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J E Coligan

Publications and source records attributed to J E Coligan.

At least 73 records · Page 4Linked to original sources
PubMed1994

Identification of the disease-related T cell epitope of ovalbumin and epitope-targeted T cell inactivation in egg allergy.

An ovalbumin (OVA)-specific T cell line (TCL) was established from a patient with hen egg allergy. The TCL was CD4+, expressed alpha beta T cell receptor, and recognized OVA presented by HLA-DR10. Based on the response of the TCL to synthetic OVA peptides, it was found that the TCL recognized OVA 323-339, which is a major T cell epitope presented by murine I-Ad. The TCL secreted high levels of IL-5, but undetectable amounts of IL-2, interferon-gamma, and IL-4 when stimulated with OVA or the OVA 323-339 peptide. Since IL-5 is an important growth and chemotactic factor for eosinophils, it is possible that these OVA 323-339-specific T cells can contribute to human egg allergy. To our knowledge, this is the first demonstration of food allergen-specific TCL establishment and identification of a T cell epitope possibly related to the allergic reaction to food antigens. An analog peptide of the OVA 323-339 which is known to strongly bind to I-Ad partially inhibited the response of the TCL to OVA 323-339 presented by HLA-DR10, raising the possibility of peptide-based immunotherapy of food allergy.

Amino Acid Sequence↗
PubMed1993

HLA-A1 and HLA-A3 T cell epitopes derived from influenza virus proteins predicted from peptide binding motifs.

The potential value of peptide binding motifs of HLA class I molecules for the prediction of viral epitopes presented to T cells has been analyzed for two common HLA alleles. CTL generated against type A influenza virus recognize peptide epitopes derived from the nucleoprotein (NP) and basic polymerase 1 presented by HLA-A1, and epitopes derived from NP presented by HLA-A3. Distinct peptide binding motifs with characteristic anchor residues were previously identified for each of these class I molecules based on the sequences of endogenous peptides: for HLA-A1, position 3 = Asp or Glu and position 9 = Tyr; for HLA-A3, position 2 = Leu and position 9 = Lys or Tyr. Six peptides containing the HLA-A1 binding motif were identified within the sequences of the NP and basic polymerase 1 proteins, and one peptide containing the HLA-A3 motif was identified in the NP molecule. Three of the six HLA-A1 peptides and the one HLA-A3 NP peptide could bind to HLA-A1 or HLA-A3, respectively, in an in vitro peptide binding assay. Two of the HLA-A1-binding peptides could sensitize target cells for lysis by influenza virus-immune CTL populations restricted by HLA-A1 (NP 44-52 CTELKLSDY and PB1 591-599 VSDGGPNLY), and the one HLA-A3 NP peptide (NP 265-273 ILRGSVAHK) could sensitize target cells for lysis by HLA-A3-restricted influenza-immune CTL. Each peptide was also shown to be able to induce peptide-specific class I-restricted CTL in vitro, and the CTL generated against two of these peptides could specifically recognize virus-infected targets. Thus, these peptide binding motifs can be used to construct immunogenic synthetic epitopes which are capable of inducing antiviral T cell-mediated immune responses.

Amino Acid Sequence↗
PubMed1993

Expression of merosin in the thymus and its interaction with thymocytes.

Merosin is a 700 kDa multichain protein that has several properties in common with laminin, one of the major extracellular matrix proteins present in basement membranes. Both contain B1 and B2 light chains, but merosin has a distinct M-chain compared with the laminin A-chain. Merosin is present in the basement membrane of placenta, striated muscle, and peripheral nerve. Using the RT-PCR assay, we demonstrate that merosin, but not laminin, is also expressed in the thymus. A partial cDNA sequence of the mouse merosin M-chain was 88% identical to the human M-chain, and the deduced amino acid sequences were 95% identical. 18-24% of adult mouse thymocytes bound to human merosin in vitro. Mg2+, but not Ca2+, was essential for binding. Binding was inhibited by antibodies recognizing VLA alpha 6 or beta 1, suggesting that the VLA-6 integrin is a merosin receptor. An anti-beta 4 integrin subunit mAb failed to inhibit binding, suggesting that the alpha 6 beta 4 integrin was not involved. Thymocytes were fractionated into immature and mature populations based on their expression of the heat stable antigen, recognized by the J11d mAb. Virtually all thymocytes expressed VLA-6, but only immature thymocytes (J11d+) bound to meroson. PMA treatment did not significantly increase the binding of J11d+ thymocytes nor did induce binding in the mature J11d- population. In constrast, both splenic T cells and unseparated lymph node cells showed enhanced binding to merosin after PMA stimulation. The expression of merosin in the thymus and its selective interaction with immature thymocytes suggest that thymocyte-merosin interactions may play a role in T cell development.

