Depth response of confocal optical microscopes

The on-axis intensity response of a confocal scanning optical microscope was measured for an objective of numerical aperture 0.9. The data compare favorably with theoretical calculations obtained by numerical integration of the standard theory, provided that lens aberrations are taken into account. The invariance of the shape of the central lobe to surface roughness and tilt is also demonstrated.

Experimental autoimmune encephalomyelitis mediated by T lymphocyte lines: genotype of antigen-presenting cells influences immunodominant epitope of basic protein

Lewis rats are susceptible to experimental autoimmune encephalomyelitis (EAE), and their T lymphocytes recognize epitopes in the 68-88 sequence of guinea pig myelin basic protein (BP). BN rats are resistant to EAE, and their T lymphocytes recognize epitopes outside of the 68-88 sequence, probably in the 43-67 portion of BP. To investigate the influence of the genome of antigen-presenting cells (APC) on the dominance of BP epitopes for T lymphocyte lines, we selected anti-BP lines from (Lewis X BN)F1 rats by using the APC of Lewis, BN, or F1 origin. We now report that the F1/Lewis and F1/F1 lines recognized the 68-88 epitopes and were highly encephalitogenic in F1 rats, whereas the F1/BN line recognized the 43-67 epitopes and was only weakly encephalitogenic. Thus, the genotype of the APC can influence the immunologic dominance for T lymphocytes of BP epitopes, and this dominance in turn can influence the expression of disease.

Monoclonal antibodies to human myelin basic protein

SJL/J and (SJL X PL) F1 hybrid mice were immunized with intact human myelin basic protein (MBP) or the three major peptic fragments of MBP, residues 1-38, 39-89, and 90-170. Immune spleen cells were fused with mouse myeloma P3 X 63Ag8 (NS1) cells in the presence of polyethylene glycol. Hybridoma supernatant culture fluids were screened for antibody to MBP by a solid-phase radioimmunoassay (RIA). The specificity of the monoclonal antibody (mAb) was characterized by RIA using the three major MBP peptic fragments and subfragments as well as MBP and MBP fragments of different species with known amino acid sequence differences. Six MBP mAbs were generated, one of them IgM isotype and the remainder IgG isotypes. One mAb each reacted against regions of residues 22-38, 39-69, 70-89, 90-116, and two reacted against residues 118-157. Immunoblots also showed that the five IgG mAbs were reactive against MBP and the peptic fragment of MBP containing the epitope. Immunohistochemical studies showed the IgG mAbs specifically stained myelinated fiber tracts in human brain tissue.

Specificity of T lymphocyte lines for peptides of myelin basic protein

T lymphocyte lines specific for myelin basic protein (BP) can mediate experimental autoimmune encephalomyelitis (EAE), or can protect against the active induction of the disease. To investigate the antigenic fine specificity of guinea pig (GP) BP-specific T cell lines raised from different rat strains, and to determine whether functionally different T lymphocyte lines and clones recognized the same or different regions of the BP molecule, the proliferation responses of line cells were assessed after stimulation with purified peptides of GP-BP. Lewis rat T cell lines and clones selected for responses to whole GP-BP responded selectively to the 68-88 amino acid sequence of GP-BP, but not to the 1-37, 43-67, or 89-169 sequences. The region of GP-BP recognized by Lewis T cells was additionally defined to include the 75-80 amino acid sequence, because a T cell clone responded equally to GP and rat BP which differed by only one amino acid at position 79, but did not respond to human or bovine BP, which had a Gly-His insertion in this region. T lymphocyte lines derived from the F344 and PVG (Weizmann) rat strains shared the same selective response to peptide 68-88, but lines from BN rats responded to an epitope(s) outside of the 68-88 sequence. The functional capacity of the various T cell lines to mediate experimental autoimmune encephalomyelitis (EAE) or to induce resistance against EAE was independent of their specificity for the different GP-BP peptides; lines specific for epitope(s) within or excluded from the 68-88 sequence could be encephalitogenic depending on their strain of origin, and various lines specific for the 68-88 peptide could induce both disease and protection, disease only, or neither activity.

