatory diseases of the central nervous system. The site of activation of these cells remains however questionable.