Amino Acid Sequence↗
PubMed1993

Role of the Q10 class I regulatory element region 1 in controlling tissue-specific expression in vivo.

The MHC class I regulatory element (CRE) region 1 has been previously described as a positive cis-acting regulatory element essential for class I gene expression. We have generated transgenic mice (CBA x C57BL/6) with the MHC class I gene H-2Dd driven by two different 400-bp promoter regions of Q10, a nonpolymorphic MHC class I gene expressed in the liver, kidney, and fetal yolk sac. One transgene contained the wild-type Q10 promoter (Q10WT/Dd). The second construct (Q10M3/Dd) had 2 bp substitutions introduced in region 1 of the CRE that reconstituted the CRE inverted repeat present in classical class I genes. Mice containing the wild-type Q10/Dd gene expressed membrane-bound H-2Dd molecules in a tissue-restricted expression pattern similar to that observed for endogenous Q10. In mice containing the mutant construct (Q10M3/Dd), H-2Dd was also expressed in the thymus, a tissue not normally associated with Q10 expression but, surprisingly, the Dd was not expressed in other lymphoid tissues. Furthermore, thymic expression was greatest on double positive (CD4+ CD8+) thymocytes. Thymic Dd expression was correlated with the presence of what appears to be a previously unidentified transcription factor in thymocytes that is capable of interacting with the CRE-inverted repeat. These results show that the mutations in region 1 altered the tissue-specific regulation of the Q10 promoter in vivo, although an intact inverted repeat did not restore the ubiquitous pattern of expression characteristic of classical class I genes. Thus, these results indicate that elements in addition to CRE region 1 in the Q10 promoter region serve to limit ubiquitous tissue expression.

Animals↗
PubMed1993

Potent stimulation of monocytic endothelin-1 production by HIV-1 glycoprotein 120.

Monocytes/macrophages play a critical role in the pathogenesis of HIV infection, both as targets for virus replication and as sources of production of multifunctional cytokines. Endothelins, peptides with potent vasoconstricting activities originally isolated from endothelial cells, are also produced and secreted by macrophages in a manner similar to that of other cytokines. In an attempt to explore the potential role of endothelins in HIV-infection, we investigated the effect of the HIV-1 envelope glycoprotein, glycoprotein 120, on monocytic endothelin-1 production. This glycoprotein has been identified as a potent stimulator of monokines such as TNF-alpha and IL-6, which have been implicated as potential mediators of HIV-encephalopathy. We found that glycoprotein 120, similar to LPS, stimulates the secretion of endothelin-1, as well as TNF-alpha, from macrophages in a concentration-dependent manner. Using reverse transcriptase polymerase chain reaction, we found that circulating monocytes in HIV-infected individuals show a distinct expression of the endothelin-1 gene that is not detectable in healthy controls, indicating chronic activation of this gene in HIV-infection. In addition, cerebral macrophages in patients with HIV-encephalopathy were strongly positive for endothelin. Thus, monocytic endothelins appear to be stimulated during HIV infection. Their potent vasoactive properties render them potential candidates for mediating alterations in the cerebral perfusion pattern associated with the AIDS dementia complex.

AIDS Dementia Complex↗
PubMed1993

Endogenous peptides bound to HLA-A3 possess a specific combination of anchor residues that permit identification of potential antigenic peptides.

A motif specific to peptides that bind to the human class I major histocompatibility complex molecule HLA-A3 was identified by sequence analysis of HPLC fractions containing endogenous peptides. Twenty-six different sequences were obtained, 19 of which were nonamers. The majority of these endogenous peptide sequences contained Leu at position (P)2, while most sequences contained Tyr or Lys at P9. In addition, Phe was shared by 16 sequences at P3. Synthetic peptides corresponding to endogenous peptide sequences were shown to bind to HLA-A3. The importance of Leu at P2 and Tyr or Lys at P9 ("anchor" residues) for peptide binding to HLA-A3 was demonstrated by the following results: (i) peptides GLFGGGGGY, GLFGGGGGK, and GLGGGGFGY, but not GLFGGGGGV, specifically bound to HLA-A3 and (ii) six nonapeptides from within the influenza A nucleoprotein, matrix, and polymerase proteins, selected for synthesis based upon their possession of P2 and P9 anchor residues, were shown to bind HLA-A3. In contrast, none of a set of eight peptides that bound to HLA-A2, or six that bound to HLA-B27, bound detectably to HLA-A3. These findings provide a rationale for the design and selection of peptides that can be recognized by HLA-A3-restricted T cells.