Specificity of T lymphocyte lines for peptides of myelin basic protein

T lymphocyte lines specific for myelin basic protein (BP) can mediate experimental autoimmune encephalomyelitis (EAE), or can protect against the active induction of the disease. To investigate the antigenic fine specificity of guinea pig (GP) BP-specific T cell lines raised from different rat strains, and to determine whether functionally different T lymphocyte lines and clones recognized the same or different regions of the BP molecule, the proliferation responses of line cells were assessed after stimulation with purified peptides of GP-BP. Lewis rat T cell lines and clones selected for responses to whole GP-BP responded selectively to the 68-88 amino acid sequence of GP-BP, but not to the 1-37, 43-67, or 89-169 sequences. The region of GP-BP recognized by Lewis T cells was additionally defined to include the 75-80 amino acid sequence, because a T cell clone responded equally to GP and rat BP which differed by only one amino acid at position 79, but did not respond to human or bovine BP, which had a Gly-His insertion in this region. T lymphocyte lines derived from the F344 and PVG (Weizmann) rat strains shared the same selective response to peptide 68-88, but lines from BN rats responded to an epitope(s) outside of the 68-88 sequence. The functional capacity of the various T cell lines to mediate experimental autoimmune encephalomyelitis (EAE) or to induce resistance against EAE was independent of their specificity for the different GP-BP peptides; lines specific for epitope(s) within or excluded from the 68-88 sequence could be encephalitogenic depending on their strain of origin, and various lines specific for the 68-88 peptide could induce both disease and protection, disease only, or neither activity.

Characterization of T cell lines and clones from SJL/J and (BALB/c x SJL/J)F1 mice specific for myelin basic protein

Lines of thymus-derived lymphocytes reactive against bovine myelin basic protein (BP) were established in vitro from SJL/J mice. These lines are stable in long-term culture and mediate inflammatory central nervous system (CNS) lesions and a low incidence of clinical experimental allergic encephalomyelitis (EAE) when injected into recipient SJL/J mice. The line cells proliferate in response to BP of bovine, rat, or mouse origin. Clones were derived from these lines, and the characteristics of these clones were analyzed. The clones express Thy-1, Ly-1, and L3T4 antigens and are negative for Ly-T2. The clones all proliferate in response to bovine BP, with different clones showing varying degrees of cross-reactivity between bovine, rat, and mouse BP. The proliferative response is MHC-restricted; antigen-presenting cells from I-As strains are required. Compatible with their phenotype as helper cells, some of the clones will provide help to primed B cells stimulating antibody production in an in vitro assay. When injected into recipients pretreated with pertussis and irradiation, clones that showed proliferation to mouse BP induced the development of inflammatory lesions in the CNS, with mortality of 28% of the recipients. T cell lines were also established in (BALB/c x SJL/J)F1 mice. In contrast to the homozygous SJL/J lines, these lines were highly encephalitogenic, inducing a high incidence of clinical and histologic EAE when injected in vivo.

Major histocompatibility complex-linked control of the murine immune response to myelin basic protein

Recent experiments have shown that different regions of myelin basic protein (MBP) are encephalitogenic for different inbred strains of mice. It was therefore of interest to determine whether the immune response to MBP was MHC associated, and if so, what subregion controlled this response. Because PL/J and A/J mice were good responders to mouse MBP and C57Bl/10SN were not, B10.PL(73NS) and B10.A mice were immunized with mouse MBP under conditions designed to induce EAE. These strains were found to be highly susceptible. Intra-H-2 recombinant mice were then assessed for susceptibility. B10.A(4R) and B10.MBR were susceptible, whereas B10.A(5R) were resistant. Thus, EAE induced by purified MBP is under the control of the MHC, and the response maps to the I-A subregion. Production of IL 2 in vitro by T cells from MBP-primed mice in the presence of antigen and adherent cells was blocked by monoclonal antibody to the I-A, but not the I-E, subregion. When the specificity of the encephalitogenic response was tested, peptide 1-37 was active in B10.PL(73NS) and B10.A mice, whereas peptide 89-169 was active in A.SW, SWR, and B10.T(6R) strains. Serum from mice immunized with MBP peptides was assayed for antibody content. PL, B10.PL, and B10.A mice made a good antibody response to peptides 1-37 and 43-88 but were nonresponsive to peptide 89-169. SJL, A.SW, SWR, and B10.T(6R) mice responded well to peptide 89-169 but were poorly responsive to peptides 1-37 and 43-88.

