Production of mouse monoclonal anti-idiotypic antibodies specific to epitopes of tumor-associated mucin TAG-12

The tumor-associated mucin-glycoprotein TAG-12 is strongly expressed in approximately 96% of all breast cancer patients and nearly 68% of all ovarian cancers. The experimental results of this work indicated that humoral immune response against TAG-12 is possible. Immunization with anti-idiotypic monoclonal antibodies produces this response. In this experiment, anti-idiotypic monoclonal antibodies represent the internal image of a specific epitope on TAG-12. Monoclonal antibody (MAb) 12H12 was selected to produce anti-idiotypic antibodies (anti-Ids) because of its high reactivity with TAG-12. Syngeneic murine anti-Ids were developed by immunization of BALB/c mice with the 12H12-Fab-KLH conjugate. A competitive assay with purified TAG-12 was utilized to identify anti-Ids with mirror image function. Two MAbs with "internal image" specificity were selected, 5H8 and 5H2. Two New Zealand White rabbits were immunized with 5H8. Serum samples tested 6 weeks after the initial immunization showed comparable titers against TAG-12. The binding capacities of the rabbit sera to different human breast as well as nonbreast cancer cell lines demonstrated strong binding with TAG-12-positive breast cancer cell lines. Competitive inhibition assays demonstrate that Ab3 and purified TAG-12 totally inhibit the binding of 12H12 antibody to TAG-12-positive cells. No inhibition was detectable with unrelated MAbs or normal mouse immunoglobulin. Binding assays with polyclonal Ab3 serum and several human cancer cell lines showed reactivity to nearly every tested cell line. Soluble TAG-12 showed no inhibition, indicating that this binding is due to a different set of idiotypes. Anti-Id 5H8 elicited an immune response to TAG-12. Utilization of anti-Id as a vaccine against the breast cancer-associated tumor antigen TAG-12 was successfully demonstrated in a xenogeneic animal model.     

HLA (A*0201) mimicry by anti-idiotypic monoclonal antibodies

Soluble MHC Ags and anti-Id (anti-anti-MHC) Abs have both been shown to inhibit MHC alloantigen-specific B cell responses in vivo. We hypothesized that some anti-idiotypic Abs function as divalent molecular mimics of soluble HLA alloantigen. To test this idea, we studied two well-defined anti-idiotypic mAbs, T10-505 and T10-938, elicited in syngeneic BALB/c mice by immunization with CRll-351, an HLA-A2,24,28-specific mAb. Each anti-Id induced "Ab-3" Abs in rabbits that cross-reacted with HLA-A2 but not with HLA-B Ags. Furthermore, each anti-Id could bind to and block Ag recognition by Ha5C2.A2, a human homologue of mAb CRll-351. Both anti-Id mAb displayed weak reactivity with the human mAb SN66E3, which recognized an overlapping but distinct determinant of HLA-A2 Ags; neither reacted with human mAb MBW1, which recognized a nonoverlapping HLA-A2 determinant. Amino acid sequence comparison of mAb CRII-351 heavy and light chain variable region complementarity-determining regions (CDRs) with those of mAb Ha5C2.A2 and SN66E3 revealed short regions of homology with both human mAb; a large insert in the light chain CDR1 of mAb SN66E3 distinguished it from both CRll-351 and Ha5C2.A2. The amino acid sequences of mAb T10-505 and T10-938, which differed markedly from each other, revealed no homology to the alpha2 domain sequence of HLA-A*0201 that contains the CRll-351 mAb-defined epitope. We conclude that structurally different anti-Id Abs can mimic a polymorphic conformational epitope of an HLA Ag. In the case of T10-505 and T10-938 mimicry was not based on exact replication of the epitope by the hypervariable loops of the anti-Id mAb.     

Active immunotherapy with ultraviolet B-irradiated autologous whole melanoma cells plus DETOX in patients with metastatic melanoma

Advances in transdermal therapeutic systems (TTS) and the technology involved have been rapid because of the sophistications of physiology and biology on skin, enhancing methodology for the skin penetration of drugs, and material and polymer sciences on the pharmaceutical additives. In this review paper, such progress was introduced and the future on the TTS was augured.     