Amino Acid Sequence↗
PubMed1993

Multiple changes in VLA protein glycosylation, expression, and function occur during mouse T cell ontogeny.

VLA molecules (beta 1 integrins) are cell-surface alpha beta heterodimers that bind to extracellular matrix (ECM) proteins such as fibronectin, laminin, and collagen. We analyzed the expression, structure, and function of VLAs on mouse thymocytes, as a first step toward understanding their role in T cell development. Two major forms of beta 1 were detected, which differed in their extent of N-glycosylation and sialylation. No evidence for alternative splicing of beta 1 mRNA was obtained by PCR analyses. The larger (135 kDa, nonreduced) more basic beta 1 was the only form on nonmature (J11d+) adult thymocytes, with 135 kDa and larger beta 1-chains expressed on fetal thymocytes from day 14 of gestation through birth. The smaller (120 kDa, nonreduced), more acidic beta-chain was found exclusively on mature (J11d-) thymocytes and peripheral lymphocytes. VLA alpha-chain expression was also analyzed. Virtually all thymocytes were VLA-alpha 4+, -alpha 6+. VLA-alpha 5 was detected in both J11d+ and J11d- thymocytes by immunoprecipitation, but could not be analyzed in detail because of the lack of an appropriate mAb for flow cytometry. VLA-alpha 1 and -alpha 2 were immunoprecipitated only from cells within the J11d- population. Only J11d+ thymocytes (12 to 15%) bound to fibronectin (via VLA-4 and VLA-5) and binding to laminin (via VLA-6) was two to fourfold higher in J11d+ compared with J11d- thymocytes (60 to 80% vs 20 to 30%). The high percentage of J11d+ thymocytes adhering to laminin suggests that VLA-6 exists in an activated state on most thymocytes, in contrast to resting peripheral T cells. These data show that major changes in VLA glycosylation, expression, and ECM-binding capacity occur as thymocytes mature, supporting the hypothesis that VLA-ECM interactions play a role in T cell ontogeny.

Animals↗
PubMed1993

Thrombin is a regulator of astrocytic endothelin-1.

Endothelin-1, a potent vasoconstrictor of cerebral vessels, is produced by rat primary astrocytes and is subject to autostimulatory regulation in these cells. In this study we examined the effect of thrombin on astrocytic endothelins and report that endothelin-1 is released into the culture fluid in response to thrombin treatment. However, increased production of endothelin-1 is not accompanied by a concomitant increase in steady-state levels of endothelin-1 mRNA as assessed by reverse transcriptase-polymerase chain reaction, even though thrombin stimulation leads to increased inositolphospholipid turnover and activation of the nuclear factor AP1. Thus, astrocytic production of endothelin-1 may be mainly post-transcriptionally regulated in response to thrombin stimulation. In addition, two endothelin receptor genes (ET(A) and ETB) were found to be transcribed simultaneously in primary astrocyte cultures, and both thrombin and endothelin-1 stimulation result in a distinct temporary decrease in ET(A) mRNA. These studies suggest a role for thrombin in the regulation of brain perfusion through astrocytic endothelin-1 expression.

Animals↗
PubMed1993

Multiple cis-acting elements are required for proper transcription of the mouse V delta 1 T cell receptor promoter.

