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Early HIV-1 envelope-specific cytotoxic T lymphocyte responses in vertically infected infants.

Pikora CA, Sullivan JL, Panicali D, Luzuriaga K - J. Exp. Med. (1997)

Bottom Line: CTLp recognizing HIV-1 IIIB and infant isolate env were detected by 6 mo of age in two infants.In a fourth infant, HIV-1 IIIB env and early isolate env-specific CTLp were simultaneously detected at 12 mo of age.These results provide evidence that young infants can generate HIV-1-specific CTL responses and provide support for the concept of neonatal vaccination to prevent HIV-1 transmission.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, University of Massachusetts Medical Center, Worcester 01605, USA.

ABSTRACT
High frequencies of cytotoxic T lymphocyte precursors (CTLp) recognizing HIV-1 laboratory strain gene products have been detected in adults within weeks of primary infection. In contrast, HIV-1-specific CTLp are uncommonly detected in infants younger than 6 mo. To address the hypothesis that the use of target cells expressing laboratory strain env gene products might limit the detection of HIV-1 env-specific CTLp in early infancy, recombinant vaccinia vectors (vv) expressing HIV-1 env genes from early isolates of four vertically infected infants were generated. The frequencies of CTLp recognizing target cells infected with vv-expressing env gene products from early isolates and HIV-1 IIIB were serially measured using limiting dilution followed by in vitro stimulation with mAb to CD3. In one infant, the detection of early isolate env-specific CTLp preceded the detection of IIIB-specific CTLp. CTLp recognizing HIV-1 IIIB and infant isolate env were detected by 6 mo of age in two infants. In a fourth infant, HIV-1 IIIB env and early isolate env-specific CTLp were simultaneously detected at 12 mo of age. These results provide evidence that young infants can generate HIV-1-specific CTL responses and provide support for the concept of neonatal vaccination to prevent HIV-1 transmission. However, the early predominance of type-specific CTL detected in some young infants suggests that the use of vaccines based on laboratory strains of HIV-1 may not protect against vertical infection.

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Heteroduplex analysis of homology between patient isolate  DNA and IIIB env sequences. Env fragments (946 bp in the V1-V3 regions) were PCR amplified from genomic DNA extracted from PBMC  infected with patient HIV-1 isolates or from a plasmid containing BH10  (IIIB) env (pAbT4603). The PCR product of pAbT44603 was internally  radiolabeled during the PCR and combined with the PCR products of  the proviral templates of the patient to form heteroduplexes as described  in Materials and Methods. Lanes 1–3 are clones of known sequence  probed with pAbT4603. Lane 1 is a PCR product of the NL 4-3 strain of  HIV-1, lane 2 is a PCR product of the MN strain of HIV-1 (prototypic  clade B strain of HIV-1), and lane 3 is a PCR product from an env clone  derived from patient VI-08 at 1 d of age (pJA-6-1D). Lanes 4–11 are  PCR products amplified from patient proviral DNA (VI-06-1D and VI-06;  VI-05; VI-05-6M; VI-08-20D and VI-08-6M; VI-11-1M and VI-11-3M;  Table 2). Lane 12 is a negative control of probe alone.
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Figure 1: Heteroduplex analysis of homology between patient isolate DNA and IIIB env sequences. Env fragments (946 bp in the V1-V3 regions) were PCR amplified from genomic DNA extracted from PBMC infected with patient HIV-1 isolates or from a plasmid containing BH10 (IIIB) env (pAbT4603). The PCR product of pAbT44603 was internally radiolabeled during the PCR and combined with the PCR products of the proviral templates of the patient to form heteroduplexes as described in Materials and Methods. Lanes 1–3 are clones of known sequence probed with pAbT4603. Lane 1 is a PCR product of the NL 4-3 strain of HIV-1, lane 2 is a PCR product of the MN strain of HIV-1 (prototypic clade B strain of HIV-1), and lane 3 is a PCR product from an env clone derived from patient VI-08 at 1 d of age (pJA-6-1D). Lanes 4–11 are PCR products amplified from patient proviral DNA (VI-06-1D and VI-06; VI-05; VI-05-6M; VI-08-20D and VI-08-6M; VI-11-1M and VI-11-3M; Table 2). Lane 12 is a negative control of probe alone.

Mentions: We began by examining the degree of diversity between infant isolate env and IIIB env. Examination of sequences through the V3 loops suggested relative homogeneity of first isolates (data not shown). Divergence in nucleotide sequence between HIV-1 IIIB and individual infant isolate env was then estimated using heteroduplex tracking assays and sequencing. Fig. 1 demonstrates that heteroduplexes formed by combining individual infant isolate and IIIB env migrate at rates between those of heteroduplexes formed by combining IIIB and MN env or IIIB and p08-6-20D (an env clone derived from the virus of patient VI-08). Sequence comparisons of a 946-bp region spanning V1 to V3 indicate that IIIB and MN env differ from each other by 8.3%, whereas IIIB and p08-6-20D differ by ∼10%. Therefore, the degree of heterogeneity between individual infant isolate and IIIB env sequences is between 8–10%.