Enhancement of cell-mediated immunity in melanoma patients immunized with murine anti-idiotypic monoclonal antibodies (MELIMMUNE) that mimic the high molecular weight proteoglycan antigen

The purpose of this study was to determine whether a combination of two anti-idiotypic antibodies that mimic the high molecular weight proteoglycan antigen found on most melanoma tumors was capable of enhancing cellular immunity in vaccinated high-risk patients with melanoma. Twenty-eight stage I-IV high-risk patients with melanoma were immunized with a mixture of variable concentrations of MELIMMUNE-1 and MELIMMUNE-2, along with the adjuvant SAF-m, using two immunization schedules. Peripheral blood mononuclear cells were collected before the first immunization and 4 weeks after the final immunization and tested for in vitro proliferation to MELIMMUNE-1 and MELIMMUNE-2 and for cytotoxicity against 51Cr-labeled target cell lines. Additionally, supernatants from in vitro proliferation cultures were tested for interleukin 10 and IFN-gamma levels. Significant in vitro proliferation to MELIMMUNE-1 and MELIMMUNE-2 were observed in postimmunization samples but not in prevaccination samples. The mean stimulation index for MELIMMUNE-2 (33.7 +/- 0.6) was significantly higher than that for MELIMMUNE-1 (13.9 +/- 0.3; P < 0.025). Supernatants obtained from 78% of the in vitro stimulated cultures pre- or postvaccination contained significant levels of interleukin 10 (range, 0.43-142 pg/ml), whereas IFN-gamma levels were elevated in 53% of postvaccination samples (range, 3-245 pg/ml) but not prevaccination samples. More importantly, we were able to generate specific CTL responses in 43% of the patients, which correlated with elevated IFN-gamma levels. These results indicate that MELIMMUNE enhances cell-mediated immunity in patients with melanoma.     

Perspective on allogeneic melanoma lysates in active specific immunotherapy

PURPOSE: To compare calcium ionophore-induced cataract formation and in vitro light scattering in cultured lenses from guinea pig and rabbit. METHODS: Lenses from guinea pig and rabbit were cultured for 5 or 6 days with calcium ionophore A23187. To assess the involvement of calpain in cataract formation; SDS-PAGE, immunoblotting and calcium determinations were performed. For in vitro light scattering, lens soluble proteins from rabbit were hydrolyzed for 24 h by either endogenous lens calpain, or by addition of purified m-calpain and then further incubated for up to 10 days. Light scattering was measured daily at 405 nm. RESULTS: Lenses from younger guinea pigs cultured in A23187 first developed outer cortical opacities followed by nuclear cataract. Total calcium was markedly increased by A23187 in lenses of all ages. Proteolysis of crystallins and alpha-spectrin were observed in nuclear cataract in younger guinea pigs. This was attenuated with age, in association with the attenuation of cataract formation with age. Calpain 80 kDa subunit in the lenses cultured with A23187 was also decreased. Co-culture with SJA6017 or E64d (reversible and irreversible inhibitors of calpain, respectively) reduced A23187-induced nuclear opacities, proteolysis of crystallins and alpha-spectrin, and loss of calpain without affecting increased total calcium. In contrast, rabbit lenses cultured in A23187 did not develop nuclear cataract, although biochemical changes in cultured rabbit lenses were similar to those in cultured guinea pig lenses. Furthermore, no appreciable in vitro light scattering occurred in soluble proteins from rabbit lenses after activation of endogenous m-calpain, or after addition of exogenous purified m-calpain, although crystallins were partially hydrolyzed by calpain. CONCLUSIONS: Both rabbit and guinea pig lenses undergo calpain-induced proteolysis upon elevation of lenticular calcium. However, factors in intact guinea pig lenses may promote light scattering and insolubilization after proteolysis by calpain, but these factors were not functional in rabbit lenses. Discovery of the factors promoting light scatter and insolubilization after proteolysis will help to explain the role of certain crystallin polypeptides in cataract formation.     