To gain insight into the developmentally regulated expression of the mouse TCR V delta-gene segments, we have investigated the role of the 5' promoter region of the V delta 1-gene. Transient transfection assays showed that a construct encompassing 267 nucleotides upstream from the mapped transcriptional start site was capable of driving promoter activity when transfected into V delta 1+ T cells. The inclusion of an additional 459-bp 5' segment to this construct did not affect promoter activity. However, a deletion of 222 5' nucleotides from the same construct dramatically decreased promoter activity. In vivo genomic footprinting localized several protein-DNA interactions to the stretch of DNA shown to have transcriptional activity. A computer analysis revealed that the segments of DNA participating in these protein-DNA interactions were identical to the previously described cyclic AMP response element (CRE), E box, and leukemia virus E26 cis-acting elements. Transient transfection assays performed with -267 bp constructs containing mutations at each of the localized cis-acting elements revealed that the CRE, E box, and Ets elements work together in driving promoter activity and that the CRE and Ets elements are the most important for driving transcription. Gel mobility shift analyses showed that each of these cis-acting elements is capable of binding specific nuclear factors present in V delta 1-expressing cells. These data indicate that multiple transcription factors acting in concert are responsible for V delta 1 gene expression.

Animals↗
PubMed1993

Isotypic and IgG subclass restriction of the humoral immune responses to human T-lymphotropic virus type-I.

We have investigated the isotypic and IgG subclass profile of the antibody response to HTLV-I structural proteins (gag and env) in patients with HTLV-I-associated myelopathy (HAM; n = 20), adult T-cell leukemia (ATL; n = 15), and HTLV-I-positive asymptomatic carriers (ASY; n = 21). IgG, IgM, and IgA were the predominant antibody responses in all HTLV-I-infected individuals; minimal IgE response was detectable in the HAM and ATL groups. Among the IgG subclasses, IgG1 was the most predominant antibody detected in responses to HTLV-I antigens, followed by IgG3 and IgG2; IgG4 could not be detected in any patient group. Levels of both IgG1 and IgG3 were significantly higher in patients with HAM, when compared to ATL and ASY (P < 0.01 for both comparisons). In addition, Ig isotypes and IgG subclass antibody in patient sera reactive with purified viral proteins and several immunodominant epitopes, represented by synthetic peptides, Gag-1a102-117, Env-1(191-214), Env-5(242-257), and recombinant proteins, MTA-1(162-209) and r21e303-440, were examined to delineate specific epitopes responsible for inducing the host immune responses of each isotype and subclass to the structural proteins of HTLV-I. IgG, IgM, and IgA responses were directed against both the gag and env gene products. Among IgG subclasses, the IgG1 and IgG3 responses were directed against both the gag (p53, p24, p19, and Gag-1a) and env (recombinant MTA-1, r21e, and synthetic Env-1, Env-5) proteins; IgG2 responses were mainly restricted to gag proteins. The frequency profile of HTLV-I-specific antigen recognition in all four IgG subclasses were similar in all of the clinical groups. These results further define the fine specificity of anti-HTLV-I immune reaction for understanding the mechanism of pathogenesis in these individuals and suggest that factors other than the humoral immune responses may be associated with the clinical manifestation of the disease.

Amino Acid Sequence↗
PubMed1993

Identification and characterization of an extended Tax protein in human T-cell lymphotropic virus type II subtype b isolates.

The tax gene sequence of human T-cell lymphotropic virus type II isolate G12 (HTLV-IIG12) was found to encode an extended Tax protein when compared with that of HTLV-IIMoT. In vitro transcription-translation of the HTLV-IIG12 tax gene produced a 40-kDa Tax protein that specifically reacted with serum specimens from HTLV-II-infected individuals. Limited sequence analysis demonstrated that isolates with an extended Tax protein were all HTLV-II subtype b (HTLV-IIb). Therefore, the extended Tax protein appears to be a unique characteristic of most HTLV-IIb isolates and may be useful in designing immunoassays to distinguish between HTLV-IIa and HTLV-IIb.

Amino Acid Sequence↗
PubMed1993

[Analysis of ovalbumin-specific T cell lines established from patients with hen egg allergy].

Ten ovalbumin (OVA)-specific T cell lines (TCLs) were established from peripheral blood mononuclear cells of 6 patients with hen egg allergy, and the antigen recognition of these TCLs was characterized. Two OVA epitopes were determined by use of 3 synthetic OVA peptides which have been known as murine T cell epitopes. Blocking of antigen-specific T cell proliferation by anti-HLA class II monoclonal antibodies suggest that all 3 HLA class II molecules could act as restriction elements for T cell recognition of OVA. This is the first demonstration of OVA epitopes recognized by T cells in patients with hen egg allergy, as far as we know.

Cell Line↗
PubMed1992

Sequence motifs important for peptide binding to the human MHC class I molecule, HLA-A2.