Characterization of T cell lines and clones from SJL/J and (BALB/c x SJL/J)F1 mice specific for myelin basic protein

Lines of thymus-derived lymphocytes reactive against bovine myelin basic protein (BP) were established in vitro from SJL/J mice. These lines are stable in long-term culture and mediate inflammatory central nervous system (CNS) lesions and a low incidence of clinical experimental allergic encephalomyelitis (EAE) when injected into recipient SJL/J mice. The line cells proliferate in response to BP of bovine, rat, or mouse origin. Clones were derived from these lines, and the characteristics of these clones were analyzed. The clones express Thy-1, Ly-1, and L3T4 antigens and are negative for Ly-T2. The clones all proliferate in response to bovine BP, with different clones showing varying degrees of cross-reactivity between bovine, rat, and mouse BP. The proliferative response is MHC-restricted; antigen-presenting cells from I-As strains are required. Compatible with their phenotype as helper cells, some of the clones will provide help to primed B cells stimulating antibody production in an in vitro assay. When injected into recipients pretreated with pertussis and irradiation, clones that showed proliferation to mouse BP induced the development of inflammatory lesions in the CNS, with mortality of 28% of the recipients. T cell lines were also established in (BALB/c x SJL/J)F1 mice. In contrast to the homozygous SJL/J lines, these lines were highly encephalitogenic, inducing a high incidence of clinical and histologic EAE when injected in vivo.

Major histocompatibility complex-linked control of the murine immune response to myelin basic protein

Recent experiments have shown that different regions of myelin basic protein (MBP) are encephalitogenic for different inbred strains of mice. It was therefore of interest to determine whether the immune response to MBP was MHC associated, and if so, what subregion controlled this response. Because PL/J and A/J mice were good responders to mouse MBP and C57Bl/10SN were not, B10.PL(73NS) and B10.A mice were immunized with mouse MBP under conditions designed to induce EAE. These strains were found to be highly susceptible. Intra-H-2 recombinant mice were then assessed for susceptibility. B10.A(4R) and B10.MBR were susceptible, whereas B10.A(5R) were resistant. Thus, EAE induced by purified MBP is under the control of the MHC, and the response maps to the I-A subregion. Production of IL 2 in vitro by T cells from MBP-primed mice in the presence of antigen and adherent cells was blocked by monoclonal antibody to the I-A, but not the I-E, subregion. When the specificity of the encephalitogenic response was tested, peptide 1-37 was active in B10.PL(73NS) and B10.A mice, whereas peptide 89-169 was active in A.SW, SWR, and B10.T(6R) strains. Serum from mice immunized with MBP peptides was assayed for antibody content. PL, B10.PL, and B10.A mice made a good antibody response to peptides 1-37 and 43-88 but were nonresponsive to peptide 89-169. SJL, A.SW, SWR, and B10.T(6R) mice responded well to peptide 89-169 but were poorly responsive to peptides 1-37 and 43-88.

Phospholipid-sensitive Ca2+ -dependent protein kinase preferentially phosphorylates serine-115 of bovine myelin basic protein

Phospholipid-sensitive Ca2+ -dependent protein kinase (PL-Ca-PK) and cyclic AMP-dependent protein kinase (A-PK) both preferentially phosphorylated serine residues of bovine myelin basic protein (MBP). Tryptic peptide maps of MBP phosphorylated by PL-Ca-PK or A-PK, however, revealed different phosphopeptides, suggesting a difference in the intramolecular substrate specificity for the two enzymes. Serine-115 of MBP, in the sequence (-Arg-Phe-Ser(115)-Trp-), was found to be a preferred and probably major phosphorylation site for PL-Ca-PK. Because serine-115 of bovine MBP corresponds to serine-113 of rabbit MBP, an in vivo phosphorylation site reported by Martenson et al. (1983), and PL-Ca-PK is present at a very high level in brain and myelin, it is suggested that the enzyme may be responsible for the in vivo phosphorylation of this and other sites in MBP.

Devic's syndrome: antibody to glial fibrillary acidic protein in cerebrospinal fluid

The cerebrospinal fluid of a patient with Devic's syndrome contained antiglial fibrillary acidic protein antibody. The serum level of antibody was less than that in cerebrospinal fluid, and the antibody was probably synthesized within the central nervous system. Similar antibody was not found in another patient with Devic's syndrome or in patients with multiple sclerosis. The role of the antibody in the patient's illness is uncertain, but is one of the few instances in which antibody against a specific brain antigen has been described in human demyelinating disease.