Neurite outgrowth is enhanced by anti-idiotypic monoclonal antibodies to the ganglioside GM1

Exogenously added gangliosides enhance sprouting, neurite outgrowth, and other neuronal activities; this effect may be initiated when a ganglioside binds to a membrane protein or when a ganglioside intercalates into the plasma membrane. To test whether binding to membrane proteins is sufficient for ganglioside-mediated activity, anti-idiotypic antibodies were generated that mimic the functional binding sites of the ganglioside GM1 as described by M. J. Riggott and W. D. Matthew (1996, Glycobiology, 6, 581-589). These anti-idiotypic antibodies are proteinaceous probes that model the biochemical and biological effects of gangliosides. Those anti-idiotypic ganglioside (AIG) monoclonal antibodies (mAb's) were selected based on their ability to bind a known GM1 binding protein, the beta-subunit of cholera toxin. These studies described neuronal cell surface proteins that were identified by immunocytochemistry and Western blotting using these AIG mAb's. Here we show that AIG mAb's mimic the functional properties of GM1 in that they facilitate neurite outgrowth from central and peripheral nervous system neurons in in vitro bioassays. In addition, AIG mAb binding modulates second messenger activity, suggesting that membrane protein binding alone is sufficient to invoke intracellular activation. The similarity in the pattern of protein tyrosine phosphorylation evoked by GM1 and the anti-idiotypic ganglioside antibodies suggests that the AIG mAb's modulate neurite outgrowth in a manner similar to that of GM1. Because antibodies cannot intercalate into the plasma membrane, these results suggest that the ganglioside GM1 can mediate neuronal cellular activity by binding to cell surface proteins.     

Detection by a solid phase independent enzyme immunoassay of monoclonal anti-idiotypic antibodies against monoclonal antibodies neutralizing Semliki Forest virus and encephalomyocarditis virus

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (EC 1.1.1.34) is the rate limiting step in the mevalonate pathway that produces isoprenoids and cholesterol. Inhibitors of HMG-CoA reductase are teratogenic in vivo and induce neural tube defects in rat embryo culture, effects which appear unrelated to cholesterol deficiency. This study is the first to localize HMG-CoA reductase mRNA by in situ hybridization (ISH). Expression of reductase mRNA was examined in post-implantation rat embryos, and for control purposes in rat liver and UT-1 cells, using a digoxigenin-11 (dig-11) labelled cRNA probe. Eighteen-day fetal liver showed heavy but patchy hybridization, and adult rat liver showed strong hybridization only on some periportal hepatocytes, which was absent in livers of fasted animals. UT-1 cells stimulated to overexpress HMG-CoA reductase mRNA were strongly positive with the same probe. Control hybridizations with sense strand RNA probe, or with cRNA probe on pre-RNased tissue were negative. Strong hybridization signal for HMG-CoA reductase mRNA was observed in all tissues of the post-implantation rat embryo, from egg cylinder to 30 somite stages (7 to 12 days). Heavy signal was noted in primitive ectoderm and neural tube. The wide embryonic and extraembryonic distribution and abundance of HMG-CoA reductase mRNA may reflect developmental requirements for products of the mevalonate pathway, e.g., isoprenoids for post-translational farnesylation of p21ras.     