Previous studies have indicated that most HLA-A2-binding peptides are 9 amino acid (aa) residues long, with a Leu at position 2 (P2), and a Val or Leu at P9. We compared the binding properties of different peptides by measuring the rate of dissociation of beta 2-microglobulin from peptide-specific HLA-A2 complexes. The simplest peptide that we identified that could form HLA-A2 complexes had the sequence (in single letter aa code) GLFGGGGGV, indicating that three nonglycine aa are sufficient for binding to HLA-A2. To determine whether most nonapeptides that contained Leu at P2 and Val or Leu at P9 could bind to HLA-A2, we tested the binding of nonapeptides selected from published HIV and melanoma protein sequences, and found that six of seven tested formed stable HLA-A2 complexes. We identified an optimal antigenic undecapeptide from the cytomegalovirus gB protein that could form stable HLA-A2 complexes that contained apparent anchor residues at P2 and P11 (sequence FIAGN-SAYEYV), indicating that the spacing between anchor residues can be somewhat variable. Finally, we tested the importance of every aa in the influenza A matrix peptide 58-66 (sequence GILGFVFTL) for binding to HLA-A2, by using Ala-substituted and Lys-substituted peptides. We found that multiple positions were important for stable binding, including P2, P3, P5-P7, and P9. We conclude that the P2 and P9 anchor residues are of prime importance for peptide binding to HLA-A2. However, other peptide side chains (especially at P3) contribute to the stability of the interaction. In certain cases, the optimal length for peptide binding can be longer than 9 residues.

Amino Acid Sequence↗
PubMed1992

The beta 2-microglobulin dissociation rate is an accurate measure of the stability of MHC class I heterotrimers and depends on which peptide is bound.

Stable, recombinant, water-soluble complexes of HLA-A2 and HLA-B27 were reconstituted from 125I-labeled beta 2-microglobulin (beta 2m), a synthetic peptide, and HLA H chain fragments expressed as inclusion bodies in the Escherichia coli cytoplasm. Using this system, we were able to show: 1) the t1/2 of beta 2m dissociation from HLA complexes at 37 degrees C varied from approximately 40 h to less than 1 h, depending on the peptide employed for reconstitution. Peptide length and composition were found to be critical factors in determining the beta 2m dissociation rate. Endogenous peptides form complexes that are about as stable as those formed with typical antigenic peptides. 2) Peptide exchange reactions, in which an exogenous peptide replaces the peptide that is already bound by the class I molecule, proceed readily for complexes that have rapid beta 2m dissociation rates. Thus, difficulties in demonstrating peptide binding to complexes that contain endogenous peptides can be attributed to the stability of the endogenous peptide/class I molecule complex. 3) The peptide exchange reaction does not require concomitant beta 2m dissociation. 4) Distal parts of the class I molecule, which are not directly involved in peptide binding or beta 2m binding, have a major impact on the stability of class I molecules. Thus, these studies show that the dissociation rate of beta 2m is an excellent measure of how tightly a given peptide binds to class I MHC molecules, that the ability to bind peptide is tightly coupled to the binding of beta 2m and vice versa, and that regions of the molecule distal from the binding site influence the stability of peptide binding.

Amino Acid Sequence↗
PubMed1992

Secretion of a soluble, chimeric gamma delta T-cell receptor-immunoglobulin heterodimer.

Soluble derivatives of T-cell antigen receptors (TCRs) should prove invaluable for studying the interaction of these receptors with antigens and major histocompatibility complex molecules, for structural studies, and for the identification of unknown ligands. We have engineered chimeric proteins, containing the extracellular domains of the mouse V gamma 1.1-C gamma 4 and V delta 6.2-C delta (V, variable; C, constant) TCR chains fused to the hinge region, CH2 (H, heavy), and CH3 domains of human IgG1 heavy chain, and expressed them by transient transfection in COS cells. We show here that TCR gamma-IgH and TCR delta-IgH chimeric chains are produced intracellularly in significant amounts, that the two chains can assemble correctly to form disulfide-linked, glycosylated heterodimers, and that a selective mechanism allows secretion of correctly paired receptor chains into the medium. Identity of the chimeric secreted TCR gamma delta-IgH heterodimer was confirmed by immunoblot analysis using V gamma 1-specific anti-peptide antiserum and immunoprecipitation analysis using the monoclonal antibody UC7, which is shown to be specific for the TCR delta chain. In addition, the soluble TCR gamma delta-IgH heterodimer can be immunoprecipitated with the anti-clonotypic monoclonal antibody F10/56, which suggests that the fusion protein likely has a structural conformation similar to that of the native TCR. The COS cell expression system may prove useful for the production of additional TCR-IgH fusion proteins.