Early HIV-1 envelope-specific cytotoxic T lymphocyte responses in vertically infected infants.

Pikora CA, Sullivan JL, Panicali D, Luzuriaga K - J. Exp. Med. (1997)

Heteroduplex analysis of homology between patient isolate  DNA and IIIB env sequences. Env fragments (946 bp in the V1-V3 regions) were PCR amplified from genomic DNA extracted from PBMC  infected with patient HIV-1 isolates or from a plasmid containing BH10  (IIIB) env (pAbT4603). The PCR product of pAbT44603 was internally  radiolabeled during the PCR and combined with the PCR products of  the proviral templates of the patient to form heteroduplexes as described  in Materials and Methods. Lanes 1–3 are clones of known sequence  probed with pAbT4603. Lane 1 is a PCR product of the NL 4-3 strain of  HIV-1, lane 2 is a PCR product of the MN strain of HIV-1 (prototypic  clade B strain of HIV-1), and lane 3 is a PCR product from an env clone  derived from patient VI-08 at 1 d of age (pJA-6-1D). Lanes 4–11 are  PCR products amplified from patient proviral DNA (VI-06-1D and VI-06;  VI-05; VI-05-6M; VI-08-20D and VI-08-6M; VI-11-1M and VI-11-3M;  Table 2). Lane 12 is a negative control of probe alone.
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Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196268&req=5

Figure 1: Heteroduplex analysis of homology between patient isolate DNA and IIIB env sequences. Env fragments (946 bp in the V1-V3 regions) were PCR amplified from genomic DNA extracted from PBMC infected with patient HIV-1 isolates or from a plasmid containing BH10 (IIIB) env (pAbT4603). The PCR product of pAbT44603 was internally radiolabeled during the PCR and combined with the PCR products of the proviral templates of the patient to form heteroduplexes as described in Materials and Methods. Lanes 1–3 are clones of known sequence probed with pAbT4603. Lane 1 is a PCR product of the NL 4-3 strain of HIV-1, lane 2 is a PCR product of the MN strain of HIV-1 (prototypic clade B strain of HIV-1), and lane 3 is a PCR product from an env clone derived from patient VI-08 at 1 d of age (pJA-6-1D). Lanes 4–11 are PCR products amplified from patient proviral DNA (VI-06-1D and VI-06; VI-05; VI-05-6M; VI-08-20D and VI-08-6M; VI-11-1M and VI-11-3M; Table 2). Lane 12 is a negative control of probe alone.
Mentions: We began by examining the degree of diversity between infant isolate env and IIIB env. Examination of sequences through the V3 loops suggested relative homogeneity of first isolates (data not shown). Divergence in nucleotide sequence between HIV-1 IIIB and individual infant isolate env was then estimated using heteroduplex tracking assays and sequencing. Fig. 1 demonstrates that heteroduplexes formed by combining individual infant isolate and IIIB env migrate at rates between those of heteroduplexes formed by combining IIIB and MN env or IIIB and p08-6-20D (an env clone derived from the virus of patient VI-08). Sequence comparisons of a 946-bp region spanning V1 to V3 indicate that IIIB and MN env differ from each other by 8.3%, whereas IIIB and p08-6-20D differ by ∼10%. Therefore, the degree of heterogeneity between individual infant isolate and IIIB env sequences is between 8–10%.

Bottom Line: CTLp recognizing HIV-1 IIIB and infant isolate env were detected by 6 mo of age in two infants.In a fourth infant, HIV-1 IIIB env and early isolate env-specific CTLp were simultaneously detected at 12 mo of age.These results provide evidence that young infants can generate HIV-1-specific CTL responses and provide support for the concept of neonatal vaccination to prevent HIV-1 transmission.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, University of Massachusetts Medical Center, Worcester 01605, USA.

ABSTRACT
High frequencies of cytotoxic T lymphocyte precursors (CTLp) recognizing HIV-1 laboratory strain gene products have been detected in adults within weeks of primary infection. In contrast, HIV-1-specific CTLp are uncommonly detected in infants younger than 6 mo. To address the hypothesis that the use of target cells expressing laboratory strain env gene products might limit the detection of HIV-1 env-specific CTLp in early infancy, recombinant vaccinia vectors (vv) expressing HIV-1 env genes from early isolates of four vertically infected infants were generated. The frequencies of CTLp recognizing target cells infected with vv-expressing env gene products from early isolates and HIV-1 IIIB were serially measured using limiting dilution followed by in vitro stimulation with mAb to CD3. In one infant, the detection of early isolate env-specific CTLp preceded the detection of IIIB-specific CTLp. CTLp recognizing HIV-1 IIIB and infant isolate env were detected by 6 mo of age in two infants. In a fourth infant, HIV-1 IIIB env and early isolate env-specific CTLp were simultaneously detected at 12 mo of age. These results provide evidence that young infants can generate HIV-1-specific CTL responses and provide support for the concept of neonatal vaccination to prevent HIV-1 transmission. However, the early predominance of type-specific CTL detected in some young infants suggests that the use of vaccines based on laboratory strains of HIV-1 may not protect against vertical infection.

Show MeSH
Related in: MedlinePlus