Production of type II collagen specific monoclonal antibodies

Immunoassays are used for the specific measurement of type II collagen, a major cartilage protein, which is lost in osteoarthritic joints. Poor immunogenicity and species dependent immune response to type II collagen make it difficult to obtain specific antibodies required for immunoassay development. In addition, type II collagen antibodies exhibit reactivity to structurally dissimilar antigens such as actin, myoglobin, thyroglobulin and ssDNA, complicating the isolation of specific antibodies. It is therefore necessary to characterize the antibody reactivity against both noncollagenous antigens and different collagen types. In this study, immune response to type II collagen was improved by conjugation to carrier proteins, KLH and BSA. Hybridomas were generated by fusions of lymphocytes derived from lymph nodes or spleens with X63-653-Ag8 myeloma cells. Compared to spleens, the utilization of lymph nodes as a source of lymphocytes resulted in a 23% higher number of hybridomas secreting type II collagen antibodies. Hybridomas secreting polyreactive antibodies were identified based on their reactivity to thyroglobulin and eliminated. Extensive testing of the remaining monoclonal antibodies with other structurally dissimilar antigens and various types of collagen for reactivity, allowed us to isolate specific monoclonal antibodies to type II collagen. We emphasize the importance of characterization of the reactivity of type II collagen monoclonal antibodies before employing them for immunoassays.     

Human high molecular weight-melanoma associated antigen mimicry by mouse anti-idiotypic monoclonal antibody MK2-23: modulation of the immunogenicity in patients with malignant melanoma

The mouse anti-idiotypic (anti-id) mAb MK2-23 bears the mirror image of the antigenic determinant defined by antihuman high molecular weight-melanoma associated antigen (HMW-MAA) mAb 763.74. The purpose of this study was to evaluate the effect of conjugation to a carrier and administration with an adjuvant and cyclophosphamide (CTX) on the immunogenicity of anti-id mAb MK2-23 in patients with malignant melanoma and to analyze the relationship between development of humoral immunity and survival time of patients. Fifty-eight patients were sequentially entered into four immunization protocols which included administration of mAb MK2-23, mAb MK2-23 conjugated to keyhole limpet hemocyanin (KLH) and mixed with Bacillus Calmette-Guérin (BCG), mAb MK2-23 and CTX, and mAb MK2-23 conjugated to KLH and mixed with BCG and CTX. Six patients could not be evaluated since they withdrew from the clinical trial after the first immunization. Sera were tested for the development of anti-anti-id antibodies, including those reacting with HMW-MAA. Testing of sera for development of antimouse Ig antibodies was used to monitor the immune competence of patients. Conjugation to KLH and administration with BCG markedly enhanced the ability of mAb MK2-23 to induce anti-anti-id antibodies, including those reacting with HMW-MAA. In contrast, pretreatment with CTX had no detectable effect on the ability of mAb MK2-23 to elicit a humoral anti-anti-id response. Kaplan-Meier survival analysis showed that the performance status of patients, anti-anti-id antibody level, and development of anti-HMW-MAA antibodies had an effect on survival time. This effect was found when the survival time was calculated both from the day of the first immunization and from 4 weeks after the first immunization to the end of the study. A multivariate analysis by Cox regression showed that the development of anti-HMW-MAA antibodies was the most important variable for predicting survival, and that performance status was the only variable that significantly added to the prediction of survival. These data have to be interpreted with caution because of the retrospective nature of the analysis. Nevertheless, the present study suggests that mAb MK2-23 represents a useful immunogen to implement active, specific immunotherapy in patients with malignant melanoma.     

Serological and molecular characterization of mouse anti-idiotypic monoclonal antibodies elicited with the syngeneic anti-HLA-A2,28 monoclonal antibody CR11-351