Search for a multiple sclerosis-specific brain antigen

Specific reactivity of multiple sclerosis (MS) cerebrospinal fluid (CSF) IgG against central nervous system (CNS) tissue has been sought. Brain proteins were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), reacted with CSF followed by 125I-Staph protein A, and developed for autoradiography. Pooled CSF from MS patients, CSF from individual MS patients, and pooled CSF from patients with other neurologic diseases and from normal patients, were used. Proteins were extracted from the white matter of MS and normal brains and from MS plaque and peri-plaque tissue. No reactivity specific for MS was observed.

Epitopes of peptide 43-88 of guinea pig myelin basic protein: localization with monoclonal antibodies

Two monoclonal antibodies, one raised by immunization with mouse myelin basic protein (MBP) and the second raised by immunization with peptide 68-88 of guinea pig MBP, were compared with respect to specificity. The former antibody (15.32) cross-reacted completely with rat, guinea pig, human, and bovine MBP. It also reacted with peptide 43-88 from each MBP. The latter antibody (22.17) was nonreactive with MBP, but cross-reacted with peptide 43-88 from rat, human, guinea pig, and bovine MBP. When tested with small peptides derived from peptide 43-88, antibody 22.17 reacted with an epitope in the C-terminal region. Antibody 15.32 reacted with an epitope in the N-terminal half of the peptide. The data show that 22.17 reacted with a unique epitope associated only with free peptide, whereas 15.32 recognized an epitope common to both peptide 43-88 and MBP.

Epitopes of peptide 43-88 of guinea pig myelin basic protein: localization with monoclonal antibodies

Two monoclonal antibodies, one raised by immunization with mouse myelin basic protein (MBP) and the second raised by immunization with peptide 68-88 of guinea pig MBP, were compared with respect to specificity. The former antibody (15.32) cross-reacted completely with rat, guinea pig, human, and bovine MBP. It also reacted with peptide 43-88 from each MBP. The latter antibody (22.17) was nonreactive with MBP, but cross-reacted with peptide 43-88 from rat, human, guinea pig, and bovine MBP. When tested with small peptides derived from peptide 43-88, antibody 22.17 reacted with an epitope in the C-terminal region. Antibody 15.32 reacted with an epitope in the N-terminal half of the peptide. The data show that 22.17 reacted with a unique epitope associated only with free peptide, whereas 15.32 recognized an epitope common to both peptide 43-88 and MBP.

Encephalitogenic activity of the small form of mouse myelin basic protein in the SJL/J mouse

Mouse myelin basic proteins (MBP) were prepared by ion-exchange chromatography of an acid extract of homogenized, delipidated mouse brain. The use of a linear salt gradient during ion-exchange chromatography gave three peaks, 1, 2, and 3, of MBP. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of these peaks showed that peaks 2 and 3 were a mixture of the large and small forms of mouse MBP, whereas peak 1 was solely the small form. Tryptic peptides of mouse and rat small form MBP were compared by high-performance liquid chromatography. The elution times and absorbances at 210 nm were identical for 16 of 21 peaks derived from small form MBP of the two species. Amino acid analysis showed that 10 corresponding peaks from the small form of mouse and rat MBP had identical amino acid composition. When tested for encephalitogenicity in SJL/J mice, both the mixture of large and small forms of mouse MBP and the small form mouse MBP were highly encephalitogenic.

Encephalitogenic activity of the small form of mouse myelin basic protein in the SJL/J mouse

Mouse myelin basic proteins (MBP) were prepared by ion-exchange chromatography of an acid extract of homogenized, delipidated mouse brain. The use of a linear salt gradient during ion-exchange chromatography gave three peaks, 1, 2, and 3, of MBP. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of these peaks showed that peaks 2 and 3 were a mixture of the large and small forms of mouse MBP, whereas peak 1 was solely the small form. Tryptic peptides of mouse and rat small form MBP were compared by high-performance liquid chromatography. The elution times and absorbances at 210 nm were identical for 16 of 21 peaks derived from small form MBP of the two species. Amino acid analysis showed that 10 corresponding peaks from the small form of mouse and rat MBP had identical amino acid composition. When tested for encephalitogenicity in SJL/J mice, both the mixture of large and small forms of mouse MBP and the small form mouse MBP were highly encephalitogenic.