Animals↗
PubMed1992

Developmentally regulated expression of the beta 4 integrin on immature mouse thymocytes.

Integrins are a superfamily of alpha beta heterodimers, most of which serve as cell surface receptors for extracellular matrix proteins. In this report, we demonstrate that the recently described alpha 6 beta 4 integrin, previously thought to be limited to epithelial cells and Schwann cells, is expressed on immature mouse thymocytes. The presence of alpha 6 beta 4 is controlled by regulation of beta 4 expression, because alpha 6 was expressed by virtually all cells examined, paired with the beta 1 integrin chain to form VLA-6. During fetal ontogeny, beta 4 was highly expressed by 35% of day-13 thymocytes, 75% of day-14 to -15 thymocytes, then rapidly declined to low levels by birth. In neonates and adults, beta 4 expression was highest on CD4- CD8- CD3- and TCR(+)-gamma delta subsets. Correlation of IL-2R, CD44 and beta 4 on CD4- CD8- thymocytes revealed maximal levels on the intermediate CD44- IL-2R+ subset. Most CD4- CD8+ TCR- thymocytes and a significant fraction of CD4+ CD8+ thymocytes were beta 4lo, whereas the most mature J11d- single positive thymocytes were beta-4. Overall, down-regulation of beta 4 was associated with up-regulation of CD4, CD8, and CD3 in the thymus. alpha 6 beta 4 was undetectable on fetal liver or bone marrow cells, lymphocytes from lymph node, spleen, or blood, and mitogen-activated splenic T cells cultured up to 10 wk with IL-2. The data suggest that alpha 6 beta 4 is up-regulated after pro-T cells enter the thymus and may have a thymus-specific function for T cells. The developmentally regulated pattern of expression and the prominence of alpha 6 beta 4 on day-13 to -16 fetal and adult CD4- CD8- CD3- thymocytes further suggest this unusual integrin may play a role in early T cell development, including stages before acquisition of the TCR.

Age Factors↗
PubMed1992

Failure to detect evidence of human T-lymphotropic virus (HTLV) type I and type II in blood donors with isolated gag antibodies to HTLV-I/II.

Of the 267,650 blood donations from members of the US armed forces, 72 (0.027%) were serologically confirmed to be positive for human T-lymphotropic virus type I/II (HTLVpos) and 379 (0.14%) were Western blot (WB)-indeterminate with banding pattern restricted to the proteins encoded by the gag gene only (HTLVind). To determine whether these apparently healthy HTLVind blood donors are infected with HTLV-I or HTLV-II, coded specimens from randomly selected military blood donors (n = 73) were tested for antibodies to HTLV by WB and radioimmunoprecipitation assay (RIPA) using HTLV-I (MT-2) antigens, by enzyme immunoassay using synthetic peptides representing the immunodominant epitopes of HTLV, and for sequences of proviral HTLV DNA by the polymerase chain reaction (PCR). Of the 73 HTLVind donors, none showed presence of env reactivity by HTLV WB and RIPA. Minimal reactivity was observed with synthetic immunodominant motifs derived from the env protein of HTLV-I (Env-1(191-214) and Env-5(242-257)) or HTLV-II (Env-2(187-209) and Env-20(85-102)) and gag protein (Gag-1a(102-117) and Gag-10(364-385)). A peptide corresponding to the endogenous retroviral sequence with structural homologies to the gag protein of HTLVs (RTVLgag) reacted with antibodies not only in HTLVpos (88%) and HTLVind (42% to 66%) specimens, but also reacted with normal control subjects (60%). Furthermore, none of the 73 HTLVind specimens demonstrated presence of the HTLV genome when amplified with primers for the pol and tax/rex region. Six to 23 months from the initial test, 27 subjects still gave indeterminate WB patterns, and 13 of these repeat specimens were still negative for the presence of HTLV genome. We conclude that individuals at low risk for HTLV infection who have HTLVind WB reactivity are rarely, if ever, infected with HTLV-I or HTLV-II.

Amino Acid Sequence↗