The molecular basis of the differential specificity of seven mouse anti-id mAb elicited with the syngeneic anti-HLA-A2,28 mAb CR11-351 was analyzed by comparing their specificity with their heavy and light chain variable region sequences. Of the six mAb recognizing idiotopes within the antigen combining site of mAb CR11-351, mAb T10-352, T10-440 and T10-505 recognize the same (or spatially close) idiotope(s) since they cross-inhibit each other in their binding to mAb CR11-351 and elicit syngeneic anti-anti-id antibodies with similar specificity. On the other hand, mAb T10-421, T10-649 and T10-938 appear to recognize spatially close but distinct idiotopes since they cross-inhibit each other, but elicit anti-anti-id antibodies which inhibit only the binding of the respective immunizing anti-id mAb to mAb CR11-351. mAb T8-203 is the only anti-id mAb which recognizes an idiotope outside the antigen combining site of mAb CR11-351 since it does not inhibit the binding of the latter to target cells and binds to mAb CR11-351 coated B lymphoid cells. In addition, mAb T8-203 defines an idiotope which is shared by seven anti-HLA mAb, while the remaining six anti-id mAb recognize idiotopes which are not detectable on the panel of anti-HLA mAb. mAb T10-352, T10-440 and T10-505 are highly homologous in their VH and VL regions and in their V(D)J junctions suggesting that they may be clonally related. On the other hand, mAb T8-203, T10-649 and T10-938 share some degree of homology in their VH region as all of them use J558 VH genes but differ considerably in their VL regions. Finally, mAb T10-421 is the most unrelated mAb as it utilizes VH, D, JH, VK and JK gene segments different from those of all the other anti-id mAb. These findings indicate that in the HLA-A antigenic system defined by mAb CR11-351 the main mechanism underlying the differential target specificity of syngeneic anti-id mAb is the combinatorial diversity together with the differential pairing of heavy and light chains.     

Apoptosis of malignant human B cells by ligation of CD20 with monoclonal antibodies

CD20 is a nonglycosylated 33 to 37 kD phosphoprotein involved in B-cell signaling that subserves important functions in the regulation of B-cell proliferation and differentiation. In addition, this B-cell surface antigen has been shown recently to be an effective target for immunotherapy of B-cell malignancies using chimeric (mouse/human) or radiolabeled murine monoclonal anti-CD20 antibodies. In this report we show that extensive crosslinking of CD20 with murine anti-CD20 monoclonal antibodies (MoAbs) in the presence of either goat anti-mouse IgG or Fc receptor (FcR)-expressing cells directly inhibits B-cell proliferation, induces nuclear DNA fragmentation, and leads to cell death by apoptosis. The apoptotic effects of these MoAbs can be inhibited by chelation of extracellular or intracellular Ca2+ by EGTA or Bapta AM, indicating that anti-CD20-mediated apoptosis may be related to changes in Ca2+ concentration. These findings suggest that ligation of CD20 in vivo by anti-CD20 antibodies in the presence of FcR-expressing cells may initiate signal transduction events that induce elevation of [Ca2+]i and lead to apoptosis of malignant B cells, thereby contributing to the impressive tumor regressions observed in mouse models and clinical trials using anti-CD20 MoAbs.     

Suppression of the benzylpenicilloyl- (BPO) specific IgE formation with isologous anti-idiotypic antibodies in BALB/c mice

In vivo effects of actively produced or passively administered isologous anti-idiotypic antisera (aId) on the benzylpenicilloyl- (BPO) specific IgE and IgG formation in BALB/c mice have been studied. Isologous anti-BPO aId were raised in BALB/c mice by immunization with purified anti-BPO antibodies isolated from ascites induced with BPO-bovine gamma-globulin in the same mouse strain. Mice producing isologous anti-BPO aId exhibited long-term suppression of BPO-specific IgE and IgG antibody responses induced by BPO-ovalbumin (BPO-OVA) in aluminum hydroxide. Simultaneously, they produced increased amounts of anti-BPO aId after each challenge with the BPO-OVA antigens. Passive administration of isologous anti-BPO aId into syngeneic mice previously sensitized with BPO-OVA caused depression of BPO-specific IgE antibody levels for 2 to 3 weeks. When anti-BPO IgE had again reached its previous level, passively administered aId had decreased to the level of untreated mice. Passive administration of anti-BPO aId also depressed the primary anti-BPO IgE formation for 2 to 3 weeks. In all these experiments the IgE antibody formation against the carrier proteins used for BPO-antigens was not affected. These results show that IgE and IgG antibodies share major idiotypic determinants and that IgE production is accessible to regulation by aId.     