Relapsing murine experimental allergic encephalomyelitis induced by myelin basic protein

Experimental allergic encephalomyelitis (EAE), an experimental autoimmune disease of the central nervous system (CNS), is readily induced in many mammalian species by immunization with CNS tissue or myelin basic protein (MBP) purified from the CNS. EAE has been frequently used as a model for multiple sclerosis (MS). However, EAE generally presents as an acute monophasic disease in the adult animal after immunization with MBP. After recovery, the animal is resistant to rechallenge with encephalitogen (1). Two exceptions to these observations have been reported. McFarlin et al. (2) reported that a variable number of Lewis rats showed signs of a single, mild relapse about a week after recovery from MBP-induced acute EAE. Panitch and Ciccone (3) have reported induction of recurrent EAE in rats immunized with human MBP. Chronic, relapsing EAE has been induced in the mouse; however, an apparent requirement for CNS tissue had been noted (4, 5). Recently, during the course of a series of experiments on the induction of EAE in SJL/J, PL/J, and (SJL/J X PL/J)F1 (SPL F1) mice, it was observed that the F1 mice frequently had paralytic relapses after recovery from MBP-induced symptoms. Experiments were initiated to examine this phenomenon, and the findings are presented below.

Relapsing murine experimental allergic encephalomyelitis induced by myelin basic protein

Experimental allergic encephalomyelitis (EAE), an experimental autoimmune disease of the central nervous system (CNS), is readily induced in many mammalian species by immunization with CNS tissue or myelin basic protein (MBP) purified from the CNS. EAE has been frequently used as a model for multiple sclerosis (MS). However, EAE generally presents as an acute monophasic disease in the adult animal after immunization with MBP. After recovery, the animal is resistant to rechallenge with encephalitogen (1). Two exceptions to these observations have been reported. McFarlin et al. (2) reported that a variable number of Lewis rats showed signs of a single, mild relapse about a week after recovery from MBP-induced acute EAE. Panitch and Ciccone (3) have reported induction of recurrent EAE in rats immunized with human MBP. Chronic, relapsing EAE has been induced in the mouse; however, an apparent requirement for CNS tissue had been noted (4, 5). Recently, during the course of a series of experiments on the induction of EAE in SJL/J, PL/J, and (SJL/J X PL/J)F1 (SPL F1) mice, it was observed that the F1 mice frequently had paralytic relapses after recovery from MBP-induced symptoms. Experiments were initiated to examine this phenomenon, and the findings are presented below.

Induction of experimental allergic encephalomyelitis in PL/J and (SJL/J x PL/J)F1 mice by myelin basic protein and its peptides: localization of a second encephalitogenic determinant

SJL/J, PL/J, and (SJL/J x PL/J)F1 mice were immunized with bovine, guinea pig, mouse, or rat myelin basic proteins (MBP) in adjuvant containing Mycobacterium tuberculosis H37Ra. Twenty-four and 72 hr later, Bordetella pertussis vaccine was given i.v. All MBP tested induced experimental allergic encephalomyelitis (EAE) in SJL/J and F1 mice; however, bovine MBP was inactive in PL/J mice. Each strain was immunized in a similar manner with peptic peptides, residues 1-37, 43-88, and 89-169 of guinea pig MBP. In contrast to the SJL/J strain, which has been shown to recognize a major encephalitogenic determinant in peptide 89-169, PL/J and F1 mice responded primarily to an encephalitogenic determinant within peptide 1-37. Analysis of antibody levels showed that SJL/J mice made no antibody to peptide 1-37, although anti-peptide 89-169 antibodies were consistently found. Conversely, PL/J mice responded well to peptide 1-37, but only an occasional animal made a significant response to peptide 89-169. (SJL/J x PL/J)F1 mice were more susceptible to EAE than either parental strain, as shown by the percentage of animals showing neurologic signs and by clinical severity.

Failure to detect antibodies to myelin basic protein or peptic fragments of myelin basic protein in CSF of patients with MS

Using the sodium sulfate precipitation radioimmunoassay and solid-phase radioimmunoassay, we measured antibody to intact human myelin basic protein and myelin basic protein peptic fragments, residues 1-44, 45-89, and 90-170, in CSF. Comparable levels of binding were obtained for MS and normal CSF by both tests. The increased amount of CSF IgG in MS patients cannot be attributed to specific antibody against myelin basic protein or its peptic fragments.

Induction of experimental allergic encephalomyelitis in PL/J and (SJL/J x PL/J)F1 mice by myelin basic protein and its peptides: localization of a second encephalitogenic determinant

SJL/J, PL/J, and (SJL/J x PL/J)F1 mice were immunized with bovine, guinea pig, mouse, or rat myelin basic proteins (MBP) in adjuvant containing Mycobacterium tuberculosis H37Ra. Twenty-four and 72 hr later, Bordetella pertussis vaccine was given i.v. All MBP tested induced experimental allergic encephalomyelitis (EAE) in SJL/J and F1 mice; however, bovine MBP was inactive in PL/J mice. Each strain was immunized in a similar manner with peptic peptides, residues 1-37, 43-88, and 89-169 of guinea pig MBP. In contrast to the SJL/J strain, which has been shown to recognize a major encephalitogenic determinant in peptide 89-169, PL/J and F1 mice responded primarily to an encephalitogenic determinant within peptide 1-37. Analysis of antibody levels showed that SJL/J mice made no antibody to peptide 1-37, although anti-peptide 89-169 antibodies were consistently found. Conversely, PL/J mice responded well to peptide 1-37, but only an occasional animal made a significant response to peptide 89-169. (SJL/J x PL/J)F1 mice were more susceptible to EAE than either parental strain, as shown by the percentage of animals showing neurologic signs and by clinical severity.

Basic protein in brain myelin is phosphorylated by endogenous phospholipid-sensitive Ca2+-dependent protein kinase

Phosphorylation of myelin basic protein (MBP) in rat or rabbit brain myelin was markedly stimulated by Ca2+, and this reaction was not essentially augmented by exogenous phosphatidylserine or calmodulin or both. Solubilization of myelin with 0.4% Triton X-100 plus 4 mM EGTA, with or without further fractionation, showed that Ca2+-dependent phosphorylation of MBP required phosphatidylserine, but not calmodulin. DEAE-cellulose chromatography of solubilized myelin revealed a pronounced peak of protein kinase activity stimulated by a combination of Ca2+ and phosphatidylserine; a protein kinase stimulated by Ca2+ plus calmodulin was not detected. These findings clearly indicate an involvement of phospholipid-sensitive Ca2+-dependent protein kinase in phosphorylation of brain MBP, although a possible role for the calmodulin-sensitive species of Ca2+-dependent protein kinase in this reaction could not be excluded or established. Phosphorylation of MBP in solubilized rat myelin catalyzed by the phospholipid-sensitive enzyme was inhibited by adriamycin, palmitoylcarnitine, trifluoperazine, melittin, polymyxin B, and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7).

Encephalitogenic activity of guinea pig myelin basic protein in the SJL mouse

GPBP was shown to be encephalitogenic in SJL mice by direct challenge and in experiments in which an adoptive transfer system was employed. The three fragments obtained by treating GPBP with pepsin were assessed in the same manner. The encephalitogenic activity resided in the C terminal half of the molecule (residues 89-169). LNC also proliferated to the same fragment in vitro. Fragments 1-37, and, to a lesser extent, 44-48 stimulated sensitized LNC to proliferate but did not induce disease.

Encephalitogenic activity of guinea pig myelin basic protein in the SJL mouse

GPBP was shown to be encephalitogenic in SJL mice by direct challenge and in experiments in which an adoptive transfer system was employed. The three fragments obtained by treating GPBP with pepsin were assessed in the same manner. The encephalitogenic activity resided in the C terminal half of the molecule (residues 89-169). LNC also proliferated to the same fragment in vitro. Fragments 1-37, and, to a lesser extent, 44-48 stimulated sensitized LNC to proliferate but did not induce disease.

[Helminth and pinworm control for primary school and kindergarten children by periodical mass-examination and treatment in Suan-Yuan District, Taipei (author's transl)]

The mass pre-control survey was done in fall semester 1978 by both methods that Kato's thick smear for helminthic infection and cellophane tape perianal swab for pinworm infection. There are about 19,000 primary school children and around 5,000 kindergarten children in Suan-yuan District, being the subjects. The helminthic positive rates (%) obtained were 5.18 and 3.81, respectively. The rates for pinworm were found 28.68% former and 29.00% for the latter. Drug was given to the egg-positive persons after mass examination, in each semester, for three consecutive years. Two broad-spectrum anthelmintics, pyrantel pamoate and mebendazole were used. The children who harbored Ascaris, hookworm or pinworm were given pyrantel tablet as a single dose of 10 mg/kg body weight, and whipworm positives were given a standard course of 100 mg of mebendazole twice daily for three days. After three-year operation, in accordance with the results of examination in Spring semester 1981, the egg positive rates were sharply dropped to 0.56% for the primary school children and 0.50% for the kindergarten. The pinworm infection rates for the above-mentioned group were also reduced to 13.05% and 18.68%, respectively.