Production and characterisation of monoclonal antibodies specific for bovine interleukin-4

This study assessed physical activity patterns in a sample of urban African Americans, whose participation in physical activity has not previously been well-described. From questions administered by interviewers during health fair screenings in 19 churches in East Baltimore, information regarding participation in regular, leisure-time activity (defined as 30 minutes of activity, 5 days per week), time spent walking on the job, and distance walked to and from work was assessed from 365 adults (69% women). Regular, leisure-time activity participation was 18% for men and 16% for women. When the definition of physical activity participation was broadened to include: (1) spending over half the day walking at work; (2) walking at least 10 blocks to and from work; as well as (3) regular, leisure-time activity, 41% of men and 38% of women were active. These data suggest that, while a small percentage of African Americans participate in regular physical activity, a substantial percentage are regularly active when non-leisure-time activity is assessed. To accurately characterize overall participation, physical activity derived from a variety of sources, including transportation and work-related activity, should be assessed.     

Production of monoclonal antibodies specific to Clostridium botulinum type B neurotoxin

Four monoclonal antibodies were produced for use in a rapid method to detect Clostridium botulinum type B neurotoxin. Cells of mouse myeloma cell line SP2/0 were fused with splenocytes of immunized BALB/c mice. An immunoblot assay of semipurified commercial neurotoxins of C. botulinum types A, B, C, D, E, and F was used to show specificity. All the monoclonal antibodies reacted with type B neurotoxin but did not cross-react with the other types. The monoclonal antibodies, separately and combined, did not neutralize the toxin in mice, and all showed specificity to the whole neurotoxin molecule and the heavy-chain component by immunoblot. No evidence of specific binding to the hemagglutinin molecule was noted. When tested against concentrated cultured supernatants of C. botulinum types A, B, E, and F, the 4 monoclonal antibodies reacted only against type B strains. They will be incorporated into a rapid assay with other specific monoclonal antibodies to detect C. botulinum neurotoxins from pure cultures or suspect foods.     

Production and characterization of monoclonal antibodies specific for Shewanella colwelliana exopolysaccharide

Six monoclonal antibodies were produced to whole cells of Shewanella colwelliana (Aco1 to Aco6) and two (Aco22 to Aco23) to purified exopolysaccharide (EPS). Aco1, -4 to -6, -22, and -23 bound to both the cell surface and the purified EPS, while Aco2 and -3 bound to cells only. The EPS of S. colwelliana was antigenically unique from those of nine other species of marine bacteria that were tested. Mapping studies revealed that all of the EPS-specific monoclonal antibodies bound to the same epitope. This EPS epitope was sensitive to cleavage of ester bonds, but neither pyruvate, acetate, nor terminal nonreducing sugars were required for antigenicity. When S. colwelliana was grown on rich media, most of its EPS was loosely associated with the cell surface.     

Preparation of monoclonal mouse antibodies against two specific eu-melanin related compounds

Two eu-melanin precursors, 6-hydroxy-5-methoxyindole-2-carboxylic acid (HMI2C) and 5,6-dihydroxyindole-2-carboxylic acid (DHI2C) were synthesized and coupled to bovine serum albumin, hemocyanin and polylysine by the combined action of carbodiimide and succinimide. These indole-carrier conjugates served as antigens for the production of specific antibodies against DHI2C and HMI2C in BALB/c mice. The specificity of these antibodies was tested using a combination of affinity chromatography and ELISA procedures. Polyclonal mouse antibodies reacted with the indole-carrier conjugates, but not with the unbound indole compounds. Monoclonal antibodies from two hybridoma cell lines were obtained from a HMI2C-immunized mouse after a fusion with four subclonings. They reacted with free HMI2C and to a lesser extent with unbound DHI2C. One monoclonal showed 50% inhibition in the ELISA test at concentrations of 0.6 mumol.l-1 and 5 mumol.l-1 for HMI2C and DHI2C, respectively. These antibodies did not show any cross-reactivity with nine structurally related compounds and should be valuable reagents for the detection and quantification of HMI2C and other eu-melanin related compounds.     