Prevention of experimental allergic encephalomyelitis in Lewis rats with peptide 68-88 of guinea pig myelin basic protein

The highly encephalitogenic guinea pig peptide 68-88 has been used to develop an effective and reproducible model of protection in the Lewis rat. Doses as low as 0.1 nmol of peptide protected 70% of rats when injected intraperitoneally six and four weeks prior to challenge with 0.05 nmol of the peptide in complete Freund's adjuvant. Fragments derived from guinea pig peptide 68-88 by selective enzyme cleavage were then tested for their capacity to provide protection in this model system. These fragments had previously been well characterized both biochemically and immunologically. The protection provided by each fragment closely paralleled its capacity to induce disease. This suggests that the region of peptide 68-88 required for protection is similar to that needed for induction of experimental allergic encephalomyelitis and the other T-cell functions of the peptide. B-cells did not appear to participate; peptide 68-85, which has no capacity to produce antibody against peptide 68-88, gave full protection, while peptide 79-88, which contains the major B-cell determinant of the peptide, afforded no protection. Rat peptide 68-88 did not protect against challenge with the guinea pig peptide, demonstrating a critical role for serine 79. These studies support the concept that nonencephalitogenic agents do not protect against experimental allergic encephalomyelitis at doses comparable to those of encephalitogenic agents.

The immune response of Lewis rats to peptide 68-88 of guinea pig myelin basic protein. I. T cell determinants

A series of peptides, produced from peptide 68-88 by selective enzyme cleavage, were used to define the amino acid sequences required for the induction of experimental allergic encephalomyelitis (EAE), an in vitro lymphocyte proliferative response (LPR), and serum antibody by peptide 68-88 in the Lewis rat. Here we present data that indicate that the T cell determinants for induction of EAE, an LPR, and helper function in the production of antibody are located in the same region of the molecule and that a minimum of 13 amino acids are involved; i.e., residues 71-85.

The immune response of Lewis rats to peptide 68-88 of guinea pig myelin basic protein. II. B cell determinants

A series of peptides, produced from peptide 68-88 by selective enzyme cleavage, were used to define the amino acid sequences reactive with Lewis rat anti-peptide 68-88 antibody. One hundred per cent of 38 rats immunized with peptide 68-88 recognized a B cell determinant residing in the region of residues 80-88. The three carboxy-terminal amino acids, residues 86-88, appeared to confer conformation on this determinant. In roughly two-thirds of the rats, the reactivity with this major B cell determinant was equal to the reactivity with the immunizing peptide. In these rats the anti-peptide 68-88 antibodies were of the IgG2 class. A third of the rats recognized an additional determinant(s) and in these the predominant class of antibody was IgG1.

Specificity of antisera from Lewis rats immunized with encephalitogenic fragment 43-88 of guinea pig myelin basic protein

Inbred Lewis rats were immunized with encephalitogenic fragment 43-88 of guinea pig myelin basic protein emulsified in complete Freund's adjuvant. After recovery from experimental allergic encephalomyelitis (EAE) the animals were given a booster immunization, bled, and the specificity of the individual anti-fragment antisera was examined by direct binding assays by using radioiodinated fragment 43-88 and peptides 43-67, 68-88, and 79-88. Competitive-binding experiments with these peptides in competition with labeled fragment 43-88 were also done. The results of these experiments indicated that the immunodominant region of fragments 43-88 was the carboxy-terminal half of the molecule. Individual antisera recognized different antigenic determinants within this region.

Molecular internalization of a region of myelin basic protein

The conformation of myelin encephalitogenic or basic protein (BP) was investigated with a double-antibody radioimmunoassay by studying the reaction of BP or its fragments with antibodies produced in two rabbits against peptide 43-88 linked to rabbit serum albumin. Both antisera reacted well with peptide 43-88 but showed little or no reaction with BP. Absorption of these antisera with a BP-immunoadsorbent did not remove the antibody activity against peptide 43-88. Within the region of peptide 43- 88 it was shown that peptides 68-88 and 79-88 gave an equivalent or better reaction than peptide 43-88, whereas peptides 43-67 and 64-73 had very little reactivity. In the BP fragments containing region 43-88, peptide 1-88 showed the best reactivity, peptide 20-166 showed minimal reactivity, while peptide 1-115 showed none. These data document the internal position of at least a portion of peptide 43-88 and all of residues 79-88 in the BP molecule. The much greater reactivity of peptide 1-88 as compared to peptide 1-115 suggests that the region or a portion of the region of BP containing residues 89- 115 participates in the conformational alignment of BP restricting access to peptide 79-88. After absorption with BP, neither of the antisera prepared to peptide 43-88 reacted with PNS myelin in fixed tissue sections but continued to react with CNS myelin in similarly treated sections. The present findings demonstrate the need to consider the role of shielded antigenic determinants in the investigation of antigens or of immune responses.

Raman spectral studies of nucleic acids. XVII. Conformational structures of polyinosinic acid

Laser-Raman spectra of poly(rI) show the formation of an ordered complex in aqueous solutions of high ionic strength. This structure exhibits the A-helix geometry, contains stacked bases and is apparently stabilized by specific hydrogen bonding involving hypoxanthine C6=0 groups. Thermal dissociation of the poly(rI) complex (Tm=45 degrees C) yields single-stranded and disordered poly (RI) chains. A disordered structure also occurs for poly (rI) in aqueous solutions of low ionic strength. In oriented films, poly (rI) forms an ordered structure probably the same as that which occurs in solutions of high ionic strength. Raman intensities measured at 815 and 1100 cm-1 in spectra of poly (rI) and poly (rU)-poly (rA)-poly(rU) indicate that the correlation previously established for single- and double-stranded ribopolymer structures is valid also for these multi-stranded structures. X-ray diffraction and model-building studies confirm the A-helix structure.

Polydisperse particulate solids mixing and segregation: nonstationary Markov chains

The feasibility of analyzing interparticulate translocations within agitated beds of polydisperse particulate solids in terms of Markov chains was investigated. A binary mixture of spherical particles subjected to vertical sine wave vibration is shown to behave in accordance with a nonstationary. Markov chain having singly stochastic transition matrixes. The transition probability elements of such matrixes, calculated from a knowledge of the initial and final occupancy vectors, agree with those estimated using tracer particles. With appropriate restrictions, the former method, based on the solution of simultaneous equations, permits a quantitative evaluation of particle mobilities throughout the bed.

Basis of microheterogeneity of myelin basic protein

The basic protein of bovine central nervous system myelin contains a single polypeptide chain of 170 amino acids. Multiple components of basic protein have been observed on disc gel electrophoresis and ion exchange chromatography at alkaline pH, but the basis of the microheterogeneity has not been established. In the present study myelin basic protein from bovine spinal cord was chromatographed on carboxymethylcellulose at pH 10.4 in glycine buffer/2 M urea. Three major peaks were obtained, identified as components 4, 5, and 6 in the oder of their elution from the column by a linear salt gradient. The amino acid compositions of tryptic peptides from components 4 and 6 were identical and the COOH-terminal sequence, Ala-Arg-Arg, was intact for all three components. Component 4 was found to differ from component 6 by partial phosphorylation of threonine 98 and serine 165. This modification was estimated to account for 50% of component 4. Component 5 differed from component 6 by partial deamidation of glutamine residues 103 and 147, which accounted for 80% of this component. These modified glutamine residues were also present in component 4 and constituted another 15% of this component. It was considered that component 6 was the native, unmodified species of basic protein and that component 4 differed by a net negative charge of 2, and component 5 by a net negative charge of.1 as a result of these modifications. The nonrandom nature of the modifications suggested the involvement of specific enzymes.

The immune response against an encephalitogenic fragment of guinea pig basic protein in the Lewis and Brown Norway strains or rat

Lewis rats which have Ir-EAE gene develop EAE after challenge with either GPBP or GPEF, a 42-residue fragment. BN rats which lack the Ir gene do not develop EAE after challenge with these proteins. The immune response against GPEF was compared in these two strains of rats. It was found that Le rats produce small amounts of antibody and a cell-mediated immune response against GPEF; in contrast BN rats did neither. These findings support the concept that the Ir-EAE gene exerts its effect by controlling the immune response against GPEF.