Anti-idiotype monoclonal antibodies specific for the MOPC167 anti-phosphocholine transgene-encoded antibody

Four rat x mouse hybridomas secreting monoclonal anti-idiotypic (anti-Id) antibodies (MAb) specific for the transgene-encoded antibody of the 207-4 transgenic mouse line, which carries the VH1/V kappa 24 gene segments of the IgA, phosphocholine-(PC) specific MOPC167 myeloma, were developed from a fusion of Ag8-X63.653 mouse cells with spleen cells from a rat immunized with MOPC167 and HPCM27 anti-PC antibodies. The anti-Id MAb were shown by ELISA to be specific for PC-binding proteins of VH1/V kappa 24 H and L chains of various isotypes. They did not bind VH1/V kappa 22, VH1/V kappa 8, or VH1/V kappa 1 PC-binding proteins or other IgA or IgM myeloma proteins. Analysis by flow cytometry demonstrated that these MAb bind to the transgene-encoded membrane immunoglobulin (sIgM) as expressed on > 95% of the B220 positive 207-4 spleen cells. All four MAb were able to inhibit the binding of MOPC167 to PC conjugated to bovine serum albumin. Differences in fine specificity of binding were demonstrated by differential staining of spleen cells of the 216-7 mu kappa delta Mem MOPC167 transgenic mice. In these mice endogenous H chains associate with the transgene encoded L chain to form MOPC167 crossreactive idiotopes. Two of the MAb, 28-4-3 and 28-6-20, stained significant numbers of cells, while MAb 28-5-15 did not bind to 216-7 cells. Three of the MAb, 28-5-15, 28-6-20, and 28-4-3, when conjugated to Sepharose beads, were able to induce DNA synthesis in cultures of 207-4 transgenic spleen cells. None of the MAb were able to induce an antibody response in vivo. These MAb should prove useful in staining PC-transgenic B cells for flow cytometry studies and in defining early cellular events in the activation of idiotype positive B cells by anti-Id antibodies.     

Characterization of two distinct monoclonal antibodies specific for glial cell line-derived neurotrophic factor

The kinesin-related motor protein CHO1/MKLP1 was initially thought to be expressed only in mitotic cells, where it presumably transports oppositely oriented microtubules relative to one another in the spindle mid-zone. We have recently shown that CHO1/MKLP1 is also expressed in cultured neuronal cells, where it is enriched in developing dendrites [Sharp et al. (1997a) J. Cell Biol., 138, 833-843]. The putative function of CHO1/MKLP1 in these postmitotic cells is to intercalate minus-end-distal microtubules among oppositely oriented microtubules within developing dendrites, thereby establishing their non-uniform microtubule polarity pattern. Here we used in situ hybridization to determine whether CHO1/MKLP1 is expressed in a variety of rodent neurons both in vivo and in vitro. These analyses revealed that CHO1/MKLP1 is expressed within various neuronal populations of the brain including those in the cerebral cortex, hippocampus, olfactory bulb and cerebellum. The messenger ribonucleic acid (mRNA) levels are high within these neurons well after the completion of their terminal mitotic division and throughout the development of their dendrites. After this, the levels decrease and are relatively low within the adult brain. Parallel analyses on developing hippocampal neurons in culture indicate that the levels of expression increase dramatically just prior to dendritic development, and then decrease somewhat after the dendrites have differentiated. Dorsal root ganglion neurons, which generate axons but not dendrites, express significantly lower levels of mRNA for CHO1/MKLP1 than hippocampal or sympathetic neurons. These results are consistent with the proposed role of CHO1/MKLP1 in establishing the dendritic microtubule array.     

Treatment of colorectal cancer with monoclonal antibodies

This article reviews the treatment of colorectal carcinoma with monoclonal antibodies. Since the late seventies, several hundred patients with advanced disease have been treated with unconjugated antibodies, especially Mab 17-1A. The response rate of the studies has been less than 10%. In contrast, Mab given as adjuvant treatment for Duke's C colorectal carcinoma increased the five year survival with 30%. The actions of different types of immunoconjugates are reviewed.